طباعة ثلاثية الأبعاد

طابعة ثلاثية الأبعاد

اللقطات المتتابعة لطابعة ثلاثية الأبعاد قيد التشغيل

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تاريخ الطباعة
الطباعة الخشبية 200 من النوع القابل للحركة 1040 النقش النقش (الطباعة) 1430 طباعة الصحيفه ج.  1440 النقش ج.  1515 Mezzotint 1642 طباعة الإغاثة 1690 أكواتينت 1772 الطباعة الحجرية 1796 الطباعة الحجرية الملونة 1837 الصحافة الدوارة 1843 منضحة 1860 طباعة أوفست 1875 تنضيد المعادن الساخنة 1884 نسخ 1885 طباعة عجلة ديزي 1889 فوتوستاتي وخط مستقيم 1907 طباعة الشاشة 1911 الناسخ الروح 1923 طباعة مصفوفة نقطية 1925 زيروجرافي 1938 طباعة شرارة 1940 التنضيد الضوئي 1949 الطباعة النافثة للحبر 1950 صبغ التسامي 1957 طباعة ليزر 1969 الطباعة الحرارية ج.  1972 طباعة بالحبر الصلب 1972 طباعة النقل الحراري 1981 طباعة ثلاثية الأبعاد 1986 طباعة رقمية 1991
الخامس ر ه

الطباعة ثلاثية الأبعاد ، أو التصنيع الإضافي ، هي بناء كائن ثلاثي الأبعاد من نموذج CAD أو نموذج رقمي ثلاثي الأبعاد . ^[1] يمكن أن يشير مصطلح "الطباعة ثلاثية الأبعاد" إلى مجموعة متنوعة من العمليات التي يتم فيها ترسيب المواد أو ضمها أو ترسيخها تحت تحكم الكمبيوتر لإنشاء كائن ثلاثي الأبعاد ، ^[2] مع إضافة المواد معًا (مثل البلاستيك والسوائل أو حبيبات المسحوق التي يتم دمجها معًا) طبقة تلو الأخرى.

في الثمانينيات ، اعتبرت تقنيات الطباعة ثلاثية الأبعاد مناسبة فقط لإنتاج نماذج أولية وظيفية أو جمالية ، وكان المصطلح الأكثر ملاءمة لها في ذلك الوقت هو النماذج الأولية السريعة . ^[3] اعتبارًا من عام 2019 ^[update]، زادت الدقة والتكرار ونطاق المواد للطباعة ثلاثية الأبعاد لدرجة أن بعض عمليات الطباعة ثلاثية الأبعاد تعتبر قابلة للتطبيق كتقنية إنتاج صناعي ، حيث يمكن استخدام مصطلح التصنيع الإضافي بشكل مترادف مع الطباعة ثلاثية الأبعاد . ^[4]تتمثل إحدى المزايا الرئيسية للطباعة ثلاثية الأبعاد في القدرة على إنتاج أشكال أو أشكال هندسية معقدة للغاية والتي كان من المستحيل بناءها يدويًا ، بما في ذلك الأجزاء المجوفة أو الأجزاء ذات الهياكل الجمالون الداخلية لتقليل الوزن. تعد نمذجة الترسيب المنصهر (FDM) ، التي تستخدم خيوطًا مستمرة من مادة لدن بالحرارة ، أكثر عمليات الطباعة ثلاثية الأبعاد شيوعًا في الاستخدام اعتبارًا من عام 2020 ^[update]. ^[5]

المصطلحات

و مظلة مصطلح التصنيع المضافة (AM) اكتسب شعبية في 2000s، ^[6] مستوحاة من موضوع الوجود المادي وأضاف معا ( في أي من الطرق المختلفة ). في المقابل، فإن مصطلح التصنيع مطروح ظهر باعتباره مركب نقلي لعائلة كبيرة من الآلات العمليات مع المواد إزالة كعملية المشتركة. لا يزال مصطلح الطباعة ثلاثية الأبعاد يشير فقط إلى تقنيات البوليمر في معظم الأذهان ، ومصطلح AMكان من المرجح أن يتم استخدامه في سياقات تصنيع الأجزاء المعدنية والاستخدام النهائي منها بين المتحمسين للبوليمر أو النافثة للحبر أو الطباعة الحجرية المجسمة. كانت Inkjet أقل التقنيات شيوعًا على الرغم من أنها تم اختراعها في عام 1950 وغير مفهومة بشكل جيد بسبب طبيعتها المعقدة. تم استخدام أقدم الطابعات النافثة للحبر كمسجلات وليس طابعات. في أواخر السبعينيات ، ارتبط مصطلح المسجل بـ inkjet. تطورت Inkjet لاحقًا إلى Inkjet عند الطلب أو Drop-On-Demand Inkjet. كانت Inkjets عبارة عن فوهة واحدة في البداية ؛ قد يكون لديهم الآن ما يصل إلى آلاف الفوهات للطباعة في كل مسار فوق سطح ما.

قبل 2010S في وقت مبكر، وشروط 3D الطباعة و مضافة التصنيع تطور الحواس التي كانوا الشروط مظلة بديلة للتكنولوجيات المضافة، واحدة تستخدم في اللغة الشعبية المجتمعات صانع المستهلك ووسائل الإعلام، والآخر يستخدم أكثر رسميا من باطن؛ داخل الصناعية استخدام منتجي الأجزاء ومصنعي الآلات ومنظمات المعايير التقنية العالمية. حتى وقت قريب ، ارتبط مصطلح الطباعة ثلاثية الأبعاد بآلات منخفضة السعر أو ذات قدرة. ^[7] 3D الطباعة و التصنيع مضافةتعكس أن التقنيات تشترك في موضوع إضافة المواد أو الانضمام عبر مظروف عمل ثلاثي الأبعاد تحت التحكم الآلي. أشار بيتر زيلينسكي ، رئيس تحرير مجلة Additive Manufacturing ، في عام 2017 إلى أن المصطلحات لا تزال مرادفة في كثير من الأحيان في الاستخدام غير الرسمي ، ^[8] ولكن بعض خبراء الصناعة التحويلية يحاولون التمييز بين التصنيع الإضافي بحيث يشمل الطباعة ثلاثية الأبعاد بالإضافة إلى التقنيات الأخرى أو الجوانب الأخرى لعملية التصنيع . ^[8]

المصطلحات الأخرى التي تم استخدامها في المرادفات أو hypernyms وشملت التصنيع سطح المكتب ، التصنيع السريع (خلفا منطقية على مستوى الإنتاج إلى النماذج الأولية السريعة )، و بناء على الطلب تصنيع (التي أصداء حسب الطلب طباعة بمعنى 2D من الطباعة ). هذا التطبيق من الصفات السريعة و بناء على الطلب إلى اسما التصنيع والرواية في 2000s يكشف السائدة النموذج العقلي للعصر الصناعي الطويل الذي إنتاج ما يقرب من جميع الصناعات التحويلية تشارك طويلة المهللتطوير الأدوات الشاقة. اليوم ، لم يحل مصطلح الطرح محل مصطلح التشغيل الآلي ، وبدلاً من ذلك يكمله عند الحاجة إلى مصطلح يغطي أي طريقة إزالة. الأدوات الرشيقة هي استخدام الوسائل المعيارية لتصميم الأدوات التي يتم إنتاجها عن طريق التصنيع الإضافي أو طرق الطباعة ثلاثية الأبعاد لتمكين النماذج الأولية السريعة والاستجابة لاحتياجات الأدوات والتجهيزات. تستخدم الأدوات الرشيقة طريقة فعالة من حيث التكلفة وعالية الجودة للاستجابة بسرعة لاحتياجات العملاء والسوق ، ويمكن استخدامها في التشكيل المائي ، والختم ، والقولبة بالحقن ، وعمليات التصنيع الأخرى.

التاريخ

أربعينيات وخمسينيات القرن العشرين

تم وصف المفهوم العام للإجراء المستخدم في الطباعة ثلاثية الأبعاد لأول مرة من قبل موراي لينستر في قصته القصيرة التي صدرت عام 1945 بعنوان Things Pass By "ولكن هذا المنشئ يتميز بالكفاءة والمرونة. أطعم اللدائن المغناطيسية - الأشياء التي يصنعونها للمنازل والسفن في الوقت الحاضر - في هذه الذراع المتحركة. تقوم بعمل رسومات في الهواء بعد الرسومات التي تمسحها باستخدام الخلايا الضوئية. لكن البلاستيك يخرج من نهاية ذراع السحب ويتصلب عندما يأتي ... بعد الرسومات فقط " ^[9]

كما وصفها ريموند ف. جونز في قصته "أدوات التجارة" التي نُشرت في عدد نوفمبر 1950 من مجلة الخيال العلمي المذهلة. أشار إليها على أنها "رذاذ جزيئي" في تلك القصة.

1970s

في عام 1971 ، حصل يوهانس إف جوتوالد على براءة اختراع للمسجل المعدني السائل ، US3596285A ، وهو جهاز مستمر للمواد المعدنية النافثة للحبر لتشكيل تصنيع معدني قابل للإزالة على سطح قابل لإعادة الاستخدام للاستخدام الفوري أو تم إنقاذه للطباعة مرة أخرى عن طريق إعادة الصهر. يبدو أن هذه هي أول براءة اختراع تصف الطباعة ثلاثية الأبعاد بنماذج أولية سريعة وتصنيع الأنماط عند الطلب.

تنص براءة الاختراع على "كما هو مستخدم هنا ، فإن مصطلح الطباعة ليس مقصودًا بالمعنى المحدود ولكنه يشمل الكتابة أو الرموز الأخرى أو الأحرف أو تشكيل النمط بالحبر. والغرض من المصطلح الحبر كما هو مستخدم في ليس فقط أن يشمل المواد الصبغية أو المحتوية على الصباغ ، ولكن أي مادة أو تركيبة قابلة للتدفق مناسبة للتطبيق على السطح لتشكيل الرموز أو الأحرف أو أنماط الذكاء عن طريق وضع العلامات.الحبر المفضل هو من النوع الساخن المصهور.مجموعة تركيبات الحبر المتاحة تجاريًا والتي يمكن أن تلبي متطلبات لا يُعرف الاختراع في الوقت الحالي. ومع ذلك ، فقد تم تحقيق طباعة مرضية وفقًا للاختراع باستخدام سبيكة معدنية موصلة كحبر ".

"ولكن فيما يتعلق بالمتطلبات المادية لمثل هذه العروض الكبيرة والمستمرة ، إذا تم استهلاكها بمعدلات معروفة من قبل ، ولكنها زادت بما يتناسب مع الزيادة في الحجم ، فإن التكلفة المرتفعة ستحد بشدة من أي الاستمتاع على نطاق واسع بعملية أو جهاز يرضي الأشياء السابقة."

"وبالتالي ، يعد تقليل استخدام المواد في عملية من الفئة المشار إليها هدفًا إضافيًا للاختراع."

"إنه هدف آخر للاختراع أن يتم إنقاذ المواد المستخدمة في مثل هذه العملية لإعادة استخدامها."

"وفقًا لجانب آخر من الاختراع ، تشتمل مجموعة الكتابة وما شابه ذلك على حامل لعرض نمط ذكاء وترتيب لإزالة النمط من الناقل."

في عام 1974 ، وضع David EH Jones مفهوم الطباعة ثلاثية الأبعاد في عموده المعتاد Ariadne في مجلة New Scientist . ^{[10] [11]}

الثمانينيات

تم تطوير معدات ومواد تصنيع المواد المضافة المبكرة في الثمانينيات. ^[12]

في أبريل 1980 ، اخترع Hideo Kodama من معهد Nagoya Municipal للبحوث الصناعية طريقتين مضافتين لتصنيع نماذج بلاستيكية ثلاثية الأبعاد باستخدام بوليمر حراري متصلب بالصور ، حيث يتم التحكم في منطقة التعرض للأشعة فوق البنفسجية بواسطة نمط قناع أو جهاز إرسال ألياف ضوئي. ^[13] قدم براءة اختراع لمخطط XYZ هذا ، والذي تم نشره في 10 نوفمبر 1981. ( JP S56-144478 ). ^{[14] تم} نشر نتائج بحثه كأوراق علمية في شهري أبريل ونوفمبر عام 1981. ^{[15] [16]} ومع ذلك ، لم يكن هناك رد فعل على سلسلة منشوراته. لم يتم تقييم جهازه بدرجة عالية في المختبر ولم يُبد رئيسه أي اهتمام. كانت ميزانية أبحاثه 60 ألف ين فقط أو 545 دولارًا سنويًا. تم التخلي عن الحصول على حقوق براءة اختراع الراسمة XYZ ، وتم إنهاء المشروع.

براءة اختراع أمريكية 4323756 ، طريقة تصنيع المواد بالترسيب المتسلسل ، منحت شركة Raytheon Technologies Corp في 6 أبريل 1982 باستخدام مئات أو آلاف "طبقات" من المعدن المسحوق ومصدر طاقة الليزر هو مرجع مبكر لتشكيل "طبقات" وتصنيع السلع على الركيزة.

في 2 يوليو 1984 ، قدم رجل الأعمال الأمريكي بيل ماسترز براءة اختراع لنظام وعملية التصنيع الآلي للكمبيوتر ( US 4665492 ). ^[17] تم تسجيل هذا الإيداع في USPTO كأول براءة اختراع للطباعة ثلاثية الأبعاد في التاريخ. كانت أول براءات اختراع من ثلاث براءات اختراع تخص Masters التي وضعت الأساس لأنظمة الطباعة ثلاثية الأبعاد المستخدمة اليوم. ^{[18] [19]}

في 16 تموز عام 1984، الان لو Méhauté قدم، أوليفييه دي ويت، وجان كلود أندريه براءات الاختراع من أجل المجسمة العملية. ^[20] تم التخلي عن تطبيق المخترعين الفرنسيين من قبل شركة جنرال إلكتريك الفرنسية (الآن Alcatel-Alsthom) و CILAS (اتحاد الليزر). ^[21] السبب المزعوم هو "الافتقار إلى منظور تجاري". ^[22]

في عام 1983 ، بدأ روبرت هوارد RH Research ، الذي أطلق عليه لاحقًا اسم Howtek ، Inc. في فبراير 1984 لتطوير طابعة نفث الحبر الملونة ثنائية الأبعاد ، Pixelmaster ، تم تسويقها في عام 1986 ، باستخدام حبر بلاستيكي حراري (تذوب ساخن). ^[23] تم تشكيل فريق مكون من 6 أعضاء ^[23]من Exxon Office Systems و Danbury Systems Division وهي شركة ناشئة لطابعات نفث الحبر وبعض أعضاء مجموعة Howtek، Inc الذين أصبحوا شخصيات مشهورة في صناعة الطباعة ثلاثية الأبعاد. أحد أعضاء Howtek ، ريتشارد هيلينسكي براءة اختراع US5136515A ، الطريقة والوسائل لبناء مقالات ثلاثية الأبعاد عن طريق ترسيب الجسيمات ، طلب 11/07/1989 الممنوح في 8/04/1992 شكل شركة CAD-Cast ، Inc في نيو هامبشاير ، وتم تغيير الاسم لاحقًا إلى Visual شركة امباكت (VIC) بتاريخ 21/8/1991. يتوفر نموذج أولي للطابعة VIC 3D لهذه الشركة مع عرض فيديو يعرض نموذجًا ثلاثي الأبعاد مطبوعًا بفوهة نفث الحبر. قام موظف آخر هربرت مينهينت بتأسيس شركة HM Research في نيو هامبشاير في عام 1991 وقدم شركة Howtek، Inc ،تكنولوجيا نفث الحبر والمواد البلاستيكية الحرارية لرويدن ساندرز من SDI و Bill Masters of Ballistic Particle Manufacturing (BPM) حيث عمل لعدد من السنوات. تستخدم كل من طابعات BPM ثلاثية الأبعاد وطابعات SPI 3D مواد نمط Howtek و Inc Inkjets و Howtek، Inc. رخص Royden Sanders براءة اختراع Helinksi قبل تصنيع Modelmaker 6 Pro في Sanders prototype، Inc (SPI) في عام 1993. James K. McMahon الذي عينته Howtek، Inc للمساعدة في تطوير Inkjet ، عمل لاحقًا في Sanders Prototype ويعمل الآن Grown Model Technology ، موفر خدمة ثلاثي الأبعاد متخصص في دعم طابعة هاوتك النافثة للحبر بفوهة واحدة وطابعة SDI. عمل جيمس ك.مكماهون مع ستيفن زولتان ، مخترع نفث الحبر عند الطلب ، 1972 ،في Exxon وحصلت على براءة اختراع في عام 1978 والتي وسعت من فهم نفث الحبر ذات تصميم الفوهة الواحدة (طائرات ألفا) وساعدت في إتقان طائرات الحبر النفاثة بالذوبان الساخن Howtek، Inc. تحظى تقنية اللدائن الحرارية بالذوبان الساخن من Howtek بشعبية في مجال صب الاستثمار المعدني ، خاصة في صناعة المجوهرات ذات الطباعة ثلاثية الأبعاد.^[24] ساندرز (SDI) كان أول عميل لـ 6Pro من شركة Modelmaker هو Hitchner Corporations ، Metal Casting Technology ، Inc في ميلفورد ، نيو هامبشاير ، على بعد ميل واحد من منشأة SDI في أواخر 1993-1995 لصب نوادي الجولف وأجزاء محرك السيارات.

في 8 أغسطس 1984 ، تم تسجيل براءة اختراع ، US4575330 ، مخصصة لشركة UVP ، Inc. ، تم تعيينها لاحقًا إلى Chuck Hull من شركة 3D Systems Corporation ^[25] ، براءة اختراعه الخاصة لنظام تصنيع الليثوغرافيا المجسمة ، حيث تتم إضافة صفيحة أو طبقات فردية عن طريق المعالجة البوليمرات الضوئية ذات الإشعاع المؤثر أو قذف الجسيمات أو التفاعل الكيميائي أو أشعة الليزر فوق البنفسجية فقط . عرّف هال العملية بأنها "نظام لتوليد كائنات ثلاثية الأبعاد من خلال إنشاء نمط مقطعي للكائن المراد تشكيله". ^{[26] [27]} كانت مساهمة هال هي تنسيق ملف STL (الطباعة الحجرية المجسمة)والتقطيع الرقمي واستراتيجيات التعبئة الشائعة في العديد من العمليات اليوم. في عام 1986 ، حصل تشارلز "Chuck" Hull على براءة اختراع لهذا النظام ، وشكلت شركته ، 3D Systems Corporation وأصدرت أول طابعة تجارية ثلاثية الأبعاد ، SLA-1 ، ^[28] لاحقًا في عام 1987 أو 1988.

التكنولوجيا المستخدمة من قبل معظم الطابعات ثلاثية الأبعاد حتى الآن - وخاصة النماذج الموجهة للمستهلكين والهواة - هي نمذجة الترسيب المنصهرة ، وهو تطبيق خاص لبثق البلاستيك ، تم تطويره في عام 1988 بواسطة S. Scott Crump وتم تسويقه بواسطة شركته Stratasys ، التي قامت بتسويق أول FDM لها الجهاز في عام 1992. ^[24]

كلف امتلاك طابعة ثلاثية الأبعاد في الثمانينيات ما يزيد عن 300 ألف دولار (650 ألف دولار في 2016 بالدولار). ^[29]

التسعينيات

عمليات AM لتلبيد المعادن أو صهرها (مثل التلبيد الانتقائي بالليزر ، والتلبيد المباشر بالليزر للمعادن ، والذوبان الانتقائي بالليزر) عادة ما تمر بأسمائها الفردية في الثمانينيات والتسعينيات. في ذلك الوقت ، كانت جميع الأعمال المعدنية تتم من خلال عمليات تسمى الآن غير مضافة ( الصب ، والتصنيع ، والختم ، والتشغيل الآلي ) ؛ على الرغم من تطبيق الكثير من الأتمتة على تلك التقنيات (مثل اللحام الآلي و CNC ) ، فإن فكرة أداة أو رأس يتحرك عبر مظروف عمل ثلاثي الأبعاد يحول كتلة من المواد الخامإلى الشكل المطلوب باستخدام مسار الأدوات ، كان مرتبطًا في الأشغال المعدنية فقط بالعمليات التي تزيل المعدن (بدلاً من إضافته) ، مثل الطحن CNC ، و CNC EDM ، والعديد من العمليات الأخرى. لكن التقنيات الآلية التي أضافت المعدن ، والتي سُميت فيما بعد التصنيع الإضافي ، بدأت تتحدى هذا الافتراض. وبحلول منتصف 1990s، تم تطوير تقنيات جديدة لترسب المواد في جامعة ستانفورد و جامعة كارنيجي ميلون ، بما في ذلك microcasting ^[30] ومواد رش. ^[31] أصبحت المواد القربانية والداعمة أكثر شيوعًا ، مما يتيح هندسة كائنات جديدة. ^[32]

يشير مصطلح الطباعة ثلاثية الأبعاد في الأصل إلى عملية طبقة المسحوق التي تستخدم رؤوس طباعة نفث الحبر قياسية ومخصصة ، تم تطويرها في معهد ماساتشوستس للتكنولوجيا بواسطة إيمانويل ساكس في عام 1993 وتم تسويقها بواسطة Soligen Technologies و Extrude Hone Corporation و Z Corporation . ^{[ بحاجة لمصدر ]}

شهد عام 1993 أيضًا بداية شركة طابعة نافثة للحبر ثلاثية الأبعاد اسمها في البداية Sanders Prototype، Inc وأطلق عليها لاحقًا Solidscape ، حيث قدمت نظام تصنيع نفاث بوليمر عالي الدقة بهياكل دعم قابلة للذوبان ، (تم تصنيفها على أنها تقنية "نقطة على نقطة" ). ^[24]

في عام 1995 طورت جمعية فراونهوفر عملية الصهر الانتقائي بالليزر .

2000s

انتهت صلاحية براءات اختراع عملية طباعة نمذجة الترسيب المنصهر (FDM) في عام 2009. ^[33]

2010s

مع نضوج العمليات المضافة المختلفة ، أصبح من الواضح أن إزالة المعادن قريبًا لن تكون عملية الأشغال المعدنية الوحيدة التي يتم إجراؤها من خلال أداة أو رأس يتحرك عبر مظروف عمل ثلاثي الأبعاد ، مما يؤدي إلى تحويل كتلة من المواد الخام إلى شكل مرغوب فيه طبقة بطبقة. وكانت 2010S العقد الأول في الأجزاء التي الاستخدام النهائي المعادن مثل الأقواس محرك ^[34] والمكسرات كبيرة ^[35] سوف تزرع (إما قبل أو بدلا من الآلات) في إنتاج العمل بدلا من obligately يجري تشكيله من الأسهم شريطأو لوحة. لا تزال الحالة هي أن الصب والتصنيع والختم والمعالجة أكثر انتشارًا من التصنيع الإضافي في صناعة المعادن ، ولكن AM بدأت الآن في تحقيق تقدم كبير ، ومع مزايا التصميم للتصنيع الإضافي ، من الواضح للمهندسين أن الكثير المزيد قادم.

أحد الأماكن التي تحقق AM فيها تقدمًا كبيرًا هو صناعة الطيران. مع ما يقرب من 3.8 مليار مسافر جوي في عام 2016 ، ^[36]لم يكن الطلب على محركات نفاثة موفرة للوقود وسهل الإنتاج أعلى من أي وقت مضى. بالنسبة لمصنعي المعدات الأصلية (الشركات المصنعة للمعدات الأصلية) مثل Pratt and Whitney (PW) و General Electric (GE) ، فإن هذا يعني التطلع إلى AM كطريقة لتقليل التكلفة وتقليل عدد الأجزاء غير المتوافقة وتقليل الوزن في المحركات لزيادة كفاءة الوقود و العثور على أشكال جديدة ومعقدة للغاية لن تكون مجدية مع طرق التصنيع القديمة. أحد الأمثلة على تكامل AM مع الفضاء كان في عام 2016 عندما تم تسليم إيرباص أول محرك LEAP الخاص بشركة GE. يحتوي هذا المحرك على فوهات وقود مطبوعة ثلاثية الأبعاد ، مما يمنحها تقليلًا في الأجزاء من 20 إلى 1 ، وتخفيض الوزن بنسبة 25٪ وتقليل أوقات التجميع. ^[37]تعتبر فوهة الوقود مثالية للطريق لتصنيع المواد المضافة في المحرك النفاث لأنها تتيح التصميم الأمثل للأجزاء الداخلية المعقدة وهي جزء منخفض الضغط وغير دوار. وبالمثل ، في عام 2015 ، سلمت PW أول أجزاء AM في PurePower PW1500G إلى Bombardier. بالتمسك بضغط منخفض وأجزاء غير دوارة ، اختار PW ثوابت الضاغط وأقواس حلقة التزامن ^[38] لطرح تقنية التصنيع الجديدة هذه لأول مرة. بينما لا تزال AM تلعب دورًا صغيرًا في العدد الإجمالي للأجزاء في عملية تصنيع المحرك النفاث ، يمكن ملاحظة عائد الاستثمار بالفعل من خلال تقليل الأجزاء ، وقدرات الإنتاج السريع و "التصميم الأمثل من حيث الأداء والتكلفة ". ^[39]

مع نضوج التكنولوجيا ، بدأ العديد من المؤلفين في التكهن بأن الطباعة ثلاثية الأبعاد يمكن أن تساعد في التنمية المستدامة في العالم النامي. ^[40]

في عام 2012 ، طور Filabot نظامًا لإغلاق الحلقة ^[41] بالبلاستيك ويسمح لأي طابعة FDM أو FFF ثلاثية الأبعاد للطباعة بمجموعة أكبر من البلاستيك.

في عام 2014 ، أظهر Benjamin S. Cook و Manos M. Tentzeris أول منصة تصنيع مضافة للإلكترونيات المطبوعة متعددة المواد ومتكاملة رأسياً (VIPRE) والتي مكنت من الطباعة ثلاثية الأبعاد للإلكترونيات الوظيفية التي تعمل حتى 40 جيجاهرتز. ^[42]

عندما بدأ سعر الطابعات في الانخفاض ، كان لدى الأشخاص المهتمين بهذه التكنولوجيا إمكانية وصول أكبر وحرية لصنع ما يريدون. كان السعر اعتبارًا من عام 2014 لا يزال مرتفعًا حيث تجاوزت التكلفة 2000 دولار ، إلا أن هذا لا يزال يسمح للهواة بالدخول إلى الطباعة خارج أساليب الإنتاج والصناعة. ^[43]

يشير مصطلح "الطباعة ثلاثية الأبعاد" في الأصل إلى عملية ترسب مادة رابطة على طبقة مسحوق برؤوس طابعة نافثة للحبر طبقة تلو طبقة. في الآونة الأخيرة ، بدأت اللغة العامية الشعبية في استخدام المصطلح ليشمل مجموعة متنوعة من تقنيات التصنيع المضافة مثل تصنيع المواد المضافة لشعاع الإلكترون والذوبان الانتقائي بالليزر. تستخدم الولايات المتحدة والمعايير الفنية العالمية المصطلح الرسمي التصنيع الإضافي لهذا المعنى الأوسع.

عملية الطباعة ثلاثية الأبعاد الأكثر شيوعًا (46٪ اعتبارًا من 2018 ^[update]) هي تقنية بثق المواد تسمى نمذجة الترسيب المنصهر ، أو FDM. ^[5] بينما تم اختراع تقنية FDM بعد التقنيتين الأخريين الأكثر شيوعًا ، الطباعة الحجرية المجسمة (SLA) والتلبيد الانتقائي بالليزر (SLS) ، فإن FDM هي عادةً الأقل تكلفة من بين الثلاثة بهامش كبير ، ^{[ بحاجة لمصدر ]} مما يقرض شعبية العملية.

2020s

اعتبارًا من عام 2020 ، وصلت الطابعات ثلاثية الأبعاد إلى مستوى الجودة والسعر الذي يسمح لمعظم الناس بدخول عالم الطباعة ثلاثية الأبعاد. في عام 2020 ، يمكن العثور على طابعات عالية الجودة بأقل من 200 دولار أمريكي لأجهزة الدخول. هذه الطابعات ذات الأسعار المعقولة عادة ما تكون طابعات نمذجة الترسيب المنصهرة (FDM). ^[44]

مبادئ عامة

النمذجة

نموذج CAD يستخدم للطباعة ثلاثية الأبعاد

يمكن إنشاء نماذج ثلاثية الأبعاد من صور ثنائية الأبعاد تم التقاطها في كشك صور ثلاثي الأبعاد.

يمكن إنشاء نماذج قابلة للطباعة ثلاثية الأبعاد باستخدام حزمة تصميم بمساعدة الكمبيوتر (CAD) ، عبر ماسح ضوئي ثلاثي الأبعاد ، أو بواسطة كاميرا رقمية عادية وبرنامج قياس التصوير . ينتج عن النماذج المطبوعة ثلاثية الأبعاد التي تم إنشاؤها باستخدام CAD أخطاء أقل نسبيًا من الطرق الأخرى. يمكن تحديد الأخطاء في النماذج ثلاثية الأبعاد القابلة للطباعة وتصحيحها قبل الطباعة. ^[45] عملية النمذجة اليدوية لإعداد البيانات الهندسية لرسومات الكمبيوتر ثلاثية الأبعاد تشبه الفنون التشكيلية مثل النحت. المسح ثلاثي الأبعاد هو عملية لجمع البيانات الرقمية عن شكل ومظهر كائن حقيقي ، وإنشاء نموذج رقمي يعتمد عليه.

يمكن حفظ نماذج CAD في تنسيق ملف الطباعة الحجرية المجسمة (STL) ، وهو تنسيق ملف CAD فعلي للتصنيع الإضافي الذي يخزن البيانات بناءً على المثلثات لسطح نماذج CAD. لم يتم تصميم STL للتصنيع الإضافي لأنه يولد أحجام ملفات كبيرة من الأجزاء المحسنة الهيكلية والبنى الشبكية نظرًا للعدد الكبير من الأسطح المعنية. تم تقديم تنسيق ملف CAD جديد ، وهو تنسيق ملف التصنيع الإضافي (AMF) في عام 2011 لحل هذه المشكلة. يخزن المعلومات باستخدام المثلثات المنحنية. ^[46]

طباعة

قبل طباعة نموذج ثلاثي الأبعاد من ملف STL ، يجب أولاً فحصه بحثًا عن الأخطاء. تنتج معظم تطبيقات CAD أخطاء في ملفات STL الناتجة ، ^{[47] [48]} من الأنواع التالية:

1. الثقوب.
2. يواجه الأعراف
3. التقاطعات الذاتية
4. قذائف الضوضاء
5. أخطاء متعددة. ^[49]

خطوة في إنشاء STL تُعرف باسم "الإصلاح" تعمل على إصلاح مثل هذه المشكلات في النموذج الأصلي. ^{[50] [51]} بشكل عام ، غالبًا ما يكون لدى STLs التي تم إنتاجها من نموذج تم الحصول عليه من خلال المسح ثلاثي الأبعاد المزيد من هذه الأخطاء ^[52] حيث يتم تحقيق المسح ثلاثي الأبعاد غالبًا عن طريق الاستحواذ / رسم الخرائط من نقطة إلى نقطة. غالبًا ما تتضمن إعادة الإعمار ثلاثي الأبعاد أخطاء. ^[53]

بمجرد الانتهاء ، يجب معالجة ملف STL بواسطة برنامج يسمى "slicer" ، والذي يحول النموذج إلى سلسلة من الطبقات الرقيقة وينتج ملف G-code يحتوي على تعليمات مصممة خصيصًا لنوع معين من الطابعات ثلاثية الأبعاد ( FDM طابعات ). ^[54] يمكن بعد ذلك طباعة ملف G-code هذا باستخدام برنامج عميل الطباعة ثلاثية الأبعاد (الذي يقوم بتحميل رمز G ، ويستخدمه لتوجيه الطابعة ثلاثية الأبعاد أثناء عملية الطباعة ثلاثية الأبعاد).

يصف دقة وضوح الطابعة سماكة الطبقة ودقة الوضوح X-Y بالنقاط في البوصة (dpi) أو الميكرومتر (m). يبلغ سمك الطبقة النموذجية حوالي 100 ميكرومتر (250  نقطة لكل بوصة ) ، على الرغم من أن بعض الأجهزة يمكنها طباعة طبقات رقيقة تصل إلى 16 ميكرومتر (1600 نقطة لكل بوصة). ^[55] دقة X – Y قابلة للمقارنة مع طابعات الليزر . يبلغ قطر الجسيمات (النقاط ثلاثية الأبعاد) حوالي 50 إلى 100 ميكرومتر (510 إلى 250 نقطة في البوصة). ^{[ بحاجة لمصدر ]} لدقة الطابعة هذه ، فإن تحديد دقة شبكة من 0.01-0.03 مم وطول الوتر 0.016 مم يولد ملف إخراج STL مثالي لملف إدخال نموذج معين. ^[56] يؤدي تحديد دقة أعلى إلى إنتاج ملفات أكبر دون زيادة جودة الطباعة.

تشغيل الوسائط

3:31 الفاصل الزمني لفيديو مدته 80 دقيقة لجسم مصنوع من PLA باستخدام ترسيب البوليمر المصهور

يمكن أن يستغرق إنشاء نموذج بأساليب معاصرة في أي مكان من عدة ساعات إلى عدة أيام ، اعتمادًا على الطريقة المستخدمة وحجم النموذج وتعقيده. يمكن للأنظمة المضافة عادةً تقليل هذا الوقت إلى بضع ساعات ، على الرغم من أنها تختلف بشكل كبير اعتمادًا على نوع الماكينة المستخدمة وحجم وعدد النماذج التي يتم إنتاجها في وقت واحد.

إنهاء

Though the printer-produced resolution is sufficient for many applications, greater accuracy can be achieved by printing a slightly oversized version of the desired object in standard resolution and then removing material using a higher-resolution subtractive process.^[57]

The layered structure of all additive manufacturing processes leads inevitably to a stair-stepping effect on part surfaces which are curved or tilted in respect to the building platform. The effects strongly depend on the orientation of a part surface inside the building process.^[58]

Some printable polymers such as ABS, allow the surface finish to be smoothed and improved using chemical vapor processes^[59] based on acetone or similar solvents.

Some additive manufacturing techniques are capable of using multiple materials in the course of constructing parts. These techniques are able to print in multiple colors and color combinations simultaneously, and would not necessarily require painting.

Some printing techniques require internal supports to be built for overhanging features during construction. These supports must be mechanically removed or dissolved upon completion of the print.

All of the commercialized metal 3D printers involve cutting the metal component off the metal substrate after deposition. A new process for the GMAW 3D printing allows for substrate surface modifications to remove aluminum^[60] or steel.^[61]

Materials

Detail of the Stoofbrug in Amsterdam, the world's first 3D-printed metal bridge.

Traditionally, 3D printing focused on polymers for printing, due to the ease of manufacturing and handling polymeric materials. However, the method has rapidly evolved to not only print various polymers^[62] but also metals^[63][64] and ceramics,^[65] making 3D printing a versatile option for manufacturing. Layer-by-layer fabrication of three-dimensional physical models is a modern concept that "stems from the ever-growing CAD industry, more specifically the solid modeling side of CAD. Before solid modeling was introduced in the late 1980s, three-dimensional models were created with wire frames and surfaces."^[66] but in all cases the layers of materials are controlled by the printer and the material properties. The three-dimensional material layer is controlled by deposition rate as set by the printer operator and stored in a computer file. The earliest printed patented material was a Hot melt type ink for printing patterns using a heated metal alloy. See 1970's history above.

Charles Hull filed the first patent on August 8, 1984, to use a UV-cured acrylic resin using a UV masked light source at UVP Corp to build a simple model. The SLA-1 was the first SL product announced by 3D Systems at Autofact Exposition, Detroit, November 1978 in Detroit. The SLA-1 Beta shipped in Jan 1988 to Baxter Healthcare, Pratt and Whitney, General Motors and AMP. The first production SLA-1 shipped to Precision Castparts in April 1988. The UV resin material changed over quickly to an epoxy-based material resin. In both cases SLA-1 models needed UV oven cure after being rinsed in a solvent cleaner to remove uncured boundary resin. A Post Cure Aparatus (PCA) was sold with all systems. The early resin printers required a blade to move fresh resin over the model on each layer. The layer thickness was 0.006 inches and the HeCd Laser model of the SLA-1 was 12 watts and swept across the surface at 30 in per second. UVP was acquired by 3D Systems in Jan 1990.^[67]

A review in the history shows a number of materials (resins, plastic powder, plastic filament and hot-melt plastic ink) were used in the 1980s for patents in the rapid prototyping field. Masked lamp UV-cured resin was also introduced by Cubital's Itzchak Pomerantz in the Soldier 5600, Carl Deckard's (DTM) Laser sintered thermoplastic powders, and adhesive-laser cut paper (LOM) stacked to form objects by Michael Feygin before 3D Systems made its first announcement. Scott Crump was also working with extruded "melted" plastic filament modeling (FDM) and Drop deposition had been patented by William E Masters a week after Charles Hull's patent in 1984, but he had to discover Thermoplastic Inkjets introduced by Visual Impact Corporation 3D printer in 1992 using inkjets from Howtek, Inc., before he formed BPM to bring out his own 3D printer product in 1994.^[67]

Multi-material 3D printing

A multi-material 3DBenchy.

Efforts to achieve multi-material 3D printing range from enhanced FDM-like processes like VoxelJet, to novel voxel-based printing technologies like Layered Assembly.^[68]

A drawback of many existing 3D printing technologies is that they only allow one material to be printed at a time, limiting many potential applications which require the integration of different materials in the same object. Multi-material 3D printing solves this problem by allowing objects of complex and heterogeneous arrangements of materials to be manufactured using a single printer. Here, a material must be specified for each voxel (or 3D printing pixel element) inside the final object volume.

The process can be fraught with complications, however, due to the isolated and monolithic algorithms. Some commercial devices have sought to solve these issues, such as building a Spec2Fab translator, but the progress is still very limited.^[69] Nonetheless, in the medical industry, a concept of 3D printed pills and vaccines has been presented.^[70] With this new concept, multiple medications can be combined, which will decrease many risks. With more and more applications of multi-material 3D printing, the costs of daily life and high technology development will become inevitably lower.

Metallographic materials of 3D printing is also being researched.^[71] By classifying each material, CIMP-3D can systematically perform 3D printing with multiple materials.^[72]

4D Printing

Using 3D printing and multi-material structures in additive manufacturing has allowed for the design and creation of what is called 4D printing. 4D printing is an additive manufacturing process in which the printed object changes shape with time, temperature, or some other type of stimulation. 4D printing allows for the creation of dynamic structures with adjustable shapes, properties or functionality. The smart/stimulus responsive materials that are created using 4D printing can be activated to create calculated responses such as self-assembly, self-repair, multi-functionality, reconfiguration and shape shifting. This allows for customized printing of shape changing and shape-memory materials.^[73]

4D printing has the potential to find new applications and uses for materials (plastics, composites, metals, etc.) and will create new alloys and composites that were not viable before. The versatility of this technology and materials can lead to advances in multiple fields of industry, including space, commercial and the medical field. The repeatability, precision, and material range for 4D printing must increase to allow the process to become more practical throughout these industries. 

To become a viable industrial production option, there are a couple of challenges that 4D printing must overcome. The challenges of 4D printing include the fact that the microstructures of these printed smart materials must be close to or better than the parts obtained through traditional machining processes. New and customizable materials need to be developed that have the ability to consistently respond to varying external stimuli and change to their desired shape. There is also a need to design new software for the various technique types of 4D printing. The 4D printing software will need to take into consideration the base smart material, printing technique, and structural and geometric requirements of the design.^[74]

Processes and printers

There are many different branded additive manufacturing processes, that can be grouped into seven categories:^[75]

• Vat photopolymerization
• Material jetting
• Binder jetting
• Powder bed fusion
• Material extrusion
• Directed energy deposition
• Sheet lamination

Schematic representation of the 3D printing technique known as Fused Filament Fabrication; a filament a) of plastic material is fed through a heated moving head b) that melts and extrudes it depositing it, layer after layer, in the desired shape c). A moving platform e) lowers after each layer is deposited. For this kind of technology additional vertical support structures d) are needed to sustain overhanging parts

The main differences between processes are in the way layers are deposited to create parts and in the materials that are used. Each method has its own advantages and drawbacks, which is why some companies offer a choice of powder and polymer for the material used to build the object.^[76] Others sometimes use standard, off-the-shelf business paper as the build material to produce a durable prototype. The main considerations in choosing a machine are generally speed, costs of the 3D printer, of the printed prototype, choice and cost of the materials, and color capabilities.^[77] Printers that work directly with metals are generally expensive. However less expensive printers can be used to make a mold, which is then used to make metal parts.^[78]

ISO/ASTM52900-15 defines seven categories of Additive Manufacturing (AM) processes within its meaning: binder jetting, directed energy deposition, material extrusion, material jetting, powder bed fusion, sheet lamination, and vat photopolymerization.^[79]

The first process where three-dimensional material is deposited to form an object was done with Material Jetting^[24] or as it was originally called particle deposition. Particle deposition by inkjet first started with Continuous Inkjet technology (CIT) (1950's) and later with drop-On-Demand Inkjet technology.(1970's) using Hot-melt inks. Wax inks were the first three-dimensional materials jetted and later low temperature alloy metal was jetted with CIT. Wax and thermoplastic hot-melts were jetted next by DOD. Objects were very small and started with text characters and numerals for signage. An object must have form and can be handled. Wax characters tumbled off paper documents and inspired a Liquid Metal Recorder patent to make metal characters for signage in 1971. Thermoplastic color inks (CMYK) printed with layers of each color to form the first digitally formed layered objects in 1984. The idea of investment casting with Solid-Ink jetted images or patterns in 1984 led to the first patent to form articles from particle deposition in 1989, issued in 1992.

Some methods melt or soften the material to produce the layers. In Fused filament fabrication, also known as Fused deposition modeling (FDM), the model or part is produced by extruding small beads or streams of material which harden immediately to form layers. A filament of thermoplastic, metal wire, or other material is fed into an extrusion nozzle head (3D printer extruder), which heats the material and turns the flow on and off. FDM is somewhat restricted in the variation of shapes that may be fabricated. Another technique fuses parts of the layer and then moves upward in the working area, adding another layer of granules and repeating the process until the piece has built up. This process uses the unfused media to support overhangs and thin walls in the part being produced, which reduces the need for temporary auxiliary supports for the piece.^[80] Recently, FFF/FDM has expanded to 3-D print directly from pellets to avoid the conversion to filament. This process is called fused particle fabrication (FPF) (or fused granular fabrication (FGF) and has the potential to use more recycled materials.^[81]

Powder Bed Fusion techniques, or PBF, include several processes such as DMLS, SLS, SLM, MJF and EBM. Powder Bed Fusion processes can be used with an array of materials and their flexibility allows for geometrically complex structures,^[82] making it a go to choice for many 3D printing projects. These techniques include selective laser sintering, with both metals and polymers, and direct metal laser sintering.^[83] Selective laser melting does not use sintering for the fusion of powder granules but will completely melt the powder using a high-energy laser to create fully dense materials in a layer-wise method that has mechanical properties similar to those of conventional manufactured metals. Electron beam melting is a similar type of additive manufacturing technology for metal parts (e.g. titanium alloys). EBM manufactures parts by melting metal powder layer by layer with an electron beam in a high vacuum.^[84][85] Another method consists of an inkjet 3D printing system, which creates the model one layer at a time by spreading a layer of powder (plaster, or resins) and printing a binder in the cross-section of the part using an inkjet-like process. With laminated object manufacturing, thin layers are cut to shape and joined together. In addition to the previously mentioned methods, HP has developed the Multi Jet Fusion (MJF) which is a powder base technique, though no lasers are involved. An inkjet array applies fusing and detailing agents which are then combined by heating to create a solid layer.^[86]

Schematic representation of Stereolithography; a light-emitting device a) (laser or DLP) selectively illuminate the transparent bottom c) of a tank b) filled with a liquid photo-polymerizing resin; the solidified resin d) is progressively dragged up by a lifting platform e)

Other methods cure liquid materials using different sophisticated technologies, such as stereolithography. Photopolymerization is primarily used in stereolithography to produce a solid part from a liquid. Inkjet printer systems like the Objet PolyJet system spray photopolymer materials onto a build tray in ultra-thin layers (between 16 and 30 µm) until the part is completed.^[87] Each photopolymer layer is cured with UV light after it is jetted, producing fully cured models that can be handled and used immediately, without post-curing. Ultra-small features can be made with the 3D micro-fabrication technique used in multiphoton photopolymerisation. Due to the nonlinear nature of photo excitation, the gel is cured to a solid only in the places where the laser was focused while the remaining gel is then washed away. Feature sizes of under 100 nm are easily produced, as well as complex structures with moving and interlocked parts.^[88] Yet another approach uses a synthetic resin that is solidified using LEDs.^[89]

In Mask-image-projection-based stereolithography, a 3D digital model is sliced by a set of horizontal planes. Each slice is converted into a two-dimensional mask image. The mask image is then projected onto a photocurable liquid resin surface and light is projected onto the resin to cure it in the shape of the layer.^[90] Continuous liquid interface production begins with a pool of liquid photopolymer resin. Part of the pool bottom is transparent to ultraviolet light (the "window"), which causes the resin to solidify. The object rises slowly enough to allow resin to flow under and maintain contact with the bottom of the object.^[91] In powder-fed directed-energy deposition, a high-power laser is used to melt metal powder supplied to the focus of the laser beam. The powder fed directed energy process is similar to Selective Laser Sintering, but the metal powder is applied only where material is being added to the part at that moment.^[92][93]

As of December 2017^[update], additive manufacturing systems were on the market that ranged from $99 to $500,000 in price and were employed in industries including aerospace, architecture, automotive, defense, and medical replacements, among many others. For example, General Electric uses high-end 3D Printers to build parts for turbines.^[94] Many of these systems are used for rapid prototyping, before mass production methods are employed. Higher education has proven to be a major buyer of desktop and professional 3D printers which industry experts generally view as a positive indicator.^[95] Libraries around the world have also become locations to house smaller 3D printers for educational and community access.^[96] Several projects and companies are making efforts to develop affordable 3D printers for home desktop use. Much of this work has been driven by and targeted at DIY/Maker/enthusiast/early adopter communities, with additional ties to the academic and hacker communities.^[97]

Computed axial lithography is a method for 3D printing based on computerised tomography scans to create prints in photo-curable resin. It was developed by a collaboration between the University of California, Berkeley with Lawrence Livermore National Laboratory.^{[98][99][100]} Unlike other methods of 3D printing it does not build models through depositing layers of material like fused deposition modelling and stereolithography, instead it creates objects using a series of 2D images projected onto a cylinder of resin.^[98][100] It is notable for its ability to build an object much more quickly than other methods using resins and the ability to embed objects within the prints.^[99]

Liquid additive manufacturing (LAM) is a 3D printing technique which deposits a liquid or high viscose material (e.g. Liquid Silicone Rubber) onto a build surface to create an object which then is vulcanised using heat to harden the object.^{[101][102][103]} The process was originally created by Adrian Bowyer and was then built upon by German RepRap.^{[101][104][105]}

Applications

The Audi RSQ was made with rapid prototyping industrial KUKA robots

A 3D selfie in 1:20 scale printed using gypsum-based printing

A 3D printed jet engine model

3D printed enamelled pottery

3D printed necklace

3D printed sculpture of an Egyptian pharaoh shown at Threeding

In the current scenario, 3D printing or additive manufacturing has been used in manufacturing, medical, industry and sociocultural sectors (Cultural Heritage, etc.) which facilitate 3D printing or Additive Manufacturing to become successful commercial technology.^[106] More recently, 3D printing has also been used in the humanitarian and development sector to produce a range of medical items, prosthetics, spares and repairs.^[107] The earliest application of additive manufacturing was on the toolroom end of the manufacturing spectrum. For example, rapid prototyping was one of the earliest additive variants, and its mission was to reduce the lead time and cost of developing prototypes of new parts and devices, which was earlier only done with subtractive toolroom methods such as CNC milling, turning, and precision grinding.^[108] In the 2010s, additive manufacturing entered production to a much greater extent.

Food industry

Additive manufacturing of food is being developed by squeezing out food, layer by layer, into three-dimensional objects. A large variety of foods are appropriate candidates, such as chocolate and candy, and flat foods such as crackers, pasta,^[109] and pizza.^[110][111] NASA is looking into the technology in order to create 3D printed food to limit food waste and to make food that is designed to fit an astronaut's dietary needs.^[112] In 2018, Italian bioengineer Giuseppe Scionti developed a technology allowing to generate fibrous plant-based meat analogues using a custom 3D bioprinter, mimicking meat texture and nutritional values.^[113][114]

Fashion industry

3D printing has entered the world of clothing, with fashion designers experimenting with 3D-printed bikinis, shoes, and dresses.^[115] In commercial production Nike is using 3D printing to prototype and manufacture the 2012 Vapor Laser Talon football shoe for players of American football, and New Balance is 3D manufacturing custom-fit shoes for athletes.^[115][116] 3D printing has come to the point where companies are printing consumer grade eyewear with on-demand custom fit and styling (although they cannot print the lenses). On-demand customization of glasses is possible with rapid prototyping.^[117]

Vanessa Friedman, fashion director and chief fashion critic at The New York Times, says 3D printing will have a significant value for fashion companies down the road, especially if it transforms into a print-it-yourself tool for shoppers. "There's real sense that this is not going to happen anytime soon," she says, "but it will happen, and it will create dramatic change in how we think both about intellectual property and how things are in the supply chain." She adds: "Certainly some of the fabrications that brands can use will be dramatically changed by technology."^[118]

Transportation industry

The Stoofbrug in Amsterdam, the world's first 3D-printed metal bridge

In cars, trucks, and aircraft, Additive Manufacturing is beginning to transform both (1) unibody and fuselage design and production and (2) powertrain design and production. For example:

• In early 2014, Swedish supercar manufacturer Koenigsegg announced the One:1, a supercar that utilizes many components that were 3D printed.^[119] Urbee is the name of the first car in the world car mounted using the technology 3D printing (its bodywork and car windows were "printed").^{[120][121][122]}
• In 2014, Local Motors debuted Strati, a functioning vehicle that was entirely 3D Printed using ABS plastic and carbon fiber, except the powertrain.^[123]
• In May 2015 Airbus announced that its new Airbus A350 XWB included over 1000 components manufactured by 3D printing.^[124]
• In 2015, a Royal Air Force Eurofighter Typhoon fighter jet flew with printed parts. The United States Air Force has begun to work with 3D printers, and the Israeli Air Force has also purchased a 3D printer to print spare parts.^[125]
• In 2017, GE Aviation revealed that it had used design for additive manufacturing to create a helicopter engine with 16 parts instead of 900, with great potential impact on reducing the complexity of supply chains.^[126]

Firearm industry

AM's impact on firearms involves two dimensions: new manufacturing methods for established companies, and new possibilities for the making of do-it-yourself firearms. In 2012, the US-based group Defense Distributed disclosed plans to design a working plastic 3D printed firearm "that could be downloaded and reproduced by anybody with a 3D printer."^[127][128] After Defense Distributed released their plans, questions were raised regarding the effects that 3D printing and widespread consumer-level CNC machining^[129][130] may have on gun control effectiveness.^{[131][132][133][134]} Moreover, armour design strategies can be enhanced by taking inspiration from nature and prototyping those designs easily possible using additive manufacturing.^[135]

Health sector

Surgical uses of 3D printing-centric therapies have a history beginning in the mid-1990s with anatomical modeling for bony reconstructive surgery planning. Patient-matched implants were a natural extension of this work, leading to truly personalized implants that fit one unique individual.^[136] Virtual planning of surgery and guidance using 3D printed, personalized instruments have been applied to many areas of surgery including total joint replacement and craniomaxillofacial reconstruction with great success.^[137] One example of this is the bioresorbable trachial splint to treat newborns with tracheobronchomalacia^[138] developed at the University of Michigan. The use of additive manufacturing for serialized production of orthopedic implants (metals) is also increasing due to the ability to efficiently create porous surface structures that facilitate osseointegration. The hearing aid and dental industries are expected to be the biggest area of future development using the custom 3D printing technology.^[139]

In March 2014, surgeons in Swansea used 3D printed parts to rebuild the face of a motorcyclist who had been seriously injured in a road accident.^[140] In May 2018, 3D printing has been used for the kidney transplant to save a three-year-old boy.^[141] As of 2012^[update], 3D bio-printing technology has been studied by biotechnology firms and academia for possible use in tissue engineering applications in which organs and body parts are built using inkjet printing techniques. In this process, layers of living cells are deposited onto a gel medium or sugar matrix and slowly built up to form three-dimensional structures including vascular systems.^[142] Recently, a heart-on-chip has been created which matches properties of cells.^[143]

Thermal degradation during 3D printing of resorbable polymers, same as in surgical sutures, has been studied, and parameters can be adjusted to minimize the degradation during processing. Soft pliable scaffold structures for cell cultures can be printed.^[144]

In 3D printing, computer-simulated microstructures are commonly used to fabricate objects with spatially varying properties. This is achieved by dividing the volume of the desired object into smaller subcells using computer aided simulation tools and then filling these cells with appropriate microstructures during fabrication. Several different candidate structures with similar behaviours are checked against each other and the object is fabricated when an optimal set of structures are found. Advanced topology optimization methods are used to ensure the compatibility of structures in adjacent cells. This flexible approach to 3D fabrication is widely used across various disciplines from biomedical sciences where they are used to create complex bone structures^[145] and human tissue^[146] to robotics where they are used in the creation of soft robots with movable parts.^[147][148] 3D printing also finds its uses more and more in design and fabrication of Laboratory apparatus ^[149]

3D printing has also been employed by researchers in the pharmaceutical field. During the last few years there's been a surge in academic interest regarding drug delivery with the aid of AM techniques. This technology offers a unique way for materials to be utilized in novel formulations.^[150] AM manufacturing allows for the usage of materials and compounds in the development of formulations, in ways that are not possible with conventional/traditional techniques in the pharmaceutical field, e.g. tableting, cast-molding, etc. Moreover, one of the major advantages of 3D printing, especially in the case of Fused Deposition Modelling (FDM), is the personalization of the dosage form that can be achieved, thus, targeting the patient's specific needs.^[151] In the not-so-distant future, 3D printers are expected to reach hospitals and pharmacies in order to provide on demand production of personalized formulations according to the patients' needs.^[152]

In 2018, 3D printing technology was used for the first time to create a matrix for cell immobilization in fermentation. Propionic acid production by Propionibacterium acidipropionici immobilized on 3D-printed nylon beads was chosen as a model study. It was shown that those 3D-printed beads were capable of promoting high density cell attachment and propionic acid production, which could be adapted to other fermentation bioprocesses.^[153]

In 2005, academic journals had begun to report on the possible artistic applications of 3D printing technology.^[154] As of 2017^[update], domestic 3D printing was reaching a consumer audience beyond hobbyists and enthusiasts. Off the shelf machines were increasingly capable of producing practical household applications, for example, ornamental objects. Some practical examples include a working clock^[155] and gears printed for home woodworking machines among other purposes.^[156] Web sites associated with home 3D printing tended to include backscratchers, coat hooks, door knobs, etc.^[157]

Education sector

3D printing, and open source 3D printers in particular, are the latest technology making inroads into the classroom.^{[158][159][160]} Some authors have claimed that 3D printers offer an unprecedented "revolution" in STEM education.^[161][162] The evidence for such claims comes from both the low-cost ability for rapid prototyping in the classroom by students, but also the fabrication of low-cost high-quality scientific equipment from open hardware designs forming open-source labs.^[163] Future applications for 3D printing might include creating open-source scientific equipment.^[163][164]

Cultural heritage and museum-based digital twin

In the last several years 3D printing has been intensively used by in the cultural heritage field for preservation, restoration and dissemination purposes.^[165] Many Europeans and North American Museums have purchased 3D printers and actively recreate missing pieces of their relics^[166] and archaeological monuments such as Tiwanaku in Bolivia.^[167] The Metropolitan Museum of Art and the British Museum have started using their 3D printers to create museum souvenirs that are available in the museum shops.^[168] Other museums, like the National Museum of Military History and Varna Historical Museum, have gone further and sell through the online platform Threeding digital models of their artifacts, created using Artec 3D scanners, in 3D printing friendly file format, which everyone can 3D print at home.^[169]

The application of 3D printing for the representation of architectural assets has many challenges. In 2018, the structure of Iran National Bank was traditionally surveyed and modelled in computer graphics(CG) software (Cinema4D) and was optimised for 3D printing. The team tested the technique for the construction of the part and it was successful. After testing the procedure, the modellers reconstructed the structure in Cinema4D and exported the front part of the model to Netfabb. The entrance of the building was chosen due to the 3D printing limitations and the budget of the project for producing the maquette. 3D Printing was only one of the capabilities enabled by the produced 3D model of the bank, but due to the project limited brief, the team did not continue modelling for the virtual representation or other applications.^[170] In 2021, Parsinejad et al. comprehensively compared the hand surveying method for 3D reconstruction ready for 3D printing with Digital Recording (adoption of Photogrammetry method).^[170]

Recent other applications

3D printed soft actuators is a growing application of 3D printing technology which has found its place in the 3D printing applications. These soft actuators are being developed to deal with soft structures and organs especially in biomedical sectors and where the interaction between human and robot is inevitable. The majority of the existing soft actuators are fabricated by conventional methods that require manual fabrication of devices, post processing/assembly, and lengthy iterations until maturity of the fabrication is achieved. Instead of the tedious and time-consuming aspects of the current fabrication processes, researchers are exploring an appropriate manufacturing approach for effective fabrication of soft actuators. Thus, 3D printed soft actuators are introduced to revolutionise the design and fabrication of soft actuators with custom geometrical, functional, and control properties in a faster and inexpensive approach. They also enable incorporation of all actuator components into a single structure eliminating the need to use external joints, adhesives, and fasteners. Circuit board manufacturing involves multiple steps which include imaging, drilling, plating, soldermask coating, nomenclature printing and surface finishes. These steps include many chemicals such as harsh solvents and acids. 3D printing circuit boards remove the need for many of these steps while still producing complex designs.^[171] Polymer ink is used to create the layers of the build while silver polymer is used for creating the traces and holes used to allow electricity to flow.^[172] Current circuit board manufacturing can be a tedious process depending on the design. Specified materials are gathered and sent into inner layer processing where images are printed, developed and etched. The etches cores are typically punched to add lamination tooling. The cores are then prepared for lamination. The stack-up, the buildup of a circuit board, is built and sent into lamination where the layers are bonded. The boards are then measured and drilled. Many steps may differ from this stage however for simple designs, the material goes through a plating process to plate the holes and surface. The outer image is then printed, developed and etched. After the image is defined, the material must get coated with soldermask for later soldering. Nomenclature is then added so components can be identified later. Then the surface finish is added. The boards are routed out of panel form into their singular or array form and then electrically tested. Aside from the paperwork which must be completed which proves the boards meet specifications, the boards are then packed and shipped. The benefits of 3D printing would be that the final outline is defined from the beginning, no imaging, punching or lamination is required and electrical connections are made with the silver polymer which eliminates drilling and plating. The final paperwork would also be greatly reduced due to the lack of materials required to build the circuit board. Complex designs which may takes weeks to complete through normal processing can be 3D printed, greatly reducing manufacturing time.

During the COVID-19 pandemic 3d printers were used to supplement the strained supply of PPE through volunteers using their personally owned printers to produce various pieces of personal protective equipment (i.e. frames)

As of 2021 and the years leading up to it, 3D printing has become both an industrial tool as well as a consumer product. With the price of certain 3D printers becoming ever cheaper and the quality constantly increasing many people have picked up the hobby of 3D printing. As of current estimates there are over 2 million people around the world who have purchased a 3D printer for hobby use.^[173]

Legal aspects

Intellectual property

3D printing has existed for decades within certain manufacturing industries where many legal regimes, including patents, industrial design rights, copyrights, and trademarks may apply. However, there is not much jurisprudence to say how these laws will apply if 3D printers become mainstream and individuals or hobbyist communities begin manufacturing items for personal use, for non-profit distribution, or for sale.

Any of the mentioned legal regimes may prohibit the distribution of the designs used in 3D printing, or the distribution or sale of the printed item. To be allowed to do these things, where an active intellectual property was involved, a person would have to contact the owner and ask for a licence, which may come with conditions and a price. However, many patent, design and copyright laws contain a standard limitation or exception for 'private', 'non-commercial' use of inventions, designs or works of art protected under intellectual property (IP). That standard limitation or exception may leave such private, non-commercial uses outside the scope of IP rights.

Patents cover inventions including processes, machines, manufacturing, and compositions of matter and have a finite duration which varies between countries, but generally 20 years from the date of application. Therefore, if a type of wheel is patented, printing, using, or selling such a wheel could be an infringement of the patent.^[174]

Copyright covers an expression^[175] in a tangible, fixed medium and often lasts for the life of the author plus 70 years thereafter.^[176] If someone makes a statue, they may have a copyright mark on the appearance of that statue, so if someone sees that statue, they cannot then distribute designs to print an identical or similar statue.

When a feature has both artistic (copyrightable) and functional (patentable) merits, when the question has appeared in US court, the courts have often held the feature is not copyrightable unless it can be separated from the functional aspects of the item.^[176] In other countries the law and the courts may apply a different approach allowing, for example, the design of a useful device to be registered (as a whole) as an industrial design on the understanding that, in case of unauthorized copying, only the non-functional features may be claimed under design law whereas any technical features could only be claimed if covered by a valid patent.

Gun legislation and administration

The US Department of Homeland Security and the Joint Regional Intelligence Center released a memo stating that "significant advances in three-dimensional (3D) printing capabilities, availability of free digital 3D printable files for firearms components, and difficulty regulating file sharing may present public safety risks from unqualified gun seekers who obtain or manufacture 3D printed guns" and that "proposed legislation to ban 3D printing of weapons may deter, but cannot completely prevent, their production. Even if the practice is prohibited by new legislation, online distribution of these 3D printable files will be as difficult to control as any other illegally traded music, movie or software files."^[177] Currently, it is not prohibited by law to manufacture firearms for personal use in the United States, as long as the firearm is not produced with the intent to be sold or transferred, and meets a few basic requirements. A license is required to manufacture firearms for sale or distribution. The law prohibits a person from assembling a non–sporting semiautomatic rifle or shotgun from 10 or more imported parts, as well as firearms that cannot be detected by metal detectors or x–ray machines. In addition, the making of an NFA firearm requires a tax payment and advance approval by ATF.^[178]

Attempting to restrict the distribution of gun plans via the Internet has been likened to the futility of preventing the widespread distribution of DeCSS, which enabled DVD ripping.^{[179][180][181][182]} After the US government had Defense Distributed take down the plans, they were still widely available via the Pirate Bay and other file sharing sites.^[183] Downloads of the plans from the UK, Germany, Spain, and Brazil were heavy.^[184][185] Some US legislators have proposed regulations on 3D printers to prevent them from being used for printing guns.^[186][187] 3D printing advocates have suggested that such regulations would be futile, could cripple the 3D printing industry, and could infringe on free speech rights, with early pioneer of 3D printing Professor Hod Lipson suggesting that gunpowder could be controlled instead.^{[188][189][190][191][192][193]}

Internationally, where gun controls are generally stricter than in the United States, some commentators have said the impact may be more strongly felt since alternative firearms are not as easily obtainable.^[194] Officials in the United Kingdom have noted that producing a 3D printed gun would be illegal under their gun control laws.^[195] Europol stated that criminals have access to other sources of weapons but noted that as technology improves, the risks of an effect would increase.^[196][197]

Aerospace regulation

In the United States, the FAA has anticipated a desire to use additive manufacturing techniques and has been considering how best to regulate this process.^[198] The FAA has jurisdiction over such fabrication because all aircraft parts must be made under FAA production approval or under other FAA regulatory categories.^[199] In December 2016, the FAA approved the production of a 3D printed fuel nozzle for the GE LEAP engine.^[200] Aviation attorney Jason Dickstein has suggested that additive manufacturing is merely a production method, and should be regulated like any other production method.^[201][202] He has suggested that the FAA's focus should be on guidance to explain compliance, rather than on changing the existing rules, and that existing regulations and guidance permit a company "to develop a robust quality system that adequately reflects regulatory needs for quality assurance."^[201]

Health and safety

Play media

A video on research done on printer emissions

Research on the health and safety concerns of 3D printing is new and in development due to the recent proliferation of 3D printing devices. In 2017, the European Agency for Safety and Health at Work has published a discussion paper on the processes and materials involved in 3D printing, potential implications of this technology for occupational safety and health and avenues for controlling potential hazards.^[203]

Impact

Additive manufacturing, starting with today's infancy period, requires manufacturing firms to be flexible, ever-improving users of all available technologies to remain competitive. Advocates of additive manufacturing also predict that this arc of technological development will counter globalization, as end users will do much of their own manufacturing rather than engage in trade to buy products from other people and corporations.^[12] The real integration of the newer additive technologies into commercial production, however, is more a matter of complementing traditional subtractive methods rather than displacing them entirely.^[204]

The futurologist Jeremy Rifkin^[205] claimed that 3D printing signals the beginning of a third industrial revolution,^[206] succeeding the production line assembly that dominated manufacturing starting in the late 19th century.

Social change

Street sign in Windhoek, Namibia, advertising 3D printing, July 2018

Since the 1950s, a number of writers and social commentators have speculated in some depth about the social and cultural changes that might result from the advent of commercially affordable additive manufacturing technology.^[207] In recent years, 3D printing is creating significant impact in the humanitarian and development sector. Its potential to facilitate distributed manufacturing is resulting in supply chain and logistics benefits, by reducing the need for transportation, warehousing and wastage. Furthermore, social and economic development is being advanced through the creation of local production economies.^[107]

Others have suggested that as more and more 3D printers start to enter people's homes, the conventional relationship between the home and the workplace might get further eroded.^[208] Likewise, it has also been suggested that, as it becomes easier for businesses to transmit designs for new objects around the globe, so the need for high-speed freight services might also become less.^[209] Finally, given the ease with which certain objects can now be replicated, it remains to be seen whether changes will be made to current copyright legislation so as to protect intellectual property rights with the new technology widely available.

As 3D printers became more accessible to consumers, online social platforms have developed to support the community.^[210] This includes websites that allow users to access information such as how to build a 3D printer, as well as social forums that discuss how to improve 3D print quality and discuss 3D printing news, as well as social media websites that are dedicated to share 3D models.^{[211][212][213]} RepRap is a wiki based website that was created to hold all information on 3d printing, and has developed into a community that aims to bring 3D printing to everyone. Furthermore, there are other sites such as Pinshape, Thingiverse and MyMiniFactory, which were created initially to allow users to post 3D files for anyone to print, allowing for decreased transaction cost of sharing 3D files. These websites have allowed greater social interaction between users, creating communities dedicated to 3D printing.

Some call attention to the conjunction of Commons-based peer production with 3D printing and other low-cost manufacturing techniques.^{[214][215][216]} The self-reinforced fantasy of a system of eternal growth can be overcome with the development of economies of scope, and here, society can play an important role contributing to the raising of the whole productive structure to a higher plateau of more sustainable and customized productivity.^[214] Further, it is true that many issues, problems, and threats arise due to the democratization of the means of production, and especially regarding the physical ones.^[214] For instance, the recyclability of advanced nanomaterials is still questioned; weapons manufacturing could become easier; not to mention the implications for counterfeiting^[217] and on intellectual property.^[218] It might be maintained that in contrast to the industrial paradigm whose competitive dynamics were about economies of scale, Commons-based peer production 3D printing could develop economies of scope. While the advantages of scale rest on cheap global transportation, the economies of scope share infrastructure costs (intangible and tangible productive resources), taking advantage of the capabilities of the fabrication tools.^[214] And following Neil Gershenfeld^[219] in that "some of the least developed parts of the world need some of the most advanced technologies," Commons-based peer production and 3D printing may offer the necessary tools for thinking globally but acting locally in response to certain needs.

Larry Summers wrote about the "devastating consequences" of 3D printing and other technologies (robots, artificial intelligence, etc.) for those who perform routine tasks. In his view, "already there are more American men on disability insurance than doing production work in manufacturing. And the trends are all in the wrong direction, particularly for the less skilled, as the capacity of capital embodying artificial intelligence to replace white-collar as well as blue-collar work will increase rapidly in the years ahead." Summers recommends more vigorous cooperative efforts to address the "myriad devices" (e.g., tax havens, bank secrecy, money laundering, and regulatory arbitrage) enabling the holders of great wealth to "a paying" income and estate taxes, and to make it more difficult to accumulate great fortunes without requiring "great social contributions" in return, including: more vigorous enforcement of anti-monopoly laws, reductions in "excessive" protection for intellectual property, greater encouragement of profit-sharing schemes that may benefit workers and give them a stake in wealth accumulation, strengthening of collective bargaining arrangements, improvements in corporate governance, strengthening of financial regulation to eliminate subsidies to financial activity, easing of land-use restrictions that may cause the real estate of the rich to keep rising in value, better training for young people and retraining for displaced workers, and increased public and private investment in infrastructure development—e.g., in energy production and transportation.^[220]

Michael Spence wrote that "Now comes a ... powerful, wave of digital technology that is replacing labor in increasingly complex tasks. This process of labor substitution and disintermediation has been underway for some time in service sectors—think of ATMs, online banking, enterprise resource planning, customer relationship management, mobile payment systems, and much more. This revolution is spreading to the production of goods, where robots and 3D printing are displacing labor." In his view, the vast majority of the cost of digital technologies comes at the start, in the design of hardware (e.g. 3D printers) and, more important, in creating the software that enables machines to carry out various tasks. "Once this is achieved, the marginal cost of the hardware is relatively low (and declines as scale rises), and the marginal cost of replicating the software is essentially zero. With a huge potential global market to amortize the upfront fixed costs of design and testing, the incentives to invest [in digital technologies] are compelling."^[221]

Spence believes that, unlike prior digital technologies, which drove firms to deploy underutilized pools of valuable labor around the world, the motivating force in the current wave of digital technologies "is cost reduction via the replacement of labor." For example, as the cost of 3D printing technology declines, it is "easy to imagine" that production may become "extremely" local and customized. Moreover, production may occur in response to actual demand, not anticipated or forecast demand. Spence believes that labor, no matter how inexpensive, will become a less important asset for growth and employment expansion, with labor-intensive, process-oriented manufacturing becoming less effective, and that re-localization will appear in both developed and developing countries. In his view, production will not disappear, but it will be less labor-intensive, and all countries will eventually need to rebuild their growth models around digital technologies and the human capital supporting their deployment and expansion. Spence writes that "the world we are entering is one in which the most powerful global flows will be ideas and digital capital, not goods, services, and traditional capital. Adapting to this will require shifts in mindsets, policies, investments (especially in human capital), and quite possibly models of employment and distribution."^[221]

Naomi Wu regards the usage of 3D printing in the Chinese classroom (where rote memorization is standard) to teach design principles and creativity as the most exciting recent development of the technology, and more generally regards 3D printing as being the next desktop publishing revolution.^[222]

Environmental change

The growth of additive manufacturing could have a large impact on the environment. As opposed to traditional manufacturing, for instance, in which pieces are cut from larger blocks of material, additive manufacturing creates products layer-by-layer and prints only relevant parts, wasting much less material and thus wasting less energy in producing the raw materials needed.^[223] By making only the bare structural necessities of products, additive manufacturing also could make a profound contribution to lightweighting, reducing the energy consumption and greenhouse gas emissions of vehicles and other forms of transportation.^[224] A case study on an airplane component made using additive manufacturing, for example, found that the component's use saves 63% of relevant energy and carbon dioxide emissions over the course of the product's lifetime.^[225] In addition, previous life-cycle assessment of additive manufacturing has estimated that adopting the technology could further lower carbon dioxide emissions since 3D printing creates localized production, and products would not need to be transported long distances to reach their final destination.^[226]

Continuing to adopt additive manufacturing does pose some environmental downsides, however. Despite additive manufacturing reducing waste from the subtractive manufacturing process by up to 90%, the additive manufacturing process creates other forms of waste such as non-recyclable material (metal) powders. Additive manufacturing has not yet reached its theoretical material efficiency potential of 97%, but it may get closer as the technology continues to increase productivity.^[227]

Some large FDM printers which melt High-density polyethylene (HDPE) pellets may also accept sufficiently clean recycled material such as chipped milk bottles. In addition these printers can use shredded material coming from faulty builds or unsuccessful prototype versions thus reducing overall project wastage and materials handling and storage. The concept has been explored in the RecycleBot.

See also

References

Further reading

Scholia has a profile for 3D printing (Q229367).

• Tran, Jasper (2017). Reconstructionism, IP and 3D Printing (Thesis). SSRN 2842345.
• Tran, Jasper (2016). "Press Clause and 3D Printing". Northwestern Journal of Technology and Intellectual Property. 14: 75–80. SSRN 2614606.
• Tran, Jasper (2016). "3D-Printed Food". Minnesota Journal of Law, Science and Technology. 17: 855–80. SSRN 2710071.
• Tran, Jasper (2015). "To Bioprint or Not to Bioprint". North Carolina Journal of Law and Technology. 17: 123–78. SSRN 2562952.
• Tran, Jasper (2015). "Patenting Bioprinting". Harvard Journal of Law and Technology Digest. SSRN 2603693.
• Tran, Jasper (2015). "The Law and 3D Printing". John Marshall Journal of Information Technology and Privacy Law. 31: 505–20.
• Lindenfeld, Eric; et al. (2015). "Strict Liability and 3D-Printed Medical Devices". Yale Journal of Law and Technology. SSRN 2697245.
• Dickel, Sascha; Schrape, Jan-Felix (2016). "Materializing Digital Futures". The Decentralized and Networked Future of Value Creation. Progress in IS. pp. 163–78. doi:10.1007/978-3-319-31686-4_9. ISBN 978-3-319-31684-0.
• "Results of Make Magazine's 2015 3D Printer Shootout". Retrieved 1 June 2015.
• "Evaluation Protocol for Make Magazine's 2015 3D Printer Shootout". makezine.com. Retrieved 1 June 2015.
• Vincent; Earls, Alan R. (February 2011). "Origins: A 3D Vision Spawns Stratasys, Inc". Today's Machining World. 7 (1): 24–25. Archived from the original on 10 March 2012.
• "Heat Beds in 3D Printing – Advantages and Equipment". Boots Industries. Retrieved 7 September 2015.
• Albert, Mark (17 January 2011). "Subtractive plus additive equals more than (– + + = >)". Modern Machine Shop. 83 (9): 14.
• Stephens, B.; Azimi, P.; El Orch, Z.; Ramos, T. (2013). "Ultrafine particle emissions from desktop 3D printers". Atmospheric Environment. 79: 334–339. Bibcode:2013AtmEn..79..334S. doi:10.1016/j.atmosenv.2013.06.050.
• Easton, Thomas A. (November 2008). "The 3D Trainwreck: How 3D Printing Will Shake Up Manufacturing". Analog. 128 (11): 50–63.
• Wright, Paul K. (2001). 21st Century Manufacturing. New Jersey: Prentice-Hall Inc.
• "3D printing: a new industrial revolution – Safety and health at work – EU-OSHA". osha.europa.eu. Retrieved 28 July 2017.
• Hod., Lipson (11 February 2013). Fabricated : the new world of 3D printing. Kurman, Melba. Indianapolis, Indiana. ISBN 978-1-118-35063-8. OCLC 806199735.

External links

• Rapid prototyping websites at Curlie