Picard Maisyn, Mohanty Amar K, Misra Manjusri
School of Engineering, University of Guelph Thornbrough Building Guelph N1G 2W1 ON Canada
Bioproducts Discovery and Development Centre, Department of Plant Agriculture, University of Guelph Crop Science Building Guelph N1G 2W1 ON Canada.
RSC Adv. 2020 Oct 1;10(59):36058-36089. doi: 10.1039/d0ra04857g. eCollection 2020 Sep 28.
There are many limitations within three-dimensional (3D) printing that hinder its adaptation into industries such as biomedical, cosmetic, processing, automotive, aerospace, and electronics. The disadvantages of 3D printing include the inability of parts to function in weight-bearing applications, reduced mechanical performance from anisotropic properties of printed products, and limited intrinsic material performances such as flame retardancy, thermal stability, and/or electrical conductivity. Many of these shortcomings have prevented the adaptation of 3D printing into product development, especially with few novel researched materials being sold commercially. In many cases, high-performance engineering thermoplastics (ET) provide a basis for increased thermal and mechanical performances to address the shortcomings or limitations of both selective laser sintering and extrusion 3D printing. The first strategy to combat these limitations is to fabricate blends or composites. Novel printing materials have been implemented to reduce anisotropic properties and losses in strength. Additives such as flame retardants generate robust materials with V0 flame retardancy ratings, and compatibilizers can improve thermal or dimensional stability. To serve the electronic industry better, the addition of carbon black at only 4 wt%, to an ET matrix has been found to improve the electrical conductivity by five times the magnitude. Surface modifications such as photopolymerization have improved the usability of ET in automotive applications, whereas the dynamic chemical processes increased the biocompatibility of ET for medical device materials. Thermal resistant foam from polyamide 12 and fly ash spheres were researched and fabricated as possible insulation materials for automotive industries. These works and others have not only generated great potential for additive manufacturing technologies, but also provided solutions to critical challenges of 3D printing.
三维（3D）打印存在许多局限性，阻碍了其在生物医学、化妆品、加工、汽车、航空航天和电子等行业的应用。3D打印的缺点包括部件在承重应用中无法发挥作用、打印产品的各向异性导致机械性能降低，以及诸如阻燃性、热稳定性和/或导电性等固有材料性能有限。这些缺点中的许多都阻碍了3D打印在产品开发中的应用，尤其是很少有新研究的材料在商业上销售。在许多情况下，高性能工程热塑性塑料（ET）为提高热性能和机械性能提供了基础，以解决选择性激光烧结和挤出3D打印的缺点或局限性。应对这些局限性的首要策略是制造共混物或复合材料。已采用新型打印材料来降低各向异性性能和强度损失。诸如阻燃剂之类的添加剂可生成具有V0阻燃等级的坚固材料，而增容剂可提高热稳定性或尺寸稳定性。为了更好地服务于电子行业，已发现仅向ET基体中添加4 wt%的炭黑就能将电导率提高五倍。诸如光聚合之类的表面改性提高了ET在汽车应用中的可用性，而动态化学过程提高了ET作为医疗器械材料的生物相容性。对聚酰胺12和粉煤灰微球制成的隔热泡沫进行了研究和制造，作为汽车行业可能的隔热材料。这些工作及其他工作不仅为增材制造技术带来了巨大潜力，也为3D打印的关键挑战提供了解决方案。
