Abstract
In the silicone material extrusion (MEX) process, product profile error and performance defects are common problems due to changes in strand shape. A process optimization method considering strand morphology, denoted as SMO, which allows adjustment of the strand shape by adjusting process parameters during the printing process is presented. The relation between process parameters (extrusion speed, moving speed, nozzle height, and nozzle radius) and the geometric parameters (strand width and strand height) of the cross-section, as well as the relationship between strand spacing, layer height, and process parameters in no void constraint is discussed and verified. SMO was utilized to produce specimens with tunable strand width and strand height. Tensile tests and profile scans were performed to compare SMO with other methods to verify its feasibility. Specimens fabricated using the SMO method have up to a 7% increase in tensile strength, up to a 10% reduction in processing time, and about a 60% reduction in strand height error over unused ones. The results show that the SMO method with adjustable strand width can effectively balance efficiency and mechanical properties compared to uniform infill, and the SMO method with adjustable strand height can provide higher accuracy compared to uniform strand height. The proposed method is validated and improves the efficiency and accuracy of silicone MEX.
Highlights
The material extrusion (MEX) method [1] for silicone is used in scaffolds for tissue engineering [2], stretchable electronics [3], manufacturing of soft robots [3], orthoses and prostheses [4], drug-delivery devices, nonwovens [5], and other components with flexible thin-walled structure, complex internal structure, as well as high elongation and fatigue life, as silicone material is an environmentally friendly raw material, with superior characteristics of softness and non-toxicity
Moisture curing methods were combined with the liquid rope coiling effect to fabricate silicone foam with variable elastic modulus [17] and three-dimensional contour nonwoven fabrics [5] to exceed the limits of silicone MEX [18]; A theoretical model for silicone MEX was established and verified to effectively control the speed and accuracy [3]
It is observed that the mean value of strand height error and the mean square deviation for the Strand Morphology (SMO) method are much smaller than the other method, which indicates that the overall error of the SMO method is smaller and more uniformly Tunable Specimen
Summary
The material extrusion (MEX) method [1] for silicone is used in scaffolds for tissue engineering [2], stretchable electronics [3], manufacturing of soft robots [3], orthoses and prostheses [4], drug-delivery devices, nonwovens [5], and other components with flexible thin-walled structure, complex internal structure, as well as high elongation and fatigue life, as silicone material is an environmentally friendly raw material, with superior characteristics of softness and non-toxicity. Moisture curing methods were combined with the liquid rope coiling effect to fabricate silicone foam with variable elastic modulus [17] and three-dimensional contour nonwoven fabrics [5] to exceed the limits of silicone MEX [18]; A theoretical model for silicone MEX was established and verified to effectively control the speed and accuracy [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
