Effect of FDM Processing Conditions on Snap-Fit Characteristic in Assembly

Abstract

Snap-fit allows plastic products to have assembly and disassembly capabilities without the use of screws, bolts, or other additional parts. For this reason, snap-fit is used in all kinds of plastic products from stationery to automotive parts. Because the mechanical and other functions of a snap-fit are greatly affected by its shape and material properties, it is desirable to fully evaluate them at the design stage. In addition, as the assembly and disassembly of products by snap-fit is generally performed by people, it is important to evaluate not only virtually but also with actual plastic parts. Therefore, there is a strong need to make a prototype and evaluate the feel of the product during assembling and disassembling, before finalizing on the shape and materials. In the past, making precise prototype required expensive molds, but in recent years, additive manufacturing has made it possible to make prototype efficiently and at low cost. In additive manufacturing, fused deposition modeling (FDM) is considered suitable for snap-fit prototype because it can use the same materials as mass-produced products. Thus, it may be possible to make a snap-fit prototype with rigidity, strength, and other characteristics similar to those of mass-produced products. However, FDM has various processing conditions such as tool path, nozzle temperature, and height of one layer. They are expected to have a significant effect on the snap-fit characteristics. Snap-fit is required to meet various requirements depending on the plastic products. The requirements can be divided into three major categories: in assembly, in disassembly, and when to use. In this study, we investigated the effect of FDM processing conditions on snap-fit characteristic in assembly.