3 Things to Keep in Mind when Designing Parts for Injection Molding

When designing plastic injection molded parts, there are several things you need to keep in mind during the design process. These include making allowances that will make it possible for you to save both time and money. It might also help you to understand the challenges faced by the manufacturer when making your injection molded parts. Here are three important things you need to keep in mind during the design phase of your final product.  
  1. Consistent Wall Thickness
  One of the most important aspects to keep in mind when designing injection molded parts is the need to keep the thickness of the walls as consistent as possible. Some variance is acceptable with injection molded parts. But when the variances are more than minimal, you risk the formation of warpage, sink marks, voids, longer cooling times, molded-in stress, and possible interruptions in material flow. If your parts must have a variation in thickness, your design should incorporate a taper that allows for a smoother transition.  
  1. Shrinkage and Warpage
  The reality is that all materials have different rates of shrinkage at various times during the cooling process. Shrinkage occurs when there is a distinct difference between the molded part and the corresponding linear mold dimensions. Warpage, on the other hand, occurs when the part distorts as a result of excessive amounts of residual stress. There are several things you must consider as part of the process of designing injection molded parts. These include tooling, part geometry, and processing. All of these play important roles in the manufacturing process.  
  1. Choosing the Right Materials
  As with any product you plan to have manufactured, the materials you choose will play a major role in the success of the part. Your material selection process can be as easy as surfing the web to find out what materials are being used in similar parts. It can also be highly complex when you identify each individual requirement for your injection molded part, along with corresponding information about the various materials available to you. The first step of the process when designing injection molded parts is to make note of how the part you are designing will be used. Will your part be used in the aerospace, automotive, or medical industry for example?   Does your final part need to be flexible or should it be rigid in design and choice of materials? What specific requirements and tolerances must your finished part must meet? In most instances, you will find it isn't necessary for you to reinvent the wheel. Instead, look for similar parts to the one you are designing and take a look at the materials being used.   From here it is just a matter of making sure your choice of manufacturer has access to the right materials. If you are interested in learning more about the process of designing and manufacturing injection molded plastic parts, contact Additive Manufacturing at (877) 238-7907 or submit your design using our online form along with the desired materials and specifications.   
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