Injection molding is an incredibly efficient and accurate way to produce and enhance parts of all shapes and sizes. If you want to optimize the manufacturability of a part for injection molding, you will need to understand the different aspects and details of this process.
There are many checks and balances necessary to reap the benefits of injection molding. Each specific and unique design has many parts that need to be aligned in order to get the most out of your finished good. Things such as material selection, operating environment, part geometry, and more all have a big effect on manufacturability.
Knowing the crucial aspects of this process will allow you to improve both the quality and the manufacturability of your designs. Here are four ways to improve the manufacturability of your injection molded part design.
1. Remember the Necessities
Determine acceptable PEG locations. Every single part will have a visible parting line, ejector pin marks, and gate location. When a part is ready to be released, the two mold halves will need to separate, creating something known as a parting line. Because of the intrinsic way mold functions, parting lines are unavoidable. Consider these details when first designing a part to make sure their locations won’t affect cosmetics or part integrity.
Shrinkage of material will also occur during the cooling process and needs to be taken into consideration. This is important to account for when designing to ensure tool build accounts for a shrink to maintain dimensional integrity but also to prevent your part from becoming stuck in a mold as the material shrinks around steel features.
2. Study Your Materials
Selecting the right material can be one of the biggest and most important considerations in the process of part design. There are many factors that go into this decision, including physical characteristics, chemical properties, operating environment, and regulatory considerations.
3. Make Room for Draft
Depending on the part design and material, adding just a few degrees of taper can allow your part to leave its mold much more smoothly. This will also minimize scraping and friction between the finished product and the mold. This means that the surface of your part will remain undamaged while the process itself moves along at a much quicker rate.
Draft can be very easily understood if you imagine an ice cube tray. When ice cubes are formed and you take them out of the freezer, do you have to pry them out of their individual molds with a tool? No, because the part design for the ice cube tray has a certain amount of draft within it that allows the cubes to smoothly pop out when placed under a little bit of pressure.
4. Carefully Choose Wall Thickness
Beside primarily impacting the visual outcome and functionality of a part, wall thickness directly affects the manufacturing cycle time. Thicker walls utilize more material and extend the length of the molding/cooling cycle and drive up the cost. Also, be wary of wall thickness when working with plastics as thicker walls are weaker.
Designing with thick walls poses other issues as well. Having thick wall sections can lead to air being trapped and creating voids in your parts with can compromise their structural integrity. You can also see the cosmetic effects of thick walls as sink or other visual imperfections.
Injection molding has become a very popular process, but you won’t gain its full benefits unless the proper steps are taken to optimize its potential. Knowing how a mold works and what the necessities of part design will help you optimize your product.
There are many moving parts to creating an optimized part design. Without a strong background in plastics, it can seem overwhelming to create an effective product or component. Luckily, a skilled molder will have the resources available to assist you in ensuring your design is optimized prior to beginning your mold build. New Berlin Plastics has the people, knowledge, and skill available to help you with this process. If you’re looking to have a project quoted and want to know you’re moving forward with a quality design, reach out to New Berlin Plastics at 262.784.3120.
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