What is Polymer Molding?

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By Jeremy Losek, Nov 17th, 2020

Polymer molding is the process of producing a product by injection molding using a polymer material. There are many different kinds of polymer, allowing for a large variety of designs and applications across multiple industries. The process of injection molding is perfect for projects that require a large volume of products with complex features.

Polymer Materials

Polymer materials are categorized into three general groups; elastomers, thermoplastics, and thermosets. Elastomers are polymers that have high elasticity and may be reversibly stretched to a high degree. Common elastomers include polyisoprene (natural rubber), neoprene, and silicone. Thermoplastics become pliable and plastic (melt) when heated. In their melted form thermoplastics can be molded through injection molding, extrusion, or thermoforming. Common thermoplastics include polyvinyl chloride (PVC), polycarbonate (PC), ABS, and polypropylene (PP). Thermosets are polymers that do not melt when exposed to heat. Common thermosets are epoxies, urea-formaldehyde, and unsaturated polyesters.

Selecting the best polymer material for your project is vital. Consider the performance, texture, density, desired color, durability, and flexibility of the material to ensure your part will perform as intended. The shrink rate should also be considered.

Custom Polymer Parts

Polymer injection molding is used to produce many common every day consumer and commercial goods including pipe fittings, toothbrushes, bottle lids, disposable razors, car dashboards, power-tool housing, electrical parts, phone cases, computer mouse, kitchenware, baking trays, toys, and more. Producing parts by injection mold is highly customizable and allows for complexity, allowing brands to add their unique features to products.

Injection Molding of Polymers

During the injection molding process, the melted polymer is transferred under high pressure into a mold cavity. First, pellets are added to the injection molding machine through a funnel-shaped hopper.  A feeding screw-like plunger rotates continuously, moving the product material forward through the barrel. A heating element placed over the barrel melts the polymer. The melted material is then injected into the mold and held there till it solidifies almost as soon as the mold is filled. Once the part has hardened and cooled, the two-part mold releases, and an ejector pin pushes the product into a bin. This method of manufacturing is highly accurate, allows for complexity and control, as well as repetition. A large number of identical parts can be made within a short period. Injection molding has a higher up-front cost when compared to CNC machining or 3D printing because the tooling is expensive. This initial investment proves to be economical over time, the larger the production run.

Pick ICOMold for Your Polymer Molding Project

Automotive manufacturer, consumer goods, medical, or industrial engineer, ICOMold can assist you in manufacturing your custom polymer injection molded part. By working with our experienced team and strong manufacturing experience, ICOMold will provide you with a seamless experience while producing your part. ICOMold is 9001:2008 certified which means we have perfected our manufacturing process to produce fewer defects than our competitors. In combination with our domestic team and overseas manufacturing, we can offer our customers a competitive price. Call us today at (419) 867-3900 or request an instant quote for your custom polymer molding project.

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