A Guide to Materials for Machined Plastic Parts

One of the main attributes of plastics materials is their ability to be directly converted into a final part or component with little or no need for subsequent finishing work to be carried out. Using CNC technology, machined plastic parts with simple or complex geometries, contours, holes and undercut features, etc. can be quickly and easily produced. In this blog, we look at some of the plastic materials available for machining and highlight the applications for which these materials are well-suited.

It is important to note that not all plastics materials can be machined. The more rigid a plastic is, the easier it is to be machined. Plastic materials which are flexible and soft do not readily lend themselves to machining. With CNC technology, machined plastic parts and components for a wide variety of applications can be readily manufactured, avoiding the costs for molds and the like.

Plastics materials for producing machined plastic parts

When choosing a plastic material for producing machined plastic parts, a consideration of the application requirements should drive the selection process. Below is a partial list of preferred material choices for certain application requirements:

  • Clear (transparent) parts and components. Some plastics are clear but become translucent or opaque when machined. Polishing of the finished part can restore the original transparency. Good material choices for this application requirement are Acrylic, Polycarbonate, and PVC.

  • Impact resistance. In high wear applications, plastic parts must be capable of withstanding the forces resulting from shocks and blow. Preferred materials for machining these parts include Nylon, Polycarbonate, UHMW, UHMPE.

  • Abrasion resistance. Parts can be subjected to abrasive wear in many applications. Preferred materials to machine parts with high abrasion resistance include UHMW, UHMPE.

  • Chemical resistance. The chemical resistance of plastics is variable. While the best practice is always to consult a plastics reference guide for specific chemical resistivity, materials which have good chemical resistance properties include UHMW, UHMPE, CTFE, PEEK, HDPE.

  • High load strength parts. Parts which require high tensile or compressive strength are important in many applications. Preferred material choices for these types of parts are HDPE, Nylon, Delrin.

  • Temperature resistance. Parts may be required to service-wide temperature ranges and extremes. Good material choices for these types of parts are PTFE, Torlon, PPS.

  • Food-Grade (FDA). Plastics produce from FDA-approved ingredients are available to machine parts for food-grade applications. Material choices include Delrin, HDPE, Nylon, Polycarbonate, Polypropylene, PET, UHMW, and UHMPE.

  • UV resistance. Parts intended for outdoor use should be made from UV-resistant materials. Preferred materials include Polycarbonate (UV stabilized), UHMPE.

Because there are a wide variety of plastic materials and grades available in the marketplace, CRG can provide guidance on selecting the best material for your application. All parts are produced in our ISO 9001:2015-registered facility using the latest CNC technology, ensuring superior part finish with no burrs, as well as tight conformity to specifications and tolerances. Throughout the production process, parts are subjected to stringent quality control, and a final inspection is carried out on all orders before they are shipped.

The CRG team is available to support you across all aspects of the product realization process, from design to prototyping through to final part production.

If you want to learn more about the machined plastic parts we can supply, please contact our sales department for assistance at crg@canadarubbergroup.com.