How to Find A Good Manufacturer for Plastic Machining?

Are you a headache that you have been searching for a plastic manufacturer but get lost in the huge market sourcing? Do you need a guide to help you to quickly identify an ideal manufacturer for your machined plastic parts? Then, you could simply get a good manufacturer for CNC palstic of low volume machining as us.

For a plastic prototype specialist, there are two key capacities, the well-coordinated teamwork, and advanced CNC machining, which lead their plastic prototyping service towards the state-of-art qualities, with machining features and aesthetic finishes as required. Furthermore, a plastic prototype specialist should understand the intricacies and characteristics of plastic materials and know how to use them to their fullest.

What We Can Do for Plastic Machining

CNC palstic machining

Machining Capacities & Tolerance Control

Precise machined plastic prototypes require manufacturers who are good at utilizing advanced machinery and CAD/CAM software to perform precision CNC machining. Combining multi CNC machining technology, like 3-axis and 5-axis milling, turning, EDM, and so on, makes plastic parts highly consistent with closest tolerances with no burrs. Indeed, even complex plastic parts are effectively processed through the immediate import of records from most CAD frameworks for accuracy machining.

For general tolerance control, manufacturers will follow the term that “tolerances are based on the general tolerances of international standards unless drawings with tolerances are supplied. For general machined plastic parts, the tolerance control will follow DIN ISO 2768 (m) while for high machined parts”. However, for plastic parts require accurate assembly, tight tolerance within +/- 0.02mm or tighter will challenge manufacturers to improve their machining process. To some extent, machining tolerance is one of the aspects to differentiate manufacturer capacities.

Material Selection & Processing

When the right material is used, it can not only ensure functional use but also help to reduce costs in many ways. Common Materials for machining plastic prototypes including ABS, PC, PMMA, POM, PP, and so on.

Among them, ABS blocks are widely applied in many commercial prototypes, which is light and easy to process, cost-saving as well. If no special requirement on material properties, ABS will be a good choice. Clear PC and PMMA could be replaced by each other. However, if for optical prototypes that need high transparency, clear PMMA will be a better choice than clear PC as PMMA is able to present perfect transparency after mirror polish while clear PC has limitations on polish due to its material properties. POM is prone to deformation due to material stress after machining, and black plastic is prone to whitening after rough polish, which challenges the wisdom in the CNC machining process solution.

Polishing Process for Machined Surface

plastic machining - manual finishing

There are 3 common polish methods for machined plastic parts, including smooth polish, mirror polish, and vapor polish. Each makes different surface roughness and aesthetic appearance. The Following are the general process for each polish method to achieve correct surface roughness as required. If a manufacturer does well in the polish finish, they will not be strange for the below steps.

  • Smooth polish: start from a rough polish with 240# sandpaper, then 320/400#, and finally finished with 600-800# so as to smoothen the tooling marks and burs on the machined surface.
  • Mirror polish/ Clear Polish: start from a rough polish with 320# sandpaper, then step by step from 400-600-800-1000# and end with 1500# fine sandpaper, further use the polishing paste to achieve mirror appearance. Both tooling marks and burs are removed through mirror polish.
  • Vapor polish: a kind of chemical vapor performed after smooth polish, by reorganizing the machined plastic surface, which is commonly used in Polycarbonate. Vapor polish is ideally suited to small features polishing, as well as a little limitation on internal and external surface finishes.

Case Study for Machining Plastic Prototypes

– Clear Optical Parts

plastic machining parts-micromilling

Auto optical designers usually concern about how to prototype manufacturers to achieve those extremely but necessarily optical detail features in the original design, such as the optical teeth on Lightguide and pillows on light blades.

In this case, if manufacturers want to get the recognition from auto optical designers, they should achieve the advantages in micro-milling on acrylic parts. Also, combining with the application of diamond cutter turning. Only in this way can they offer cost-effective machining solutions to produce ideal optical parts as required. Precision CNC micro-milling ensures perfect profile tolerance without deformation so as to make light travel in the correct direction. Last but not least, a high-quality polish process ensures the homogeneous light output of the clear optical parts.

Plastic Machining Solutions To Your Project Demands

The Above information about plastic machining can be used as basic information to test plastic manufacturers you choose. So that you can narrow the range and find out the suitable one you need.

As a specialized expert on plastic machining, we are able to offer optimal solutions. So as to prevent unnecessary defects or product failures during production. Here in AutoProtoWay.com, clients can get supports from material selection for complex plastic parts to design modifications for the test applications. Both one-off plastic prototypes and low-volume CNC machining plastic production can find direct supports here.

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