Plastic Machining – Art or Science?
June 22, 2009
Plastic machining is both an art and a science. Plastics can change dimensionally due to humidity, temperature and machining process and there is an “art” to keeping machined components within stated tolerances. All polymers and copolymers react differently to coolant and machining technique- the science required to properly machine plastic.
Plastic can be machined or molded to create plastic components. Plastic machining is typically used for low volume components or components that may have a short life span. While creating a mold is costly up front, each individual component created from the mold is a cost effective way to produce high volume, long life span components.
Machining a plastic component can allow an OEM to test certain materials for reactivity as well as tolerance to stresses. Parts can be turned or milled or both turned and milled. In selecting a shop for plastic machining, it is important that the shop have experience in both the science and art of plastic machining. Plastic only shops in particular will help to avoid contamination with coolants and metal fragments usually found in a metal shop. They are also familiar with both annealing and polishing of your plastic component.
In selecting a shop for your plastic machining, three criteria are important:
- Does the shop have the expertise and experience to produce your component within your stated tolerances?
- Does the shop use up-to-date equipment and machining techniques?
- Does the shop care about quality and producing quality parts 100% of the time?
- In order to find the answers to these questions, review the company’s web site and talk to their salesperson.
- Additionally, ask for a sample lot before full production in order to review your component.
Machined Polysulfone
June 17, 2009
This part is made out of Polysulfone. Polysulfone is known for being tough, wear resiting, and high temperature stability. It is also a dielectric material that can be used in capacitors. Dielectric means that it will not transmit electricity.
This part is milled in the milling department here at East Coast Precision. It is approximately 1.5 inches square. It features a milled out body, some threaded holes and a polished top. Due to the geometry, the part is actually able to spring a little bit.
Round Acrylic Manifold
June 10, 2009
Sometimes it is necessary to utilize multiple machines to effectively produce a part for our customers. This is an example of that. This manifold is machined from acrylic. A turning center (lathe) is used to turn the outside diameter and round features that are concentric to the center of the part. A vertical machining center (mill) is used to complete the rest of the features. On this part, we can see some port work, deep hole milling, and thread milling.
The manifold is also vapor polished for a nice finish. Acrylic vapor polishes quite well but if you need “optical” clarity, polycarbonate would be the way to go.
Milled and Vapor Polished Acrylic Manifold
June 8, 2009
Take a look at this acrylic manifold we made for one of our customers. It features four ports connected to a main track. Each port features thread-milled threads.
This part also showcases our vapor polishing process. Not only can we polish the exterior of a part, we can polish interior features that would not normally be able to be polished otherwise.
The mainfold is approximately 3″ x 1″ x 3/4″
