Processes
Plastic Machining Lathe
As a premier plastics fabricator we pride ourselves on creating some of the finest turned components in the plastic machining industry. For precision plastic machining requirements, we have developed lathe tooling technology capable of delivering superior plastic surface finishes and optical clarity. Our continuous upgrades to machining equipment have allowed us to maintain the highest quality machined plastic components in the industry.
Our CNC machining equipment can process a wide range of components from micro turning to 20 inches in diameter. Equipped with milling heads and subspindles, our lathes can produce many components complete with efficient cycle times. The best and most consistent components in plastic machining are produced without secondary operations such as deburring.
Plastic Milling
At Connecticut Plastics, we have assembled a state of the art plastic milling department for plastic machining. We are proud to produce mill components with a high degree of consistency to close tolerances with no burrs. Surface finishes can be optical-quality grade as needed via plastic polishing. Complex components are easily manufactured through the direct import of files from most CAD systems for precision machining.
Polishing
Common plastic polishing methods are vapor polishing and mechanical buffing. Each process is best suited for particular configurations and materials.
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Vapor polishing utilizes a chemical vapor which attacks the surface of the plastic, causing it to flow. The best plastics for this process are polycarbonate, Ultem®, and polysulfone. Acrylics do respond to this method, though not quite as well. The most appropriate acrylic polishing technique depends on the configuration of the component. Vapor polishing is not for an inexperienced person as special equipment is needed in order to avoid vapor contact with the operator. However, when done properly, it can provide absolute optical quality finishes. This method can be used for both internal and external features, including threads and drill holes.
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Mechanical polishing is the most common, easiest to do, and is useful on any plastic. This method tends to leave very fine scratches on the surface and while it will usually look nice, it is not an acceptable polishing method for optical work. In addition, buffing would degrade the surfaces of the two other methods above.
Annealing of Plastics
Annealing, or stress relieving, of plastics is an important step in the plastic machining process. While not all components require annealing, it can provide important advantages for some materials and part configurations.
Many manufacturers believe that their own internal annealing process is sufficient. However, in practice, batch processing can yield inconsistent results.
Paragon Medical has multiple programmable ovens for precise control during the stress relieving process making our plastic fabrication capabilities superior. Our own annealing process allows us to create highly consistent material qualities from one rod to the next for the highest precision machining possible.
In addition, post-machining annealing can improve the properties of some components, especially those in the harder materials. These materials are sensitive to stress cracking, accumulated from the rod stock or precision machining. To achieve the lowest possible stress and the most stable component, consider stress relieving after machining. This operation is a must post plastic polishing. Plastic components polished without annealing will likely crack in operation.