why must polyacetal be capped

Polyacetal, also known as polyoxymethylene (POM), is a thermoplastic material that is prone to oxidation when exposed to air and ultraviolet (UV) radiation. This can lead to degradation of the material, causing it to become brittle and lose its mechanical properties over time.

To prevent this, polyacetal is often capped with a protective layer or coating to shield it from the environment. This can be done by applying a layer of paint, varnish, or other protective material to the surface of the polyacetal.

Capping polyacetal helps to extend its lifespan and maintain its strength and performance over time. It also helps to prevent discoloration and other aesthetic issues that can arise from exposure to UV radiation and other environmental factors