Modern plastics have revolutionized almost every industry. In fact, they are affecting our daily lives in ways we may never realize. Each innovation builds on the one that came before, and we're used to the spectacle of wonder materials: rayon, nylon, acrylic, Kevlar, Teflon, etc. With the invention of acetal in the 1950s, the plastic age gave manufacturing one of its greatest gifts.
There are many advantages to using acetal for manufacturing, but engineers often conclude that acetal is the easiest plastic to work with. It is ideal for precision parts because of its high strength and low friction, as well as excellent dimensional stability and low moisture absorption. All this leads to excellent machinability.
At Miller Plastics, we often turn to acetals when precision parts need to be strong, smooth or flexible -- or all three. Acetal is unique in that it is inherently slippery, making it ideal for reducing friction. The material is ideal for sliding mechanisms, gears, and even plastic molded protectors at the bottom of furniture legs. That's right: Thanks to acetal, you can slide sections across the wood floor.
Acetal copolymer
Acetal copolymers are made of different types of monomer units that combine to form a common polymer structure. Compared with homopolymers, copolymers have:
Better dimensional stability
Higher chemical resistance
More wear-resisting
The porosity is small during extrusion
Two forms of acetal
Acetal thermoplastics are also known as polyformaldehyde or POM. It is a white semi - crystalline resin. There are two classes of acetals, each with some differences:
Acetal homopolymer
Homopolymers are composed of repeating monomer units, each with a similar molecular structure. Compared with copolymers, homopolymers have:
Higher rigidity
Higher impact strength at room temperature
Higher tensile strength
The operating temperature is slightly higher
Hardness is a slightly higher
More smooth
The Basis
Acetals are called thermoplastics because of the way they react to heat. Thermoplastics become liquid at their melting point, 175 ° C for acetal homopolymer plastics and 162 to 173 ° C for copolymers. Thermoplastics are useful because they can be heated, melted, cooled, and reheated without significant degradation. So instead of burning, acetals are liquefied for manufacturing, which can then be recycled.
Acetal is sold under brands such as Celcon, Duracon, Keital -POM, Tecaform, Tepcon, Hostaform and Ultraform. You may also have heard of acetal called Delrin. This is the duPont registered name for a commonly used acetal homopolymer. In the United States, Delrin is usually sold in bars or sheets.
Acetal is marketed in pellet form. The manufacturer applies heat and pressure until it becomes liquid and can be shaped into different shapes. Originally designed to compete with zinc and aluminum castings, acetal is the most popular material of choice for projects that require the best properties of plastic without the full strength of metal.
