|
ACETAL STOCK SHAPE APPLICATIONS AND MACHINING
There are two types of acetals, the
homopolymer (Delrin® from DuPont),
and copolymer (Celcon® from
Hoechst Celanese or Ultraform® from
BASF). Acetal is an engineering thermoplastic based on formaldehyde
polymerization. The highly crystalline material is strong, rigid and offers a
low coefficient of friction against metals, acetals and other plastics. They are
also creep resistant which makes them ideal for parts that require dimensional
stability.
Acetal can be fabricated for a broad range
of applications from industrial to automotive and plumbing to mechanical
components. Several grades have also been approved by the FDA for direct food
contact.
Generally speaking, acetals do not absorb a
large amount of moisture and are resistant to a wide range of solvents. They can
be attacked by both strong acids and oxidizing agents and the homopolymer is not
recommended for strong caustic environments. The copolymer is more resistant to
hot water and air than the homopolymer. NOTE: Due to the differing properties
between the homopolymer and copolymer, it is not recommended that they be
substituted without careful consideration.
Acetal is available in a variety of stock
shapes (see charts page 30 and 31). The homopolymer and copolymer are offered in
several unreinforced and glass fiber-reinforced grades, PTFE-filled and silicone
grades, and the homopolymer is available in chemically lubricated low-friction
formulations.
Known for its high tensile strength,
stiffness, resilience, fatigue endurance and toughness, acetals are resistant to
organic solvents, provide dimensional stability, offer a low coefficient of
friction, and abrasion resistance. Good electrical properties also make them
ideal for electrical applications. Machining
Acetal stock shapes can be easily machined
into a wide variety of parts using general machining practices and standard
polished carbide tooling. Virtually any sharp cutting tool capable of high speed
without vibration can be used. ACETAL APPLICATIONS INCLUDE:
- Bearings
- Bushings
- Cams
- Conveyors
- Electronic industry
- Gears
- Guides
- Impellers
- Plumbing applications
- Steering columns
- Pumps
- Valves
- Wear strips
For more information, contact the Plastics Distributor and Fabricator.
|
