Acetal
Acetal is a crystalline engineering polymer that is formed by polymerzing anhydrous formaldehyde in order to form an oxymethlylene chain.
Acetal is a strong material that provides good dimensional stability along with a low coefficient of friction.
The material provides good all around resistance to different chemicals types. It has excellent resistance to substances like oils, alcohols and formaldehydes as well as good protection to methylenthylketons. Acetal will only offer limited resistance to solvents if used for a short time and has poor resistance to acids.
Acetal is suitable for machining and is also quite easy to process. It is normally used for applications such as plates, spring, gears, pulleys, sheaves as well as bushings and housings.
Acetal is a formaldehyde based material, as such care should be taken when processing it as any formaldehyde released can irritate skin and eyes.
Mechanical Properties of Acetal
|
Flexural Modulus (MPa)
|
Tensile Strength
(MPa) |
Elastic Modulus (MPa)
|
Compressive Strength (MPa)
at yield or break |
Flexural Strength (MPa)
at yield or break |
Elongation at break (%)
|
Hardness
Rockwell M |
|
2553 – 3105
(23 ºC) |
57 - 72
|
3105 (compressive)
|
110
( at 10% strain) |
90
|
15 - 75
|
75 - 90
|
Thermal Properties of Acetal
|
Coef of Thermal Expansion (10-6/ºC)
|
Deflection Temperature (ºC) at 0.46 MPa
|
Thermal Conductivity (W/m-ºC)
|
|
61 - 110
|
85 - 121
|
0.230
|
Physical & Electrical Properties of Acetal
|
Specific Gravity
|
Water Absorption (% weight increase)
|
Dielectric Strength (V/mil);
1/8" thick specimen unless noted |
|
1.4
|
0.2 - 0.22 (24 hrs)
|
500 (90 mil thick)
|
|
0.65 - 0.8 (saturated)
|
