Polyoxymethylene is a linear polymer with no side chains, high density, and high crystallinity. According to the chemical structure in the molecular chain, it can be divided into two types: homopolyformaldehyde and acetal copolymer. The important difference between the two is that the homopolyformaldehyde has high density, crystallinity and melting point, but the thermal
stability is poor, the processing temperature range is narrow (about 10 ¡ã C), the acid-base stability is slightly lower, and the copolymerized formaldehyde density, crystallinity, The melting point and strength are low, but the thermal stability is good, it is not easy to decompose, the processing temperature range is wide (about 50 ¡ã C), and the acid-base stability is good. It is an engineering plastic with excellent comprehensive performance. Has good physical, mechanical and chemical properties, especially with excellent friction resistance. Commonly known as Saigang or Steel, it is the third largest general plastic. Suitable for making wear-resistant parts, transmission parts, and parts such as chemicals and instruments.
1) Excellent mechanical strength;
2)High hardness strength;
3)High wear resistance;
4)Self-lubrication;
5)Higher modulus;
6)Chemical resistance and etc.
Application :
1. AV equipment such as VCRs, CD/laser disk/MD players, radio cassettes, headphone stereos;
2. OA equipment such as printers, keyboards, and CD-ROM drives;
3. Home electrical appliances such as washing machines and dryers
4. Auto parts such as seat belt mechanical components, outer door mirrors, door mirrors, and engine room components;
5. Precision components used in such products as cameras and watches, construction materials, toys such asgame machines, and stationer
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ASTM or UL
test
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Property
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Acetal Copolymer
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Delrin ®
Homopolymer
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Delrin ®
AF PTFE-filled
|
|
D792
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Density (g/cm3)
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1.41
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1.41
|
1.50
|
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D570
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Water Absorption, 24 hrs (%)
|
0.2
|
0.2
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0.2
|
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D638
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Tensile Strength (psi)
|
9,500
|
11,000
|
8,000
|
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D638
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Tensile Modulus (psi)
|
400,000
|
450,000
|
435,000
|
|
D638
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Tensile Elongation at Break (%)
|
30
|
30
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15
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D790
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Flexural Strength (psi)
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12,000
|
13,000
|
12,000
|
|
D790
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Flexural Modulus (psi)
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400,000
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450,000
|
435,000
|
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D695
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Compressive Strength (psi)
|
15,000
|
16,000
|
16,000
|
|
D695
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Compressive Modulus (psi)
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400,000
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450,000
|
350,000
|
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D785
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Hardness, Rockwell
|
M88 / R120
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M89 / R122
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M85 / R115
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D256
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IZOD Impact Notched (ft-lb/in)
|
1.0
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1.0
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0.7
|
|
D696
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Coefficient of Linear Thermal Expansion
(x 10-5 in./in./¡ãF)
|
5.40
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4.70
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5.00
|
|
D648
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Heat Deflection Temp (¡ãF / ¡ãC) at 264 psi
|
220 / 104
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250 / 121
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244 / 118
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|
D3418
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Melting Point Temp (¡ãF / ¡ãC)
|
335 / 168
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347 / 175
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347 / 175
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|
-
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Max Operating Temp (¡ãF / ¡ãC)
|
180 / 82
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180 / 82
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180 / 82
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|
C177
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Thermal Conductivity (BTU-in/ft2-hr-¡ãF)
(x 10-4 cal/cm-sec-¡ãC)
|
1.6
5.5
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2.5
8.6
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-
|
|
UL94
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Flammability Rating
|
HB
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HB
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HB
|
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D149
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Dielectric Strength (V/mil) short
time, 1/8" thick
|
420
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450
|
400
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D150
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Dielectric Constant at 1 MHz
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3.8
|
3.7
|
3.1
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|
D150
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Dissipation Factor at 1 MHz
|
0.005
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0.005
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0.010
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D257
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Volume Resistivity (ohm-cm) at 50%RH
|
1015
|
1015
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3.0 x 1016
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