Engineering plastics POM
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engineering plastics pom
SPECIFICATION & DATA SHEET Chemical Analysis
Product Code: SP167-00 Chemical Name: Polyoxymethylene
Trade Name: POM CAS No. : 66455-31-0
Molecular Formula: [CH2O]nCH20-[CH2-CH2]m(n>>m) . Molecular Weight: --
HS Code 3907101000
Technical item Unit Test method
Melt Index g/10min D1238 9
Gravity g/cm3 D792 1.41
Rockwell hardness M scale D785 80
R scale 115
Bending strength Kgf/cm2 D790 950
Bending modulus D790 26.00
(Yield point) Kgf/cm2 D638 620
(Breaking point) % D638 60
Compressive Strength 1%deformation Kgf/cm2 D695 320
10%deformation Kgf/cm2 D695 1,100
(Concave 23 oC 50% RH) Kgf/cm D256 6.5
(In 23 oC water 24 hrs) % D570 0.22
Deflection temperature under load(18.6Kgf/cm2) oC D648 110
Shrinkage for molding % 1.8-2.2 1.8-2.2
POM is one of the 5 kinds general engineering plastics, the full name Polyoxymethylene or polyacetal, it is high degree of crystallinity polymer, besides the high hardness, strength and rigidity modulus, it has others excellent physical properties compare to other general plastics,
1. High mechanical hardness;
2. Excellent fatigue resistivity;
3. High creep resistance, excellent rebound resilience;
4. High antifriction and anti-abrasion, used for high friction machine parts;
5. it can be processed among wide temperature range;
6. High dimension stability, hard to change according to the temperature
7. Its flow is good, easy to mold, surface gloss.
It has high resistance against organic reagent (alcohols, aldehyde, ester and ether) , hydrocarbon (oils) , drugs, hot water (80oC) , the chemical resistance properties are excellent, affected by the high content acid and alkali.
Hot deformation temperature (HDT) is one index represent plastics thermal property, it means the thermal resistance during the short time utilize as well as the critical temperature against external force. However consider the safety factor the short time utilize temperature must be about 10oC lower than the HDT. POM-H melt point 175-179oC, HDT 124-136oC (18.6kg/cm2) , our POM Melt point 165 oC, HDT 110 oC (18.6kg/cm2) , our POM have the C-C line between the molecules, so it is harder to pyrolysis compare to POM-H, thus it has the good thermal stability.
Our POM has lower melt point and HDT than POM-H, but has good long term thermal stability than POM-H, moreover
The mold temperature is lower at least 10 oC, it releases little formaldehyde gas than POM-H when process and easy to recycle.
POM is mainly applied for household electrical appliances, electric motor, automotive, universal machine, construct.
Universal machine Agriculture implement and parts, knitting machine, vending machine, optical machine, clock, bicycle as well as every kinds machine parts
General parts Clothes slide fastener and button, medical appliance parts, toy parts, aerosol can, lighter, door and windows lead rail, furniture parts, gas meter, water meter, pipes and water heater parts
Electronic product and electric motor House electrical appliance parts (fan, washing machine, refrigerator ) , switch, tape recorder and video recorder parts and crust
Automotive parts Rim parts, tank cup, carburetor, air bleed control valve, air-conditioner parts, lock, seatbelt parts, hand grip, clock parts, brake par.
General mold process needs the good flowability, low injection pressure and temperature, low shrinkage and warp as well as the short cycle, when POM BS090 as the materials, the barrel temperature sets 180-200 oC and mould temperature sets 40-80 oC, materials dry 3-4hrs under the temperature 80-90 oC. Plastics remain about 15min in the barrel, max 10 min for staining compound.
Our POM BS serials is crystallized plastics, the moldings product shrinkage is 1.8-2.2%, the shrinkage depends on the degrees of crystallization and the process conditions (mould temperature, jet pressure, gate, molding cycle) .