旭化成POM 8520

8520 physical property table
Basic performance rating unit test method
Melt flow rate
45g/10minASTM D1238
(190℃/2.16kg)45g/10minISO 1133
Water absorption (24 hr) 0.2% ASTM D570
Test method of physical performance rating unit
Specific gravity 1.41 g / cm ASTM D792, ISO 1183
Molding shrinkage
(Flow)1.6-2%ASTM D955,ISO 294-4
(Across Flow)1.6-2%ISO 294-4
Rockwell hardness ASTM d785
(M-Scale)80
(R-Scale)115
Mechanical properties - rating units - Test methods
Tensile modulus 2900 MPa ISO 527-2
Yield tensile stress 67 MPa ISO 527-2
Tensile stress 61 MPa ASTM D638
elongation at break 
45%ASTM D638
30%ISO 527-2
Bending modulus 2630 MPa ASTM D790
Bending strength 90 MPa ASTM D790
Taber abrasion resistance (1000 cycles) 14 mg ASTM d1044
Charpy notched impact strength (23 ℃) 4.5 kJ / M ISO 179 / 1ea
Izod notch impact strength: 39 J / M ASTM D256
Thermal performance rating unit test method
Hot deformation temperature
(0.45MPa,unannealed)158℃ASTM D648
(0.45MPa,unannealed)156℃ISO 75-2/B
(1.8MPa,unannealed)110℃ASTM D648
(1.8MPa,unannealed)105℃ISO 75-2/A
Linear thermal expansion coefficient of flow direction: 0.0001 cm / cm / ℃ ASTM e831
Flame retardant grade HB UL 94

无论对于均聚POM，还是共聚POM，当成型薄壁或者采用多型腔成型制品时，均应采用较快的注塑速度。这是因为，注塑成型此类制件时，要求体系有很好的流动性能。前面讲过，POM熔体属切敏性聚合物，要增加流动性能，可通过增加注塑速度来实现；同时，在上述应用场合，POM结晶冷却速度会很快，制品很容易产生表面缺陷如折皱、斑纹及熔接痕等，为此也需要提高注塑速度。