POM CH-15日本宝理----The longer the process length is, the higher the injection pressure is needed to ensure the parts are full. The higher the holding pressure, the higher the dimensional accuracy of POM parts. POM has large crystallinity and narrow melting range, and the volume shrinkage can reach 2.8% when cooling and hardening. It is necessary to have enough pressure to make up for the size defects. Therefore, in the injection molding of POM, properly increasing the packing pressure can reduce and eliminate the phenomenon of warpage, shrinkage pits and internal holes of POM products
造粒温度：POM使用双螺杆挤出造粒时，往往会产生颗粒中心孔洞现象。这是由于POM为结晶型聚合物，其熔体在冷却时往往伴随着较大的体积变化，在挤出过程中，熔融状的料条进入冷却槽后，表面会瞬间固化成表面皮层，而芯层部分还处于熔融状态，随着料条由外向里逐渐硬化的继续，因体积减小所引起的收缩力将作用于芯部尚未硬化的树脂，相当于芯部受到均等的拉力，其结果是在料条的芯部沿长度方向形成连续的缩孔。在挤出过程中，***控制冷却槽中的水温，在可操作的前提下，尽量提高水温。
Physical performance rating unit system test method
Density: 1.45 g / cm? ISO 1183
Melt flow rate (melt flow rate) (190 ° C / 2.16 kg) 3.0 g / 10 min ISO 1133
Dissolution volume flow rate (MVR) (190 ° C / 2.16 kg) 2.40 cm3 / 10min ISO 1133
Mechanical properties rating unit system test method
Tensile modulus 11700 MPa ISO 527-2
Tensile stress 130 MPa ISO 527-2
Tensile strain (fracture) 1.5% ISO 527-2
Bending modulus 10000 MPa ISO 178
Bending stress 185 MPa ISO 178
Friction coefficient JIS k7218
Dynamic 1 0.35 JIS K7218
And steel - Dynamic 2 0.27 JIS k7218
Wear factor JIS k7218
0.49 MPa, 0.30 m/sec 3 10 10^-8 mm³/N·m JIS K7218
0.060 MPa, 0.15 m/sec 4 200 10^-8 mm³/N·m JIS K7218
0.49 MPa, 0.30 m/sec 5 500 10^-8 mm³/N·m JIS K7218
0.060 MPa, 0.15 m/sec 6 10000 10^-8 mm³/N·m JIS K7218