聚甲醛塑料，俗称赛钢，为结晶性热可塑性塑料，具明显熔点165~175℃，性质Zui接近金属。
优点 1、具高机械强度和刚性
2、Zui高的疲劳强度
3、环境抵抗性、耐有机溶剂性佳
4、耐反覆冲击性强
5、广泛的使用温度范围(-40℃~120℃)
6、良好的电气性质
7、复原性良好
8、具自已润滑性、耐磨性良好
9、尺寸安定性优
缺点 1、加工过程若长时间高温下易起热分解
2、无自熄性
3、抗酸性差
4、成形收缩率大
用途 电子电器：洗衣机、果汁机零件、定时器组件
汽 车： 车把零件、电动窗零件
工业零件：机械零件、齿轮、把手、玩具、螺杆
They walked on slowly and came to the camp, and at once heard acheerful whistling going on, andthe sound of someone digging.George looked over the top of thedug-out trench2 insurprise.
She almost toppled in, she was so amazed at what shesaw!
The boy was there, digging carefully, whistling as he did so! Hebrushed his tousled hair from his hotforehead and caught sight ofGeorge and the others. He looked rather astonished.
'How on earth did you get down here so quickly?' said George. 'Doyou have wings or something?'