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
'No - actually we're packing,' said Julian. 'We've been sleepingin the old cottage, but we've decidedto move out. Is it very, veryold?'
'Oh yes - and it's supposed to have queer things happening in it atnights,' said the woman.
'We know that!' said Julian. 'My word - we were pretty scared lastnight, I can tell you - weird7 noisesand horrible,ghastly lights. We decided not to stay there any longer.'
'That's right,' said the woman. 'Don't you stay! You get as farfrom this place as you can! I can tellyou, I wouldn't come by it atnight. Where are you going?'