在科学技术飞速发展的今天,塑料产品的用途日益广泛,化学工业中一种很重要的质材——塑料正打进各行各业的生产系统中,特别是新问世的塑料网,作为煤层开采的假顶材料,使有史以来的假顶材料得到了改革。以塑代木,以塑代钢,这是煤炭工业发展的必然前景,也是社会生产力发展的必然需要。在全国统配矿井中,厚煤层分层开采铺设金属网假顶的产量占总产量的四分之一,再加上搪材假顶和其它形式的假顶,分层开采的产量占总产量的三分之一以上,全国每年铺设金属网消耗钢材9万余吨,铺荆笆消 Today, with the rapid development of science and technology, plastic products are increasingly used for a wide range of purposes. As a kind of important material in the chemical industry, plastic is entering the production system of all walks of life, especially the newly emerged plastic net. Of the false top material, so that the history of the false top material has been reform. To plastic-wood, plastic-steel, which is the inevitable prospects for the development of the coal industry, but also the inevitable need for the development of social productive forces. In the nationwide coal mines, the production of layered metal roofing in thick coal seam mining accounts for one quarter of the total output, plus the roofing and other forms of roofing, the output of stratified mining accounts for the total output More than a third of the country each year laying metal mesh consumption of more than 90,000 tons of steel,