| 摘要 |
<p>1448319 Paper like polyethylene film DU PONT OF CANADA Ltd 21 Nov 1974 [22 Nov 1973] 50448/74 Heading B5B Polyethylene film containing an inorganic filter is formed by extruding through a circular die a mixture of (a) 70-98% by wt. of a polyethylene having a maximum melt flow index of 5 decigrams per minute, (b) 2-30% by wt. of inorganic lamellar filler particles, the largest dimensionofthe particles being less than 150 microns, to form a seamless tubing, expanding and simultaneously cooling the tubing while in the plastic formative state to a blow up ratio in the range 1À2 : 1 to 10 : 1. The polyethylene preferably has a melt flow index from 0À1-1À0 decigrams per minute and a density of 0À945-0À970 gms. per cubic centimetre and the lamellar filler is mica of about 12 microns or talcum of about 6 microns. The film has a thickness 0À3- 10 mils.</p> |
