Polyethylene polypropylene waterproofing membrane forming. Secondary molding, what does it mean? How to distinguish?
The second compound is, first produced or bought from the market polyethylene film, by heating the polypropylene non-woven composite up. This method is not enough heating, non-woven stickers are not strong, heating is too high, the polyethylene film damage, polyethylene plastic through the second heating to speed up his aging. Further, the polyethylene film for secondary compounding, the proportion of the recycled plastic is too high, and the anti-aging property is lowered.
Polyethylene polypropylene waterproofing membrane from the middle of the "polyethylene" chip, two-sided composite "polypropylene non-woven" made, one method is in the extrusion production of polyethylene film at the same time, when the polyethylene is still in a soft state , In the upper and lower sides of the membrane composite polypropylene non-woven, the temperature can not be too high and polypropylene buried too much, the temperature can not be too low, otherwise the sticky on the sticky.
In the appearance and mechanical analysis, these two processes is difficult to distinguish, a composite also has poor quality, the second compound can also be done better. So, only in the approval of the production line, to control.
