| 摘要 |
<p>Composite plastic film is 30-120 micro m thick has a mixed plastic layer sandwiched between linear low density polyethylene layers of density = 0.919-0.930. The mixed plastic is 50-70% polypropylene of density = 0.895-0.905 and melt index = 0.75-0.85, 10-30% of the linear low density polyethylene, and 10-30% thermoplastic polyolefin of density = 0.885-0.905 and melt index = 0.55-0.65 An Independent claim is also included for forming a valve by welding together the two superposed films, so when stretched they form a conduit. A straw is inserted into the conduit and has an enlarged end to retain it there.</p> |
