| 摘要 |
The present invention provides a plastic bag to which a zipper (24, 32) having fins (26, 34) may be attached without fusing the fins together. The bag has an excellent seal between the fins and the respective body panels (12, 14) of the plastic bag. The zipper includes a male and female track. The male track includes a male profile (24) and a first fin (26) with the first fin having an inner layer (28) and an outer layer (30). The female track includes a female profile (32) and a second fin (34) with the second fin having an inner layer (36) and an outer layer (38), in which the inner layers of the fins are formed from a higher melting point material than the outer layers of the fins. Preferably, the inner layer should have a melting point at least about 5 DEG C higher than the outer layer seal to be produced between the fins and their respective body panels without fusing the fins to each other. Some examples of higher melting point material resins comprising the inner layer include the following: high density polyethylene (HDPE), linear low density polyethylene (LLDPE), metallocene-catalyzed LLDPE, polypropylene (PP) and ethylene-propylene copolymer (E-P copolymer). Resins comprising the lower melting outer layer include the following: ethylene vinyl acetate copolymer (EVA), low density polyethylene (LDPE), very low density polyethylene (VLDPE), LLDPE and metallocene-catalyzed LLDPE. |
