초록 ▼

The present invention is a multi-layer film which has an improved composite structure for providing hermetic seals to packages manufactured in high speed packaging apparatus. The structure of the multi-layer film of the present invention includes a main substrate and a sealant layer. The sealant lay

The present invention is a multi-layer film which has an improved composite structure for providing hermetic seals to packages manufactured in high speed packaging apparatus. The structure of the multi-layer film of the present invention includes a main substrate and a sealant layer. The sealant layer, in turn, includes two components, an intermediate layer which has the primary function of compliance during sealing, and a sealing layer which has the primary function of providing adhesivity to the completed seal. As a result of this invention, high strength hermetic seals can be provided to multi-layer films effectively and efficiently, and hermetic seals are provided with the ability to be peeled open without destruction of several layers of the film.

대표청구항 ▼

[ What is claimed is:] [1.] A multi-layer film for forming hermetic seals on packages comprising:(a) a main film substrate;(b) a sealant layer adjacent and bonded to said main film substrate, said sealant layer comprising,(i) an intermediate layer bonded to said main film substrate and having suffic

[ What is claimed is:] [1.] A multi-layer film for forming hermetic seals on packages comprising:(a) a main film substrate;(b) a sealant layer adjacent and bonded to said main film substrate, said sealant layer comprising,(i) an intermediate layer bonded to said main film substrate and having sufficient flow property under sealing conditions to deform and comply with all unfilled space between sealing jaws during sealing, and(ii) a sealing layer bonded to said intermediate layer to provide a seal under sealing conditions; and(c) a composite structure of said main film substrate and said sealant layer such that said intermediate layer has a composition different than said sealing layer's composition, and said sealant layer has sufficient thickness in relationship to the thickness of said main film substrate to eliminate tunnels from being formed during sealing, whereby hermetic seals are formed during sealing, rein the minimum thickness of said sealant layer in relationsip to said main film substrate is detemind by solving for S.sub.0 in the following relationship: ]EQU3 ] and wherein, S.sub.0 is said sealant layer thickness,t is total thickness of said composite structure,G' is the storage shear modulus of said sealant layer(G' is temperature and rate dependent)T is applied compression stress on a seal jaw,L is 1/2 jaw seal length, andW is a seal tooth width.