Abstract Hollow, multi-layered plastic structures are provided comprising a layer of thermoplastic polyester material and a layer of polyethylene, the polyethylene and polyester layers being crosslinked together at their interface. A process for producing such structures which comprises charging a mold with thermoplastic polyester material, rotating and heating the mold so as to fuse and form a layer of the polyester material on the inner surface of the mold, cooling the mold to a point below the melting point of the polyester but above the melting point of a subsequently added cross-linkable polyethylene material, stopping the rotation and charging the mold with the cross-linkable polyethylene material, resuming the rotation of the mold and heating it to a temperature sufficient to fuse and cross-link the polyethylene with the polyester layer, cooling the mold to a point below the melting point of the polyethylene and removing the finished structure from the mold.
A LAMINATE COMPRISING A FIRST LAYER OF A THERMOPLASTIC POLYESTERA AND A SECOND LAYER OF CROSS-LINKABLE POLYETHYLENE, THE MELTING POINT OF THE POLYETHENE BEING LOWER THAN THE MELTING POINT OF THE POLYESTER, SAID LAYER BEING DIRECTLY CROSSLINKED AT THEIR INTERFACE.
Claim 2
Dependent Claim
40 words
A LAMINATE COMPRISING A FIRST LAYER OF A THERMOPLASTIC POLYESTERA AND A SECOND LAYER OF CROSS-LINKABLE POLYETHYLENE, THE MELTING POINT OF THE POLYETHENE BEING LOWER THAN THE MELTING POINT OF THE POLYESTER, SAID LAYER BEING DIRECTLY CROSSLINKED AT THEIR INTERFACE.
Claim 3
Dependent Claim
15 words
A laminate as defined in claim 1 wherein said polyester contains a fibrous filler material.
Claim 4
Dependent Claim
40 words
A laminate as defined in claim 1 wherein said polyester is a linear, highly polymerized ester of terephthalic acid and a glycol of the series HO(CH2)n OH wherein n is a whole number within the range of 2 to 10.
Claim 5
Dependent Claim
36 words
A laminate as defined in claim 1 in the form of a battery case comprising a first layer of glass-filled thermoplastic polyester and a second cross-linkable polyethylene layer, said layers being directly cross-linked at their interface.
Claim 6
Dependent Claim
16 words
A laminate as defined in claim 1 wherein said polyethylene contains a halogenated flame retardant agent.