Patent ID: 11969928
Assignee: VISKASE COMPANIES, INC.
Field: Surface technology, coating (Chemistry)
Classification: CPC B  A  C  G | IPC A  B  C  G

Claim 16:
17. The thermoplastic film as defined in claim 2:
wherein the thermoplastic film has been obtained by a method comprising the following steps:
a first step of introducing the detectable particles into a molten plastic resin to produce a mixture comprising the molten plastic resin and the detectable particles, and
wherein the detectable particles are introduced into the molten plastic resin in the form of a particulate compounded mixture comprising the detectable particles together with and distributed in a carrier plastic resin, wherein the particulate compounded mixture comprises the detectable particles in amounts in the range of from 10 to 80 wt. %, based on the particulate compounded mixture; and

(ii) followed by a second step of extruding the mixture comprising the molten plastic resin and the detectable particles, wherein the step of extruding the mixture comprising the molten plastic resin and the detectable particles is performed as a co-extrusion process wherein the plastic film comprising the detectable particles incorporated therein is co-extruded with the at least one other plastic film of different plastic material on both sides of the plastic film so as to obtain:
as the core layer, the plastic film comprising the detectable particles incorporated therein in homogeneous distribution; and
as the outer layers on the both sides of the plastic film of the core layer, the at least one other plastic film.