Process for producing a laminate by coextrusion and laminates produced thereby

Abstract From the Canadian patent

A process for the production of a laminate comprising thermoplastic material with a multi-layer wall by co-extrusion provides that added to the material for forming at least one of the layers of the laminate is a substance which makes it possible for that layer to be rendered reconginisable in the laminate by the action of physical and/or chemical means. The added substance may be a fluorescing phosphorescing, or luminescing substance so that the layer containing that substance can be rendered visible in the wall of the laminate by the action of UV radiation of appropriate wavelength.