Patent ID: 6644552
Filing Date: 2003-11-11
Classification: B32B,B42D

Abstract:
A multi layered card comprising:a layer of polyester terepthalate (PET) material having a first coefficient of expansion as a function of temperature; a layer of polyvinyl chloride (PVC) material having a second coefficient of expansion as a function of temperature; where said first and second coefficients of expansion have substantially different values; and a buffer layer of plastic material attached on one surface to the PET layer and attached on its other surface to the PVC layer, said buffer layer having a coefficient of expansion as a function of temperature whose value is intermediate that of said first and second coefficients of expansion; whereby the stress between the PET layer and the buffer layer and between the buffer layer and the PVC layer due to temperature are less than the stress that would exist if the PET and PVC layers were in direct contact with each other.