Abstract: A method and apparatus for producing carpet liners successively applies a pre-coating and a heavy coating material to a carpet band to be treated. The pre-coating material, which contains an activated isocyanate-polyol mixture, is applied to the carpet band at a temperature at which the components of the mixture will not react with each other. A heavy coating thermoplastic material is subsequently applied to the carpet band. The heavy coating is applied at a sufficiently high temperature to cause the components of the pre-coating mixture, which already has been applied to the carpet band, to react with each other and form polyurethane. Accordingly, a pre-coating layer of polyurethane is formed simultaneously with the application of the heavy coating material.