DPL laminate flooring (Direct Pressure Laminate) has a surface that consists of a decorative paper. The coating of the carrier plate with the paper is a complex process, consisting of several partial steps. The entirety of the machines used is the press line.
First the carrier plate passes through a brushing machine in which adhering dust is removed. This is followed by laying in the laying area or in the laying machine: Here, stacks of backing paper (also called balance paper), carrier plate and a structure of several layers on the top side are formed. In the case of high-quality products, the latter consists of up to five functional layers (kraft paper, decorative paper and top layer, also known as overlay). Each layer must be separately impregnated with resin in advance.
This is followed by the actual pressing process, in which pressure and temperature cause the resin to harden chemically. There are continuous presses (also: double belt presses) and short cycle presses (also called KT plants). The latter offer the possibility to structure the surface: By using an appropriate press plate, a relief is embossed into the surface. A special feature here is the so-called synchronous pore: the embossing is brought to coincide with the decor of the paper, making it possible to achieve a particularly realistic reproduction of natural motifs such as wooden surfaces. The process is also known as Register Embossing or EIR (embossed in register).
After pressing, the coated boards must be cooled in a cooling star.