The lamination process is done on our lamination production line. The substrate (PVC foam board) and the surface material are glued together by PUR hot melt adhesive. PUR hot melt adhesive is currently one of the most widely used adhesives in the building materials industry. It has excellent adhesive strength, water resistance and aging resistance.
In order to have a better lamination effect, the thickness tolerance of PVC foam board should be within ±0.1mm. For us, for PVC sheet with a thickness of less than 15mm, we can make the thickness tolerance within the range. If the thickness of the board exceeds 15mm, our solution is to sand the PVC foam board through a sanding machine first, and then proceed to the lamination process. Sanding can even out the thickness of the PVC sheet. The resulting laminate will be flatter and last longer. Therefore, the lamination cost of thick substrates is higher due to the additional sanding process.
For our manufacturer, to control the thickness of the PVC sheet, the quantity is the key. The number of PVC sheets produced at a time should be large enough. If 1000 sheets are produced, their thickness uniformity will definitely be better than if only 100 sheets are produced. This is because the operation of the production machine has not yet fully stabilized in the first 10 hours after start-up. We keep adjusting the machine until the PVC foam board becomes stable. So if there are only 100 sheets to be produced, they are all produced in less than 10 hours after starting up. Thickness tolerances for these boards may be within ±0.3mm. In short, more quantity allows better quality control.