Understanding lamination adhesives

For beginners, here are descriptions of several lamination applications, along with the most common adhesives used in the various lamination applications.

Adhesives play a minimal part in the overall cost of the laminated end product; but poor adhesive selection and lack of supplier support and knowledge will affect the bottom line faster than any difference in price.

Effective surface cleaning is an essential step in the production of high-quality products. The substrates, machine and the adhesive must be kept free of dust and debris as customers are not going to pay for laminated parts with contamination under the laminate material.

These not only look bad they could also create adhesion issues. This can be addressed utilising a panel brush cleaner, web vacuum, low static adhesive rollers and/or compressed air.

Flat panels

Polyvinyl Acetate (PVA) is a water-based adhesive that is primarily used for paper lamination. Vinyl Acetate Ethylene (EVA) is also a water-based adhesive most used for lamination of vinyl. These can also be used for paper lamination if looking to consolidate products.

Epoxy (a two-part system) offers a destruct bond when miter folding is needed. Polyurethane reactive hotmelt (PURHM) is a 100% solids technology that can be successfully used on a very wide range of substrates.

All these adhesives can be applied by roller to the board/base substrate or as a web coat (adhesive coating on the laminate material.) A few applications apply adhesive to both substrates.

Water-based adhesives may allow swelling of the wood fibres, grain raise, when applied directly to the board, which can be aesthetically objectionable. This can be mitigated by adjustment of heat, rate of application or use of a web coater.

As always, a higher quality board can reduce the chance of grain raise.