6.9.1.1 Vinyl Acetate Monomer (VAM) - Based Emulsions (EVA or PVA Emulsions)
Polyvinyl Acetate Emulsions (PVAs) are used mainly for porous substrates such as wood (furniture), board (boxes manufacturing) and lamination (corrugated board manufacturing). The product bonds in a mechanical way, penetrating into the fibre of the substrate.
(b) Finger joint assembly
Some paper manufacturers use coatings to impart water resistance to paper. For such paper, EVA-based adhesives are more suitable than PVA-based adhesives. EVA-based emulsions are used for difficult substrates, including water resistant paper, PVC and medium-density fiberboard (MDF).
6.9.1.2 Acrylic-Based Emulsions
Figure 199 Clear labels
Pressure Sensitive Adhesives (PSAs) are tacky and are mainly used for labels. It is necessary to first evaporate the water and then apply a release paper to make removing the label easier. The performance of these products is measured in terms of tack, peel and shear force. It is important to have a very clean surface before applying these adhesives. These products have a high temperature performance of around 50°C (122°F).
PSAs are ideal for the clear labels found on bottles because they are clear when dry.