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.
6.9.1.3 Natural-Based (or Bio-Based) Adhesives
Figure 200 For corrugated lamination natural-based products are used
These products contain raw materials derived from natural sources, such as potato dextrins. Usually, this adhesive is sold in powder form. The customer must activate the adhesive by adding water and additional additives. These products are limited to paper or boards without coatings. Normally they are rigid. Because they are derived from natural sources, they are prone to microorganism attack, making it necessary to use preservatives. They are the most cost-effective water-based adhesives, but their properties vary depending on their source.