6.9.1.4 Natural Rubber (NR) Adhesives
NR adhesives are also called water-based contact adhesives because they are made from NR emulsified in water. These products are applied on both substrates and are allowed to sit until the water evaporates. When it is dry to the touch, the parts are bonded by applying as much pressure as possible.
6.9.1.5 Liquid polyurethane (PU)
Also known as flexible packaging, liquid PU is commonly used for food packaging. Films from different materials are bonded to create a package that preserves food; film selections are important because they need to provide the required attributes for the food product.