Surface energy adhesive application engineer

When a designer is selecting an adhesive for a specific application, the engineering properties of the individual plastic will be considered carefully. All too often, however, the data supplied by the plastic manufacturer will include melting point, mould shrinkage, tensile modulus, hardness, dielectric properties, water absorption, density and thermal conductivity but almost never the surface energy of the plastic, which is one of the key properties required for the adhesive application engineer. 

Low-surface-energy plastics such as the polyolefin family will always be a challenge to the adhesive application engineer, especially if the adhesive bond line is to be subjected to peel loading. Bonding to difficult plastics and the wetting of adhesives is discussed in more detail in Section 6.1. 

PP has an excellent balance of physical and mechanical properties, and the products based on PP are economical and can be easily recycled. The bulk properties of PP are attractive and can be varied via synthesis conditions however, the surface properties are not easily controllable [10]. Due to its low surface energy, the adhesion of PP to other polar materials is generally low, which significantly limits its engineering applications. To increase the surface energy, surface modification via chemical or physical means is necessary [11]. 

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