Colloquia

Samenvatting

Before production of polymer parts, material is supplied as a granulate. Most polymers are known to be hygroscopic materials, which is a material property that determines the ability to adsorb and absorb water molecules on or into the material. Other well-known hygroscopic materials are rice and salt, which withdraw and absorb moisture from the atmosphere. Hygroscopicity is determined by multiple factors, such as the crystal structure and pore shapes, but the most important factor is the ability to form hydrogen bonds. Other factors such as the humidity and temperature of the environment also determine how much moisture the polymer granules absorb. However, the risk of moisture in a polymer granule is failure in the production process. Therefore, before polymer granules are used in production, they must be dried.

The current drying techniques are energy intensive and represent a significant part of the total energy consumption of the polymer industry. This thesis investigated a novel method to potentially decrease energy consumption and create a sustainable solution. The literature shows that the novel method has the ability to specifically break the hydrogen bonds, open pores, and agitate water molecules, leading to a potentially higher diffusion rate in hygroscopic materials, with lower energy costs. However, with the risk that it potentially causes chain scission. This is a degradation process that leads to a reduction in the mechanical properties of the material. The effect of the drying process and on the material properties of polymer granules are investigated and discussed. Based on the results, recommendations are made about dryer designs and the integration of the novel method in the drying process.