Like all hot melts, EVA is supplied in a solid form and usually – for applications where it is to be applied as part of a process – packed in sacks or bags ready for remelting on site. As well as being convenient for the end user, this is also highly desirable in terms of storage, distribution and handling as it ensures that the chemical mix remains exactly as intended. Hot melts mainly consist of paraffin wax and resin, blended to a specific recipe. Were this carefully calculated mix to be stored or transported in liquid form – in a heated tank truck for instance – the individual products would begin to separate out into different layers, making it unusable without thorough remixing.
In a solidified form, the chemical formulation of this complex product is maintained. The challenge faced by hot melt manufacturers is which of the two main solidification processes to use to achieve this state: Underwater pelletizing or steel belt granulation.
During the presentation both processes will be explained in detail and differences with respect to technology, operation and sustainability will be highlighted.