Using Coperion's ZSK twin screw extruders to produce hot melt adhesives and pressure sensitive adhesives allows the use of a wide range of different recipe components and ensures consistently high product quality without batch-to-batch variations.
Hot melt adhesives are applied while hot and molten. A functional binding is formed when the adhesive cools and solidifies. Pressure sensitive adhesives are highly viscous, permanently tacky substances that are applied by pressure to a substrate.
The ZSK twin screw extruder in modular design and individually configured to the product group combines various process steps in one machine: plasticizing/masticating, melting, mixing, homogenization, venting and devolatilization. By using special equipment, even non free flowing raw materials (e.g. rubber bales) can be fed into the continuous process in a controlled manner. Large volumes of resins and/or softeners can be incorporated. Entrained air, moisture and volatile organic components are removed from the product flow by applying a vacuum.
Pressure sensitive adhesives can be directly discharged to application systems, processed further in-line, granulated and powdered or even filled into containers. Hot melt adhesives are usually underwater pelletized and filled into bags.