Compounding extruder. (Brochures).

With the company's hot melt adhesive compounding extruder, continuous twin-screw mixing is said to enhance the quality of hot melt pressure-sensitive adhesives, according to this two-page, color bulletin. The counter-rotating, tangential screw design is said to provide thorough mixing of resins with a wide range of viscosities and melting temperatures. This design is said to generate high shear without high temperature to protect heat sensitive resins, according to the literature. The multi-stage feed design is said to eliminate the need for pre-blending, while assuring uniform fluxing of high-melt viscosity polymers. These polymers are introduced first and extruded into a uniform state by the twin-screw action. The low-viscosity materials, which can be pre-melted if desired, are added using the multistage feed. In the final stage, oil is injected into the barrel of the compounder. The continuous compounding action of the twin-screw mixing process is said to improve quality control and produce a uniform hot-melt adhesive. Twin-screw mixing is said to virtually eliminate the crosslinking of polymers that occurs during batch processing when high temperatures are maintained over extended periods. Residence time is often no longer than 15 seconds. (NFM Welding Engineers)

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