SSP for PA and other polymers

POLYMETRIX SSP processes are used when there is a requirement for high molecular weight/viscosity that is not easily achieved in the melt phase. Other polymers suitable for SSP include PBT, PEN, PLA and PA.

The process comprises an optional crystallization step, which is followed by preheating to SSP temperatures, the SSP reaction and cooling. Nitrogen from the process is continuously cleaned in a catalytic combustion or gas washing system with water.

With PA the pellet moisture content is critical for downstream processing. Here we offer SSP systems with simultaneous conditioning (drying to equilibrium moisture content) as well as independent SSP plants followed by separate conditioning. Drying/conditioning and SSP can be performed at the same time in one process or performed separately (see following section) depending on process requirements. POLYMETRIX conditioning systems are typically installed directly upstream of the spinning extruders.

PA requires consequent treated under nitrogen due to its sensitivity to oxygen. With the use of a de-oxer (catalyst bed) the oxygen content can be reliably controlled below 5ppm.

Features and advantages

• Capacities up to 300 t/d
• Stand-alone plants
• Simultaneous control of final viscosity and moisture content
• Integrated conveying of pellets to maintain material characteristics (optional)
• Deoxidizer for O2 content < 5 ppm
• Gas scrubber or catalytic combustion for gas purification