Optimizing barrel temperature profiling for recycled polymers requires a nuanced approach because these materials often contain contaminants, degraded chains, and inconsistent compositions compared to virgin resins

The first step is to understand the thermal history of the recycled material

Recycled polymers may have been exposed to multiple processing cycles, which can lower their molecular weight and alter their melting behavior

As a result, they often melt at lower temperatures and can degrade more easily if overheated

Prioritize detailed physical and thermal profiling of the recycled batch

Employ DSC and MFI analyses to map out the thermal transition points and flow behavior

Your temperature zones must be calibrated based on this empirical evidence

Using standard profiles for new resin can cause charring, uneven viscosity, or flow instability

Establish a smooth thermal gradient across all barrel sections

The feed zone should be kept relatively low, just above the material’s glass transition temperature, to prevent bridging or premature melting that can cause poor feeding

Gradually elevate temperature in the compression section to promote uniform fusion

Hold the final zone just under the polymer’s critical decomposition point

Track real-time melt viscosity via an accurate inline sensor

This real-time feedback is critical because recycled materials can vary batch to batch

When melt exceeds target, lower rear barrel settings and decrease screw RPM to cut shear-induced heat

If the melt is underheated, raise front zone temps modestly and boost RPM—only if degradation resistance permits

Limit exposure duration to prevent thermal aging

These materials degrade faster under extended heat, so shorten cycles and eliminate idle holds

Scrape and تولید کننده کامپاند پلیمری flush the barrel and screw after each run to eliminate carbonized residues

Finally, consider blending recycled material with a small percentage of virgin resin if possible

It smooths out inconsistencies and lessens reliance on extreme settings

Validate settings through controlled small-scale runs and log effects on appearance, integrity, and performance

Over time, you’ll build a reliable profile tailored to your specific recycled stream