Reading fusion time from a torque curve in an ACR processing-aid trial

Does “acrylic additive” identify an impact modifier or a processing aid?

An acrylic product can serve either purpose. Before ordering samples, specify whether the goal is better fusion, greater melt strength or another property.

Identify fusion on the torque curve

Hold PVC formulation, filler loading and speed constant. Record torque against time, identify the fusion features and operating window, and check extrudate appearance and dimensional stability alongside fusion time.

Can fusion times from different formulations be compared directly?

Align temperature, stabiliser, lubricant and PVC resin first. Rigid PVC extrusion: Record fusion time, torque and finished surface gloss. Foamed profiles: In the same foaming system, compare melt strength, density and cell structure.

Checking Powder particle size and Apparent density

Powder particle size (µm or % sieve residue): Distinguish sieve residue from the fraction passing and confirm the sieve standard. Apparent density (g/cm³): Use the same loose-fill method to verify the published apparent density. Fusion behavior (Time or torque profile): Keep PVC grade, lubricant package and test temperature constant.

What to record

• ACR function
• Rotational speed
• Fusion time
• Torque
• Extrudate appearance

Technical references

• Arkema Plastistrength 576: PVC processing aid grade ↗

Products and processes