PVC processing aid for PVC blinds

Acrylic processing aids (ACR) are polymeric acrylate powders copolymerized from methyl methacrylate and acrylates. Exhibiting excellent compatibility with rigid PVC resin, they serve as indispensable rheological aids for the extrusion and injection molding of PVC shutters. PVC shutters often feature thin-walled, narrow slats, foamed structures, or transparent designs. Pure PVC tends to exhibit slow plasticization and insufficient melt strength, leading to defects such as strand breakage, surface ripples, uneven thickness, pitting, and "fish-eyes" during high-speed production; ACR effectively resolves these processing challenges.

ACR functions by wrapping its long molecular chains around PVC particles, rapidly transferring shear force and heat from the screw to accelerate overall resin plasticization. This allows for lower processing temperatures, thereby mitigating PVC degradation and yellowing caused by high heat. Simultaneously, the formation of temporary entanglements between molecular chains significantly enhances melt strength and tensile elasticity; this prevents thin-walled slats from sagging or tearing after extrusion, ensuring they remain straight and uniform. Furthermore, the additive promotes the even dispersion of fillers and additivessuch as calcium carbonate, stabilizers, and pigmentsreduces additive migration (blooming), and supports high-filler, low-cost formulation systems.

In terms of production, adding ACR effectively boosts extrusion output and lowers defect rates associated with strand breakage, melt fracture, and "shark-skin" surface defects. It also reduces material buildup at the die exit, extending the intervals between mold cleanings, and is suitable for various processes, including solid, lightweight micro-foamed, and transparent shutters, as well as injection-molded varieties. Regarding appearance, the finished products feature a smooth, high-gloss surface with uniform wall thickness and no warping or rippling. Transparent shutters remain clear without hazing, and the inherent UV resistance of the acrylic component ensures long-term color stability and resistance to yellowing during outdoor use.

Regarding performance, ACR improves the low-temperature toughness of PVC, making shutters resistant to brittle cracking during transport or in cold environments. Crucially, it achieves this without significantly compromising rigidity, ensuring dimensional stability and resistance to deformation over long-term use. Various molecular weight grades are available to suit different types of blinds products. A general-purpose, medium-molecular-weight grade is commonly used for standard solid-colored or white blinds, with an addition rate of 1.52.5 phr. High-molecular-weight grades featuring high melt strength are suitable for foamed blinds and ultra-thin, narrow slats, meeting the more rigorous melt tension requirements of high-speed, thin-wall extrusion.