Low-Temperature Brittleness Requires More Than Simply Adding Impact Modifiers
PVC conduits are widely used to protect electrical wiring in residential, commercial, and infrastructure projects because of their excellent corrosion resistance, electrical insulation, and long service life. However, maintaining reliable low-temperature impact strength remains a challenge for many manufacturers.
A conduit that performs well under normal conditions may still become brittle during winter transportation, outdoor installation, or low-temperature impact testing. To address this, manufacturers often increase the dosage of impact modifiers or switch to higher-grade raw materials. While these approaches may provide some improvement, they also increase formulation costs and do not always deliver consistent results.
This raises an important question:
If impact modifiers are not always the answer, what else determines the low-temperature performance of PVC conduits?
The answer often lies in the processing system—particularly the lubrication strategy used during PVC extrusion.
Learn more about Rallychem’s PVC processing solutions:
Why Lubrication Strategy Matters in PVC Processing?
Every PVC formulation is unique. Differences in resin systems, stabilizers, fillers, extrusion equipment, and processing conditions mean that the same lubricant can perform very differently from one production line to another.
When the lubrication system is not properly matched to the formulation, PVC fusion may become unstable, melt flow may fluctuate, and the compound may not reach its optimal processing condition. As a result, the finished product can exhibit inconsistent mechanical performance, even when the same resin and impact modifier are used.
For many manufacturers, improving low-temperature impact strength is therefore not simply about adding more impact modifiers. It is about creating a better balance between lubrication, fusion, and overall processing performance.
Different PVC Formulations Require Different Lubrication Strategies
Every PVC formulation is different. Resin grades, stabilizer systems, filler content, extrusion equipment, processing temperatures, and production speeds all influence how a lubricant performs during processing.
A wax additive that performs well in one formulation may not provide the same processing stability or mechanical performance in another. This is why more manufacturers are moving away from standard lubricant packages and looking for lubrication systems that better match their own production conditions.
At Rallychem, we have developed the RLWAX® customized wax additive portfolio to support a wide range of PVC extrusion applications. By combining different wax chemistries and lubricant technologies, RLWAX helps manufacturers optimize lubrication balance, improve fusion behavior, and enhance overall processing stability.
Whether the application involves PVC conduits, electrical pipes, profiles, fittings, or other extrusion products, selecting the right wax system allows manufacturers to improve mechanical performance while maintaining production efficiency and formulation consistency.
Case Study: Better Low-Temperature Performance Through Lubrication Optimization
One PVC conduit manufacturer contacted Rallychem after experiencing inconsistent low-temperature impact performance. Although the products passed routine quality inspections, some batches became brittle during winter transportation and low-temperature impact testing.
Customer Challenge
The customer initially increased the dosage of impact modifiers, expecting to improve low-temperature toughness. However, the improvement was limited while formulation costs continued to rise.
Rallychem’s Analysis
After evaluating the formulation and extrusion process, Rallychem found that the limitation was not the impact modifier itself, but the lubrication system. The existing lubricant package prevented the PVC compound from achieving optimal fusion, reducing the effectiveness of the overall formulation.
Customized Solution
Instead of recommending more impact modifiers or expensive raw material changes, Rallychem optimized the lubrication package by developing a customized wax additive designed specifically for the customer’s formulation and processing conditions.
Results
Following production trials, the customer achieved:
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More stable extrusion performance
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Better PVC fusion consistency
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Improved low-temperature impact strength
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Lower formulation optimization costs
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More consistent product quality between batches
This application demonstrates that improving PVC impact performance is often achieved through better processing balance rather than simply increasing additive dosage.
Read the complete application story:
Build More Reliable PVC Conduits Through Smarter Lubrication Design
Improving low-temperature impact strength is not simply about adding more impact modifiers or selecting higher-cost raw materials. More often, it is about ensuring that the existing formulation performs to its full potential.
By optimizing lubrication balance, improving PVC fusion, and enhancing the interaction between processing additives, manufacturers can achieve better mechanical performance while maintaining stable production and cost efficiency.
At Rallychem, we help PVC manufacturers evaluate their complete processing system and develop customized wax additive solutions that match their formulations, production conditions, and performance objectives.
Whether you’re manufacturing PVC conduits, electrical pipes, profiles, fittings, or other extrusion products, our technical team is ready to help you improve processing stability, product consistency, and long-term production efficiency.
Looking for the right customized wax additive for your PVC formulation?
Contact Rallychem to discuss your application or request a recommendation from our technical team.
PVC Processing Solutions
Customized Development Service
Customer Application Story
Frequently Asked Questions
Why doesn’t increasing impact modifiers always solve PVC brittleness?
Because impact modifiers are only one part of the formulation. If lubrication balance and fusion behavior are not optimized, simply increasing impact modifier dosage may increase cost without fully improving mechanical performance.
Which PVC products can benefit from customized wax additives?
Customized wax additives are widely used in PVC conduits, electrical pipes, profiles, fittings, pipes, sheets, and other PVC extrusion products that require improved processing stability and mechanical performance.
How do customized wax additives improve PVC processing?
By optimizing lubrication balance, customized wax additives improve melt flow, promote more uniform fusion, enhance processing stability, and help manufacturers achieve more consistent product quality.
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