Understanding PVC Lubrication Balance: How Internal Lubricants Improve Extrusion Performance

In rigid PVC processing, achieving a stable extrusion process requires a good balance between resin fusion, melt flow and lubrication.

Many PVC manufacturers focus mainly on processing aids and impact modifiers, while the lubrication system is sometimes overlooked. However, the selection and balance of internal and external lubricants can directly influence processing efficiency, surface appearance and final product performance.

During PVC extrusion, lubricant molecules control the friction between PVC particles, polymer chains and processing equipment. A properly designed lubrication system helps PVC achieve suitable fusion behavior and smooth melt flow.

The Role of Internal Lubricants in PVC Processing

Internal lubricants mainly work within the PVC melt. They help adjust the friction between polymer chains and improve the movement of PVC molecules during processing.

When internal lubrication is insufficient, common production issues may include:

• Longer fusion time

• Higher processing torque

• Unstable melt pressure

• Poor plasticization

• Uneven surface appearance

However, excessive internal lubrication can also create problems. Too much lubrication may slow down fusion, reduce melt strength and affect the mechanical properties of finished products.

Therefore, the purpose of using an internal lubricant is not simply to increase lubrication, but to achieve the right balance between fusion and flow.

How to Optimize Lubrication System for Rigid PVC Applications?

For different PVC applications, the lubrication requirement can vary significantly.

For example:

• PVC profiles and window systems require good fusion control and surface finish.

• PVC pipes need stable processing and consistent mechanical performance.

• PVC foam boards require balanced lubrication to support proper plasticization and foam structure.

• PVC sheets and compounds may require different adjustments depending on formulation and filler content.

In practical production, internal lubricants are usually combined with external lubricants, processing aids and impact modifiers to achieve the desired processing window.

KRT-60 PVC Internal Lubricant Solution

VIKEM KRT-60 is designed for rigid PVC processing applications where balanced internal lubrication is required.

It can be used together with PVC processing aids, impact modifiers and external lubricants to help manufacturers improve processing consistency and control melt flow behavior.

By optimizing the lubrication system, PVC processors can achieve:

• More stable extrusion operation

• Better fusion control

• Improved product surface quality

• More consistent production performance

The actual dosage and formulation adjustment depend on PVC resin type, processing conditions, filler loading and final product requirements.

FAQ About PVC Internal Lubricants

1. Why is lubrication balance important in PVC extrusion?

Lubrication balance affects how PVC resin melts and flows during extrusion. A proper balance helps achieve stable fusion, suitable processing torque and better product appearance.

2. What happens when PVC has poor internal lubrication?

Insufficient internal lubrication may lead to slow fusion, high torque, unstable extrusion pressure and poor surface quality.

3. Can adding more lubricant always improve PVC processing?

No. Excessive lubrication may delay fusion and reduce melt strength. PVC formulation requires a balanced combination of internal and external lubricants.

4. What factors affect the choice of PVC internal lubricant?

The selection depends on:

• PVC resin type

• Calcium carbonate loading

• Extrusion temperature

• Processing equipment

• Product application

A lubricant suitable for PVC pipes may not be the best choice for foam boards or profiles.

5. How does VIKEM support PVC manufacturers?

VIKEM provides PVC additive solutions including processing aids, impact modifiers, foaming regulators and lubricant systems.

With application experience in different PVC industries, VIKEM supports customers in optimizing formulations and improving production stability.

Contact VIKEM for PVC Additive Solutions

If you are looking for a reliable PVC internal lubricant supplier in China, or need technical support for PVC extrusion formulation optimization, please contact VIKEM for TDS, samples and application recommendations.