How to solve the problem of unstable dimensions of PVC carbon crystal board, where the middle is thick and the edges are thin?

During the production of PVC foam board – carbon crystal board, it is often observed that the middle part is thicker while the edges are thinner, sometimes accompanied by cellular structures in the cross-section or burnt material on the edges, leading to decreased product quality and even affecting normal production. These issues are typically related to the plasticization state, which may be either over-plasticized or under-plasticized.

Analysis of the Problem

There are many ways to adjust plasticization in the production process of PVC foam board – carbon crystal board. From the perspective of lubrication alone, the following methods can be employed:

Under-plasticization: When plasticization is insufficient, the edges of the board are thinner. This can be improved by increasing the use of internal lubricants (such as polyester wax) to enhance plasticization.

Over-plasticization: When plasticization is excessive, the middle part is thicker. This can be balanced by reducing the use of internal lubricants or appropriately increasing the use of external lubricants (such as PE wax). Alternatively, using high-efficiency external lubricating PE wax products can control the total amount of lubrication and achieve a balanced lubrication scheme that is both efficient and minimal.

Solutions

Adjustment of the Lubrication System:

For under-plasticization, increase the use of internal lubricants (such as polyester wax) to improve plasticization.

For over-plasticization, reduce the use of internal lubricants or increase the use of external lubricants (such as PE wax) to balance plasticization.

Additionally, Oxidized Wax for Plasticization Adjustment: Oxidized wax (such as OP-30) can quickly adjust plasticization, improve mold release properties, and balance internal and external lubrication effects, making it particularly suitable for high-filler formulas. Adjusting the speed of plasticization by adding or subtracting oxidized wax is more rapid and effective.

Rallychem Chemical Solutions

Rallychem Chemical offers mature lubrication formulas specifically for the production of foam boards, ensuring balanced lubrication, improved production efficiency, and product quality:

• Internal Lubricant Polyester Wax RL-1116 Series: Suitable for high-filler PVC products, with high dispersion, anti-precipitation properties, and excellent lubrication performance, maintaining stable lubrication throughout the entire production process.
• External Lubricant PE Wax RL-1002 Series: With a high melting point and excellent mold release properties, it is suitable for customers seeking cost-effectiveness and stable production.
• High-Density Oxidized Polyethylene Wax OP-30: With excellent internal and external lubrication properties, it can rapidly increase the plasticization speed of PVC, making it particularly suitable for high-filler formulas.

By combining the use of RL-1116, RL-1002, and OP-30, Rallychem Chemical’s products can achieve efficient lubrication and synergistic effects, meeting various production needs and improving product quality.