How to correctly use PVC rigid transparent calcium-zinc stabilizer

To correctly use PVC rigid transparent calcium-zinc stabilizer, the following points can be referred to:

Select formula to match product demand

If producing white or transparent products, it is necessary to choose a calcium-zinc stabilizer with good initial coloring inhibition effect; if producing colored products, emphasis can be placed on selecting products with good long-term heat stabilization performance.

The ratio of calcium and zinc can be adjusted to meet specific needs: increasing the calcium content can enhance long-term thermal stability, while increasing the zinc content can improve initial thermal stability. Additionally, organic auxiliary heat stabilizers such as phosphites, antioxidants, epoxy compounds, and diketones can be used in combination to synergistically enhance thermal stability. For example, phosphites can comprehensively improve thermal stability, while diketones can effectively inhibit initial coloring.

Control the addition amount and mixing ratio

In the calcium-zinc composite heat stabilizer system, if the proportion of calcium stearate is too low, the initial heat stabilization performance of PVC products will be poor; if it is too high, the products will turn yellow and have poor weather resistance. Therefore, the proportion of the two must be precisely controlled.

If calcium stearate is added to transparent PVC products, the amount should not exceed 0.5 parts, otherwise it will affect the transparency of the product.

Adaptive machining process

During the processing of rigid PVC products, due to the high shear force and temperature, it is necessary to appropriately increase the amount of stabilizer added to ensure stable performance.

This stabilizer has good lubricity, but it is important to ensure compatibility with traditional PVC processing equipment to avoid disruption of lubrication balance, which can lead to the PVC melt consuming a large amount of heat stabilizer in the homogenization section without achieving the desired viscosity and elasticity. Formulations or processing parameters can be adjusted accordingly.

Pay attention to the combination of special additives

If used in combination with AC blowing agent, the addition of stabilizer can be appropriately increased to cope with the decrease in decomposition temperature of AC blowing agent from 211℃ to 162℃ due to calcium stearate.

If used in the production of wire and cable materials, it is necessary to pass the volume resistivity test. Some formulations can add calcined kaolin to improve electrical properties.

If you need to know the specific application formula of this stabilizer in a specific PVC product, please feel free to contact me.