company news about Problems that should be paid attention to when using calcium and zinc stabilizer in PVC processing and production:

The main components of calcium and zinc stabilizer are calcium stearate and zinc stearate. Because the structure of calcium stearate, zinc stearate and stearic acid is similar, there are more charged calcium and zinc ions. How to understand an ion with a charge, the polarity is essentially the attraction of the charge. The charge of calcium and zinc ions greatly enhances its polarity. You should know that the polarity of calcium stearate and zinc is strong in the commonly used PVC lubricant. This gives it a stronger affinity with PVC resin, which weakens the attraction of the subbond of each layer inside the PVC resin particles, promotes the easy diffusion of the PVC intertwined chain segments, forms a sliding layer with high viscosity, large friction heat generation, high transfer efficiency of mechanical force, accelerates the material temperature rise, and causes the resin transition plasticization. Lead salts on their own have no such effect.

Problems that should be paid attention to when using calcium and zinc stabilizer in PVC processing and production:

1. Confirm the green environmental protection of the stabilizer formula; It is necessary to pay attention to whether the content of heavy metals (lead, cadmium, tin, barium) can meet the requirements of the product and meet the requirements of the new national standards.

2, calcium zinc stabilizer internal lubrication effect is strong, need to add more external lubricant. This is described below.

3, the thermal stability of calcium zinc stabilizer is weaker than that of lead salt, the processing window is narrower, and the control requirements are higher.

4. Pay attention to the mold cleaning cycle during the operation. The addition of calcium and zinc stabilizer lubricant is too large, which is easy to lead to the increase of precipitation, thus affecting the film cleaning cycle. For large - scale production impact is greater, to select the stabilizer varieties strictly. If it is its own stabilizer, it needs to cooperate with PE wax with good lubrication effect in the middle and late period (such as Qingdao Bonny 108, etc.) or oxidized wax. Also strictly control the vacuum degree, can reduce precipitation, prolong the cleaning mold time.

5, a good stabilizer formula and the appropriate amount of the product appearance, material properties, aging resistance and so on have little impact. In the process of replacing lead salt stabilizer with calcium and zinc stabilizer, the process parameters should be properly adjusted to achieve the material properties and plasticization degree we need in the final analysis. Of course, it should be noted that the amount of calcium and zinc stabilizer used in lubricant is more than the amount of lead salt.