PVC products, the most important and indispensable material can be said to be a stabilizer, the stabilizer on the market basically no longer the same as before: three salt, two salt, lead stearate, barium stearate. In addition to transparent products and a few soft products in the use of organic tin, liquid cadmium calcium cadmium, composite stabilizer accounted for most of the market, mainly calcium and zinc composite stabilizer, lead salt composite stabilizer, hydrotalcite composite stabilizer, rare earth compound stability Agents, etc., after the composite stabilizer is even more indispensable, then the stability of the stabilizer how to evaluate it?
From the requirements of view, the stability of PVC stabilizer can be divided into initial stability, long-term stability and residual stability. The initial stability refers to the color to maintain stability, refers to the stability of the color of the product from the mixing to the output in any one production cycle, or color to maintain within the allowable range. Long-term stability refers to the color change caused by accidental breakdown of the material decomposition, but does not shut down the stability of cleaning. Residual stability refers to pvc finished products in the late use of the stability.
From the test method, the stability can be divided into static thermal stability and dynamic thermal stability. Static thermal stability refers to the ability of thermal stabilizers to retard the thermal decomposition of PVC in the presence of only heat or heat and air. Dynamic thermal stability is the ability of thermal stabilizers to retard the thermal decomposition of PVC under the combined action of heat, air and shear forces.