lubricants and lubrication is currently no real sense of theories and laws

Right - like PVC-U formulation design , the author believes that the difficulties formulation and the main contents of the inner and outer lubricant selection of species and their proportions and adding the total design. Lubricant to the total amount should be suitable , and PVC stabilizer for cable  internal and external lubricant ratio is more important , even though the total amount sufficient , but if imbalance, nor co- continuous production of qualified products.
However, for the processing of PVC-U critical lubrication system , in theory there is no known theory , and even formulation can effectively guide the experimental law no . The  magnesium stearate only rule is to learn from the so-called general chemistry , " like dissolves like " rule, which is the lubricant of PVC resin polarity polarity more similar to its compatibility with the more evil , and thus its role within the lubrication better ; against outside lubrication is strong, but this rule for guiding formulation also very limited. Because the polarity judgment lubricant is a lubricant according to the chemical structure, that the lubricant molecules containing hydroxyl groups , ester groups, carboxyl groups , amide group and  epoxidized soybean oil an ether group , a ketone group such as a polar functional group species , quantity and with a long alkyl ratio. As the lubricant chemical structure complex, diverse , and the interaction between adjacent functional groups , such that the polarity of the lubricant is more difficult to determine the size , which resulted in a polar lubricant alone to infer lubricant and lubrication lubricant is actually played by the difference between the lubrication is far beyond people's imagination .