Internal and external lubricants are commonly used in plastics processing to improve the flow and reduce friction between the polymer chains. However, they have different functions and impacts on the final product.
Internal lubricants are incorporated directly into the polymer matrix during the manufacturing process. They are typically low molecular weight compounds that are miscible with the polymer and reduce the intermolecular forces between the polymer chains. This improves flow properties, reduces energy consumption, and reduces wear on processing equipment. Internal lubricants improves the surface finish of the final product and reduce the occurrence of surface defects such as sink marks.
External lubricants, on the other hand, are added to the surface of the polymer pellets or molded parts during processing. They are typically higher molecular weight compounds that do not dissolve in the polymer matrix but instead form a thin layer on the surface. This layer reduces the friction between the polymer and the processing equipment, resulting in improved flow and reduced processing times. External lubricants also reduce the occurrence of surface defects such as flow lines, weld lines, and surface marks.
The impact of lubricants on plastics can vary depending on the type and amount used, as well as the processing conditions and the specific properties of the polymer. In general, internal and external lubricants can improve the processability of plastics, reduce wear on processing equipment, and improve the surface finish of the final product. However, excessive use of lubricants can also lead to reduced mechanical properties, decreased dimensional stability, and reduced adhesion to other materials.
It is important to carefully select and use the appropriate lubricants and amounts to achieve the desired properties and minimize any negative effects. Chemyork provides to its customers with the right lubricants that meet their specific needs.