Polypropylene, a thermoplastic polymer, is known for its versatility in applications ranging from plastic parts to textiles. One key characteristic of polypropylene is its shrinkage factor, which is crucial for manufacturing and design processes. This shrinkage occurs due to the polymer cooling and crystallizing after being molded, and the factor can vary based on several parameters, including the part design, mold design, processing conditions, and the grade of polypropylene used. Typically, the shrinkage factor for polypropylene ranges from 1% to 2.5%. Manufacturers must account for this shrinkage to ensure the dimensional accuracy of the final product. By adjusting the mold dimensions and processing conditions, it's possible to mitigate unwanted effects of shrinkage, ensuring the final product meets the required specifications. Understanding and managing the shrinkage factor is essential for the successful use of polypropylene in any application.

PVC, or Polyvinyl Chloride, is a versatile and widely used plastic polymer. It comes in two basic forms: rigid (RPVC) and flexible, made so by adding plasticizers. PVC is known for its durability, resistance to chemicals, water, and abrasion, making it a popular choice in construction for pipes, window frames, and vinyl siding. Its flexibility also sees it utilized in a range of products from clothing and piping to electrical cable insulation. However, the production and disposal of PVC raise environmental concerns due to the release of toxic chlorinated compounds. Efforts are underway to recycle and manage PVC waste more effectively, but its environmental impact remains a topic of debate.

Removing PVC glue from clothing requires careful handling to avoid damaging the fabric. Begin by allowing the glue to dry completely; this prevents spreading. Gently scrape off excess glue with a plastic knife or a similar tool. Avoid using sharp objects that could tear the fabric. For any residue, apply a commercial adhesive remover or acetone (found in nail polish remover) to a cotton ball and dab it on the stained area. Test in an inconspicuous area first to ensure it won’t damage the color or fabric. Rinse out the remover thoroughly with cold water. Wash the clothing item according to its care instructions, but air-dry instead of using a dryer in case the glue isn't fully removed. Heat can set the stain permanently.