20mm 24mm 28mm Black Ribbed Smooth Plastic Screw Cap Induction Sealing Gasket or Pressure Sensitive Sealing Gasket

Packaging Context (Most Common)

This is the typical cap found on bottles and jars.

• Primary Function: To seal the container, prevent leakage, block oxygen and contaminants, and preserve the freshness of the contents.

• Common Applications: Water bottles, soda bottles, milk jugs, ketchup bottles, shampoo bottles, medicine bottles, and many cosmetic containers.

• Key Features:

  • Tamper-Evident Band (TE Band): A ring that breaks or separates when the cap is first opened, showing that the product has not been previously opened.

  • Child-Resistant (CR) Feature: A special design requiring a specific combination of pushing, squeezing, or turning to open, preventing access by young children.

• Common Materials:

  • Polypropylene (PP): Excellent chemical resistance and can withstand high-temperature filling. Widely used for carbonated beverage caps.

  • High-Density Polyethylene (HDPE): Good rigidity and moisture barrier, often used for milk and juice caps.

  • Low-Density Polyethylene (LDPE): More flexible, used for squeeze bottles.

    

    

    Industrial & Mechanical Context

    This refers to plastic caps used with screws, bolts, or threaded rods in machinery, furniture, or electronics.

    • Primary Function: To protect exposed screw threads or bolt ends from damage, corrosion, and dirt. Also used to prevent injuries from sharp edges and to provide a finished, aesthetic look.

    • Common Names: Thread protectors, screw covers, bolt caps, or acorn nuts (plastic).

    • Common Applications: Covering exposed bolts on playground equipment, furniture assembly, automotive parts, and electronic device casings.

      Summary of Key Terms

      
      

      
      

      Term	Meaning
      Closure	Another word for the cap or lid itself.
      Neck Finish	The threaded part of the bottle that the cap screws onto.
      Tamper-Evident	A security feature that visibly indicates if the cap has been opened.
      Liner	An inner seal (often foam or foil) inside the cap that provides an extra barrier against leaks and oxygen.