Plastic Caps & Closures Wholesale Suppliers

Plastic screw caps and closures are produced predominantly in polypropylene (PP) and high-density polyethylene (HDPE) — the two materials covering the vast majority of food, beverage, household, and personal care packaging closure applications. PP closures are more rigid, better tolerating higher heat applications (hot-fill beverages, heat-sterilised products), and available in a wider colour range. HDPE closures are slightly more flexible and impact-resistant, widely used for household chemical and personal care applications. Key cap specification parameters are: finish/neck diameter and thread standard — the most important parameter for fitment compatibility. Common standards are PCO 1810 and PCO 1881 (carbonated beverage PET bottle caps, 28mm thread), 28mm 400 and 28mm 410 (common food and beverage standards), 38mm and 43mm (wide-mouth jar caps), and DN25/DN32/DN38 ROPP standards for aluminium ropp closures. Cap liners provide the sealing function between the cap and the bottle or jar rim. Liner types include: foam (PE foam, the most common general-purpose liner for non-carbonated beverage and food products), induction seals (a foil-foam-polymer laminate liner that is bonded to the bottle rim by electromagnetic induction after filling — providing a hermetic seal and tamper evidence), EPE (expanded polyethylene foam with a PE facing — for carbonated beverages and oxygen-sensitive products), and full-lining for chemical resistance in agrochemical and household chemical products.

Child-resistant closures (CRC) are mandated for pharmaceutical products (tablets, capsules, and liquid medicines), many household chemicals, and agrochemicals in most major markets. The primary CRC standard is ISO 8317 (with equivalent US CPSC 16 CFR Part 1700) — closures must be tested to confirm that young children cannot open them within a specified time, while adults can open them. CRC designs include push-and-turn closures (press down while turning to release), squeeze-and-turn closures (squeeze the cap sides inward while turning), and press-tab designs. For pharmaceutical applications, the closure manufacturer should hold ISO 8317 test certificates for the specific closure and matching container combination. Dispensing closures are functional closures that integrate a dispensing mechanism — flip-top (sports cap or snap-hinge) closures for liquid dispensers, pump dispensers for lotion and soap applications, trigger sprayers for household cleaners, and disc-top closures for food condiments. When ordering plastic caps at wholesale volume, specify: cap diameter and thread standard, material (PP or HDPE), liner type, colour (RAL or Pantone reference), and surface finish (gloss, matte, or soft-touch coating). For branded applications, custom colour matching and embossed or debossed logo features are available from most Chinese closure manufacturers. MOQs for standard stock caps are typically 5,000–10,000 units; custom colour or custom embossed caps are typically 10,000–50,000 units.