The tamper-evident aluminum screw cap, also known as an aluminum ROPP (Roll-On Pilfer Proof) cap, is manufactured using specialized rolling equipment. During production, the pre-formed threads on the aluminum cap precisely engage with the external threads of the glass bottle neck, creating a tight seal. Once opened, the tamper-evident band at the base of the cap separates from the bottle neck, ensuring one-time opening to prevent refilling or tampering.
Aluminum ROPP caps are suitable for both PET bottles and glass bottles, with glass bottle applications being the most common.
ROPP (Roll-On Piracy Proof) aluminum screw caps are widely used on glass bottles because their thread design closely matches the bottle opening, achieving a tight seal and preventing leakage. The anti-theft ring also ensures a one-time opening, preventing refilling or tampering. Furthermore, aluminum itself offers excellent ductility and corrosion resistance, and is easily printed and anodized. This ensures both liquid storage safety and facilitates brand customization and aesthetic enhancement, making it an ideal choice for glass bottle packaging.
Structure of the Tamper-Evident Aluminum Screw Cap
Cap Body: Made from aluminum alloy via stamping; the surface can be anodized, painted, or printed.
Thread Area: Rolled to precisely match the bottle neck threads, ensuring a tight seal.
Tamper Band: Located at the bottom of the cap; breaks off upon opening to prevent reuse.
Sealing Liner: Typically made from EPE, TPE, or composite materials to enhance airtightness and prevent leakage.
Liner Materials for Aluminum Screw Caps
Foamed Polyethylene (EPE) Liner: Excellent elasticity and sealing performance; widely used for beverages, sauces, and similar products.
Cork Liner: Traditional and elegant; mainly used for wine bottles, providing good breathability and moderate elasticity.
PVC Liner: Good elasticity and chemical stability, though less environmentally friendly.
PET Liner: Eco-friendly alternative gradually replacing PVC liners.
Aluminum ROPP Cap Sizes
18x12 mm / 22x15 mm: Small bottles for pharmaceuticals or beverages
28x15 mm / 30x35 mm: Bottled water, juice
30x60 mm: Most common for wine and spirits
31.5x24 mm: Olive oil bottles
31.5x44 mm: Whiskey, vodka bottles
38x15 mm / 38x30 mm: Edible oil, condiments
Customization Options
Color Customization: Combine anodizing, painting, and printing to create brand-specific colors.
Logo and Pattern Printing: Supports screen printing, pad printing, UV printing, hot stamping, and other methods.
Anti-Counterfeit Design: Optional laser coding, holographic labels, QR codes.
Bottle Neck Matching: Custom thread molds designed to match client bottle shapes, ensuring reliable sealing.
Mass OEM Production: Capable of producing orders ranging from tens of thousands to tens of millions, meeting international brand supply requirements.
