Aluminum anti-theft cap

31.5mm ROPP Cap - HAOMEI

The 31.5 mm ROPP cover is stamped from high-quality aluminum and undergoes multiple precision processing steps, including stamping, knurling, wire drawing, inner coating and printing, to achieve excellent sealing, anti-counterfeiting, leak-proof and aesth

ISO,SGS
L/C Accepted
7*24H Response

What Is a 31.5mm Aluminum ROPP Cap?

The 31.5mm aluminum ROPP (Roll-On Pilfer-Proof) cap is a widely used tamper-evident aluminum screw cap designed for sealing glass and PET bottles. Made from high-quality aluminum, these caps are precisely manufactured through multiple processes including stamping, knurling, brushing, interior coating, and printing, offering excellent sealing, anti-counterfeiting, leak-proof protection, and an attractive appearance.

Widely Used In:

Pharmaceutical bottles (e.g., oral liquids, syrups)

Premium wine and liquor packaging

Essential oil and cosmetic bottle sealing

Food/condiment bottle packaging

31.5mm Neck Size

The 31.5mm diameter is one of the international standard neck sizes (e.g., ISO 9006), particularly suitable for packaging in glass or PET bottles used for food and beverages such as olive oil, beer, and premium mineral water. This size is compatible with most filling and capping lines, significantly reducing mold-change costs for customers.

31.5mm-aluminum-ropp-cap.jpg

Product Specifications – 31.5mm Aluminum ROPP Closure:

Item	Description
Product Name	31.5mm Aluminum ROPP Bottle Cap
Material	Aluminum 8011-H14/H16
Diameter	31.5 mm
Height	18mm / 24mm / 44mm (customizable)
Type	Screw Cap
Liner Options	PE liner, anti-corrosion liner, vertical seal liner, etc.
Surface Finish	Anodizing, electrophoretic coating, printing, brushing
Colors	Gold, silver, red, green, custom colors available
Process	Knurling, tamper-evident ring, internal coating, anti-corrosion treatment
Opening Method	Twist-off
Applications	Oil, wine, spirits, and more
MOQ	50,000 pieces

Features of the Tamper-Evident Aluminum ROPP Cap:

1. Superior Sealing Performance
Equipped with EPE or PE/PP composite liners to ensure tight sealing with no leakage or evaporation. It effectively blocks moisture and oxygen, helping to extend product shelf life.

2. Tamper-Evident Design
The tamper-evident ring breaks upon first opening, preventing reuse. Laser coding, custom logo printing, and anti-counterfeit layers can also be applied for enhanced brand security.

3. High-Strength, Food-Safe Aluminum
Made with pharmaceutical/food-grade aluminum (e.g., 8011-H16), providing excellent mechanical strength and ductility. Treated with non-toxic, odorless, corrosion-resistant coatings.

4. Compatibility with Various Bottles and Capping Machines
Designed to match standard 31.5mm threaded bottle necks, suitable for both glass and PET bottles, and adaptable to high-speed automatic capping lines.

5. Customizable Appearance to Enhance Branding
Supports various finishes like matte, glossy, brushed metal, electrophoretic black, and custom printing (silkscreen, offset, hot stamping logos and patterns) for strong brand identity.

Why Choose HAOMEI Aluminum?

Multiple high-speed automated aluminum cap stamping and printing lines
Over 10 years of expertise in R&D and production of aluminum caps and closures
Full packaging solutions: aluminum caps + bottles integration
Certified by ISO 9001 Quality Management System
OEM/ODM accepted, free samples available

As a leading aluminum cap manufacturer, HAOMEI Aluminum specializes in the production of a wide range of ROPP caps, including 31.5mm ropp cap, 25mm ropp cap, 28mm ropp cap, 38mm ropp cap, colored ropp cap and 22mm ropp cap etc. We offer customized solutions, short lead times, direct factory pricing, and flexible order quantities to meet diverse customer needs.