Aluminium Pilfer Proof Caps

Aluminium pilfer-proof caps are packaging components made primarily from aluminium alloys, featuring tamper-evident functionality. They are widely used in the packaging of alcoholic beverages, food, drinks, pharmaceuticals, and more.

Aluminium ROPP caps offer unparalleled tamper-evident performance, product safety, and brand promotion versatility across various industries. They are compatible with high-speed capping lines, making them an indispensable material in modern packaging.

Aluminium pilfer-proof caps are specialized closures designed to provide tamper evidence, product integrity, and secure sealing for a wide range of containers, from beverages to pharmaceuticals. They typically adopt the Roll-On Pilfer Proof (ROPP) technology, in which the cap is rolled onto the bottle neck, tightly matching the threads to form a secure, leak-proof seal.

These caps are mainly made from high-quality aluminium alloy and are equipped with removable bands or rings that remain attached to the bottle neck after first opening. This mechanism helps detect any prior opening, preventing counterfeiting and contamination.

Modern production lines can manufacture caps with diameters ranging from 17mm to 38mm and offer customization options such as color, logos, liners, and embossing for brand identification and functional labeling.

Aluminium pilfer proof caps (PP caps) are specialized closures designed to prevent tampering and ensure product integrity. They are widely used in industries requiring secure sealing, such as pharmaceuticals, beverages, cosmetics, and food packaging.

Aluminium Pilfer Proof Caps Materials

Mainly made from aluminium alloys such as ‌8011-H14‌ and 3003-H16‌.

Strict requirements are placed on material strength, elongation, and dimensional accuracy to avoid rupture or creases during processing.

The surface must be flat and free of scratches to ensure print adaptability.

Aluminium Pilfer Proof Caps Structure

Component Name	Material Description	Function and Features	Processing and Structural Notes
Aluminium Shell	AA8011 aluminium alloy sheet	Excellent corrosion resistance and mechanical strength	Formed into bottle cap shape by stamping and drawing, providing the base structure for roll-on threads and tamper-evident bands
		Lightweight and durable
		Suitable for various containers such as water, beer, juice, and pharmaceuticals
Tamper-Evident Band	Integrally formed with aluminium shell (lower edge of the cap)	Connected to the main cap before opening	The lower edge of the cap is processed by rolling/cutting to form breakable bridges, achieving visual tamper evidence
		Detaches when unscrewing, indicating whether the seal has been broken
Liner / Gasket	Polyethylene (PE), butyl rubber, silicone, PVC-free materials (depending on contents)	Provides sealing function	Embedded design, fixed inside the cap by hot pressing, mechanical insertion, or injection molding
		Prevents liquid leakage
		Contacts the bottle mouth to ensure product safety
Thread (formed by rolling)	No preforming needed, on-site forming enabled by the plasticity of aluminium	Ensures a tight fit between the cap and bottle mouth	ROPP (Roll-On Pilfer Proof) equipment presses the aluminium cap onto the bottle mouth while rolling threads into the cap
		Forms a screw structure that can be repeatedly opened and closed

Types of Aluminium Pilfer Proof Caps

Roll-On Pilfer Proof (ROPP) Caps

ROPP caps are non-prethreaded aluminum closures whose threads are formed by a capping machine using cold-rolling onto the bottle neck, ensuring perfect fit and seal integrity. As they are resealable and comply with safety regulations, ROPP caps are widely used for mineral water, juices, alcoholic beverages, and industrial or medicinal liquids.

Push-Pull and Flip-Top Types

In addition to ROPP caps, aluminum push-pull (PP) caps feature a two-piece design that opens with an upward pull, making them convenient for spray bottles and beverage containers, while maintaining tamper-evident protection and sealing performance. Flip-top aluminum caps combine hinged lids and tamper-evident bands, suitable for personal care and food-grade products.

Key Features and Design of Aluminium Pilfer Proof Caps

Material: Made from aluminum alloy sheets, typically of 8011 H14 or 3003 grades, with thickness ranging from 0.20 to 0.23 mm.
Security Mechanism: Equipped with a perforated security band that breaks upon first opening, providing tamper evidence.
Customization: Available in various diameters (17 to 38 mm) and heights, with options for color, logo printing, as well as surface treatments like spraying or lithography.
Liners: Includes molded or foamed polyethylene (PE) liners to enhance sealing, with options for pasteurization or desiccant use.
Tamper-Evident Seal: Designed with breakaway or opening structures that cannot be restored once broken, providing tamper-evident indications. Some versions incorporate vacuum sealing or liner materials (such as PE, EPE) to enhance seal integrity.
Customized Appearance: Supports embossing, UV printing, hot stamping, and other decorative techniques, with customizable dimensions (e.g., 22mm, 20mm) and colors to meet various brand requirements.

Aluminium Pilfer Proof Caps Production Process

Produced from hot-rolled or continuous cast and rolled billets, with continuous casting and rolling offering superior performance.

Processed via automated production lines, which are highly efficient but require strict process control.

Aluminium shell production
Deep drawing and trimming to form the main cap body
Knurling and tamper-evident band cutting
Edge knurling for grip and formation of tamper-evident seal band
Liner insertion
Liner molding or embedding into the cap shell
Embossing / decoration
Brand logos or trademarks can be embossed on the cap surface
Roll-on capping

Aluminium Pilfer Proof Caps Key Benefits

Feature	Advantage
Tamper Evident	Ensures consumer trust and product safety
Re-sealable Option	Allows multiple reuses on compatible bottles
Varied Liners	Customizable for specific products/fill methods
Large Scale Production	Capable of >1, 200–2, 500 caps/min lines
Branding Options	Can be printed, colored, embossed, or lacquered

Aluminium Pilfer Proof Caps Performance and Compliance

Performance and Standard Category	Description
Barrier Properties and Seal Integrity	Aluminium offers excellent barrier properties, effectively blocking light, oxygen, and moisture, thus extending the shelf life of the contents.
Barrier Properties and Seal Integrity	The liner design effectively prevents liquid leakage and maintains the freshness and stability of the internal medium.
Tamper-Evident Features	Equipped with a tear-off sealing band (tamper-evident ring), which breaks upon first opening, providing clear visual and tactile cues to help users determine whether the product has been opened, ensuring packaging integrity and safety.
Material Compatibility	Aluminium is chemically stable and non-reactive with most food, beverage, and pharmaceutical ingredients.
Material Compatibility	Liner materials (such as PE, silicone, etc.) are suitable for hot-fill and inert packaging requirements, ensuring no contamination of contents.
Regulatory and Physical Standards	Available in various internationally standard sizes such as 28×15 mm, 28×18 mm, 31.5×18 mm, and 38×18 mm to meet the requirements of different bottle types.
Regulatory and Physical Standards	Liner materials comply with FDA/CE food and drug contact standards, ensuring regulatory compliance for global markets.

Aluminium Pilfer Proof Caps Sizes and Specifications

Material Specifications

Aluminium Alloy: Primarily AA8011 grade aluminium sheets (temper: H13–H26), thickness range: 0.016–0.23 mm.
Ductility Advantage: Aluminium's ductility allows for precise thread forming without compromising structural integrity.
Liner: Crucial for seal integrity and compatibility with contents.

Liner Type	Applications	Properties
Molded PE	Carbonated drinks, spirits	Gas retention, chemical resistance
Foamed PE	Spirits, functional drinks	Cushioning, high seal compression
Butyl Rubber/Silicone	Pharmaceuticals, syrups	Drug compatibility, leak prevention
EPE/Sarnex	Agri-chemicals, oils	Resistance to corrosive liquids

Aluminium Pilfer Proof Caps Common Sizes

Short Skirt: 28×15.5 mm (water, beer), 22×15 mm (pharma vials) .
Long Skirt: 30×60 mm (spirits), 38×18 mm (industrial oils) .

Size (mm)	Application Field	Description
28 × 15.5 Aluminium Pilfer Proof Caps	Bottled Water, Beer	28 × 15.5mm Aluminium Pilfer Proof Caps are commonly used in the packaging of fast-moving consumer goods such as bottled water and beer. This compact size offers excellent sealing performance and is compatible with high-speed automated packaging lines. The cap features a tamper-evident breakable ring, allowing consumers to easily identify whether the product has been previously opened, thereby enhancing product safety.
22 × 15 Aluminium Pilfer Proof Caps	Pharmaceutical Vials (Oral Liquid, Vaccines)	22×15 mm Aluminium Pilfer Proof Caps are widely used in the pharmaceutical industry, especially for oral liquids, small-dose medications, and vaccine vials. The small size fits narrow-neck medical glass bottles and offers excellent sealing and chemical compatibility. They are typically paired with butyl rubber or silicone gaskets to ensure drug stability and aseptic conditions.
30 × 60 Aluminium Pilfer Proof Caps	Spirits, Wine	30×60 mm Aluminium Pilfer Proof Caps are mainly used for sealing bottles of spirits and premium wines. These long-skirted caps are not only aesthetically pleasing but also provide excellent sealing and anti-counterfeiting functions. The metallic surface is suitable for printing and embossing, offering opportunities for customized branding while ensuring clear tamper-evident identification for consumers.
38 × 18 Aluminium Pilfer Proof Caps	Industrial Lubricants, Engine Oils	38×18 mm Aluminium Pilfer Proof Caps are widely used for packaging industrial lubricants, engine oils, and similar liquids. These caps ensure strong sealing while featuring a larger inner diameter for convenient pouring or refilling. The aluminum material offers excellent corrosion resistance, suitable for complex storage and transportation conditions in industrial environments.

Aluminium Pilfer Proof Caps Tamper-Evident Mechanism

Designed with a twist-off (rotational) mechanism that cannot be restored once opened, achieving anti-tampering functionality.
Combined with embedded or molded liners to enhance sealing performance.

Aluminium Pilfer Proof Caps Surface Treatment

Surface properties are enhanced by processes such as anodizing and powder coating, offering corrosion resistance, abrasion resistance, and a variety of color options.
Some finishes require high-temperature curing (180℃–250℃) to form a stable coating.

Industrial Applications of Aluminium Pilfer Proof Caps

Industry	Typical Applications
Pharmaceuticals	Used for glass/PET bottles, applicable for syrups, tinctures, and liquid medicines; the liner prevents interactions with the contents.
Beverages – Carbonated Drinks	28×18 mm Aluminium Pilfer Proof Caps with molded PE liner (capable of retaining carbon dioxide).
Beverages – Spirits/Wine	30×35 mm Aluminium Pilfer Proof Caps with foam PE liner.
Food and Cosmetics	Yogurt containers, edible oils, perfumes; customizable printing available for brand promotion.

Aluminium Pilfer Proof Caps (ROPP) offer a reliable, efficient, and tamper-evident sealing solution for glass bottles across multiple industries. Combining a durable aluminium shell, secure liner, and tamper-evident band, they are an ideal choice for safety-conscious packaging. Standardized sizes and customizable decoration options make them suitable for high-volume roll-on capping and specialized filling processes.

Alcoholic Beverages: A mainstream choice for glass-bottled drinks such as liquor and wine, accounting for about 50% of the market due to low cost, recyclability, and premium printing quality of aluminium caps.
Pharmaceuticals: Used for injection solutions, oral liquids, and single-dose medications, typically compliant with CE certification and ISO standards.
Beverages: Ideal for carbonated drinks, spirits, and functional beverages due to their rust resistance and resealable properties.
Food and Cosmetics: Ensure the sealing of products like juice, oil, and lotion, preventing contamination.

Beverage Industry

Aluminium pilfer proof caps are widely used for glass and PET bottles of mineral water, soft drinks, wine, and spirits, ensuring leak prevention during transportation and showcasing premium brand image through customized surface treatments.

Pharmaceuticals and Health Supplements

Aluminium caps are crucial for sterile liquids, injectables, and over-the-counter supplements. They ensure tamper evidence and compatibility with high-pressure sterilization, helping to maintain sterility before administration.

Cosmetics and Personal Care

From lotions to serums, pilfer proof aluminium caps prevent contamination while creating a luxurious brand image through metallic finishes and embossing.

Chemicals and Hazardous Substances

Chemicals and agrochemicals benefit from the chemical inertness and child-safe design of aluminium caps, which reduce accidental contact and leakage.

Standards and Regulations for Aluminium Pilfer Proof Caps

ISO 15378 applies to primary packaging materials for the pharmaceutical industry.
EU Regulation (EU) No 10/2011 applies to food contact materials.
FDA 21 CFR Part 177 applies to indirect food additives.

Advantages of Aluminium Pilfer Proof Caps over Plastic Caps

Better Sealing: Compared to plastic, aluminium caps are more resistant to environmental factors such as moisture and gas, whereas plastic tends to degrade or attract static dust.
Cost-Effective: Aluminium caps are approximately 50% cheaper than plastic caps and support high-temperature sterilization.
Eco-Friendly: Aluminium is fully recyclable and aligns with sustainability goals.

HC popular aluminum pilfer proof caps

Product	Description
28mm Aluminium ROPP Cap for Juice Bottles	A standard roll-on pilfer-proof cap commonly used for sealing juice bottles, ensuring tamper evidence and product integrity.
28mm Aluminium Pilfer Proof Caps for Drinking Bottles	Designed for various beverages, these caps provide a secure seal and are often used in the pharmaceutical and food industries.
Custom Printed Aluminium Pilfer Proof Caps	These caps feature customizable printing options, allowing brands to enhance their product's visual appeal and authenticity.
28mm Roll-On Pilfer Proof Aluminium ROPP Cap	A versatile cap suitable for both glass and plastic bottles, offering a reliable seal and tamper-evident features.
Printed Aluminium Pilfer Proof Caps for Alcohol Glass Bottles	Specifically designed for alcoholic beverages, these caps combine security with aesthetic customization.