28mm Aluminum-plastic Cap

The 28mm aluminum-plastic cap is a hybrid closure solution designed for secure sealing, combining the advantages of aluminum and plastic materials. The 28mm measurement refers to the outer diameter, making it compatible with standard bottle necks in industries such as pharmaceuticals, food, cosmetics, and chemicals.

The 28mm aluminum-plastic bottle cap is a precisely designed closure that offers the strength and aesthetic appeal of aluminum along with the sealing efficiency of plastic. It is widely used in beverage packaging (such as carbonated mineral water bottles) and even in pharmaceutical applications that require secure and tamper-evident closures.

28mm Aluminum-plastic Cap Structure

Material Composition

The composite structure typically consists of a laminated aluminum foil layer (for barrier performance) as the outer layer of the cap, and a plastic layer (such as polyethylene) as the inner layer.

Aluminum Shell: Provides a smooth, durable, and lightweight surface with excellent corrosion resistance.
Plastic Interior: Often made of TPE or foam liners, which form a tight seal with the bottle neck through compression, ensuring a leak-proof closure.

Tamper-evident Design

Many models feature an integrated tamper-evident mechanism (such as a breakable band) that provides visual confirmation of whether the cap has been previously opened. This is essential for maintaining product integrity and consumer safety.

28mm Aluminum-plastic Cap Specifications

Specification	Description
Nominal Size	Designed for 28mm necks, with an outer cap diameter typically around 30mm
Precision Tolerance	Inner Diameter: 28.6±0.1mm; Inner Height: 10.2±0.1mm (Example for pharmaceutical versions)
Printing/Decoration Process	Lithographic Printing, Embossing, UV Printing, Hot Stamping
Customization	Branding, Product Information, Additional Design Features
Manufacturing Technology	Precision Metal Forming, Plastic Injection Molding
Manufacturer	HC Aluminum
Quality Assurance	High production capacity with strict quality control measures to ensure consistent performance for large orders

HC Aluminum Production and Quality

These caps are manufactured using advanced technologies, including precision metal forming and plastic injection molding. HC Aluminum's high production capacity and rigorous quality control measures ensure consistent performance for large orders.

28mm Aluminum-plastic Cap Features

Features	Description
Tamper-proof Design	The 28mm Aluminum-plastic Cap adopts an advanced crimp sealing structure, which generates irreversible physical damage when first opened, ensuring it cannot be restored to its original state. This design effectively prevents the product from being illegally opened or contaminated during circulation, making it ideal for packaging products with high safety requirements such as pharmaceuticals and health supplements.
Induction Seal Function	The 28mm Aluminum-plastic Cap features a high-performance aluminum foil layer that can form a complete seal with the bottle mouth using professional induction sealing equipment. The sealing layer of the 28mm Aluminum-plastic Cap maintains product freshness while providing an intuitive first-opening verification function. Consumers can check the integrity of the seal to determine if the product has been opened.
Custom Printing	The 28mm Aluminum-plastic Cap supports various surface finishing techniques, including high-precision lithographic printing, embossing, UV printing, and hot stamping. The aluminum surface of the 28mm Aluminum-plastic Cap can display high-definition brand logos, product information, and anti-counterfeit markings, while also supporting Pantone color matching to meet the brand image needs.
Structural Characteristics	The 28mm Aluminum-plastic Cap is made from an aluminum-plastic composite material, combining the strength of metal with the flexibility of plastic. The 28mm Aluminum-plastic Cap is approximately 30% lighter than a full metal cap, while maintaining excellent compressive and impact resistance. It effectively protects the bottle mouth from damage during transportation and storage.

28mm Aluminum-plastic Cap Applications

Application Industry	Description
Beverage Industry	The 28mm Aluminum-plastic Cap is designed for sparkling mineral water and carbonated beverages, featuring an airtight sealing structure that effectively preserves the carbonation of the beverage. The tamper-proof feature of the 28mm Aluminum-plastic Cap prevents illegal opening during transportation and supports high-precision printing processes, allowing for custom branding and product information to enhance shelf appeal.
Pharmaceutical Industry	The 28mm Aluminum-plastic Cap meets pharmaceutical-grade packaging standards, with precise tolerances (inner diameter 28.6±0.1mm) ensuring perfect compatibility with pharmaceutical bottles. The induction-seal aluminum layer of the 28mm Aluminum-plastic Cap provides a sterile barrier to prevent contamination of the drug, and its tamper-proof design meets GMP certification requirements, ensuring medication safety.
Cosmetics Industry	The 28mm Aluminum-plastic Cap is suitable for products like serums and creams. The aluminum-plastic composite material is resistant to chemical corrosion, protecting the stability of the contents. The 28mm Aluminum-plastic Cap supports hot stamping/UV printing, presenting high-end decorative effects, and its peel-off sealing layer allows for easy first-time opening by users.
Food Industry	The 28mm Aluminum-plastic Cap is used for packaging products such as seasonings and edible oils, with its lightweight design (about 30% lighter than full metal caps) reducing transportation costs. The leak-proof sealing structure of the 28mm Aluminum-plastic Cap prevents liquid leakage, while the aluminum layer blocks oxygen and light, extending the shelf life of food products.
Household Chemicals Industry	The 28mm Aluminum-plastic Cap is the preferred choice for products like cleaners and insecticides, as its corrosion-resistant material can withstand strong acids and alkalis. The crimp tamper-proof design of the 28mm Aluminum-plastic Cap prevents accidental opening by children, and the PE liner enhances sealing reliability, ensuring safe storage of chemicals.