38x18mm Aluminum ROPP Cap

The 38×18mm aluminum ROPP cap is a sturdy, secure, and highly customizable tamper-evident closure suitable for industries ranging from beverages to pharmaceuticals. It offers strong sealing, attractive branding options, supports high-efficiency mass production, and is fully recyclable.

The 38×18mm aluminum ROPP cap is a high-performance sealing solution in beverage packaging. It features food-grade aluminum, high-capacity automated production, and multi-process surface customization as core advantages, making it compatible with the global glass bottle market.

38x18mm Aluminum ROPP Cap Functions

ROPP Mechanism: Initially a smooth sleeve; during capping, the threads are formed by rollers at the bottleneck, creating a tamper-evident seal.
Tamper-Evident Ring: Visible upon opening, designed with perforated bridges that break during first use.
Knurling: Textured sidewall enhances grip when applying or removing the cap.

38x18mm Aluminum ROPP Cap Structure

Aluminum shell + built-in sealing liner (formed inside the shell), suitable for sealing glass bottle necks. Some models do not include a tamper-evident ring.

Structural Component	Description
Thread Structure	The ROPP cap (Roll-On Pilfer Proof Cap) has a threaded interior surface precisely matching the bottle neck. It ensures a tight seal between the cap and bottle through a simple twist-on/twist-off motion, enhancing leak prevention and user convenience. The thread is formed by mechanical rolling and provides excellent resealability.
Tamper-Evident Ring Design	The bottom of the cap is connected to a tamper-evident ring. Upon first opening, the ring breaks away from the cap and remains on the bottle neck, indicating the product has been opened. This prevents unauthorized access during transportation or sale and safeguards product authenticity and consumer interests. The bridges connecting the ring to the cap must be precisely designed to ensure tamper-evidence without compromising user experience.
Sealing Liner	The cap's interior features a sealing liner made from TPE (thermoplastic elastomer), EPE (expanded polyethylene), or laminated composite materials. When the cap is tightened, the liner compresses against the bottle rim, forming a tight seal that prevents air, moisture, and dust from entering, while also preventing liquid leakage. This helps preserve product quality and extends shelf life. The liner offers elasticity and chemical resistance, making it suitable for various liquid contents such as alcohol, medicine, or beverages.

38x18mm Aluminum ROPP Cap Liner Options

The liner is critical for sealing and compatibility:

PE, TPE: Used for juices, beer, and general beverages
EPE or PVC-free compounds: Expands to fill bottlenecks, prevents leakage
Foam liners: Common in wine, spirits, and cold-fill applications

38x18mm Aluminum ROPP Cap Customization & Decoration

Decoration Techniques: Offset printing, embossing, UV coating, hot stamping, roll printing (1–6 colors), and fluorescent inks for anti-counterfeiting
Branding Options: Embossed logos, side or top printing, and tamper-evident bands

38x18mm Aluminum ROPP Cap Applications

Widely used for sealing:

Beverages: Water, juice, beer, soft drinks
Alcoholic drinks: Wine, spirits (e.g., vodka, whiskey)
Special applications: Edible oil, vinegar, pharmaceuticals, medical bottles

Application Field	Description
Beverage Industry	This aluminum ROPP cap is widely used in packaging of carbonated drinks, juice beverages, tea drinks, and sports drinks. Its excellent sealing performance prevents leakage and spoilage, extending shelf life. Consumers can easily twist open and drink directly. It is particularly suitable for 38mm-neck canned tea and energy drinks, such as vitamin drinks, due to its balance of sealing strength and user convenience.
Alcohol Industry	The 38x18mm aluminum ROPP cap is common in packaging for liquor, wine, and spirits. It effectively prevents alcohol evaporation, oxidation, and contamination, preserving the product's quality. Additionally, the aluminum material offers excellent decorative and processing capabilities, allowing enhancements such as hot stamping, printing, and embossing, making it ideal for premium liquor and gift-box wines. For example, some aged liquors use this cap to reinforce their premium branding.
Pharmaceutical Industry	The 38x18mm aluminum ROPP cap is also applicable to bottled pharmaceuticals, especially liquid forms such as nutritional supplements, oral solutions, or medicinal wines. The cap provides a tight seal that blocks air, moisture, and bacteria, preventing contamination and preserving efficacy, which meets the strict safety and hygiene requirements of pharmaceutical packaging. The tamper-evident ring ensures that the product has not been opened, enhancing supply chain safety.

38x18mm Aluminum ROPP Cap Advantages

Tamper-Evident + Secure Sealing: Threads are formed during capping; once opened, it cannot be resealed.
High Sealing Reliability: Excellent moisture and gas resistance to reduce leakage.
Aesthetic Variety: Multiple surface treatments and printing options to enhance brand image.
Recyclable: Made entirely of aluminum – 100% recyclable.

38x18mm Aluminum ROPP Cap Material Features

Durability: Made from high-quality aluminum alloy, it offers strong corrosion and abrasion resistance. It performs reliably under various environmental conditions, resists external damage, and ensures long-term protection for the contents of the bottle.
Lightweight: Aluminum has a relatively low density, making the 38x18mm aluminum ROPP cap lightweight while maintaining strength. This facilitates transportation, storage, and handling, and helps reduce the overall product weight.
Gloss and Finish: Aluminum naturally has a metallic sheen. After surface treatments such as polishing or matte finishing, it can exhibit various glossy effects, enhancing the cap's aesthetic appeal and improving the overall packaging image to attract consumer attention.

HC Aluminum can customize according to client requirements, including printing brand logos, trademarks, patterns, text, and more. We also offer personalized design of cap shape, size, and structure to meet different customers' branding and product differentiation needs.

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