38-400 Aluminum Cap

The 38-400 aluminum screw cap is a continuous thread closure designed specifically for 38-400 bottleneck containers, where "38" refers to the outer thread diameter (38 mm) and "400" indicates a single-turn continuous thread. It is made from stamped aluminum material, ensuring leak-proof sealing for glass/plastic bottles, jars, and jugs. With its premium metallic appearance, it is an ideal choice for high-end packaging.

38-400 Aluminum Cap

38-400 Aluminum Cap Material and Structure

Shell Material: Lightweight and durable aluminum. Offers corrosion resistance and impact protection, while also being fully recyclable.
Surface Finish Options: Typically brushed silver or raw silver surface; can be customized with matte, brushed, or polished finishes according to customer preferences.

38-400 Aluminum Cap Liner Types

Foam (PP or PE): Standard moisture barrier for general use.
PE Film/Pressure Seal (PS): Excellent moisture resistance, ideal for moisture-sensitive products.
Pulp/PE or Pulp/Polyester: Suitable for powders, non-acidic foods, candles, and chemicals requiring corrosion resistance.
Plastisol: Melts during hot filling to form a vacuum seal; commonly used in the food industry.

Liner Customization: Multiple liner options cater to product-specific sealing needs:

Liner Type	Applications	Key Properties
PE (Polyethylene)	Cosmetics, lotions	General-purpose moisture barrier
Pulp & Poly	Honey, syrups	Chemical resistance
Heat Induction	Sauces, food	Hermetic seal via specialized equipment
Plastisol	Hot-fill beverages	High-temperature tolerance

Temperature Range: The aluminum cap can withstand high temperatures (melting point approximately 660°C / 1, 221°F), making it suitable for sterilization, hot filling, and autoclaving.

38-400 Aluminum Cap Key Functional Highlights

Seal Integrity: High-performance liners ensure a tight seal and leak-proof protection — essential for food, beverage, pharmaceutical, and personal care products.
Tamper-Evident: Cap can fracture upon first opening, ensuring product integrity.
Chemical Resistance: Suitable for high-salt, high-humidity, greasy environments, cleaning agents, and general consumer goods.
Aesthetics: Brushed or polished finish offers a premium appearance, enhancing product branding.
Recyclability: Fully recyclable aluminum shell, highly favored in environmentally conscious markets.

38-400 Aluminum Cap Applications

Commonly used in packaging for:

Industry	Product Types
Food & Beverage	Syrups, honey, sauces, hot-fill items
Personal Care	Lotions, oils, creams
Pharmaceuticals	Supplements, ointments
Household/Cleaning	Auto cleaners, rust removers
Candles & Crafts	Jar candles, decorative items

38-400 Aluminum Cap Production and Quality Control

Manufacturing Process:

Stamping Forming: Aluminum sheets are stamped into cap blanks, followed by thread processing using CNC machines.
Liner Installation: Liners are bonded using heat pressing. Standard liners require 1–2 weeks; plastisol liners require 3 weeks.

Production Workflow:

Aluminum coil slitting → Multi-station stamping → Thread forming → Liner injection → Surface treatment (anodizing/coating) → Online inspection

Quality Assurance:

Dimensional Inspection: Verifies "T" (thread diameter), "S" (thread engagement), and "H" (neck height) dimensions based on GPI/SPI standards.
Performance Testing: Includes torque testing to ensure cap integrity, leak simulation, and liner adhesion checks under varying temperatures.

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