What is Cold Forming Aluminum Foil?
Cold forming aluminum foil is a high-performance aluminum-based composite material formed by a cold rolling process at room temperature. It features excellent mechanical properties, barrier performance, and forming precision, and is widely used in pharmaceutical, food, and electronic fields.
Cold forming aluminum foil, also known as cold stamping aluminum foil or pharmaceutical packaging foil, is essentially an aluminum foil packaging material that can be molded into shape “without heating.”
Cold forming aluminum foil is a multi-layer composite material, usually used in pharmaceutical blister packaging.
The common structure is OPA/Al/PVC:
OPA (Oriented Polyamide/Nylon) layer enhances strength; the middle aluminum layer provides barrier protection; the bottom PVC (Polyvinyl Chloride) layer is used for sealing.
- The aluminum layer provides very strong protection (“100% barrier”), preventing the ingress of moisture, oxygen, and ultraviolet light.
- The typical total thickness of many cold forming aluminum foils is about 140–160 microns (μm).
- Commonly used aluminum alloys include 8021 and 8079, selected for their ductility and formability.
Specification of Cold forming Pharmaceutical Aluminum Foil
| Alloy | 8021, 8079 |
| TEMPER | F, O, H12, H14, H16, H18, H19, H22, H24, H26, H28, H32, H34, H36, |
| H38, H111, H112, H114 | |
| Thickness(mm) | 0.006-0.2 |
| Width(mm) | 20-2650 |
| Length(mm) | 500-16000 |
| Application | Tablets, pills, capsules packaging |
Cold Forming Aluminum Foil Structure and Composition
Cold forming aluminum foil is not a single-layer aluminum foil but a multi-layer composite structure, with each layer serving a specific function. A typical structure (from outer to inner) is as follows:
- Outer layer: Polyamide (OPA) or nylon film to enhance mechanical strength and printability.
- Middle layer: 45–65 micron aluminum foil substrate, providing barrier performance.
- Inner layer: Polyvinyl chloride (PVC) or polyethylene (PE) for heat sealing and product contact.
Outer Layer (Support Layer):
- Material: Usually nylon or PET.
- Function: Provides mechanical strength and printability. Protects the middle aluminum foil from scratches or abrasion, and allows printing of brand, product information, and usage instructions.
Middle Layer (Core Barrier Layer):
- Material: Hard aluminum foil.
- Function: This is the most critical layer. It provides extremely high barrier properties, completely blocking oxygen, water vapor, light, and microorganisms. Its hardness and special toughness allow it to be stretched and formed at room temperature without breaking.
Inner Layer (Sealing Layer):
- Material: Medical-grade PVC or polypropylene, polyethylene, and other heat-sealing adhesives.
- Function: Under a certain temperature and pressure, this layer melts and firmly heat-seals with another covering material (usually rigid PVC or PET), completely sealing the product inside the blister.
Cold Forming Aluminum Foil Characteristics
- High barrier performance: Waterproof, oxygen-resistant, and UV-resistant. When thickness ≥0.015mm, gases cannot penetrate, making it suitable for long-term preservation of pharmaceuticals and food.
- Mechanical adaptability: After cold processing, the hardness is relatively high but easy to crease, so it is usually laminated with PVC and other materials to enhance strength.
- Temperature resistance: Withstands high-temperature sterilization and low-temperature freezing; thermal conductivity reaches 55%, suitable for cold chain packaging.
- Excellent product protection: Particularly suitable for products highly sensitive to moisture, oxygen, and light, such as hygroscopic, oxidizable, or photodegradable drugs, health products, and high-value foods. It greatly extends shelf life.
- Easy to use: Consumers can easily “push through” or “tear open” the foil to access the product, known as “PUSH-THROUGH” packaging.
- Safety and anti-counterfeiting: Once sealed, the packaging is difficult to open without damage, providing good tamper evidence and child safety protection.
Why Use Cold Forming Aluminum Foil?
- Excellent barrier protection — The thicker aluminum core effectively blocks moisture, oxygen, and light, which is critical for sensitive medicines.
- Stability/Shelf life — Helps extend the shelf life of medicines, especially those that are hygroscopic (moisture-absorbing) or light-sensitive.
- High mechanical strength — Even after forming, the composite structure resists cracking.
Advantages of Cold Forming Aluminum Foil
Exceptional Non-Breaking Formability
Cold Forming Aluminum Foil has excellent formability, demonstrating high ductility during deep drawing processes. This allows it to form without breaking into complex shapes and deep blister cavities, ensuring the integrity of the packaging.
High Thermal Stability
This aluminum foil has high thermal stability, maintaining its structure and performance under extreme temperature conditions. It does not deform or deteriorate due to heat treatment or environmental changes, ensuring consistent packaging quality.
High Ductility for Deep Blister Cavities
The high ductility of Cold Forming Aluminum Foil allows it to perform excellently in the deep drawing blister forming process, enabling the formation of deeper blister cavities that effectively protect the contents from external influences.
Extended Shelf Life
Due to the excellent barrier properties of Cold Forming Aluminum Foil, products packaged with this material can enjoy a longer shelf life, ensuring that medicines remain in optimal condition throughout their lifecycle.
Flexibility and Customization
Cold Forming Aluminum Foil is highly flexible and can be customized according to the specific needs of different products. It can easily be formed into various shapes and sizes of packaging while supporting high-quality printing to achieve exquisite branding and labeling, enhancing the product's market competitiveness.
Tamper-Evident Mechanism
Cold Forming Aluminum Foil packaging is equipped with a tamper-evident sealing mechanism, effectively preventing unauthorized opening and ensuring the safety and integrity of the product during transportation and storage, protecting the consumer's interests.
Chemical Composition of Cold Forming Aluminum Foil
| Alloy No. | Si | Fe | Cu | Zn | Others | Al |
| 8079 | 0.050 – 0.30 | 0.70 – 1.3 | ≤ 0.050 | ≤ 0.10 | ≤ 0.15 | REMAIN |
| 8079 Aluminum Foil | ||||||
| Alloy No. | Si | Fe | Cu | Mn | Mg | Zn | Others | Al |
| 8021 | ≦0.15 | ≦1.7 | ≦0.05 | ≦0.05 | ≦0.05 | ≦0.05 | ≦0.05 | Remain |
| 8021 Aluminum Foil | ||||||||
Haomei Aluminum's 8021 aluminum foil, 8079 aluminum foil, and others are preferred raw material suppliers for cold-forming pharmaceutical aluminum foil to various pharmaceutical packaging companies domestically and internationally, due to their high cupping value, high heat seal strength, absence of pinholes, and excellent airtightness.
Cold Forming Aluminum Foil Applications
- Pharmaceutical packaging: Used for blister capsules (PTP foil), tablet sealing, such as cold-formed aluminum composite hard film.
- Food packaging: Such as blister foil and frozen food sealing; 9–12μm thickness is an economical and practical choice.
Pharmaceutical Packaging
- Alu-Alu Blister: Used for high-barrier packaging of tablets and capsules, such as antibiotics and vaccines, maintaining drug stability even in hot and humid climates.
- Composite flexible packaging: Inner aluminum foil laminated with outer plastic film for moisture-proof packaging of powders and granules.
Food and Beverage
- Premium food packaging: For products sensitive to oxygen and light such as chocolate and cheese, cold forming aluminum foil extends shelf life and enhances visual appeal.
- Ready-to-eat containers: Aluminum containers formed by cold stamping combine aesthetics with corrosion resistance.
Electronics and New Energy
- Lithium battery current collector: Ultra-thin aluminum foil (e.g., 6–12 microns) used in power batteries and energy storage systems.
- Electromagnetic shielding material: Copper-plated aluminum foil provides shielding effectiveness >40dB, used in 5G devices and consumer electronics.
Other Fields
- Cosmetic packaging: Light-proof containers for creams and serums.
- Industrial sealing: High-pressure sealing materials for aerospace components.
Cold Forming Aluminum Foil Manufacturing / Process
- Lamination: The three layers (OPA, Al, PVC) are bonded together using adhesive.
- Cold forming (stamping): Instead of heating, the laminated aluminum foil is pressed into the mold at room temperature to form the blister “cavity.”
- Since heating is not required, the process relies on the ductility (stretchability) of the aluminum foil to ensure it does not crack during forming.
Quality control is critical — manufacturers test parameters such as Water Vapor Transmission Rate (WVTR), Oxygen Transmission Rate (OTR), and sealing strength.
Cold Forming Aluminum Foil vs. Tropical Aluminum Foil
| Feature | Cold Forming Aluminum Foil | Tropical Aluminum Foil |
| Forming Method | Formed at room temperature by mechanical stamping and stretching | Formed by heating and vacuum/air pressure molding |
| Barrier Property | Extremely high, nearly complete barrier | Good, but generally not as strong as cold forming foil |
| Cost | Higher (both material and equipment costs are higher) | Relatively lower |
| Blister Appearance | Deeper cavities, well-defined contours, uniform thickness | Thinner bottom of the blister, higher transparency |
| Suitable Products | High-value products highly sensitive to moisture and oxygen | Common pharmaceuticals and foods with moderate barrier requirements |
Cold Forming vs. Thermoforming: Key Differences Between the Two Aluminum Foil Forming Processes
Traditional Thermoforming: The rigid PVC or PET sheet is heated above its glass transition temperature to soften it, then vacuum or air pressure is applied to draw it onto the mold to form the blister. It solidifies upon cooling.
Cold Forming:
- Place the cold forming aluminum foil (laminated layers) and the bottom rigid sheet (such as PVC) on the mold.
- A punch moves downward at room temperature, pressing the aluminum foil and rigid sheet forcefully into the mold cavity.
- Under high pressure, the middle aluminum layer undergoes plastic deformation and is stretched into the desired blister shape. Due to its special hardness and toughness, it can withstand a stretch ratio of up to 30% or more without forming micro-holes.
- The product (such as tablets) is placed into the formed blister cavity.
- Finally, the top lidding material (another heat-sealable film) is sealed to the inner heat-sealing layer of the cold forming foil under heat and pressure, completing the packaging.
Limitations of Cold Forming Aluminum Foil
- Cost: Due to the more complex lamination and materials, it is more expensive than simple blister materials like PVC/PET.
- Processing speed: Cold forming can be slower than thermoforming because the forming process is more delicate.
- Opaque packaging: Unlike transparent blister packs, opaque packaging prevents visual inspection of contents, which may be a drawback in some cases.