What is PTP foil?
PTP is the abbreviation for Press Through Package, commonly known as “cold formed packaging, ” “press-through packaging, ” or “pharmaceutical aluminum foil blister packaging.” It is a functional composite material designed specifically for pharmaceutical packaging, enabling sealed packaging through pressure.
PTP Aluminum Foil provides high barrier properties through its aluminum layer, blocking light, oxygen, and water vapor. Its heat-seal layer is compatible with PVC, PVDC, and various other plastic substrates. The surface can be printed with pharmaceutical information and customized designs.
PTP aluminum foil is a composite material mainly consisting of the following layers:
- Outer layer (protective layer): Usually a printed layer made of polyester film, nylon film, or paper, serving as protection, printing identification, and labeling. It also provides certain barrier properties.
- Middle layer (base material): The core component—aluminum foil. Industrial-grade aluminum with a purity of over 99% is typically used, with a thickness between 20–40 microns. Aluminum foil provides extremely high barrier performance, completely blocking oxygen, water vapor, light, and microorganisms, and is key to ensuring the stability and shelf life of medicines.
- Inner layer (sealing layer): Usually a heat-seal coating such as PVC, PVDC, or other specialized heat-seal adhesives. This layer melts under heat and pressure, bonding with the plastic sheet underneath to form a sealed blister.
PTP Aluminum Foil Material Specifications
- Common alloys: 8011-H18 (hard temper) or 8011-O (soft temper) aluminum alloy, featuring high purity, low pinhole rate, and good mechanical properties.
- Thickness range: 0.016–0.04 mm; 0.02 mm is commonly used for pharmaceutical packaging.
- Width range: 80–1000 mm; common widths are 275–500 mm.
- PVC/PVDC sealing strength: ≥9N/15mm.
The most commonly used aluminum foil thicknesses for blister packaging are 20µ / 25µ / 30µ. Haomei Aluminum provides OP/AL 20–40μ (H)/VC and OP/AL 20–40μ (O)/VC PTP blister aluminum foil.
PTP Aluminum Foil Coating Thickness Options
- 4–6 g/m², with a tolerance of +/- 0.5 g/m².
- 6–8 GSM, with a standard tolerance of +/- 0.5 GSM. If not specified, the heat-seal coating GSM is 4 with a tolerance of +/- 0.5.
PTP Aluminum Foil Printing Methods
To meet pharmaceutical packaging requirements for product identification, brand recognition, and anti-counterfeiting, Haomei Aluminum offers comprehensive PTP aluminum foil printing solutions, mainly including the following methods:
Unprinted foil
Surface without any printing, retaining its original metallic luster and providing excellent barrier performance. Suitable for general pharmaceutical packaging with simple appearance requirements.
Printed foil
- By number of printed sides: supports single-side or double-side printing to accommodate different structures and sealing requirements.
- By color: available in single-color, two-color, or multicolor printing to accurately reproduce brand identity, pharmaceutical information, and instructions, enhancing recognition and professionalism.
Colored foil
Available in single-side gold, double-side gold, green base, and various other customized base colors. These enhance visual appeal while maintaining functional performance, supporting brand differentiation and patient medication compliance.
Anti-counterfeiting foil
Features hidden text, special patterns, positive/negative printing, and other anti-counterfeiting designs, effectively preventing product imitation or tampering, and enhancing safety in pharmaceutical distribution.
We offer flexible customization according to customer requirements. Through precise printing process control, we ensure superior visual appearance without affecting sealing integrity or barrier performance.
PTP Aluminum Foil Working Principle
PTP aluminum foil must be used together with plastic rigid sheets.
- Forming: The plastic sheet is heated and formed via thermoforming or blow forming into individual blisters that hold tablets/capsules.
- Filling: Medicines are placed into the formed blisters.
- Heat sealing: PTP aluminum foil is placed over the filled blister sheet and sealed under heat and pressure using heated rollers. The heat-seal layer melts and bonds firmly with the plastic sheet, completely sealing the medicine inside.
- Punching: Finally, the large sheet is punched into smaller blister packs of the required size.
PTP Aluminum Foil Features & Advantages
Excellent barrier performance
- Oxygen barrier: Almost completely blocks oxygen, preventing oxidation of medicines.
- Moisture barrier: Blocks water vapor infiltration, keeping medicines dry and stable.
- Light barrier: Outstanding light-shielding capability prevents photolysis and extends shelf life.
- Contamination prevention: Blocks dust and microorganisms, ensuring pharmaceutical safety.
Unique functional performance
- Easy opening: “Press-through” design allows patients to take medicine easily, improving medication compliance.
- Heat-sealability: Forms a strong seal with PVC/PVDC blisters under heat and pressure.
- Printable: Smooth surface suitable for high-quality printing to meet labeling and identification needs.
- Mechanical strength: Thin yet strong; puncture-resistant, tear-resistant, and suitable for high-speed automated packaging.
Other advantages
- Lightweight: Density only 2.7 g/cm³, reducing packaging weight.
- Safety: Non-toxic, odorless, and compliant with pharmaceutical packaging hygiene standards.
- Eco-friendly: 100% recyclable, aligned with sustainability requirements.
PTP Aluminum Foil Applications
The most important and widely used application of PTP aluminum foil is in the pharmaceutical industry, for packaging:
Pharmaceutical field (main application)
- Solid dosage forms: tablets, capsules, pills, lozenges, etc., in blister packaging.
- Medical devices: small medical devices, diagnostic test strips, and other individual packaging.
- Health supplements: vitamins, nutritional supplements, and similar single-dose packaging.
Other fields
- Food packaging: moisture-proof packaging for small food items, candies, chocolate, etc.
- Electronics industry: used for PCB substrates and electronic component protection due to conductivity and heat dissipation.
- Personal care products: single-dose packaging for creams, masks, serums, etc. It can also be used for foods, supplements, and electronic components requiring high moisture and light protection.
PTP Aluminum Foil Production Process
Aluminum foil base material preparation
- Raw material selection: High-purity aluminum or specialized 8011 aluminum alloy is used to ensure material purity and mechanical performance.
- Melting & refining: Hydrogen content is strictly controlled below 0.12 mL/100 g during melting, and impurities above 5 μm are removed through advanced filtration to reduce pinholes at the source.
- Casting & cold rolling: Continuous casting and precision cold rolling produce aluminum coils with uniform thickness and dense structure, providing a smooth substrate surface for further processing.
- Intermediate annealing: Controlled annealing eliminates work-hardening and improves ductility and stability.
- Slitting: Wide aluminum coils are slit to customer-specified widths with smooth edges and no burrs.
Surface treatment and coating application
- Substrate cleaning & inspection: Cleaning and surface tension testing ensure the foil achieves ≥32 mN/m to guarantee coating adhesion.
- Protective coating: A transparent protective lacquer is applied to the non-heat-seal side to improve printability and mechanical strength.
- Precision printing: High-speed gravure printing enables high-quality single-color to multi-color printing to meet branding and anti-counterfeiting needs.
- Heat-seal coating: A specialized heat-seal adhesive (e.g., VC lacquer) is evenly applied to the heat-seal side—this critical step determines sealing strength with PVC/PVDC sheets.
- Curing & drying: After each coating, the foil passes through controlled-temperature drying tunnels to ensure complete curing and stable performance.
- Final inspection & packaging: Comprehensive inspection covers pinholes, thickness, surface tension, and sealing strength before packaging and shipment.
Why Choose Haomei Aluminum for PTP Aluminum Foil?
To ensure the safety and stability of pharmaceutical packaging, PTP aluminum foil produced by Haomei Aluminum strictly follows the following critical testing standards.
Precise control of physical properties
- Thickness uniformity: Deviation strictly controlled within ≤±5%, ensuring mechanical stability during high-speed filling and punching, preventing breakage or poor forming caused by uneven thickness.
- Tensile strength: ≥168 MPa, ensuring resistance to deformation and stretching during transportation and processing.
- Burst strength: ≥90 MPa, effectively resisting pressure changes and protecting contents from damage.
Excellent barrier performance
Through oxygen transmission rate, water vapor transmission rate, and light transmission tests, we ensure absolute barrier properties against light, oxygen, and moisture—extending medicine shelf life and protecting photosensitive ingredients.
Zero-tolerance surface quality
- Pinhole rate: ≤1 pinhole per square meter, forming an extremely dense layer to eliminate any leakage risks.
- Surface wetting tension: ≥32 mN/m, ensuring strong adhesion between printing coating and aluminum substrate, improving durability of printed labels.
Reliable heat-seal performance
Dedicated testing ensures sealing strength with PVC/PVDC and other pharmaceutical packaging materials—leak-free, easy-to-open, and suitable for high-speed automated production lines.
Reasons to choose Haomei Aluminum:
Our data-driven quality control system ensures every batch undergoes full-item inspection, creating a closed-loop management system from raw materials to finished products. Haomei’s PTP aluminum foil not only meets pharmacopeia standards but exceeds typical industry performance, providing zero-defect packaging solutions for pharmaceutical manufacturers and reducing quality-related market risks. With stable physical performance, superior barrier technology, and precision surface treatment, Haomei has become a trusted global supplier for pharmaceutical companies.