What Materials Are Commonly Used in Thermoforming Blister Packaging?

Thermoforming blister packaging most commonly uses plastic films and sheets such as PVC (Polyvinyl Chloride), PET (Polyethylene Terephthalate), PP (Polypropylene), PETG, and PS (Polystyrene). Each material offers distinct advantages in terms of clarity, barrier properties, formability, cost, and sustainability — making material selection one of the most critical decisions in the thermoforming blister packaging process.

This guide breaks down every major material used in thermoforming blister packaging, compares their properties side by side, and helps you make an informed choice for your specific application — whether in pharmaceuticals, food, retail, or electronics.

Understanding Thermoforming Blister Packaging

Thermoforming blister packaging is a manufacturing process in which a flat plastic sheet is heated until pliable, then shaped over a mold using vacuum or pressure to form cavities — commonly called "blisters" — that hold individual products. The formed plastic tray is then sealed with a lidding material such as foil, paper, or another film.

This packaging format is widely used across industries because it offers excellent product visibility, tamper evidence, portion control, and cost efficiency. The base material used in the thermoforming process directly influences every performance characteristic of the final package — from seal integrity and moisture barrier to recyclability and shelf appeal.

Choosing the right material for thermoforming blister packaging requires balancing technical performance with commercial and regulatory requirements. Below, we explore each primary material in depth.

The Most Common Materials in Thermoforming Blister Packaging

1. PVC — Polyvinyl Chloride

PVC is historically the most widely used material in thermoforming blister packaging, particularly in the pharmaceutical industry. Its popularity is rooted in its low cost, excellent thermoformability, and good clarity.

• Clarity: High optical transparency for excellent product visibility
• Formability: Extremely easy to thermoform at low temperatures
• Cost: Among the lowest-cost materials available
• Barrier: Moderate moisture barrier; low oxygen barrier without coatings
• Sealing: Seals well with aluminum foil using heat
• Sustainability: Difficult to recycle; contains chlorine; declining use in eco-sensitive markets

PVC is the dominant material in pharmaceutical unit-dose blister packs for tablets and capsules. However, growing environmental concerns have prompted many manufacturers to transition to more sustainable alternatives for thermoforming blister packaging.

2. PET — Polyethylene Terephthalate

PET has emerged as one of the leading alternatives to PVC in thermoforming blister packaging. It offers superior clarity, better environmental credentials, and strong mechanical properties.

• Clarity: Crystal-clear; often preferred for premium retail packaging
• Formability: Requires higher thermoforming temperatures than PVC
• Cost: Moderate; slightly higher than PVC
• Barrier: Good oxygen and moisture barrier
• Recycling: Widely recyclable (resin code #1); accepted in most municipal programs
• Stiffness: Stiffer than PVC; good puncture resistance

PET is extensively used in food packaging, cosmetics blisters, and retail clamshells. Its recyclability makes it a preferred choice in sustainability-driven thermoforming blister packaging strategies.

3. PETG — Glycol-Modified PET

PETG is a modified form of PET that is more flexible and easier to thermoform. It is gaining popularity in thermoforming blister packaging for complex-shaped cavities.

• Clarity: Exceptional; among the clearest available materials
• Formability: Outstanding; forms at lower temperatures than standard PET
• Impact resistance: Superior to standard PET
• Chemical resistance: Good
• Recycling: Less straightforward than PET; often not accepted in standard streams

PETG is often used in medical device packaging and premium consumer goods where deep-draw blister cavities and outstanding visual appeal are required.

4. PP — Polypropylene

PP is one of the most chemically resistant thermoplastics used in thermoforming blister packaging. It is especially favored in pharmaceutical and food contact applications where regulatory compliance is essential.

• Clarity: Naturally hazy; clarified grades available
• Formability: More challenging; requires precise temperature control
• Barrier: Very good moisture barrier; moderate oxygen barrier
• Chemical resistance: Excellent; compatible with many pharmaceutical compounds
• Temperature resistance: Higher heat resistance than PVC or PS
• Recycling: Recyclable (resin code #5); increasingly accepted

PP is widely used for pharmaceutical blister packaging, food trays, and medical device packaging. Oriented PP (OPP) and cast PP are both used in various thermoforming blister packaging configurations.

5. PS — Polystyrene

PS (Polystyrene) is one of the oldest thermoforming materials and remains in use for lower-cost, non-sensitive product applications.

• Clarity: Good with GPPS (general purpose); opaque with HIPS
• Formability: Excellent; thermoforms easily
• Cost: Low
• Barrier: Poor moisture and oxygen barrier
• Brittleness: Brittle; prone to cracking under impact
• Recycling: Difficult; rarely accepted in curbside programs

PS finds application in retail display blisters for stationery, toys, and hardware items. Its declining use reflects both performance limitations and environmental challenges.

6. PVDC — Polyvinylidene Chloride (Barrier Coating)

PVDC is typically applied as a coating on PVC or PET base films to dramatically enhance barrier performance in thermoforming blister packaging — particularly for moisture-sensitive pharmaceutical products.

• Moisture Vapor Transmission Rate (MVTR): Extremely low — ideal for hygroscopic drugs
• Oxygen barrier: Excellent
• Common combinations: PVC/PVDC, PVC/PVDC/PE, PET/PVDC
• Cost: Higher than uncoated films
• Recyclability: Complicated due to multi-layer structure

7. ACLAR® / COC — Specialty Barrier Films

ACLAR (polychlorotrifluoroethylene, PCTFE) and COC (Cyclic Olefin Copolymer) are premium materials used in high-barrier pharmaceutical thermoforming blister packaging.

• Moisture barrier: Best-in-class; used for the most sensitive pharmaceuticals
• Clarity: Outstanding
• Drug compatibility: Excellent chemical inertness
• Cost: Significantly higher than standard films
• Application: Biologics, lyophilized drugs, moisture-critical APIs

Material Comparison for Thermoforming Blister Packaging

The table below offers a side-by-side comparison of the primary materials used in thermoforming blister packaging across key performance dimensions.

Lidding Materials in Thermoforming Blister Packaging

While the formed cavity is the defining element, the lidding material completes the package. In thermoforming blister packaging, lidding must bond reliably with the base film and provide adequate barrier and functionality.

Aluminum Foil Lidding

The most common pharmaceutical lidding — typically cold-formed or heat-sealed foil laminates. Provides excellent barrier to moisture, oxygen, and light. Push-through or peel-able configurations available.

Paper / Paperboard Lidding

Used in retail and consumer goods packaging where recyclability and print quality are priorities. Often used in sustainable thermoforming blister packaging designs.

Plastic Film Lidding

PET, PP, or PE films are used as lidding when transparency or specific seal performance is needed. Common in food and cosmetic applications.

Industry Applications by Material

Pharmaceutical Thermoforming Blister Packaging

The pharmaceutical industry relies most heavily on thermoforming blister packaging. Unit-dose blisters for tablets and capsules must protect the drug from moisture, oxygen, and contamination. Preferred materials include PVC, PVC/PVDC, PP, and ACLAR. Regulatory compliance with FDA 21 CFR, EU GMP, and ICH guidelines drives material specification.

Food Thermoforming Blister Packaging

Fresh produce, meat, cheese, and confectionery products use thermoforming blister packaging made from PET, PP, and HIPS. FDA food-contact compliance is mandatory. Modified atmosphere packaging (MAP) often incorporates high-barrier multilayer films.

Retail and Consumer Goods

Hardware, electronics accessories, toys, and cosmetics use PET, PETG, and PS-based thermoforming blister packaging for maximum product visibility and theft deterrence. Clamshell designs with integral hinges are popular in this segment.

Medical Device Packaging

Medical devices require sterile barrier packaging in compliance with ISO 11607. PETG, PP, and HDPE are commonly used alongside Tyvek® lidding for thermoformed medical device trays.

Sustainability Trends in Thermoforming Blister Packaging Materials

Sustainability is reshaping material selection across the entire thermoforming blister packaging industry. The following trends are gaining momentum:

• PVC Reduction: Many markets are phasing out PVC in favor of recyclable alternatives like PET and PP due to chlorine content and recycling challenges.
• Mono-material structures: Moving from complex multi-layer films to single-material solutions (e.g., all-PET) simplifies recyclability.
• Recycled content (PCR): Post-consumer recycled PET is being incorporated into thermoforming films, reducing virgin material use.
• Bio-based plastics: PLA (polylactic acid) and bio-PET derived from plant sources are emerging options in select applications.
• Paper-based blisters: Fiber-based thermoforming substrates are in development as fully recyclable alternatives for certain product types.

Balancing sustainability goals with functional performance remains the central challenge in selecting materials for thermoforming blister packaging — particularly in regulated industries like pharmaceuticals where patient safety must take precedence.

How to Choose the Right Material for Your Thermoforming Blister Packaging

Selecting the optimal material involves evaluating several interdependent factors:

• Product sensitivity: Does the product require high moisture or oxygen barrier protection? If yes, consider PVC/PVDC, PP, or ACLAR.
• Regulatory requirements: Pharmaceutical and food packaging require specific material compliance certifications.
• Optical requirements: High-clarity retail display applications favor PET or PETG.
• Budget constraints: Lower-cost options like PVC or PS may be appropriate for non-sensitive retail applications.
• Sustainability commitments: Target materials with recyclability or use of recycled content where compatible with product requirements.
• Thermoforming equipment compatibility: Ensure the chosen material is compatible with existing line temperatures and tooling.
• Lidding compatibility: The base film must form a reliable, airtight seal with the intended lidding material.

Frequently Asked Questions About Thermoforming Blister Packaging Materials

Conclusion

The material selection process in thermoforming blister packaging is far more nuanced than simply choosing the lowest-cost option. Each plastic — from the ubiquitous PVC and eco-friendly PET to the high-performance ACLAR — occupies a specific niche defined by its barrier properties, processability, regulatory status, optical quality, and sustainability profile.

As the packaging industry evolves, the push toward recyclable mono-materials, bio-based films, and reduced PVC use will continue to reshape material preferences in thermoforming blister packaging. The most successful packaging solutions are those that balance product protection, regulatory compliance, consumer experience, and environmental responsibility.

Understanding the full landscape of available materials empowers manufacturers, procurement teams, and product developers to make informed decisions that serve both their products and their sustainability commitments — now and into the future.