Choosing the Right Thermoforming Sheet for Your Packaging
At DESU, we know that selecting the right thermoforming plastic sheet is one of the most important decisions for manufacturers in the packaging industry. The material you choose affects product safety, appearance, durability, and cost-effectiveness. Whether you are producing food trays, clamshells, blister packs, or custom containers, understanding the differences between PET, PP, PS, PETG, and GAG sheets can help you make the best decision for your business.
Introduction to Thermoforming
Thermoforming is a manufacturing process where a plastic sheet is heated until it becomes pliable, then shaped over a mold, cooled, and trimmed to create a finished product. It is widely used in the food, electronics, cosmetics, and medical industries due to its efficiency, flexibility, and relatively low tooling costs compared to injection molding.
The success of a thermoformed product depends heavily on the properties of the chosen sheet material. For example:
- Food-grade PET offers high clarity and barrier protection.
- PP excels in heat resistance and microwave-safe packaging.
- PS provides cost efficiency for disposable products.
Common Plastic Materials for Thermoforming
Several plastic sheet types are popular in thermoforming due to their balance of clarity, durability, and cost-effectiveness. The most common include:
1. PET (Polyethylene Terephthalate)
- Advantages: Excellent transparency, high impact resistance, recyclable, FDA-approved for food contact.
- Applications: Food trays, bakery packaging, beverage blister packs, medical packaging.
- Notes: Requires controlled heating to avoid crystallization.
2. PP (Polypropylene)
- Advantages: High heat resistance, lightweight, good chemical resistance, microwavable.
- Applications: Microwaveable food containers, yogurt cups, medical lab trays.
- Notes: Lower transparency than PET, but better for hot-fill or heat-resistant needs.
3. PS (Polystyrene)
- Advantages: Low cost, easy to thermoform, good rigidity.
- Applications: Disposable cutlery trays, clamshells, bakery boxes.
- Notes: Brittle and not as impact-resistant as PET or PP.
4. PETG (Polyethylene Terephthalate Glycol-Modified)
- Advantages: High clarity, excellent impact resistance, easy to thermoform without pre-drying.
- Applications: Medical trays, retail blister packs, electronics packaging.
- Notes: Slightly higher cost than PET but better formability.
5. GAG (PETG + APET Sandwich Sheet)
- Advantages: Combines the cost-effectiveness of APET with the forming benefits of PETG.
- Applications: High-clarity blister packs, folding boxes.
- Notes: Offers a good balance for both cost and performance.
Material Comparison Chart
| Material | Clarity | Impact Resistance | Heat Resistance | Food Safety | Cost Level | Common Applications |
|---|---|---|---|---|---|---|
| PET | Excellent | High | Medium | Excellent | Medium | Food trays, clamshells, bakery packaging |
| PP | Good | Medium | High | Excellent | Low-Medium | Microwave containers, hot food trays |
| PS | Fair | Low | Medium | Good | Low | Disposable trays, drink cups |
| PETG | Excellent | Very High | Medium | Excellent | Medium-High | Cosmetic packaging, high-end food packaging |
| GAG | Excellent | High | Medium | Excellent | Medium | Blister packs, folding boxes |
Factors to Consider When Choosing a Thermoforming Sheet
1. Food Contact Safety
If your product is food-related, selecting a food-grade material is critical. PET, PP, PETG, and GAG all meet FDA and EU standards for direct food contact. PS is food-safe for cold or dry products but less suitable for oily or high-heat foods.
2. Clarity and Shelf Appeal
Visual presentation is key for retail packaging. PET and PETG offer crystal-clear transparency, ideal for showcasing product quality. PP has moderate clarity, while PS can appear slightly cloudy.
3. Heat Resistance
If your packaging must withstand hot-fill processes, microwaving, or pasteurization, PP is the top choice. PET has moderate heat resistance, PETG is similar, and PS performs well only in lower-temperature applications.
4. Impact Resistance
Durability during shipping and handling is important for reducing product loss. PETG leads in toughness, followed by PET and GAG. PP has good flexibility, while PS is more brittle.
5. Cost Efficiency
Budget often determines material choice. PS is the lowest-cost option, followed by PP. PET and GAG are moderately priced, and PETG tends to be more expensive due to its superior properties.
Example Applications from DESU
At DESU, we have supplied thermoforming plastic sheets for:
- Ready-meal containers that can go directly from freezer to microwave (PP).
- High-transparency bakery clamshells (PET).
- Rigid blister packs for batteries and electronics (GAG).
- Cosmetic display cases with premium visual appeal (PETG).
- Low-cost disposable drink cups for events (PS).
Industry-Specific Advice
Food Packaging:
- Cold food: PET or PETG for clarity and freshness.
- Hot food / microwave: PP for heat resistance.
- Disposable trays: PS for low cost.
Cosmetics & Personal Care:
- PETG and GAG offer high transparency and luxurious appearance, making them perfect for cosmetic cases and blister packs.
Electronics & Hardware:
- PET and PETG protect products while offering high clarity for retail display.
Medical Packaging:
- PETG is widely used for sterile blister packs and trays because of its toughness and ease of sealing.
Final Tips from DESU
When choosing the right thermoforming sheet material, think beyond cost. Consider your product’s handling, storage, transportation, and display requirements. The right material will improve not only your packaging performance but also your customer’s brand perception.
At DESU, we provide custom-cut PET, PP, PS, PETG, and GAG plastic sheets in thicknesses ranging from 0.18mm to 2.0mm, with color and finish options to suit your design. Our team can help you balance performance and budget to achieve the best results for your application.
