Top 10 Things You Didn’t Know About Thermoforming

John Li
June 3, 2025
6:57 am

Thermoforming is a fascinating manufacturing process that transforms plastic sheets into a variety of products by heating them to a pliable state, molding them into shapes, and cooling them to set. You might know it from everyday items like food packaging or car dashboards, but there’s much more to this technique than meets the eye.

Thermoforming heats plastic sheets to shape them into products like packaging and automotive parts. It’s cost-effective for low to moderate production volumes¹, versatile across industries², and faster for prototyping, though it may result in uneven part thickness.

In this blog post, we’ll uncover the top 10 things you didn’t know about thermoforming, shedding light on its versatility, cost benefits, and unique applications³. Whether you’re a manufacturer, designer, or just curious, these insights will deepen your appreciation for this widely used process.

Thermoforming is only used for packaging.False

While packaging is a major application, thermoforming is also used in automotive, aerospace, and medical industries for parts like dashboards, luggage bins, and surgical trays.

Thermoforming is more cost-effective than injection molding for large production runs.False

For high-volume production, injection molding often becomes more cost-effective due to economies of scale, despite higher initial tooling costs.

Table of Contents Hide

1. What is Thermoforming?
2. What are the Common Materials Used in Thermoforming?
3. What are the Steps in the Thermoforming Process?
4. What are the Key Factors in the Thermoforming Process?
5. What are the Applications of Thermoforming?
6. What are the Differences Between Thermoforming and Other Plastic Forming Processes?
7. Conclusion

What is Thermoforming?

Thermoforming⁴ involves heating a plastic sheet until it’s soft and pliable, then forming it into a specific shape using a mold—often with the help of vacuum or pressure—and cooling it to create a finished product. It’s a go-to method for producing everything from blister packs to refrigerator liners due to its simplicity and adaptability.

A blue panel being shaped on a CNC machine with numbered markings — Thermoforming process

Full Technical Name: Thermoforming
Common Aliases: Plastic thermoforming⁵, vacuum forming⁶ (a subset), pressure forming
Core Principles: Heating to soften, molding to shape, cooling to solidify (Wikipedia - Thermoforming).

What are the Common Materials Used in Thermoforming?

Thermoforming’s versatility shines through its compatibility with a variety of thermoplastics, each chosen for properties like strength, clarity, or chemical resistance.

A machine producing clear plastic wrap with large rolls of plastic material — Thermoforming material

Common thermoforming materials include PET, PVC, ABS, PS, and PP, each selected for specific traits like clarity or durability in applications from packaging to automotive parts.

Material	Properties	Common Applications
PET	Clarity, strength	Food packaging, trays
PVC	Durability, chemical resistance	Medical trays, enclosures
ABS	Toughness, impact resistance	Automotive parts, electronics
PS	Lightweight, easy to form	Disposable packaging, cups
PP	Chemical resistance	Automotive, medical devices

Polyethylene Terephthalate (PET)

PET stands out for its clarity and strength, making it a favorite for food packaging like trays and beverage containers. Bonus: it’s recyclable!

Polyvinyl Chloride (PVC)

PVC’s durability and chemical resistance make it perfect for medical trays and industrial components that need to withstand harsh conditions.

Acrylonitrile Butadiene Styrene (ABS)

ABS brings toughness and impact resistance to the table, ideal for automotive parts and consumer electronics that require durability.

Polystyrene (PS)

Lightweight and easy to shape, PS is commonly used for disposable packaging and food service items like cups and lids.

Rolls of BOPP film being manufactured in a factory setting — Thermoforming material

Polypropylene (PP)

PP offers excellent chemical resistance, making it a top pick for automotive components and medical devices.

Thermoforming can be done with a variety of plastic materials.True

Thermoforming works with many thermoplastics, including PET, PVC, ABS, PS, and PP, each suited to different needs.

All thermoforming materials are equally suitable for all industries.False

Material properties like clarity or chemical resistance make some better suited for specific applications than others.

What are the Steps in the Thermoforming Process?

The thermoforming process⁷ is a streamlined sequence of steps that turns a flat plastic sheet⁸ into a functional 3D product.

Thermoforming involves heating a plastic sheet, forming it into a mold using vacuum or pressure, cooling, trimming, and finishing—each step critical for quality and precision.

Various types of plastic food containers and lids in different sizes and shapes — Thermoforming products

Heating

The plastic sheet is heated to a pliable temperature (typically 100–600°F, depending on the material) to make it soft and moldable.

Forming

The heated sheet is stretched over or into a mold, shaped by vacuum, pressure, or mechanical force, depending on the method used.

A large manufacturing machine in operation with industrial fans in the background — Thermoforming process

Cooling

The formed plastic cools—often aided by mold cooling channels⁹—to lock in its new shape and ensure stability.

Trimming

Excess material is trimmed off using tools like CNC routers to finalize the product’s edges and shape.

Finishing

Optional steps like printing or assembly add functionality or branding to the finished piece.

Thermoforming always results in uniform thickness across the part.False

Stretching during forming can lead to thinner areas, especially in deeper sections.

Precise temperature control is crucial in thermoforming.True

Temperature affects pliability and quality, making precise control essential to avoid defects.

What are the Key Factors in the Thermoforming Process?

Several factors determine the success of a thermoformed product, from material choice to mold design.

Key factors in thermoforming include material selection¹⁰, temperature control¹¹, mold design¹², and forming method, all impacting the final product’s quality and performance.

Person holding a large red plastic mold with smooth edges and indents — Thermoforming products

Material Selection

Picking the right thermoplastic is vital—each material offers unique benefits tailored to specific uses.

Temperature Control

Too hot or too cold, and you’ll get defects. Precise heating ensures the plastic forms correctly without warping.

Mold Design

The mold’s shape and features (like undercuts or textures) dictate the part’s complexity and quality.

Close-up view of a metal cake pan with several round molds, each labeled with measurements — Thermoforming Molds

Forming Method

Vacuum forming is simple and cost-effective, while pressure forming offers more detail—method matters!

Mold design is a critical factor in thermoforming.True

The mold shapes the part and determines its detail and quality.

All thermoforming methods produce the same level of detail.False

Pressure forming provides higher detail than vacuum forming.

What are the Applications of Thermoforming?

Thermoforming’s reach extends far beyond what you might expect, serving industries with diverse needs.

Thermoforming is used in packaging, automotive, aerospace, and medical fields for products like trays, dashboards, and surgical enclosures, thanks to its versatility and cost-effectiveness.

A sturdy black plastic military ammo crate with a grid-like structure — Thermoforming products

Packaging

Think blister packs and clamshells—thermoforming excels at creating protective, eye-catching packaging.

Automotive

Lightweight dashboards and door panels? Thermoforming delivers durability without the heft.

Open Duraliner cargo box with a black textured surface — Thermoforming products

Aerospace

Large, lightweight parts like luggage bins make thermoforming a hit in aerospace design.

Medical

Sterile trays and equipment housings benefit from thermoforming’s precision and material options.

Thermoforming is only suitable for small parts.False

It can produce large parts like automotive panels, up to 84\

Thermoforming is widely used in the medical industry.True

Its ability to create sterile, precise products makes it invaluable in healthcare.

What are the Differences Between Thermoforming and Other Plastic Forming Processes?

Thermoforming isn’t the only game in town—here’s how it stacks up against injection molding and blow molding.

A transparent plastic tray with compartments, laid on top of a black divided tray on a blue background — Thermoforming products

Thermoforming offers lower tooling costs and faster prototyping than injection molding but may produce more waste and less precision for complex parts.

Aspect	Thermoforming	Injection Molding	Blow Molding
Tooling Costs	Lower (1/2 to 1/5 of injection)	Higher, complex tooling	Moderate, size-dependent
Production Speed	Faster for prototypes, small runs	Slower setup, faster mass production	Moderate, hollow parts focus
Material Usage	More waste from trimming	Precise material use	Efficient for hollow shapes
Design Flexibility	Great for large, simple parts	Best for complex, detailed parts	Limited to hollow designs

Tooling Costs

Thermoforming’s molds are cheaper and quicker to make, perfect for smaller runs.

Production Speed

Need a prototype fast? Thermoforming’s your friend—samples in 8–10 weeks.

Material Usage

Trimming means more waste compared to injection molding’s precision.

Design Flexibility

Thermoforming shines with large parts; injection molding wins for intricate details.

Thermoforming allows for faster prototyping than injection molding.True

Simpler tooling means quicker setup and prototype production.

Thermoforming is better for high-volume production than injection molding.False

Injection molding’s per-part costs drop with scale, outpacing thermoforming.

Conclusion

Thermoforming is more than just a manufacturing process—it’s a versatile, cost-effective solution that powers industries from packaging to aerospace. With its ability to work with diverse materials, produce parts quickly, and adapt to complex designs, it’s no wonder thermoforming is a hidden gem in production. Next time you open a clamshell package or sit in a car, you might just be experiencing thermoforming in action!

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