Thermoforming vs. Injection Molding: What’s the Difference?

Blog, Wednesday, August 31, 2022

Thermoforming vs. Injection Molding: What’s the Difference?

Are you looking for the best way to manufacture your plastic parts or products? Not sure which option will meet your needs and give you the best bang for your buck? Concerned with lead times from thermoforming companies in Illinois interfering with your shipping and delivery schedule? CBM Plastics knows how important it is to find the right manufacturing process for your production needs. They are based in the U.S., which helps eliminate overseas shipping issues and provides you with shorter overall lead times so you can get your plastic parts and products to their destination when you need them there. Interested in learning whether thermoforming vs. plastic injection molding is right for your production needs? Read in to find out more, or contact CBM Plastics today to discuss your manufacturing project.

What is Thermoforming?

Thermoforming is a process used to create smaller quantities of plastic products, especially large parts. Thermoplastic sheets will be heated to high temperatures until they are softened and then stretched over a mold and manipulated until it is the desired shape. The manipulation can be done through pressure forming, mechanical forming, or vacuum forming. Once the manipulation is complete, the plastic will be cooled and removed.

What is Plastic Injection Molding

Plastic injection molding is a type of manufacturing process typically used for high volume runs to get a lower per-piece price. A mold is made and injected with softened thermoplastics. The plastic will then cool and harden in the mold, where it will take its final shape. This type of manufacturing process can be used for small products as well as larger ones.

What Are the Differences Between Thermoforming vs. Injection Molding?

The primary difference between thermoforming vs. injection molding is the way the plastic is molded and the way the plastic is formed with the mold. Thermoforming involves laying sheets of plastic over the mold and is a good option for small or one-time runs, products with complicated designs, and when larger plastics are needed.

The thermoplastic pellets are melted and injected into a closed mold with injection molding. This option is best for high-volume runs, extremely small parts, and intricate parts that have varying thickness throughout the piece.

Thermoforming vs. Injection Molding: Which is Cheaper?

Thermoforming tooling costs are usually less expensive than injection molding. The molds for thermoforming can often be made from more cost-effective materials, such as aluminum. The tool used for molding is also single-sided.

An injection molding mold is a double-sided mold and has to be able to handle a much higher amount of pressure. Because of this, the injection molding tooling will often be made from beryllium-copper alloy, heavy aluminum, or steel. These materials are more costly, making the upfront cost of injection molding higher.

But when it comes to overall costs, injection molding can be cheaper for high-volume and repeat runs as the mold is designed to last through more repeated use than a thermoforming one.

Thermoforming vs. Injection Molding: Which is Faster to Market?

Thermoforming will often have a shorter lead time than injection molding, primarily due to the tooling lead time. The prototyping and design of a thermoforming mold are much quicker than that of a 3D mold required for injection molding. Aside from the time for tooling, the processes can have similar lead times, which may make injection molding a shorter lead time if you are reusing a previous die.

What Are the Applications of Injection Molding?

There are many industries and companies that use injection molding for their parts and products. Some of the primary areas you will see injection modeling used for production include:

  • Construction and building materials: Plastic injection molded parts are often used in building and construction as they are durable when exposed to elements. They are more stable and come in a range of materials and finishes.
  • Food and beverage components and packaging: Injection molded parts are used for food and beverage processing and packaging applications. It is the ideal manufacturing option for small parts such as beverage caps.
  • Pharmaceutical and medical parts and packaging: You can use food-grade and engineering-grade plastics in injection modeling, which makes it perfect for industries that require certified resins for safety. Popular products created with injection modeling are pharmaceutical packaging, test kits, and products for surgical prep.
  • Point of purchase and merchandising displays: Parts and setups for marketing and display products, such as pegboard hooks, shelf dividers, and product stops, are also created with injection molding.
  • Door frames and windows: Injection molded products can be made with weather-resistant materials with good thermal insulation, making this ideal for creating parts for door frames and windows.

What Are the Applications for Thermoforming?

While thermoforming is a popular manufacturing option for any sized parts in smaller runs, it is most often used in packaging. Thermoforming can be used to make everything from blister packs to packing trays to packaging for electronic appliances. Thermoforming is used in several industries, including:

  • Electronics
  • Aerospace
  • Automotive
  • Transportation
  • Shipping
  • Consumer products
  • Construction and building

What Are the Advantages and Disadvantages of Thermoforming?

As with any manufacturing process, there are pros and cons to using thermoforming for your plastic parts and production needs.


Some of the best reasons for choosing thermoforming for your manufacturing is the fact that:

  • You can make several different types of parts from the same material.
  • It can allow you to identify and fix issues with the design before it is too late.
  • It can be suitable with a wide range of plastics.
  • You can achieve high-quality pieces.
  • It can be a cost-effective option for large parts.


While thermoforming can be the perfect option for many products, there are some drawbacks to choosing this option. Cons of the thermoforming process include:

  • The design may be limited to thin walls.
  • The thickness can become uneven, creating weaker points,
  • It can be more costly than other options.
  • It is limited to plastic sheets.
  • It requires more plastic.

What Are the Advantages and Disadvantages of Injection Molding?

Some pros and cons come with choosing injection molding, and choosing the best option will largely depend on whether the positives outweigh the drawbacks of that specific process.


The injection molding process has many advantages, including:

  • It is ideal for tight tolerances and complex geometries.
  • It can achieve greater consistency in wall thickness.
  • It can give you parts close in quality to CNC-produced parts.
  • There is a wide range of plastics and colors that can be used.
  • It is an efficient production method for large volumes.
  • It produces less waste as the leftover plastic can be reused.


Even though there are many pros to injection molding, there are also some cons. Some of the drawbacks of injection molding include:

  • Tooling and initial costs can be higher, making it less cost-effective for low-volume production runs.
  • First-run lead times can be long as the tooling takes weeks to produce.
  • Changing the design can be expensive as it will require complete re-tooling of mold.

Why CBM When Choosing an Injection Molding Company?

When looking for plastic injection molding companies in Illinois for your next project, look no further than CBM Plastics. A leader in the plastics manufacturing realm for more than 25 years, CBM Plastics knows what it takes to produce high-quality plastic parts and products, no matter the run size. Contact CBM Plastics today to find out more about the differences between thermoforming vs. injection molding and how they can help make your next plastics manufacturing project a success.