What Is The Difference Between Vacuum Forming and Vacuum Die Casting?

Last Updated on March 8, 2024 by assistant

Manufacturing processes such as vacuum forming and vacuum die-casting play crucial roles in the production of various products across industries. While both methods involve the use of a vacuum, they differ significantly in terms of their techniques, materials, and applications. In this article, we will delve into the details of vacuum forming and vacuum die-casting, highlighting their definitions, processing characteristics, and key differences.

1. Vacuum Forming

Vacuum forming, also known as thermoforming, is a technique used to shape thermoplastic sheets into three-dimensional objects. The process begins with a heated sheet of plastic being positioned over a mold. A vacuum is then applied to draw the softened plastic onto the mold, creating the desired shape. Once cooled, the formed plastic product can be trimmed and finished as required.


Key Characteristics of Vacuum Forming:

I. Suitable for low-volume production and prototyping.
II. Utilizes a wide range of thermoplastic materials, including ABS, PVC, and PETG.
III. Relatively low tooling and equipment costs.
IV. Ideal for producing large, lightweight, and non-structural parts.
V. Limited in terms of intricate detail and precision.

2. Vacuum Die-Casting

Vacuum die-casting, also known as vacuum casting or vacuum pressure casting, is a process used to produce high-quality metal parts with excellent surface finishes. It involves injecting molten metal, typically aluminum or zinc alloys, into a mold under vacuum conditions. The vacuum helps remove air and gases from the mold cavity, minimizing porosity and improving the mechanical properties of the cast part.


Key Characteristics of Vacuum Die-Casting:

I. Suitable for medium to high-volume production.
II. Primarily used for manufacturing metal parts with complex shapes and fine details.
III. Offers superior dimensional accuracy and tight tolerances.
IV. Enables the production of parts with excellent surface finish and reduced porosity.
V. Requires specialized equipment and tooling, resulting in higher initial costs compared to vacuum forming.

Differences between Vacuum Forming and Vacuum Die-Casting


Vacuum forming employs thermoplastic materials, while vacuum die-casting uses molten metals, predominantly aluminum and zinc alloys.

Production Volume

Vacuum forming is more commonly used for low-volume production and prototyping, whereas vacuum die-casting is suitable for medium to high-volume production.

Complexity and Detail

Vacuum forming is limited in terms of intricate detail and precision, whereas vacuum die-casting excels in producing complex shapes and fine details with high dimensional accuracy.

Surface Finish

While vacuum forming can achieve decent surface finishes, vacuum die-casting offers superior surface quality, providing parts with excellent finishes and reduced porosity.

Vacuum Forming


In vacuum forming, the thermoplastic sheet is heated until it becomes pliable and then placed over a mold. The air between the sheet and the mold is evacuated using a vacuum, which causes the sheet to conform to the shape of the mold. Once the plastic has cooled and solidified, it is removed from the mold, trimmed, and finished as necessary.


Vacuum forming is commonly used in industries such as packaging, automotive, aerospace, and signage. It is suitable for producing a wide range of products, including trays, blister packaging, automotive interior components, shower enclosures, and point-of-sale displays.


1. Low tooling and equipment costs make it an affordable option for low-volume production and prototyping.
2. Quick setup and turnaround times.
3. Can produce large parts with relatively simple shapes.
4. Suitable for both thin and thick plastic sheets.
5. Offers design flexibility and customization options.


1. Limited in terms of achieving intricate details and sharp corners.
2. Not suitable for high-strength or load-bearing applications.
3. The uniformity of wall thickness may be challenging to achieve.

Vacuum Die-Casting


In vacuum die-casting, the process is similar to conventional die-casting, but with the added step of creating a vacuum environment in the mold cavity. Molten metal is injected into the mold under high pressure, and the vacuum helps remove air and gases, ensuring a more consistent and void-free casting. Once solidified, the casting is removed from the mold for further processing.


Vacuum die-casting is commonly used in industries such as automotive, aerospace, electronics, and consumer goods. It is ideal for manufacturing complex metal parts, including engine components, electronic housings, decorative fixtures, and precision components.


1. Excellent dimensional accuracy and tight tolerances.
2. Superior surface finish and reduced porosity compared to conventional die-casting.
3. Enables the production of intricate and complex shapes.
4. Enhanced mechanical properties due to reduced porosity.
5. Suitable for high-strength and load-bearing applications.


1. Higher initial costs due to specialized equipment and tooling.
2. Longer cycle times compared to other casting processes.
3. Not as suitable for low-volume production or prototyping due to higher setup costs.

Cost Considerations

Vacuum forming generally incurs lower tooling and equipment costs compared to vacuum die-casting, making it more cost-effective for low-volume production.


Both vacuum forming and vacuum die-casting are valuable manufacturing processes, each with its distinct characteristics and applications. Vacuum forming is well-suited for low-volume production of large, lightweight plastic parts, while vacuum die-casting excels in producing intricate metal parts with high precision and superior surface finishes.

It’s important to note that both vacuum forming and vacuum die-casting have their strengths and limitations, and the choice between the two processes depends on factors such as production volume, part complexity, material requirements, and cost considerations.

Do you have a die-casting or thermoforming project and need a free quote? Please feel free to contact us. Ruitai Mould is an experienced parts processing manufacturer and can provide you with the best quote. Simply send your 3D drawings to our team and we’ll get back to you with a quote within a few hours.