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8 Things You Need to Know About Thermoforming Molds - Part 1


A thermoforming mold is a type of mold that can be used to create a variety of shapes and sizes for packaging. The process for making these molds involves heating up the plastic until it becomes malleable, then using the mold to shape the plastic into various packaging forms. The process can be used for a number of different applications, including food packaging, industrial packaging or even medical packaging, etc. In the packaging industry, precise and quality thermoforming molds are a critical part to create high-quality packaging products. If you're new to the world of thermoforming molds and are looking for a few tips on how to get started, here are 8 things you need to know. This is part 1. Read on.

1. How does a thermoforming mold work?

Thermoforming has different processes. And how the mold works is different in these processes. Though, there are many processes, but we'll go with the most commonly used processes to explain how thermoforming mold works. These processes are:

  • Vacuum Forming:

    The process uses air created by the vacuum. A two-dimensional thermoplastic sheet is heated to a forming temperature. The mold is already designed in the desired shape or form. The heated plastic is then placed directly on the mold. The air in the mold will be evacuated from the mold which will pull down the heated plastic to sit inside the mold. This will make the plastic assume the shape or form of the mold. After cooling, the desired part is then removed and trimmed to specifications.

  • Pressure Forming:

    This process is similar to the vacuum forming process. But there's an extra step. In this process, the heated plastic material is pulled into the mold just like the vacuum. A pressing tool is then used to apply more pressure on the plastic in the mold to exact its definite shape or form.

In general, a thermoforming mold is designed in different shapes and forms to collect the heated thermoplastic sheet, and give it form or shape as designed or required.

Read also: 5 Minutes to Understand Vacuum Thermoforming : Mold Design & Examples

thermoforming molds

2. What are the different types of thermoforming mold?

There are different types of thermoforming mold. Each of them is used in different phases of thermoforming.

  • Forming Mold:

    These are the essential parts of thermoforming. They are placed underneath the heated thermoplastic sheet to create the desired shape or form. These molds are of different design according to the product to be thermoformed, and are made from different materials. Ranging from aluminum, steel, and others.

  • Trimming Mold:

    These molds are designed as the forming mold but with greater precision. They're used to trim the thermoformed products. These molds give the thermoformed products the desired shape or form. Some of these molds have holes in them. Pins are also used in the molds to help locate the holes before trimming.

thermoforming molds - forming molds and trimming molds

3. What are some examples of thermoforming molds?

Thermoforming molds are literally everywhere. They're the building blocks of most of the products that surround us. Thermoformed Food Packaging including cups, lids, containers, trays, to-go boxes, cake boxes, clamshells, egg boxes, and the plastics we use are thermoformed using these molds.

For more thermoforming mold examples: Mold Introduction

You may be also interested in: Thermoforming Cup Mold Design.  |  Clamshell Packaging Design.

examples of thermoforming molds

4. How to Create a Custom Thermoforming Mold ?

There are many different ways to create a custom thermoforming mold. Each method has its own advantages and disadvantages, so it is important to know about all of them before making a final decision. Here's how to get started:

  • Define your needs and wants.

  • Choose a material that fits your needs and wants.

  • Create a prototype of the thermoforming mold that includes details like any holes or vents that need to be incorporated into the final product.

  • Test out multiple prototypes until you've found the one that works best for your needs and wants.

Read also: Choosing the Right Cutting Dies and Tools for Thermoforming Machine

5. Design Considerations for Thermoforming Mold

Before you can design a mold, there are some factors you need to consider. The design of your mold is dependent on the following factors:

  • Production volume:

    For high-volume production, compared to injection molding mold, thermoforming is better suited for producing smaller quantities of parts with complex shapes and geometries.

  • Thermoforming forces:

    The mold should have enough strength to withstand the forming forces involved in the process. Forces such as vacuum forces, pressures, or mechanical actions will definitely test the strength of the material used in making the mold. Their intensity will depend on the type of material of the product to be thermoformed, sheet gauge, and requirements on part quality.

  • Thermoforming temperature:

    Depending on the material to be used, the mold is expected to have higher thermal resistance. It is best if cooling channels like holes are included in the molds. Pins can be used to locate the holes in the mold. These cooling channels can improve the thermoformed, and mold's cooling rates, increase its part-to-part uniformity, and minimize cycle times.

Read also: Design considerations for thermoforming food packaging

Click here to read more about 8 Things You Need to Know About Thermoforming Molds - Part 2


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