What is the difference between thermoforming and injection molding?

Plastics can be used in all types of industries and can provide versatility and strength in a variety of applications from car body parts to human body parts. Each application requires a unique manufacturing process that can mold parts according to specifications.

Thermoforming and injection molding are the two most popular manufacturing processes for plastic parts, and they provide unique advantages based on specific applications. Although thermoforming is often used for large-scale designs and shorter production runs, for small, complex parts and larger production runs, injection molding is often the better choice.

Thermoforming is the process of forming a heated plastic sheet on the surface of a male or female mold. Unlike injection molding, this is a single-sided plastic manufacturing process. Only one side of the plastic plate is controlled by a mold or tool. Vacuum forming and pressure forming are popular methods of thermoforming

According to the needs of the project, thermoforming can provide several obvious advantages, including:

Compared with injection molding, mold cost is lower
Rapid product development and prototyping
Bright color and texture options
Strong adaptability and simple adjustment
Thermoforming is ideal for small batches (250 to 3000 parts per year).

Reduce mold costs

The tools used for thermoforming are cheaper than injection molding. Molds used for thermoforming are usually made of cheap aluminum. In contrast, injection molds are usually made of thicker aluminum, steel, or other heavier alloys to withstand higher pressures and can be continuously reused in larger production runs. In addition, thermoforming uses only single-sided tools instead of double-sided injection molds. This actually reduces the material required for mold manufacturing by half, thereby greatly reducing the initial cost of thermoforming. However, the mold has poor durability and cannot be used for large-scale or repetitive production.

Compared with injection molding, the size of the part plays an important role in the cost-effectiveness of thermoforming. The larger the component, the greater the gap between mold costs. As part sizes increase, thermoforming becomes more and more cost-effective.

Rapid product development and prototyping

Since thermoforming molds can be produced quickly, thermoforming is much faster than injection molding in terms of product development and prototype testing. Since the mold is a double-sided mold and consists of a harder material (such as steel), the processing of the injection mold is more time-consuming. In contrast, thermoforming molds are easier to design, manufacture, and modify, making them ideal for development and testing.

Multiple textures and bright color options

Thermoforming provides multiple benefits for product design and brand promotion. Bright colors can be added to thermoformed plastics to achieve vivid and long-lasting coloration on the entire material. In addition, thermoforming materials can accept painting, screen printing, printing, decoration and coating to provide unique designs, textures and finishes, thereby improving the appearance and service life of the product.

Strong adaptability and simple adjustment

Since thermoforming uses a simple one-sided mold made of highly formable materials, the thermoforming design can be modified quickly and at the lowest cost. On the other hand, injection molding requires dual molds with heavier materials, which is more time-consuming and expensive in tools.

Applications using thermoformed products

The low cost, versatility and adaptability of thermoforming make it ideal for many applications, including:

Automotive: dashboard, seat components, interior trim panels, bumpers and air ducts
Aerospace: air ducts, seat parts, interior panels, kitchen equipment and curtains
Structure: equipment shell, tool box, internal and external panels
Medical: Diagnostic and imaging equipment housings, bed and furniture components, auxiliary equipment and walls and ceilings
Public transportation: interior and exterior trim panels, seat components, instrument panels and lamps
Office equipment: faxes, printers, computer and copier housings, switchboards, walls and ceilings, and furniture

Therefore, whether it is thermoforming or injection molding, the one that suits you is the best!