The Process of Thermoforming Plastics
Thermoforming is, at its core, the process of taking a sheet of plastic material, heating it up until its pliable, and forming it to a three-dimensional shape, then trimming and finishing it into a usable product. Here’s how the process works.
Every thermoforming project starts out with a design. Usually, thermoformed plastic is used as a part of a larger product. Often (though certainly not always), it’s the outer protective and aesthetic covering for a piece of equipment. Whatever it’s being used for, most thermoformed plastic products start out as a CAD model or drawing. Often, when our customers come to us with a CAD file, our engineers work with the customer to refine the model into a shape that will work well with our plastics manufacturing process.
After the final designs are ready, we work with our customers to select the right plastic material for their project. ABS plastic is the most widely used plastic material for thermoforming machining, but there are quite a few other options that can be selected for either aesthetic or functional reasons, including fire-rated and high heat materials. Every plastic material has unique physical properties and benefits, and thermoforming also allows for a selection of colored and textured materials that can greatly enhance the appearance of the final product.
The next step in the thermoforming machining process is the creation of the mold that the plastic will be heated to, commonly called tooling. Our thermoforming plastic process uses aluminum molds. Depending on the size and complexity of the materials being used in the project, it’s often possible to combine several individual parts into a single mold, reducing tooling costs, material costs and production times. Our large scale thermoforming machine makes this a compelling option for many Ray Products customers.
Once the materials are selected and the tooling has been created, the next step is to actually form the plastic to the mold. This is done by first heating the plastic sheet to a pliable temperature, then shaping it to the mold using vacuum pressure, air pressure or a combination of both. Once the material has been formed to the mold, it’s cooled and removed from the mold, retaining its final shape. Since the final project cools against the mold surface under ambient temperatures, finished parts have zero residual stress.
Once a piece of plastic is thermoformed, there’s still some of the original material that needs to be trimmed away. At Ray Products, we use fully robotic 5 and 6-axis trimmers that can quickly cut complex and precise shapes, resulting in faster production times and more accurate and flexible cuts. At Ray Products, our robots also perform secondary operations such as cutouts, through holes and other features that require the removal of material.
After a custom plastic piece has been thermoformed and trimmed, that’s still not always the end of the story. At Ray Products, we offer many secondary operations in-house, including painting, silk-screening, EMI/RFI shielding, the installation of inserts and other fastening devices and the assembly of hinges, handles, and other hardware. Combined with our proven supply chain management, these services let us work as a single-source partner for many of our customers so that when they receive the completed part from Ray Products, it’s fully ready to integrate with the rest of their manufacturing process.