Why CNC Machining Is a Necessary Step in Thermoforming

Whether you need a run of 50 custom plastic parts or 50,000, each part must be accurate to the prototype and consistent from one part to the next. While proper molding techniques are necessary, the finishing steps are just as important to meet our clients' needs. That's why we rely on CNC trimming and machining to ensure precision. Learn more about this practice, what it is, and the challenges that come from alternatives.

What Is CNC Trimming?

CNC stands for "computer numerical control," thus CNC machines move and operate in accordance with programmed software and are equipped with grinders, lathes, and cutting tools in order to make cuts, create angles, and shape materials to create different parts and components.

More specifically, we are able to use the 3D models and computer-aided designs used to form the prototype as the basis for how to code the CNC trimming machine, ensuring the measurements, angles, and part details are precise and accurate. Once the data is programmed, the equipment will cut and separate pieces, create windows, or trim angles to meet the design specifications.

Why Is CNC Trimming Used for Thermoformed Plastics?

Thermoforming involves taking a large sheet of plastic, heating it to where it is soft and flexible, and fitting it over a custom mold. Vacuums and air pressure draw the plastic tightly to the shape to get the most accurate fit. Once the plastic is shaped, it needs to be finished into the necessary product. Often, this involves cutting away excess, cutting out holes and spaces, deburring the plastic sheets, or, if multiple shapes are pressed into one piece of plastic, they need to be separated.

CNC trimming is the ideal solution for both large cuts as well as adding intricate, precise details. Not only is it incredibly accurate, but it's also versatile and repeatable. We use five-axis trimming equipment that offers multi-dimensional rotation and allows us to get within approximately 0.12 mm accuracy to the design. Because most thermoformed plastics are one component of something else and need to fit or join with other components or pieces, this level of accuracy is necessary to the success of the finished product and overall project.

Alternatives to CNC Trimming

Not every thermoforming company relies on CNC robotic trimming to finish their plastic components. Laser cutting and die-cutting are also used to trim or make cutouts in plastic components. However, there are concerns with both of these methods.

  • Laser cutting is more commonly used in metal cutting, but it can be used with plastics. However, the main drawback is the cost of equipment which is significantly more than CNC equipment. These costs pass through to the customer, increasing per-unit prices without increasing or improving the final product.
  • Die-cutting involves creating a die in the necessary shape and using the shape to make cuts into plastic. In a way, it's similar to using a cookie cutter. While this is effective for thin plastics, it doesn't offer the same precision, nor does it trim away any excess.

Get a Quote for Custom Plastic Thermoforming

Advanced Plastiform, Inc. is a leading thermoforming company in North Carolina. We take pride in manufacturing durable, high-quality plastics with a low per-unit price and rapid lead time for a wide range of industries. To learn more about our services or get a free quote on custom plastics, reach out to us today by giving us a call  919-404-2080 or filling out our form . . We serve the Southeast and Mid-Atlantic states, including North Carolina, South CarolinaTennesseePennsylvaniaMarylandGeorgia, and Virginia.

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