Why Medical Thermoforming Needs Value-Added Engineering

Profile Plastics thermoforms highly-engineered plastic parts with close tolerances and challenging cosmetic requirements. Through value-added engineering, our Lake Bluff, Illinois company has helped bring thermoforming to the medical industry. Traditionally, medical equipment designers were limited to plastic injection molding. Thermoforming has lower tooling costs, however, and it supports intricate tools along with multi-axis CNC machining for parts trimming.

As Steve Murrill, the former president of Profile Plastics, explained in an article for Design to Part (D2P) magazine, five-axis CNC machining enabled thermoformers to produce medical parts with a consistent fit and function. This was a major advance over the labor-intensive and imprecise hand trimming used years ago. Today, thermoformed parts compete with precision injected molded ones in a variety of medical applications.

Thermoforming for the medical industryOften, thermoforming is used to produce covers and enclosures for medical carts, machines, and equipment. Yet X-ray tables, diagnostic imaging technologies, CT scans, MRI machines, and other physically large pieces of equipment are also good candidates for thermoforming and its lower tooling costs. Keep reading to learn more and contact Profile Plastics if you’re ready to discuss your project or learn more about thermoforming’s many advantages.

Medical Carts and More

Reduced Costs, Increased Aesthetics: Plastic Thermoforming for Medical EquipmentThermoforming is ideal for medical carts and portable equipment, but the term “cart” doesn’t do these product designs justice. Typically, companies want their carts to look different than the competition’s. Carts can also come with onboard computers and sensors, and healthcare personnel may need a way to package and transport supplies. If a cart carries a blood analyzer, for example, a medical technician needs to be able to see and interact with this device.

Case Study: Medical Waste Management SystemProfile Plastics can help you to design medical carts and equipment with the functionality and aesthetics that you need – even if your design is complete. Our salespeople are sales engineers who understand that product design is an iterative process, and that you may only have a back-of-the-napkin sketch instead of an initial CAD file. It’s this combination of value-added engineering and heavy-gauge thermoforming that makes us the partner you’ve been looking for.

Medical Thermoforming Case Study

Multi-part enclosure for panoramic dental x-ray unit.

Multi-part enclosure for panoramic dental x-ray unit.

An original equipment manufacturer (OEM) needed nine mating and matching parts for a dental imaging unit. The OEM wanted aesthetically-pleasing parts with smooth, clean edges. Profile used pressure forming to produce the parts with a consistent color, texture, and gloss. Snap-fits ensured the unit was easy to assemble, and our engineers optimized the points of attachment in their efforts to help the medical OEM meet its production and marketing goals.

Instead of exposed fasteners, the dental imaging unit used hidden tabs. As each tab was assembled, that tab was hidden by the next tab in the assembly sequence. Profile’s ability to machine receiving inserts into the plastic parts also sped assembly and supported a more iterative approach than injection molding could provide. Because injection molding involves machining points of attachment into the tool instead, it’s more difficult and expensive to make changes for fit.

Multiple Machines and Processes

At our 100,000 square foot manufacturing facility, Profile Plastics operates more than a dozen thermoforming cells and a similar number of 5- and 6-axis CNC trimming cells. We also offer three different thermoforming processes: vacuum forming, pressure forming, and twin sheet forming. Each process has its advantages and applications, and Profile applies a creative problem-solving approach to all your medial projects.

Vacuum Forming vs. Pressure Forming

Vacuum forming is used for non-cosmetic parts and for very low volumes of parts that need the least expensive tooling. By contrast, pressure forming is used for parts with greater cosmetic requirements. Molding the sheet against the tool improves part aesthetics, but pressure forming tools are more expensive. Yet both types of forming tools are less expensive than injection molds, tools that use both sides of a machined metal mold to produce part features.

Twin Sheet Thermoforming

Like injection molding, twin sheet thermoforming is a two-sided process. Originally, users in the automotive industry called it “sheet blow molding” because this type of thermoforming uses two thermoplastic sheets and can produce the same types of parts as blow molding, which uses compressed air to inflate a molten plastic tube into the shape of a mold cavity. Blow molding is a low-cost process at high volumes, but only for polyethylene and only with sufficient part quantities.

Twin sheet thermoforming is ideal for medical projects with lower-volume requirements. It supports the use of thermoplastic sheets made of any type of resin, and thermoformers can use two sheets made of different materials, two different thickness of materials, or two different colors. Because this process creates a hollow space, there’s room for installing thermal or acoustic insulation or for running wires, such as with an air duct.

Miniaturization: Injection Molding vs. Thermoforming

As the computers in medical equipment became smaller, injection molding became more cost-effective. Years ago, when Profile thermoformed GE Medical’s first ultrasound machine, the unit stood 5 feet tall, 3 feet wide, and 3 feet deep. Today, this machine uses the same patient contact sensors and is about the size of a notebook.

People today are the same size and weight, however, so the X-Ray tables that patients use haven’t shrunk and remain a good choice for thermoforming. The same is true for diagnostic imaging technologies, CT scans, MRI machines, and other physically large pieces of equipment. There are limits to miniaturization, at least where patient contact is involved.

Thermoforming Keeps Evolving

twin sheet medical equipmentToday, thermoforming is mainly for cosmetics instead of structural applications. Structural thermoplastic composites are available, however, and twin sheet forming can create structural parts because of the hollow beam strengths involved. By contrast, pressure forming and vacuum forming produce only one-sided parts and, in that sense, are like die forming.

As plastic materials continue to improve, thermoformers can choose sheets that resist chemicals and high temperatures, and that won’t produce smoke and toxins when burned. Sheets like this are used in the aerospace and aviation industries, but they also have medical applications. Today, thermoformed medical carts are delivering advanced technologies to patients’ bedsides. Healthcare technicians want carts with conveniences, but thermoforming supports complexity.

From X-Ray Machines to Digital Diagnostics

Molded-In-Color GenDex Dental 3D imagingYears ago, dentists used film X-ray machines instead of digital diagnostic equipment. Because the patient’s orientation to the machine was different, so was the patient interface. With the advent of digital technology, Profile worked on a dental imaging project with 15 different parts. Moreover, because the machine was designed for use in a dentist’s office or hospital, these thermoformed parts had high cosmetic requirements.

For this project, the customer also needed a plastic material that could resist the kinds of chemicals that are commonly found in medical environments. Injection molding and thermoforming were both options, but the project’s production volumes were low. Thermoforming enabled the medical OEM to save on tooling while getting multiple pieces that combined chemical resistance with an attractive appearance.

Faster Parts, Longer Lives

Children's Hospital Medical Device Molded-in color Twin Sheet ThermoformingWith multi-part projects like medical equipment, customers usually leave the covers until the end. That can be a problem when there’s a deadline such as a tradeshow preview or a formal product launch. Pressure forming lets a thermoformer produce and paint an initial batch of parts with speed. By texturing the tools that are used in pressure forming, customers can also save time and money with both molded-in colors and molded-in textures.

Like industrial machinery, medical equipment tends to outlive consumer products. In part, that’s because many consumer products are meant to last longer than just a few years. In the medical industry, it’s not uncommon to find equipment that’s 20 years old. In terms of sales volumes and applications, some of these medical products are as robust as they were five or ten years ago.

The Profile Advantage

Profile Plastics specializes in thermoforming highly-engineered plastic parts with close tolerances and challenging cosmetic requirements. With our value-added engineering, we can help you to get your products to market faster and while meeting multiple requirements, including ease of assembly. How can we help you with your next project?

To get started, contact Profile Plastics