Everyday Objects that Wouldn’t Exist Without Plastic Welding

Welding is a technique that has been used for thousands of years to bond metals together. From the ancient Egyptians and Mesopotamians to Henry Ford and the rise of automobiles, welding has helped to shape the world’s history. But with more and more manufacturing processes relying on thermoplastics instead of heavy metals, new machinery has had to adapt for plastic welding.
What is plastic welding? Similar to traditional welding, plastic welding is the process by which two plastic workpieces are joined by creating a molecular bond. There are a number of methods that are utilized for welding plastics, including spin welding, ultrasonic welding, hot plate welding, and laser welding. Each of these methods use their own equipment, but they all rely on the same basic processes of applying pressure, heating, and cooling. Pressure holds the workpieces in place and compresses them to allow for quicker bonding. It is necessary to heat plastics to the point where a nearly melted layer forms across the adjoining surfaces. This allows the molecules from each workpiece to diffuse and bond with each other, creating a chemical bond. Finally, during the cooling phase, the newly formed bond solidifies into one piece for a finished weld. The strength of the weld depends on a number of factors, including the types of plastics, joint design, the amount of heat and pressure applied, and the rate of cooling.
What are some objects that wouldn’t exist without plastic welding? The list includes everything from kitchen utensils and medical supplies to automobile parts and military equipment. Smart key fobs for newer cars use a transponder chip to start the engine. This chip is bonded to the plastic top of the key using ultrasonic welding. Because ultrasonic welds can create airtight seals without producing contaminants, they are extremely popular in building sterile medical equipment. IV filters and tubes, breathing aides, dialysis tubes, catheters, and even hospital gowns and masks are all constructed using ultrasonic welding. Juice boxes, milk containers, and a lot of food packaging are also hermetically sealed with ultrasonic welds to produce a stronger closure than glue could provide. This helps to prevent air contamination and keep food fresh.
In fact, the computer or tablet you’re holding right now likely underwent plastic welding at some point in its manufacturing. Apple has changed the design of some of its devices to allow for stronger bonding between internal plastic components and the exterior metallic shell. These designs include surface irregularities that better allow for the flow of melted plastics, which can then be joined using ultrasonic welders. The goal is for these stronger bonds to improve the durability of technological devices.
Whether you’re looking to begin plastic welding for home improvement projects or you need to repair broken plastics, learning plastic welding techniques can have long-term benefits. If you are a welding beginner who wants to improve your skills before investing in higher-priced equipment, consider pre-owned ultrasonic welders or used ultrasonic welders. This equipment will allow you to get comfortable with the process as you hone your skills and move on to bigger and better projects.