While clients may not fully understand the science behind contract sewing, they can undoubtedly appreciate a process that delivers them affordable, efficient, and durable goods. Soft goods welding has become synonymous with the success of the industrial sewing industry, and below, we will look at just why that is.
Welding, What is it?
When considering the word welding, metals, blowtorches, and sparks come to mind. But welding can apply to many different types of materials and applications of heat. Put simply, welding refers to the heating and melting of materials so that they form a harmonious and cohesive bond. In our industry, there are two types of welding that we often use to bond different fabrics and polymers together: radio-frequency welding (RF) and ultrasonic welding.
Radio-Frequency Welding (RF)
Similar to microwaving, radio frequency welding emits high-frequency waves that result in the heating and structure change of certain materials. These materials eventually melt and blend together. Once the waves stop and material particles cool down, they remain forever bonded. A radio frequency welder consists of a generator and a press. The generator is the machine that creates and emits the radio waves at an average frequency of 27.12 megahertz, while the press (or sealer) holds and compresses them into place.
Ultrasonic Welding
On a cold morning, you might take to quickly rubbing your hands together to generate a small amount of heat for yourself. Ultrasonic welding uses focused sound waves to create a similar type of friction, the frequency of which is around 20, 30, or 40 kilohertz. This rapid sound-friction is so fast and powerful that it not only heats materials but fuses them together. An ultrasonic welding machine uses a computer to control the specific pressures and temperatures. After pressure is applied, a sonotrode (or horn) directs the ultrasonic vibrations, which rapidly move less than a millimeter up-and-down or side-to-side, heating and bonding the materials together.
Why is it Critical?
Welding benefits the contract manufacturing industries that use it, as well as their clients:
Reduced maintenance costs
Welding requires less energy, lower temperatures, and literally, fewer hands than other forms of sealing. The manufacturer does not need to expend as much energy, making it a cheaper, faster, more precise, and safer option. The process occurs in fractions of a second as compared to one that might typically take a few seconds. The ultimate result is that it bonds polymers faster than most methods.
Increased safety
Workers are not exposed to flammable gases or harmful solvents.
Consistency
Manufacturers can calibrate welding machines to whatever materials it is bonding, creating a quick and consistent flow of products.
Leak-proof products
A massive benefit of radio-frequency and ultrasonic welding is that they produce leak-proof and impenetrable seals and seams. Such craftsmanship is critical for sporting goods, luggage, medical and military gear.