High frequency welding machines produce electromagnetic emission during work. To ensure worker’s safety, each HF welder should have special protection against such exposure. Standard, open-design linear HF welding machines are protected against electromagnetic emission with a special grounding foot, which is usually located behind the welding electrode or a die. During the welding process the grounding foot is pressed down onto a worktable. The grounding foot closes the circuit between the welding electrode and the worktable – encasing the HF emission. It is a necessary element, ensuring full safety.
There are some disadvantages of using this feature. To complete the loop and to prevent emission from escaping, the ground foot must lay very flat on the worktable. There are limitations in the amount and the type of fabrics and materials that can be placed under the grounding foot for proper grounding operation. It means that a limited number of fabric layers which can be placed under the foot can be used during the production process. Also the joined fabrics must always be flat on the table, with no wrinkles or folds. It is not possible to weld products that already have attached eyelets, valves or spatial profiles, which could be interfering with the position of the grounding foot.
Improperly set grounding foot creates an unnecessary HF emission danger to the operator and does not allow to obtain the right parameters needed for proper HF welding process.
Zemat Technology Group developed an innovative FreeWeld™ system, which allows to eliminate the use of the ground foot during the HF weld process with the use of a special, patented, HF welding electrode. This special electrode can be used in all linear HF welders manufactured by Zemat Technology Group.
After insfixing the FreeWeld™ electrode on the machine, it’s automatically recognized by the PLC, the grounding foot stays in the upward position, and the HF welding process can begin.
The machine is secure and safe for the operator, there is no escaping electro-magnetic emission and this solution is even safer than this with the traditional grounding foot
A perfect weld can be made and the only visible difference is the look of the welding line. Instead of one, there are two parallel lines. But this is an additional advantage for HF welding process. The outflow of melted polymer remains inside between these lines. The weld is much stronger, smoother and more aesthetic.
The FreeWeld™ system is only available with Zemat HF welding machines.