The customer’s challenge

The customer needed to weld very long components made from polyolefins such as PP and PE. High-frequency (HF) welding was unsuitable for this application, so the process required impulse welding.

For linear impulse welds, Zemat would normally consider a machine from the PULSA range. This project, however, had an additional constraint: the products were very long, and the application did not suit a conventional impulse welder with a fixed working length.

The customer needed a workstation that would:

• weld very long sections of material,
• use impulse welding instead of HF welding,
• produce consistent, repeatable welds over long distances,
• allow the material to be laid out on a long worktable,
• make different types of welds without requiring separate workstations,
• retain HF welding capability for other materials.

The technical challenge

With very long components, making the weld is only part of the challenge. Handling and positioning the material matter just as much. On conventional impulse welders, the machine design and the length of the welding electrode limit the weld length. Producing large components can therefore involve extra steps: moving the material, dividing the process into sections or repositioning the product.

That approach would have been impractical here. Long material is harder to control when it must be moved repeatedly. It also increases the risk of misalignment, uneven feeding and adjustments between successive operations.

The customer therefore wanted the opposite arrangement: the material would remain laid out on the table while the welding head travelled along the product. This would make handling easier for the operator and give them better control over the process.

Zemat’s solution

Zemat proposed a TARPA PRO with a travelling welding head. This design is well suited to long products because the workstation’s working length depends primarily on the length of the table, rather than on a fixed machine frame.

In practice, the worktable can be several dozen metres long. For specific applications, it can reach approximately 100 metres. The head travels along the table and makes the weld without the entire component having to be moved.

For this project, TARPA PRO was equipped with an impulse welding electrode with additional cooling. This allows the machine to make long linear welds in materials that are unsuitable for HF welding.

The workstation also needed to be flexible. The operator can change electrodes to suit the task:

• a linear electrode makes long welds along the material,
• a narrower electrode makes transverse welds,
• after an electrode change, the machine can still operate using HF technology.

The customer received more than a dedicated machine for a single operation. The workstation combines impulse welding with the ability to continue using HF welding when needed.

Why TARPA PRO?

TARPA PRO was selected for its travelling welding head. With very long products, moving the head is more practical than moving the entire material. It reduces the handling of large components and helps make better use of the available production space.

The impulse electrode extended the machine’s capabilities. The customer can weld materials that require an impulse process while retaining HF welding for applications where it remains the right choice.

This matters when production involves more than one material or type of weld. One machine can handle several production scenarios.

The result

With the modified TARPA PRO, the customer gained a workstation tailored to the production of very long components. The machine makes long linear welds using impulse technology, can produce transverse welds with a narrower electrode and retains its HF welding capability.

The main results of the project are:

• very long products can be welded at one workstation,
• the material remains laid out on the table instead of being moved repeatedly,
• impulse technology allows the customer to work with materials unsuitable for HF welding,
• the travelling head helps the operator make welds over long distances,
• interchangeable electrodes allow both linear and transverse welds,
• additional cooling supports stable operation of the impulse electrode,
• the machine retains its HF welding capability,
• one workstation handles different materials and applications.

Summary

This project shows how impulse welding can be combined with a machine designed to work along a very long table. Zemat used TARPA PRO with a travelling head and equipped it with a cooled impulse electrode to meet the customer’s requirements.

The customer can now make very long welds without moving the entire product. They also retain the option of HF welding when another material or application calls for it.

TARPA PRO with an impulse electrode is suited to applications where weld length, control over material positioning and process flexibility matter, particularly in the production of large technical components.