bielomatik Leuze GmbH & Co.KG

Compact Lasers Economical for Prototypes and Series Production

Laser welding of sensitive parts

Laser welding systems can be modularly configured for various applications.

The K3632 compact laser system (surface area: 800mm x 1200mm) with standard laser integration module from bielomatik is designed for welding small parts, in particular for the fields of medical and laboratory technology, biochemistry, bioanalysis, electronics and electrotechnology, among others. It offers high productivity with minimum space requirements. Through its modular design and flexible equipment, it can be used universally. Either diode lasers or diode-pumped fibre lasers can be used as laser sources. Various image fields and laser spot sizes can be achieved by adjusting the optical machine components based on the requirements from the application. For example, a large image field permits welding several parts, each with a small contour to be scanned.

The laser compact system can be loaded and unloaded manually, semiautomatically by means of rotary indexing tables, or in a completely automated manner through belt feed systems. And so it is suitable both for individual parts, prototypes and small series in the laboratory as well as for medium- and large-scale series in production. As no friction arises in laser welding, it is preferred when the highest degree of cleanliness and lack of particles is important.

Laser welding also has enormous advantages if vibrations need to be avoided. This applies to small and very small housings in medicine and electrotechnology as well as housings with a fine channel structure for microfluidics. Lasers are also ideally suited for thermally sensitive materials and components. The reason for this is a focused laser spot that applies the heat in a very targeted way only in a small area of the components to be welded.

Classic “light-dark connections” can be welded without difficulty, such as dark housings with transparent coverings.
To achieve sufficient absorption by the parts, the plastic is frequently compounded with an additive, such as talc, chalk, soot or glass fibres. Alternatively, sufficient absorption can be achieved by colouring the selected plastic. The application technicians at bielomatik will advise you competently and informatively on the selection of suitable pigments.

Moreover, transparent bonded parts, which cannot be welded using conventional laser beam sources with smaller wavelengths (λ ≈ 980 to 1070nm), can be welded with suitable laser sources that generate light with a wavelength of around 1940nm. In the larger wavelength range, typical technical plastics absorb sufficient light to apply the required energy.

An additional application area of laser welding is the joining of low-viscosity materials and foils that require high temperatures for melting. The laser spot concentrated on a small area achieves a sufficiently high energy density to reach the temperatures required for a reliable weld connection.

One Company - All Technologies …

… is the trade fair motto of bielomatik. The Neuffen-based machine builder has mastered the widest array of welding processes and so can offer optimal solutions for almost all technically used plastics. In scientific projects and its own R&D, bielomatik develops solutions and concepts for the high-performance plastics which are penetrating the “welding market” more and more, including fibre-reinforced lightweight construction materials (organic sheets) and high-temperature plastics (PPA, PPS, etc.). The spectrum includes contact heating elements, contact-free infrared heaters with short and medium wavelengths, low- and high-frequency vibration welding systems, hot gas, heat contact and high-frequency processes. Ultrasonic applications can also be designed and integrated into special applications. With their comprehensive know-how from several decades of experience, the Neuffen-based experts will advise you individually and competently, select the appropriate procedure and create an optimal configuration. And so production operations, from compact laser-integration modules to comprehensive automated systems for large parts with several combined welding processes, obtain joining technology that is carefully adapted to their needs.

Picture: Small plastic parts which are sensitive to vibrations and strong heat application, such as those used in medical technology, bionalysis, electronics and electrotechnology, can be welded especially well with lasers