Laser welding technology has application potential in the packaging industry

The United States Blackfoss Laser Technology recently announced a new plastic welding technology, which is believed to have great potential in the packaging industry.

Laser welding is based on the fact that joints that exceed the strength of the connected base material can be achieved by the process of emitting a high-energy laser beam to the connected base material, the parent material absorbing, melting, and fusing together. The traditional laser welding technology relies on optical fiber to transmit the laser. As a result, the width of the weld seam is only about 1 mm. This limitation makes laser welding of large components or geometrically complex plastic components a time-consuming and difficult process.

However, the bifocal high-energy laser system developed by Blackfoss has a width of up to 20mm for the welded joints, enabling the welding of large-size thermoplastic materials. This technology has been successfully applied to the welding of polypropylene, polycarbonate and film materials. According to the company, this technology can also be used to weld between plastics of different materials, such as between foam and plastic film, and between plastic molds.

The introduction of this technology is undoubtedly a good news for the packaging industry, one of the big players in plastics. Plastics have been used as packaging materials for a long time, but in order to ensure their connectivity and tightness, chemical adhesive bonding and thermoplastic compression bonding are mainly used. The main problem is the waste of materials, and the reliability of connection and sealing is poor. . In food, chemical and other packaging, the advantages of using welding technology are very obvious. In addition to the wider weld seam, the welding does not directly touch the plastic. This is ensured by a non-contact system so that there will be no product contamination. There is no need to add binders or fluxes. When using a polyolefin-based plastic with a lower surface energy, it is not necessary to add auxiliary materials or the parent metal to be preheated. Direct welding can be used to obtain a joint with better sealing properties.

Another advantage is that the bipolar laser system is highly controllable and energy is stable, so the quality of welded joints is good and has high reliability. Ultra-fine welding of extremely thin materials is possible. Bipolar laser systems do not limit the size and geometry of the welded components.

Experts predict that this technology has at least the following potential applications in the packaging industry:

The first is the packaging of products that require higher sealing requirements. Including milk powder, salt and other food and crystal chemical agents and chemical products such as sealed packaging. This type of product is relatively easy to deliquescence, and its packaging must not only consider the sealing property, but also prevent the contaminants from being introduced into the sealing process. The contactless nature of the bipolar laser welding of plastic bags can meet this requirement.

The second is the replacement of plastic containers with iron or paper containers. In a high humidity environment, the paper package is susceptible to moisture deformation, and the shock resistance performance is deteriorated. The use of plastic plates for welding into containers with lids can obviously overcome these unfavorable factors. In high salt, highly corrosive gas environments, iron or aluminum containers can rust and corrode, and they also provide a place for plastic containers. Because the process of laser welding plastic containers is simple, the cost is not high, and the reusability is good. Therefore, replacing paper or iron containers, large-scale entry into daily life can be expected. And use of bipolar laser welding technology, the production of plastic shaped containers or shaped brackets. Applications include various glass, crystal, and ceramic handicrafts and precision instruments that are fragile or shock-resistant. This kind of product mainly relies on the foam plastic and the wooden bracket to shockproof. The former uses more materials and needs a single mold. The latter has somewhat less impact resistance. The use of bipolar laser welding technology to produce these shaped brackets overcomes these deficiencies. The cost is not high, the effect is good, and flexibility is strong. This is the application of the advantages of bipolar laser welding technology.