Patents for laser welding of plastics II

The development of laser welding of plastics represents a fascinating chapter in the history of materials processing. Although the patent application filed by Mobil Oil Corporation in 1964 can be regarded as an example of early considerations in this field, older patents prove that the use of radiation for joining plastics had already been initiated before then. A particularly noteworthy example in this context is German patent specification DE 863 257, which was filed in 1953 by Nürnberger Schraubenfabrik und Elektrowerk GmbH.

In this patent specification, the inventors secure the exclusive right to a process developed specifically for welding thermoplastic materials. What is striking here is that the heat required to process the materials is generated by a radiation source that is focused by means of lenses and concave mirrors. This demonstrates an early understanding of the importance of optical technologies in materials processing and opens up a discussion about potential that may not have been fully exploited at the time.

The subclaims of this patent specification are also particularly interesting. They mention through transmission welding, an innovative technique in which radiation is passed directly through the material and absorbed at another point. In addition, the patent specification discusses the possibility of creating absorbent areas by coloring or using absorbent interlayers. These aspects illustrate the advanced thinking of the inventors at the time. Had laser technologies already existed in the early 1950s, it can be assumed that the inventors would also have integrated this groundbreaking technology into their process. The idea of how the knowledge of that time could be combined with today’s technologies gives rise to an exciting look at the development history of laser welding. The progress that has been made since then is not only proof of technological innovation, but also of the constant search for efficient and effective solutions in the processing of modern materials.