Blog - Laser welding a flexible solution for welding plastics.
Most common welding techniques reduce the chosen solution to a single product. With laserwelding it is possible to weld different forms at the same time in the same machine without changing the machine or fixtures. With laserwelding it is possible for the machine to recognize the product and adjust the welding to the product.
Welding of plastics can be divided into two groups; with or without additives. Reasons for selecting a welding solution without additives are:
- Short cycle times
- High guaranteed reproducibility
- Easy automation
- No chemical additives for cradle to cradle products
In the past decennia different techniques have been developed to weld plastics without additives. Techniques like hot plate welding, ultrasonic welding, vibration and rotation welding zone all based on the principle that heat is being generated between the two parts of the product. The thermoplastic is heated up until melting point, mixed and cooled down. Laserwelding is based on the same principle. Heat is generated by using the difference in the trans luminance at a certain wavelength of the two parts to be welded.
With the exception of laserwelding all other techniques require mechanical contact between functional parts of the welding machine. Parts like hot plate, sonotrode with the use of ultrasonic welding or fixtures with the use of vibration or rotation welding.
The laser beam however is free positioned above the products and can be moved free. With 2- till 6-axis driven robotic systems the optic can make a large variation of forms, totally depending on the software.
The force needed for the weld of the two parts can be generated by the product itself or a separate clamping device. The positioning in the machine is guaranteed a fixed reference in the machine. When the welding installation has a recognition system for the supplied fixtures (like barcode) the product or fixtures can be made unique. The installation will recognize the product and will select the needed contour for the weld.
If it is possible to use laserwelding for the welding of products more product can be welded in the same machine and even in the same cycle without setting up the machine over and over again. With this laserwelding is a flexible solution.