The product shown here is a standard security seal laser marked with a unique barcode serial number. The item is used for sealing everything from mail bags to booze trollies on your holiday destination aircraft.
Plastics as a group of materials, change in a number of different ways when exposed to laser energy. While there are always exceptions to the rule most react in 1 of 3 ways. This includes those with receptive additives.
- A thermochemical foaming, creating gas bubbles to the surface of the material, is the most common. The light scatters across the affected area producing the light marking that appears.
- Bleaching is another effect that is common. Here, the pigment used to achieve the product colour is removed creating a visual difference.
- The third mechanism is vaporisation where the material is heated, very quickly, to the point where it vaporises and is removed leaving behind the created image.
These three laser marking effects, can be enhanced by the adding of laser sensitive additives and can generate considerable advantages. The additive acts as an abortion barrier, boosting the ability of the laser to process better. In some materials, the laser marking ability would not be possible without this additive. Being able to process, using additives can provide faster processing times, leading to a reduction of per unit costs. It is possible that the reduced per unit costs, compensates for the additive cost.
The addition of iriodine to the material master batch, allows for the very sharp image creation, very important for the formation of barcodes as seen here. In this application, the barcode and its human readable data were placed on the main body, while the end user name was placed onto the stem.
In normal production, this kind of product would come of the tool in multiple part strips. The laser process can be set up to deal with this format creating a simple step and repeat function while incrementing the serial number to match.
If you would like further information on this laser marking application, or any other application, please request a call back or talk to one of our laser marking specialists on 01737 826902