Over the last 30 years, the advent of plastic as the material of choice for consumer goods has caused a seismic shift in the manufacturing process of goods and parts that were historically made from other materials.
Glass and steel have been replaced by plastic in so many areas of our everyday life, including automotive interiors and exteriors, electronics, household goods, lawn and garden items, containers, and medical components.
As a consequence textures and grains on plastic products are becoming more important. The physical appearance of plastic items when treated and enhanced makes them more aesthetically pleasing and can improve quality perceptions too.
OEMs in many industries understand this and are demanding higher quality and variety in terms of the surfaces their suppliers provide. Because of this, mould makers are seeking new methods of improving the level of quality and variety in surface texturing of blow moulds and injection moulds.
Traditionally, mould makers have used what is referred to as chemical etching to surface moulds to achieve the desired effect.
This process involves submersing the mould surface in a chemical mixture that will eat away the surface in the areas not covered by a protective coating, producing a pattern or grain on the mould surface.
Chemical etching is by no means an exact science and there is no way of predicting the exact appearance of a product until it is moulded. This can make it a costly exercise if mistakes are made, or the pattern created is not up to scratch.
Furthermore the toxic and corrosive chemicals used in this process have a negative impact on the environment and are extremely harmful to the people exposed to them. Government regulations for the handling and disposal of these chemicals are becoming more onerous and expensive, and these costs usually end up being passed onto the customer.
Laser ablation technology, on the other hand, has virtually no impact on the environment and takes the black art out of texturing moulds.
A specific strength of the technology is that the customer knows exactly what the product will look like before the laser applies the texture because it can be simulated on a computer screen. These results can be repeated exactly and precisely over and over again - irrespective of where the parts are ultimately made.
The fact that textures can be produced directly from digital files ensures high repeatability.
Laser Ablation involves turning a solid material into vapour. Most metals can be turned into vapour using laser technology, where the focused energy in a laser beam is absorbed by the surface of a metal. This energy is converted into heat that increases the surface temperature to the point of vaporisation. Fibre lasers are an ideal heat source because they can be controlled for varying energy levels by a variety of lenses with different focal lengths.
Laser ablation is a highly automated process. Other than programming, the laser does the rest, resulting in lower labour costs. The turnaround times for chemical etching and laser ablation are roughly the same because the ablation process can take time to complete the texture application.
However, this is more than offset by lower labour costs and increased quality and repeatability, and the detail that five-axis laser technology can achieve (for example) is virtually limitless.
Laser Ablation technology can achieve up to 50 different layers of texture on a surface to micron accuracy.
Virtually any texture, grain or pattern, organic or non-organic, can be copied into the software and replicated on the mould surface.
The only limitations are the limitations of the moulding process.