As engineered products are always pushing the limits of performance, tire molds perform a crucial role in the integration of complex tread architectures into tires. This helps to improve tires’ water displacement rates, as well as their durability and grip.
Three crucial components which contribute to the overall quality of the tire are the materials used, its tread design, and the surface of the mold itself. The latter is liable to become contaminated and foul as a result of repeated curing.
What Are Tyre Moulders Doing About It?
Based in Wem in Shropshire, Kingpin Tyres is a family-run tire remolder. It is a forerunner business in its industry, and has begun to investigate laser solutions for cleaning tire remolds.
In order to guarantee that they deliver re-molds of the highest possible quality, and consequently the best performance tires for their clients, Kingpin Tyres has a vested interest in cutting-edge technology.
Kingpin and ANDRITZ Powerlase engaged in a collaborative feasibility project in order to achieve this. The focus of the study was to measure how suitable high average power nanosecond pulse lasers were for cleaning mold surfaces to a condition which was ‘ready-for-use'. They did so by the selective removal of curing residue.
According to the investigation’s results, the custom optics developed by ANDRTIZ Powerlase enabled mold fouling by-products to be removed in less than 30 seconds per mold segment. This was achieved without altering the metal substrate of the mold. The Vulcan 1600e and Vulcan 500c laser systems were both successfully tested with the custom optics installed in the handheld Vulcan tool.
Tyre Moulds Courtesy of Kingpin Tyres
Conventional Cleaning and the Need for Change
When excessive contaminants are present on a mold’s surface, such that the curing process is liable to be altered, this is called ‘mold fouling’. This process can lead to the denaturing of the final tire surface, which can compromise performance.
Moreover, this contamination undermines release agents’ effectiveness. This worsens the fouling on the mold, increasingly degrading successively molded tires which can lead to them being scrapped.
Tire molds are cleaned at regular intervals in order to avoid wasting resources by ensuring they are able to continue to be used. Yet, most traditional cleaning techniques occur off-line, and require the removal and cooling of tire molds prior to the clean taking place.
When the clean occurs, methods such as polymer media blasting or shot blasting are used. These factors curb productivity, lead to an opportunity-cost regarding the volume of tires made, and lead to prolonged period of down time.
Furthermore, the integrity of the tire mold surface may be at risk when using blasting processes, as an abrasive shot is often required to completely remove tough residue when using softer media. Additionally, media or shot blasting produces a large volume of non-recyclable waste material, which gives this method a negative environmental footprint.
Consequently, manufacturers have been searching for alternative methods which are able to clean surfaces faster while reducing the amount of waste material that is produced.
For on-line cleaning, methods like dry-ice cleaning can be effective. This is when molds are still hot, but rapidly fall short when an attempt is made to remove cold residue – the contamination which builds up on molds after successive processes, which has been removed from the production line and left to cool.
It is laser cleaning technologies, however, which have been able to provide for the quick removal of contaminants of all grades of hot and cold residue, while minimizing waste production and consequently getting rid of the disposal stage altogether.
Damage to the metallic substrate is prevented by the custom optics fitted in the Vulcan systems, as they maintain laser process parameters far below the damage threshold for the mold. Laser cleaning solutions consequently offer an environmentally conscious and attractive alternative to conventional polymer and shot media blasting.
This information has been sourced, reviewed and adapted from materials provided by Andritz Powerlase Limited.
For more information on this source, please visit Andritz Powerlase Limited.