Users are asking us frequently, why the wear lining of the processing bowls must be regularly renewed.
Thanks to their excellent abrasive characteristics the media are effectively grinding off material from the work piece surface. The hardness of the wear lining in the work bowl is precisely adapted to the respective application. Because of the intensive contact between the media and the wear lining, the latter must be replaced within certain time intervals… similar to the replacement of automobile tires, when they are worn.
But… Is it sufficient to just add another layer of polyurethane to the lining? What happens, if the mounting parts no longer fit? And what happens, if other equipment accessories are also worn? Since it has already been disassembled, does it not make sense to thoroughly inspect the complete processing bowl? During the mass finishing process the drive systems and mounting fixtures are exposed to significant mechanical loads… that’s the price for effective mass finishing.
The Trowal exchange program: A win for the environment
For the above reasons we offer an exchange program that includes the complete refurbishment of the processing bowl. This allows to keep the processing bowls in circulation without having to scrap them – a prime example for industrial sustainability.
The exchange program is not just limited to relining the inside of the processing bowl. It can also include a complete inspection of all components and if needed, repair welding of the steel construction and the replacement of worn out components with original Trowal spare parts. This reassures our customers that after the refurbishment their mass finishing machine works again as if it was brand-new.
A comprehensive inspection guarantees process safety and reliability
Each processing bowl received at our Haan facility undergoes a comprehensive inspection that not only covers the condition of the wear lining but also the structural integrity of the steel fabrication as well as all built-in components and, if requested by the customer, also the drive mechanism.
The refurbishment process starts with the thermal removal of the existing wear lining. Then the processing bowl is shot blasted, checked for cracks with a crack highlighting spray and, if required, repair-welded. For the welding operation we have developed special procedures that ensure that the work bowl is not warped. This is extremely important: The vibratory motors mounted to the work bowl generate a high amount of torque that must be absorbed by the steel fabrication. For this reason, the motors must be carefully mounted. Even tiny distortions of the mounting flange, induced by the heat of the welding operation, can cause a catastrophic failure of the vibratory motor mount.
Refurbished processing bowls – like new
A processing bowl will only receive a new wear lining after it has been confirmed that the steel construction is 100% OK. Before the refurbished processing bowl is dispatched to a customer, worn accessories and components are repaired or replaced with original Trowal spare parts. In a last step the entire machine undergoes a rigorous functional test to ensure that is running without any flaws.
The result: A processing bowl that is working as if it was brand-new. For this reason, after the exchange we provide a one year warranty for the complete processing bowl. The casting molds for all processing bowl types and sizes are in stock at our Haan location and, therefore, immediately available. This ensures short turnaround times for the processing bowls sent by our customers within the framework of our exchange program.
Wear rate indicator guarantees high uptime
Most mass finishing machines are firmly integrated into the manufacturing process and must always be operational. But how can you find out, when it is time for refurbishing the processing bowl? If the bowl is overhauled too early, the user is giving away valuable usable time. And sometimes it can be too late, because the work pieces and media destroy the processing bowl by “scratching” on the bare metal.
There is a simple solution: The integrated wear rate indicator, a feature that only Walther Trowal can offer. We are using a method that everybody knows from automobile tires. The wear lining contains polyurethane cones in a color that is significantly different from the color of the surrounding lining material.
Once these cones become visible, the user knows that a refurbishment will soon be necessary. The diameter of the now visible cones provides a good indication of the time frame, within which the bowl must be refurbished. This allows him to place a purchase order for an exchange bowl within a time period that keeps the equipment down time at a minimum.
We then deliver a refurbished processing bowl per the agreed upon schedule. Once the processing bowl has arrived at the customer site, the respective mass finishing machine will be up and running again within one or two working days.