in Vol. 20 - September Issue - Year 2019
Continuous Processing Of Parts That Must Be Glued Together
The fully automatic de-oiling/washing and mass finishing system is directly linked to the punch press and allows for continuous feed operation. The only manual operation is the replacement of the full transport bins every few hours.
By the perfectly tuned de-oiling and mass finishing operation the brake pad carrier plates receive the perfect surface finish for the subsequent bonding process
International market leader Rösler Oberflächentechnik GmbH offers total solutions in the field of mass finishing and shot blasting, painting & preservation systems and mass finishing consumables. In addition, Rösler offers a broad spectrum of surface finishing technologies (deburring, descaling, desanding, polishing, surface grinding,…) for work pieces made from metal and other materials. Headquartered in Germany with plants in Untermerzbach/Memmelsdorf and Bad Staffelstein/Hausen, the Rösler group also maintains sales and manufacturing branches in Great Britain, France, Italy, the Netherlands, Belgium, Austria, Serbia, Switzerland, Spain, Romania, Russia, Brazil, India, China and the United States.
LUMAG, a well-known Polish brake pad manufacturer, presented Rösler with the challenge of finishing a surface in order to maximize its adhesion characteristics for a subsequent bonding stage. Rösler offered a solution for de-oiling and surface finishing of brake pad carrier plates directly linked to a punch press.
LUMAG Sp. z o.o., founded by Mr. Marek Zak in 1988, is specialized in the production of brake pads for drum and disk brakes for commercial vehicles. For the latter, the company, located in Budzyń, Poland, developed its own manufacturing technology resulting in significant quality improvements. In addition, LUMAG develops, produces and sells brake pads for passenger cars and motorbikes under the trade name Breck.
De-oiling, deburring and surface roughening
As a result of changing the production method for the brake pad carrier plates from casting to stamping, LUMAG decided to install a new in-house manufacturing line for these products. This included a solution for de-oiling, deburring and surface roughening of the stamped carrier plates with lengths of 210-250 mm and widths between 90-110 mm. It should be noted that the components have a slit or drilled hole for placing a sensor, which monitors the wear of the brake pad. These steps were intended to ensure that the delicate stampings provide optimum adhesion characteristics for the following bonding of the brake pads. Another requirement presented by the customer was to directly link the finishing equipment with the punch press, maintain extremely gentle processing and complete automation of the cleaning (de-oiling) and mass finishing stages in continuous feed operation. LUMAG decided to partner with Rösler for this important project, because Rösler not only enjoys an excellent reputation in the industry, but was also able to supply the equipment for both processes including the finishing media and compounds from one single source.
Intelligent media selection allows cleaning without the need for drying
After the stamping process, a conveyor belt transfers the work pieces to the drum washing machine equipped with an internal transport auger. In the drum, the carrier plates are initially passed through an un-perforated zone into which cleaning liquid is injected by flat spray nozzles. This creates an immersion bath for de-oiling. In the following perforated drum section, the cleaning liquid is drained, and in a secondary de-oiling step, the work pieces are spray-washed. This cleaning zone is followed by a drip-off section, a rinse station, and another drip-off section. Subsequently, a conveyor belt transfers the work pieces into the mass finishing machine.
Replenishment of the cleaning liquid takes place with a Dosatron proportional dosing pump. Since the cleaning liquid and the compound for the mass finishing process have practically the same chemical characteristics – including the placement of a temporary corrosion protection – carryover of the cleaning liquid into the mass finishing machine presents no issue. This clever trick eliminated the need for a drying stage after the cleaning process, resulting not only in significant savings in the overall capital expenditure but also in reduction of operational costs. For proper maintenance of the cleaning liquid the washing machine is equipped with filtration units and an oil separator.
Gentle mass finishing process
Deburring and surface roughening of the work pieces takes place in a linear, continuous flow vibrator R 550/6600 DA with a specially adapted work piece loading system. Loading actually takes place at the rear end of the processing bowl instead of on the lateral bowl side with greatly reduced dropping heights. An equally gentle work piece transfer process was incorporated in the vibratory screening unit and the dryer filled with Supervelate drying media. After drying a certain work piece quantity, which is precisely measured by weight, the work pieces are discharged into a transport bin. The process water from the mass finishing machine is continuously cleaned in a fully automatic peeling centrifuge Z 1000 equipped with automatic sludge discharge.