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Tire retreading leads to an increase in efficiency

Andreas Bauer's picture

The investment in modern machines led to a considerable increase in material efficiency. The quality of products also increased, helping make the small business more competitive and more attractive to potential new clients. The improvements in Hofdmann Tire Centre were very concrete: new employees were hired and new machines are being acquired.

Project background
The Hofdmann company was founded in 1984 as a tire workshop with a small car dealership. Since 1988, the company also does tire retreading. In 1998, Reiner Hofdmann took over the company and, in 2005, he started researching and developing tire retreading for agricultural tires. During this time, that department grew from 13 to 26 employees. The main business is still tire retreading, tire changes, car reparation and the reparation and replacement of conveyor belts. Hofdmann Tire Centre currently has 47 employees.

The problem
Tire retreading is a process that makes old tires that lack tread usable again. The process is similar to changing the sole of a shoe. The first step is to test the usability of the old tire. It is essential to determine whether the carcass can still be used. The carcass is the skeleton of the tire, on which the new treading will be applied. In order to do this, the old treading must be removed. Afterwards, damaged areas are polished, a rubber solution is applied as an adhesion agent and improved with extrusion rubber. Finally, the new treading is custom-made and applied with a binding rubber. The last step is to place the tires in a vacuum, warm them and vulcanize them. Errors in remolding can happen when nail holes in the wire mesh went undetected or when the contact surface between wire mesh and the rubber of the carcass or between the rubber of the carcass and the rubber of the treading are not fully connected. This leads to complaints or defective products and is also a concrete safety risk.

Material cost-saving measures
Wolfgang Wrobel, a consultant authorized by the German efficiency agency (demea), analysed and observed the work process in collaboration with employees and management. He identified sources of loss and suggested measures for improvement in a potential analysis. It was decided that old tires would be controlled with a nail hole detector in addition to the usual light beam control. The machine detects reliably nail holes in the wire mesh and helps better select damaged tires. This improved the quality of the tires and the material efficiency of the tire treading process.
In the future, a “Shearography” process will be used to detect irregularities in order to have a seamless connection of the rubber layers within the tire and to recognize interface errors. Shearography is an optical measuring process based on a laser technique which is used to measure heterogeneity in material. With the integration of these two testing procedures, the characteristics of the tires can be improved and the complaints declined.
These measures significantly increased the material efficiency. Concretely, the annual savings consist of 12,000kg of old tires, 14,200 of tread and 700 kg of binding rubber and extrusion rubber. These savings amount to a monetary value of 70,000 EUR every year. According to consultant Wolfgang Wrobel: “The two machines are obviously a big initial investment, but the cost is amortised in a few years. In addition, we organised the warehouse more efficiently, we optimised the walkways and trained the employees. This means that we not only improved the material efficiency of the company, but also increase the general quality of the work and the products.”

Summary
The investment in modern machines led to a considerable increase in material efficiency. The quality of products also increased, helping make the small business more competitive and more attractive to potential new clients. The improvements in Hofdmann Tire Centre were very concrete: new employees were hired and new machines are being acquired.

Contact in company:
Reiner Hofdmann
Reifencenter Hofdmann GmbH
Aselerstraße 8
26409 Wittmund
Telefon: +49 4462 9494-01
Fax: +49 4462 1722
E-Mail: info@hofdmann.de
Internet: www.hofdmann.de

Contact:

PIUS-Internet-Portal2
c/o Effizienz-Agentur NRW
Henning H. Sittel
Tel. 0203 378 79 51
E-Mail: info@pius-info.de

Green Eco Net
c/o Ecologic-Institut gGmbH
Dr. Martin Hirschnitz-Garbers
Tel. 030 86880 272
E-Mail: martin.hirschnitz-garbers@ecologic.eu

Source in german: Bundesministerium für Wirtschaft und Energie
http://www.pius-info.de/dokumente/download/1984/