14th November 2016
Cost reduction plays a key part for manufacturers in maintaining an edge in the competitive market and lightweight technology can support this by reducing material requirements and the associated costs. A recent German study has shown that the production costs of a static component can be reduced by up to seven percent by using topology optimization technologies, the process of using mathematics to discover where material can be removed from a structure while maintaining the required performance levels.
The subject of the study was the standard design of a static heavy machine component, namely a needle bed in an industrial flat knitting machine. A topology optimization study was carried out on the needle bed to evaluate the part through a linear static and modal analysis. By using topology optimization, the amount of original material used could be reduced by about 30 percent. This amounts to a weight reduction from 251.2 kilograms down to 173.8 kilograms. The required manufacturing costs fell as a result by approximately seven percent.
Material reduction through lightweighting has a strong potential to reduce production costs in many sectors. The costs for resources and materials make up about 46 percent of the gross production value in the manufacturing and industrial sector in Germany according to the Federal Statistical Office. In comparison, energy costs accounted for only 2.1 percent.
The study showed that the material costs had the greatest influence on cost reduction during the manufacturing process of the knitting machine. By reducing weight, the manufacturer was also able to reduce transportation costs marginally as a positive secondary effect.
The implementation of a lightweighting solution would incur one-off costs for development. An investment in weight reduction would break even after about eight months with otherwise equivalent production output, resulting in positive returns over the medium term. Other possible effects of investing in material reduction include shorter post-processing times and increased revenue enabled through the total weight reduction of the machine.
The study was carried out by the flat knitting machine manufacturer H. Stoll AG & Co. KG based near Stuttgart at the initiation of Development Agency for Lightweighting BadenWuerttemberg and with the cooperation of wbk Institute of Production Science in Karlsruhe and the DLR Institute of Vehicle Concepts in Stuttgart.
“We have been able to significantly reduce costs with our machines in recent years – and now 6.5 percent in one shot. It is rare that we can achieve so much in so little time,” notes the development director of the company involved in the study.
“In light of material costs making up 46 percent of the total costs of the manufacturing process, a cost reduction of 6.5 percent through lightweighting presents a significant competitive advantage,” says Leichtbau BW GmbH managing director Dr. Wolfgang Seeliger.
At the same time, vital resources can be saved. According to Seeliger, “The application of this business case to German machinery manufacturing would result in a steel consumption reduction of 1.53 million tons per year. This could reduce CO2 emissions by about 2 million tons – the equivalent of the annual emissions of a city the size of 200.000 inhabitants.”