Prove Their Worth at PT. Leuwijaya Utama, Indonesia
Along with the rest of Indonesian industry, PT. Leuwijaya Utama textile company, (Leuwitex), was confronted with a government-enforced increase in electricity costs in July 2010. For Leuwitex, it meant an increase of approximately 18%. For a company with 300 textile weaving machines and 176 twisting machines consuming 2,120 kWh per month in their Bandung factory, this represented a major increase in operating costs, and one that needed a speedy reaction in order to reduce the effect on the threat to bottom line profitablility.
Immediately after the increases were announced, the management of the Leuwitex Bandung factory set about searching for ways to reduce energy consumption. As well as ensuring unnecessary lighting, standby machinery, etc., was switched off, they took a detailed look at production. The factory, one of three in Indonesia, produces some of the most sought after fabrics in the country, and exports to Middle East, Malaysia and Europe.
Over the years, Leuwitex has developed its design and manufacturing techniques to create a range of fabrics, including a lot of custom-made fabric, that customers report has exceptional feel, design and wear properties and has placed them among the top 10 producers in Indonesia.
Attention Turned to Twisting Machines
To produce the daily volume of almost two tons of fabric, the Bandung factory has the usual range of textile machinery including electric motors, weaving machines, spinning machines, twisting machines, etc. First investigations showed that 30% of the factory’s energy consumption was consumed by the twisting machines, an important piece of machinery that is critical to fabric quality. So as well as taking measures to correct electric motor energy losses and optimizing frequency converters for the overall electricity supply, the energy consumption of the twisting machinery was discussed.
Mechanically, the twisting machines are fairly straightforward: a series of lines of high-precision spindles are driven by two powerful motors. Frictional energy losses occur in the rotational motion, as these machines operate 24 hours per day, by virtue of the quality of the bearings fitted at each end of each spindle. With 176 twisting machines, each having 256 spindles, this was clearly an opportunity for energy saving.
Tests Compare Three Options
Mr. Zenzen, Leuwitex plant manager, decided on a very practical and specific way to investigate a way to reduce energy consumption for the long term. He would select three of the most likely ways to optimize bearing cost and frictional losses and put them to test in his spindles. These potential “solutions” were :
- New bearings from the supplier of those in the original spindles.
- Low cost bearings of local Chinese manufacture.
- SKF Energy Efficient bearings, claiming up to 30% friction saving.