Energy reduced at textile plantTextile manufacturer PT Leuwijaya Utama has adopted SKF E2 bearings as part of an urgent cost-saving programme, which was triggered by a sharp rise in local energy costs. The plant now has 25,600 SKF E2 bearings installed on its machinery and is reaping the on-going rewards of energy efficiency.
The cost-saving programme began in July 2010, when Indonesian industry at large faced a government-enforced increase in electricity costs. For PT Leuwijaya Utama, a textile company with 300 weaving machines and 176 twisting machines consuming 2,120 megawatt-hours (MWh) per month in its Bandung factory, this meant an increase in costs of approximately 18%. To reduce the negative effect on bottom line profitability, a speedy and effective reaction was required to identify and achieve energy savings fast.
Having ensured that no unnecessary lighting was being used, or machinery left on standby when it could be switched off, the management took a detailed look at production. First investigations showed that 30% of the factory's energy consumption was consumed by the twisting machines, which are critical in ensuring fabric quality. So, as well as taking measures to correct electric motor energy losses and optimising frequency converters for the overall electricity supply, the energy consumption of the twisting machinery was discussed.
Inside the Leuwitex twisting machines, lines of high precision spindles are driven by two powerful motors. As these machines operate 24 hours per day, frictional losses (and ultimately energy losses) occur in the rotational motion dependant on the quality of the bearings fitted at the ends of each spindle. With 176 twisting machines incorporating 256 spindles, this clearly presented an opportunity for energy saving.
Mr Zenzen, Leuwitex plant manager, took a pragmatic approach to investigating the potential for reducing energy consumption, with three potential 'solutions': a) to use new bearings from the supplier of those in the original spindles; b) to install low cost bearings of local Chinese manufacture; and c) to switch to SKF Energy Efficient bearings. Mr Zenzen fitted the three alternative bearing solutions to separate spindle lines and ran them for three months, monitoring the energy consumption of those lines. The result was an overwhelming victory for the SKF Energy Efficient bearings, with around 10% total energy savings.
"Having satisfied myself on the energy savings issue," said Mr Zenzen, "I also needed to be sure that the overall SKF bearing performance was equally reliable in terms of the final product quality. The twisting machines have two contra spinning spindles rotating in synchrony in opposite directions. To maintain product quality it is of utmost importance that these two spindles are rotating exactly as expected through the entire and continuous spinning/twisting operation."
Mr Zenzen's next test was therefore to fit SKF Energy Efficient bearings to ten twisting machines and begin a 'production run'. "I was delighted to find that the product quality was exactly the same as before, with constant, uniform delivery of the various designs, material thickness and feel," said Mr Zenzen. This test was extended by adding more lines of spindles while keeping the original ten operating. Regular product quality checks among the machines convinced Mr Zenzen that he had indeed found the best possible bearings for his textile machines, both in terms of energy efficiency and performance.
Other News from SKF (UK) Ltd
Latest news about Rotary bearings