The noise from the looms has been repeatedly complained about, and the support team suggests implementing vibration and noise reduction measures together.

"To reduce noise, we've closed the windows and installed wooden boards and soundproofing panels, but the results haven't been ideal." Frequent complaints about loom noise have left the business owners in the riverside textile industrial park in Yongfu Village, Xucun Town, Haining City, Jiaxing, Zhejiang Province, perplexed.

As a crucial link in the textile industry chain, the weaving industry is facing increasingly prominent noise problems. Identifying the sources and transmission methods of noise, resolving noise pollution issues, and proposing targeted rectification measures have become urgent priorities.

“These two companies are separated from residential areas by only a river, less than 30 meters away in a straight line, with no walls or tall trees in between to absorb or buffer the noise. The textile factory has five floors, and the noise generated by the textile equipment on the upper floors breaks through the company's soundproof barrier and reaches the residents' homes directly.” In order to find the root cause of the problem, the Haining Branch of the Jiaxing Municipal Bureau of Ecology and Environment invited a team of expert engineers who make soundproofing facilities to conduct on-site investigations and visits to the companies.

On-site experts used professional noise and vibration detection equipment to measure noise levels near the company's main noise sources, along the riverbank behind the factory, and in residential areas. They found that the noise level near the company's loom equipment could reach 95 decibels, with noticeable ground vibration. After initial soundproofing by the company, the noise level was reduced to 68 decibels, and further reduced to 66 decibels in residential areas. However, the noise level was still 11 decibels higher than the standard at night.

"The noise caused by the mechanical collision and vibration of the loom is low-frequency noise. It has strong penetrating power, slow attenuation, long sound waves, and diffracted waves that can easily bypass obstacles. The loom directly contacts the factory floor, causing the entire factory to vibrate, turning the factory into a loudspeaker," the expert pointed out. "There are narrow passageways between the factory buildings. After sealing off the windows along the river, the company has to use exhaust fans to circulate the air in the factory area. The noise of the exhaust fans themselves, plus the low-frequency noise sound waves escaping from them, reflects and superimposes between the walls of the passageway, and finally propagates into the residential area through the horn at the end of the passageway."

In response to these characteristics, the support team suggested addressing the noise problem from two aspects: vibration resistance and noise reduction. "The windows on the riverside walls lack sound insulation, and disregarding lighting factors, they can be completely sealed off," the support team pointed out. "For the side exhaust fans, adding L-shaped soundproof ducts can absorb some of the noise while redirecting sound waves from the vertical walls towards the far end of the river, reducing noise reaching residential areas."

The support team also suggested that companies enclose open spaces with high-quality soundproofing materials such as fiberglass, and only open the goods access channels to minimize noise leakage.

"Thank you for your professional help; you've helped us pinpoint the problem." The company's representative said excitedly after listening to the support team's analysis and suggestions. "Next, we will work with the engineering team to calculate specific data within the factory area and truly implement the noise reduction and rectification measures."

Article Source | China Environment