Kam Ng | Acoustical Solutions

Kam Ng

Vice President of Engineering


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  • Virginia

Noise Reduction for OSHA Standards (Case Study)

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Noise Reduction for OSHA Standards

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The Issue:

Our client (a large multinational industrial manufacturing company in Newark, Delaware) needed noise reduction for OSHA standards. A noise evaluation was conducted to assess the noise levels generated by the various manufacturing processes, equipment, and machinery in the fluid bottling production line. Based on results of noise measurements and analysis, acoustical treatments and corrective actions were recommended to reduce the noise levels to 80 dB(A).

Noise Reduction for OSHA Standards Solution:

The company follows its own corporate noise limit targets which fall in line with the US Occupational Safety and Health Administration’s (OSHA) standard guidance. The aim of this project was to quantify the noise levels in the production line and assess the applicability of the Hearing Conservation Program as per OSHA. The noise levels requirement for the fluid bottling production line is 80 dB(A) or below.

The dominant noise source was due to the agitation generated by the shaker bowl, and pneumatic and mechanical noise of the actuator for tightening the caps. The peak A-weighted noise level at the Secure-Chuck Capper operation reached 87.0 dB(A). Typical noise spectra of the Capper are shown in the figure below. As shown, the noise spectra of the Capper are relatively flat with the peak noise around 500 Hz.

Noise Control for OSHA Standards Services Provided:

Noise measurements and analysis were conducted to determine the dominant noise sources and frequency characteristics of the fluid bottling production line. Based on the results of the noise measurements and analysis, corrective actions and noise reduction recommendations were developed and provided.

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Noise Reduction for OSHA Standards Recommendations:

Based on the results of noise analysis, the following three acoustic treatments were recommended for noise reduction for OSHA standards: acoustic blankets, vibration damping layer, and clear acoustical barrier. Specifically, the acoustic treatments were ABSC-25 AudioSeal Sound Blanket, VibStop Vibration Damping Sheet, and AudioSeal Clear Sound Barrier.

The acoustic blanket is a sound barrier with a Class 1 fire rating and is commonly used for interior applications. The blanket has a septum encapsulated with fiberglass, allowing for both sound absorption and sound attenuation.

To minimize the vibration induced noise generated at the Secure-Chuck Capper, damping material was recommended to attach to the vibrating surface of the shaker bowl and caps hopper. The vibration damping sheets use an advanced butylene rubber bonded to a thin layer of aluminum. It is a self-sticking rubber sheet that reduces vibration and ringing on resonating surfaces. The damping sheets are lightweight which require no special tools to install.

With the requirement of having a clear viewing of the Secure-Chuck Capper operation, it was recommended to apply clear acoustical barrier material around the Secure-Chuck Capper Station. The acoustical barrier material to be installed around the Secure-Chuck Capper requires a minimum distance of 6 to 8 inches from the sound radiating surfaces. The coverage area of the clear acoustical material should be large enough to embody the Secure-Chuck Capper Station.

To further reduce the noise levels well below the 80 dB(A) requirement, the following corrective actions are recommended:

  • Change operating condition, such as lower the air pressure, slow down the acceleration and deceleration of machinery, and adjust the time interval of power on and off
  • Mechanical tool which uses rotating elements or moving parts should be well lubricated

The Results:

With the application of ABSC-25 AudioSeal Sound Blanket, AudioSeal Clear Vinyl Sound Barrier around the Secure-Chuck Capper Station, and VibStop Vibration Damping Material on the shaker bowl (caps hopper), the noise levels at the Capper Station would be reduced to meet the 80 dB(A) noise goal.

The OSHA noise standard defines an Action Level (AL) as the equivalent 8-hour time-weighted average (TWA) noise level of 85 dB(A). When noise exposures reach the Action Level, OSHA requires that a Hearing Conservation Program be implemented for all affected workers.

To learn more about how Acoustical Solutions can solve your noise control problems, use our contact form, call one of our Acoustical Sales Consultants at (800) 782-5742, or visit us on the web at www.acousticalsolutions.com.