Process improvement by eliminating a hazardous, manual labor task

Problem: A medical device manufacturer was using Polyisobutylene polymer to produce Electrocardiogram heart patches. Although the customer’s material usage was relatively low, the feed material was only available in 79 lb bale form. The customer had employees cutting small squares from rubber bales using razor blade knives. Several lost time injuries resulted from this process. In this situation, an automated manufacturing process was needed in order to increase the efficiency of their process.

One example of this commercial requirement was:

  • Product Rates: <1500 lbs/hr
  • A secondary acrylic product contained residual acetic acid requiring 304 L product contact parts
  • Since the end use for the product was for use in a medical application, the entire process had to be validated.

Additional manufacturing automation initiatives included:

  • Sanitary / easily cleanable design
  • An automated manufacturing system that requires minimal personnel oversight
  • Explosion proof design required due to the presence of solvents

Solution: The PB15 Heavy Duty Rubber Chopper® size reduction system from Bepex International was used to take polymer bales approx. 6” x 17” x 31” at a rate of approx. 1500 lbs/hr and grind the material into small pieces approx. ¼” x ½” x ½:. The bales were loaded onto a conveyor belt via a pneumatic lifting device. The conveyor belt passed through the wall into a dedicated room which fed the inlet chute of the Rubber Chopper. A pneumatic ram feeder equipped with 2 explosion proof solenoid valves, 3 photo eyes and 2 safety limit switches controlled the operation of the belt conveyor. The ram feeder provided constant pressure throughout the feeding of the bale to produce a uniform and consistent product size. At the discharge of the Rubber Chopper, the product dropped into an agitated dissolving tank.

At Bepex’ Process Development Center, our Rubber Chopper system was tested using the customer’s exact feed material. Since this is a full production scale grinding machine, there was no scale up involved.

Benefits and Results:

  • The customer’s process was more efficient thanks to our fully automated manufacturing process
  • Manual labor and lost time accidents were eliminated
  • Faster dissolving rates were obtained from the Rubber Chopper product due to the increased surface area as compared to the hand cut chunks
  • Higher throughput rates were obtainable with the Rubber Chopper system allowing market expansion
  • The customer was able to show his plant and maintenance personnel the full scale operation of this process system before purchasing. This assisted in developing the IQ/OQ/PQ procedures for their validation process.