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FIBC Handling

Bulk Bag Unloading - Handling System Upgrades Calendering Operation

Oplex S.A. de C.V. calenders polyvinyl chloride (PVC) sheet for applications like advertising banners, automotive seat covers and door-panel liners, truck canopies, awnings, shower curtains and synthetic leather. The company produces sheet on two calendering lines that receive PVC compounds from a central batch-mixing system.
Previously, workers had manually loaded 25 kg paper sacks of PVC resin and calcium carbonate (CaCO3), the solids components of the formulations, into a mixer and used a special conveyor system of the company’s own design for adding liquid components such as plasticisers, stabilisers and lubricants.
During the process, manual loading created problems, notably in quality control. Oplex were mixing six batches per hour, (144 per day) each batch weighing 200 kg, including liquid additives. With one batch mixed and discharged every 10 minutes, workers were rushed, which led to mistakes.
It was not unusual for them to forget how much product had been added to a batch and since bags were opened with knives, particles of paper sometimes fell in the mix. The work was repetitious, which created the potential for injuries from carrying bags to the mixing station and the empty bags also had to be collected and disposed of, increasing production costs.
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