Bulk Bag Filling Issue: Inlet Spout Slipping

Posted by Chris Wheeler on August 16,2019

Does your bulk bag slip off the fill spout during filling?

The last thing an FIBC customer needs is bag inefficiency or bag failure in their production line. During a recent site visit, our sales rep was testing our bulk bag at a new customer’s filling station. He discovered that the inlet spout of our bulk bag was slipping off of the fill spout during the filling process.

The first thing he and our team checked was that the inlet spout and the bulk bag were designed to the specifications required by the customer. If the inlet were too wide, or too short that would be a cause for the bag to slip off the fill spout. Fortunately, our FIBC was in spec and we were able to eliminate inlet size as the culprit for the bulk bag failure.

The next potential issue would be whether or not the FIBC was being supported at the base during filling. If the bag were only supported by the lifting loops, then once filling began the weight of the fill material can push the center of the suspended bulk bag down and cause the bag to deform and slip away from the fill spout.

After much head scratching and a thorough inspection of both our FIBC and the filling spout, our rep asked the company when they had last replaced the inflatable neck seal of their filling equipment.

fibc-filler-neck-sealThe inflatable neck seal on a filling station is constructed of a bladder covered by a rubber sleeve. The bladder expands to seal the bulk bag spout to allow for dust-free filling.

Spiroflow, a manufacturer of this type of bulk bag filler equipment offered additional insight. According to Spiroflow’s COO, Don Mackrill “The bladder should have its own, dedicated pressure regulator as it is critical to maintain an air pressure of no more than 4-5 psi. Putting too much pressure on the collar will cause it to fail rapidly.”

The company’s Production Manager checked maintenance records and discovered that it had been a couple of years since their neck seal had been replaced. Fortunately, he had a replacement part on-hand and was able to switch out the inflatable neck seal. After replacing the part, the inlet spout was held in place securely and the bulk bag worked perfectly.

infatablenecksealFIBCSo how often should you replace your neck seal? Mr. Mackrill advises, “There is no standard replacement time. As part of a regular preventative maintenance program, the collar can be tested by inflating it without a bag in place to look for any distortion of the collar, leads, cracks or hardening of the rubber membrane. We find that the primary cause of failure is over pressure. After that, wear and age are the culprits.”

Keeping your FIBC bag specifications up to date can help you narrow the potential cause of issues such as these in your own production environment and following a routine preventative maintenance schedule helps too.

If you are experiencing a bulk bag failure or are adding unnecessary steps to your filling and discharging processes as a patch for addressing the root cause of your bag failure have one of our representatives come out for a site visit and let us help you identify what could be causing the issue.

Photo credit: Spiroflow, https://www.spiroflow.com/product/base-model-bulk-bag-fillers/ 
Photo credit: Spiroflow, https://www.spiroflow.com/product/c-series-bulk-bag-fillers/

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Tags: Flexible Packaging

Chris Wheeler

Chris Wheeler

Material Science Engineer at Conitex Sonoco