_{Packaging World Article, published 04.04}

EQUIPMENT UPGRADE
Rinker invests in process improvement

Rinker’s multiwall valve-bag filling operation made big gains in productivity, accuracy, and ergonomics after management invested in three key upgrades.

Rinker Material Corp. is one of the largest producers of bagged cement, ready-mix concrete, and concrete block in the United States. When the firm was looking to increase the productivity of its Port Everglades, FL, terminal, management turned to Thompson Scale for the solution.

The improvements Rinker sought in filling its powdery products into multiwall, valve-style bags required three key additions: an in-line checkweigher, data collection software, and a packer upgrade. All three were implemented within the past 12 months, with the checkweigher coming first.

“We were using manual labor to check bag weights every 30 minutes,” says terminal manager Juan Alvarez. “This meant stopping bag production while someone pulled a bag and put it on a scale. Not only did this hurt productivity, it was hard on our workers, too.”

The small amount of space available in Rinker’s existing conveyor line made installation of a checkweigher a real challenge. Normally, heavy-duty checkweighers require about 4’ of linear space. Rinker had only 3’ to spare. Also required was a product rejector powerful enough to remove off-spec bags from the production line, yet compact enough to fit within the same space.

Thompson Scale met this challenge by designing a Model 4693 heavy-duty checkweigher with a space-saving reject ram. To minimize the machine’s overall footprint, the pneumatic reject ram is built onto a support isolated from the scale, yet its reject pusher plate—suspended from an oversized rodless cylinder—is situated directly at the discharge end of the scale. The pusher plate is capable of rejecting an off-spec bag, weighing about 90 lb, and returning to the home position before the next bag enters the scale.

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