Case Study

Quick-Release Belt Take-Ups Help Reduce Bakery Conveyor Washdown Time

Oil saturation from bread dough necessitates daily washdown and routine maintenance checks on the conveyor lines. On dough-divider, inclined discharge conveyors, for example, oil can cause belt stretch and tracking problems.

"Automated processing lines in bakeries should run like well oiled machines; sometimes they become a little too well oiled," says an engineer at the Interstate Brands Corp. bakery in St. Louis. "Considerable downtime to washdown, re-tension and track the belt robs us of expensive production time."

"Our belting supplier, Midwest Industrial Rubber Inc., Hilliard, OH, worked with us on the ultimate solution," continues the Interstate engineer. "First, the solid woven belt was replaced with a reinforced PVC belt. Since the belt change, and the switch to quick release take-ups, we have virtually eliminated unscheduled interruptions, and reduced sanitation washdown time by more than 75%." To see a diagram of how the take-up configuration changed, click here.

Making bread
The bread making process at the St. Louis bakery starts with mixing a 500-lb dough-sponge for four minutes at 74°F. Next, the dough is placed in a fermentation trough for three hours at 80°F and 75% humidity. Then the batched dough ball is sent to a divider which slices off predetermined sized pieces of dough for single loaves.

The dough pieces are moved on the PVC conveyor belt to a conical rounder. The dough receives a five minute intermediate proof, then passes through two cross-grain moulders and a curling chain into 4- or 5-strap pans. Line speeds are 150 loaves per minute.

After receiving a 60-minute proof at 115°F dry and 112°F wet in a traveling tray proofer, the bread bakes for 18 minutes at 425°F before depanning and traveling to a ceiling cooler for 62 minutes. The loaves then pass through a slicer/bagger and an inkjet printing system that prints price, code date and price per pound on the bag.

Active area concerns
"Obviously, each step in the production process is critical to maximize throughput," states the engineer. "However, in active areas where production equipment is running constantly, unscheduled downtime must be kept to a minimum. The mixer-to-conveyor-to-rounder is a key active area. Reducing maintenance needs, and the time it takes to clean the various components in this area, was a prime target for efficiency improvements.

"For example, during a typical washdown procedure, conveyor belts are slackened so that 100% of the underside area of the belt can be cleaned and/or sterilized. Before, the final washdown step was repositioning pulleys, and refastening take-up devices, then tinkering and jogging to assure proper belt tracking.

"Now, we simply release the take-up's toggle clamp, move back the pulley to slacken the belt and prop up the belt so that sanitation personnel can clean under it. Once the washdown is complete, we remove belt props, move the pulley into position and reclamp the take-up to its original position. The take-up always returns to the original tension and tracking setting so there is no need for time-consuming tension and tracking tinkering."

Take-up details
Key to the Quick Release Telescoper's performance is a patented, easy to operate, lock/release, pull-action toggle clamp that eliminates all pulley and belt tracking adjustment required. These take-ups are ideally suited for application on both new conveyors and for retrofit.

Using this Telescoper, releasing the toggle clamp allows belt slack, but does not disturb the Telescoper's take-up position. After the washdown cycle is complete, relocking the clamp resets take-up and tracking to the previous and correct position. All Telescoper take-ups feature a threaded adjuster rod totally enclosed in a stainless steel tube, protected from product build-up, rust, corrosion and thread damage.

In many applications, up to 90% time and labor savings are possible during belt washdown and maintenance activities. In addition to baking, applications include: poultry, fish, meat and food processing, beverage bottling and unit handling, among others.

Bryant Products, Inc., P.O. Box 270, Ixonia, WI 53036. Tel: 800-825-3874. Fax: 800-553-5733.