Bulk bag dischargers and flexible screw conveyors join forces to deliver automation and control at peanut butter facility

Once Again Nut Butter has come far from its humble origins without compromising its founding values. When Jeremy Thaler and Constance Potter created the company in 1976, they bought a small, used coffee roaster to roast nuts and used discarded bulk pails from a bakery to pack their organic and natural nut butters — all in their 800-sq-ft basement. The employee-owned company’s commitment to sustainably made products and a business model that promotes transparency and integrity has earned it a steady, loyal following over the last 40 years. Today Once Again produces 12 million pounds of natural and organic products every year, including honey, sesame tahini and various nut butters. It distributes those products nationwide to retail, private label, foodservice, industrial and export customers. 

To meet the growing demand for its products and cater to customers concerned about peanut allergens possibly cross-contaminating other Once Again products, the Nunda, New York-based company built a new facility solely dedicated to peanut butter production. The 37,000-sq-ft plant features two bulk bag dischargers and five flexible screw conveyors from Flexicon Corporation that gives Once Again a higher degree of automation and control to double production capacity while improving operator safety.

Once Again installed Flexicon bulk bag dischargers and flexible screw conveyors in 2016 during the construction of its new peanut butter plant. The company decided to outfit the new plant with the Flexicon bulk-handling equipment because it was pleased with how its Flexicon equipment performed over the years in its older plant, which now only processes nut and seed products, including organic cashew butter, sunflower butter and hazelnut butter as well as organic and natural honey. In addition, employees were already comfortable using the Flexicon equipment, while the company is able to reduce the costs associated with spare parts management.

“We had other Flexicon systems installed, so there’s a spare parts advantage in things like the flexible screws are all the same pitch and the same construction. The gear boxes, the tubes and a lot of the other components in the system are cross-functional,” says Peter Millen, process engineer at Once Again. “So it minimizes our spare parts inventory.”

Safe and sound

The new Flexicon equipment also helps to enhance worker safety at Once Again’s peanut butter plant, according to Millen. Two Flexicon BULK-OUT BFC bulk bag dischargers feed the new line. Each bulk bag discharger is equipped with a cantilevered I-beam, hoist and trolley that lift and position the bag in the discharger frame without the need for a forklift. When the raw and shelled peanuts arrive at the facility, they come in super sacks weighing 2,200 lb each. An operator attaches the bag straps to the lifting frame and actuates the electric hoist and trolley using a pendant to position the bag in the discharger frame. 

The bag’s outlet spout is pulled through an iris valve, which closes around the spout, preventing material flow. The operator then unties the drawstring, closes the access door, and releases the valve slowly to let peanuts gradually flow into the 5.5-cu-ft hopper. The dischargers are fitted with pneumatically actuated FLOW-FLEXER bulk bag activators, which increasingly raise and lower opposite bottom edges of the bag into a V shape as it empties and lightens, promoting complete evacuation. 

In the older facility, employees manually hoisted and emptied the super sacks of peanuts into the hopper of the roaster — a labor-intensive process that posed a larger risk to worker safety and ergonomics. The new bulk bag dischargers reduce physical strain on the employees, protect workers from being hit by a large burst of peanuts, and contain the fugitive peanut air and dust from contaminating the facility.

“The Flexicon bulk bag dischargers have some nice features designed into them that gives you the ability to safely untie and open those bags,” Millen says. “The access door with the iris valve lets you reach up and get that bag open without getting the entire contents of the bag rushing out of this 10-in. opening. If for some reason the straps of the bag break, the peanuts are not going to drop on your arms and crush them.”

Twice the throughput

When Once Again built its peanut butter facility, it not only wanted to improve worker safety, but also increase its efficiency and double production capacity. With the Flexicon bulk bag dischargers and flexible screw conveyors, Once Again can manufacture up to 7,000 lb of peanut butter per hour, according to Millen.

The two bulk bag dischargers ensure Once Again can continuously feed peanuts to its two new roasters. Positioned side by side, the bulk bag dischargers allow one frame to discharge material while the other is reloaded. It also provides redundancy in the event one of the systems is offline.

The 20-ft long flexible screw conveyors transport the peanuts from each of the discharger’s hoppers at a 45-degree incline into a gravity separator. The gravity separator removes any foreign material that is lighter or less dense than the peanuts, such as twigs or peanut shell pieces. 

From the gravity separator, a third flexible screw conveyor, which is about 15 ft long and angled at 45 degrees, takes the peanuts to the de-stoner to remove any material heavier and denser than the peanuts, such as pebbles. 

A 50-ft long pneumatic conveying line then loads the peanuts into an intermediate storage silo until they are ready to be roasted. Another 50-ft pneumatic conveying line transfers the peanuts from the silo to the roaster. 

Once the peanuts are roasted, a 70-ft pneumatic conveyor transfers them to a blancher, which removes the peanut skins. Another 70-ft long pneumatic conveyor delivers the blanched peanuts to two holding silos.

From each silo, a 15-ft flexible screw conveyor feeds the peanuts to a roasted peanut transfer bin. Then another flexible screw conveyor transports the peanuts from the bin to a 90-ft long pneumatic conveyor line for grinding before going into packaging.

Like the bulk bag dischargers, the Flexicon flexible screw conveyors bring convenience, control and consistency to the manufacturing process, according to Millen. Each of the flexible screw conveyors uses a flat wire spiral housed in an enclosed tube measuring 4.5 in. O.D. that prevents peanut air and dust from escaping into the facility. Plus Millen appreciates that the flexible screw conveyors take up a small footprint in the plant, integrates seamlessly with the plant’s equipment, including the gravity separator and de-stoner, and can be configured to various angles to accommodate the placement of the equipment in the processing line. “Without the Flexicon flexible screw conveyors, I don’t know that we would have been able to put the equipment in their current configuration in the plant and have it function effectively,” Millen says.

In addition, variable frequency drives (VFD) control the drive motor rotating the screw. This enables operators to control the speed and torque of the conveyors so that the conveyors can adapt to the pace of the upstream and downstream equipment. VFDs also reduce the amount of power required at startup, eliminate voltage fluctuations, and reduce wear and tear on the motor, extending its life.

With the flexible screw conveyors and bulk bag dischargers in place, Once Again has been able to meet its target production rates and set the foundation for future expansion, according to Millen. “We designed this facility to handle higher volume. We needed to produce more product, and we had to do it more efficiently,” Millen says. “The Flexicon units give us the efficiency, the level of automation, integration and control over the entire system.”