Toll Processor Meets Food Specs with Centrifugal Sifters
HAMMOND, INDIANA— PacMoore Products, Inc. is a contract food manufacturer that processes, packages, re-packages and warehouses products to customer specifications. Founded in 1989, the company operates a manufacturing facility in Hammond, Indiana that mainly performs dry blending and consumer packaging, and another in Mooresville, Indiana that performs spray drying and food extrusion for items such as protein fortified crisps, snacks, cereals, and TVP. The company also owns and operates a small extrusion innovation lab in Gridley, Illinois.
Jose Ramirez, Manager of Engineering and Maintenance in Hammond says, "Ingredients typically arrive in one package format and leave in another. We sift, blend, repackage and ship to customer manufacturing facilities or directly to retail stores."
The plant handles a variety of ingredients including plant proteins, bakery mixes, flour blends, drink mixes, starches, sweeteners, fibers, gums, cocoa blends, protein crisps and rice.
Ingredients typically arrive in 50 lb bags, bulk bags, bulk trucks or rail cars. End products intended for retail sale leave the facility in pouches, direct-fill cartons, bag-in-box or other retail packaging, explains Ramirez. Small retail pouches range in size from 4.5 oz (619 g) to 5 lb (2.3 kg). Packaging for products that customers will use in further processing could be 30 lb (13.6 kg) bag in box, 50 lb (23 kg) bags, bulk bags, or whatever customers specify.
Sifting meets customer specs
A rectangular sifter pre-screens the bulk ingredients, which gravity discharge into the mixer. When the customer’s process dictates it, liquid is added and the mixture is blended until uniform. “Sometimes moisture can produce agglomerates or larger chunks of material,” says Joseph Williams, Engineering Manager at PacMoore Process Technologies in Mooresville, Indiana.
To maintain high throughput and product integrity immediately prior to packaging, the Hammond plant installed two Kason CENTRI-SIFTER centrifugal sifters. A high-capacity Model YOB-SS with a 7.5 hp (5.6 kW) motor is dedicated to the Hammond baking soda line that packages product for retail sale. A smaller 3 hp (2.2 kW) Model MO-SS is mounted on a mobile platform to insert into a second production line for products requiring sifting after blending. The Mooresville plant also has a portable 3 hp unit performing final sifting when needed.
"Final centrifugal sifting guarantees the product coming out of the blender is at the right classification. This granule size is very specific and typically requested by the customer,” Ramirez explains.
Blended material entering the centrifugal sifter is metered by a rigid auger into a horizontally oriented cylindrical screen, as rotating helical paddles tipped with nylon brushes create centrifugal force that propels the material against the screen.
On-size material passes through the screen and gravity discharges into a bagger. The centrifugal action also serves to break down soft agglomerates into on-size particles. Oversize particles are propelled in a helical path until they exit the downstream end of the cylinder where they discharge by gravity into an "overs" receptacle.
“A lot of the material passing through the screens can be clumpy. In a regular screener, material would build up, blind the screen, and slow our throughput, but the self-cleaning nylon brushes on the rotating paddles keep the screen clear of buildup,” says Williams.
Screen mesh size depends on customer requirements. “Different products necessitate different screen sizes, so we provide several options,” Ramirez says, and “screen changing takes no more than two minutes.”
For the baking soda line at Hammond, baking soda arriving in rail cars is transferred to a process tank and, in turn, to the dedicated centrifugal sifter. The sifted baking soda is conveyed by rigid auger to direct-fill carton equipment which fills retail packaging in sizes from one to four lb (0.45 to 1.8 kg), Ramirez explains.
Evaluating centrifugal versus vibratory sifting
Circular vibratory sifters were considered for these duties, Williams said, but centrifugal sifters proved the better option for final sifting where the material can be clumpy and build up on the screen.
Williams points out that rapid sieving action was another requirement to avoid bottlenecks in the process. “If we used a regular sifter like a circular vibrating screener, product clogging the screen would slow the sifting rate and the whole process.”
Also important for the application was high strength construction to withstand jolts encountered by the mobile sifters, and the continuous duty required of the permanently installed unit on the baking soda line.
Portability placed additional constraints on the choice of sifters. They needed to be small enough to mount on moveable platforms, and to minimize vibration to prevent shaking of the platforms.
"The hinged door and cantilevered shaft of the Quick-Clean design allow operators to quickly remove the screen cylinder and paddle assembly without tools. This allows cleaning and inspection more easily than flat deck sifters, which is critical in food applications," says Ramirez, citing cross contamination as the most common reason for product recalls in the industry.
The screens last for years, reports Williams. “With other sifters we had screen breakage quite often, but have not had any with the centrifugal sifters.”
PacMoore Products, Inc.
+1-219-932-2666
www.pacmoore.com
CENTRI-SIFTER centrifugal sifters screen ingredients to meet particle size requirements and maintain product quality. In second photo, 50 lb (23 kg) bags of ingredients await sifting.
Centrifugal sifting maintains high throughput and product integrity at PacMoore's Mooresville, IN, plant. Screened product gravity-discharges through a central chute.
Rotating helical paddles create centrifugal force that accelerates on-size material through the screen, while propelling oversize particles through the downstream end of the screen cylinder. Nylon brushes affixed to the paddles prevent screen blinding.
A hinged door with safety interlock provides interior access for cleaning, inspection and screen changes.