Making the Grade: Screening Nuts for Quality and Classification

Posted by Kason Corp on 06/8/2022 5:48 PM

Consumers seeking healthier snack options or better-for-you plant-based proteins have been steadily increasing the demand for nuts for decades. There are more than 20 types of edible nuts in the world, with a market value estimated to reach $459.1 billion by 2030

Varieties include almonds, peanuts, walnuts, pecans, pine nuts, macadamias and more. Each type of edible nut and each stage of the supply chain from "farm to fork" requires sorting to meet size, quality and purity standards, all while maintaining high throughput.  

Nut processing requires durable sifter machines with multiple vibrating sieves or screens to help growers, packers and processors meet their production goals while adhering to food safety standards. Companies can eliminate waste and maximize profit potential by working closely with Kason’s application engineers. With decades of experience in the food processing industry, Kason’s experienced team can provide recommendations to help optimize the nut separation and classification process. 

While many of Kason's industrial processing equipment can be used in nut processing, Kason's VIBROSCREEN circular vibrating screener is the model most often utilized for the industry.   


Working Smarter (Not Harder) With Vibratory Screeners   

Nut processing or sorting begins in the field. During harvesting, sorting and sifting machines can separate nuts from foreign and unwanted debris, such as twigs, stones, leaves and even dust.  

Once the nuts are dried in preparation for cracking, the outer shell or hull must be separated from the nutmeat and the nuts sorted according to size. The U.S. Department of Agriculture provides the industry with voluntary grades for classifying nuts according to size and color, among other specifications. The size helps determine the end use or application for the nut.  

Packers or copackers might package whole nuts according to individual variety, or as part of a snack mix, blend or trail mix. In this instance, the packers typically want to eliminate dust, crumbs and fines or broken pieces in preparation for packing. In addition, whole nuts are "graded" according to size and quality, with larger nuts often commanding a greater price.  

Bulk suppliers will typically separate the nuts into whole nuts, halves, splits, butts (cashews) or pieces, depending on end-use application. The nuts might undergo further processing such as roasting or an applied confectionary coating, requiring sorting both prior to and after coatings are applied.  

Baked goods, ice cream, confections and cereals often utilize nut halves, splits or pieces. A whole nut usually is not required, but identifying the part of the nut adds value to the end product.  

Nuts destined for use in nut butter need to have the skin removed before grinding, and circular vibratory screeners can also help with this process. For example, roasting a peanut loosens the outer skin and the Kason VIBROSCREEN easily removes the skin to free the nuts for further processing.  

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How Screener Design Makes it Easier to Achieve Food Grade Quality

Depending on the processing stage, a perforated plate can supply a sturdy and durable sorting element during the first phase of sorting. The perforated plate has a stagger, allowing for excellent separation and nut sizing. Later, a vibrating sieve or mesh screen is used for scalping and de-dusting to remove fines, crumbs, or dust in the processing stream. 

As with any food processing, thorough cleaning is a top concern. The stainless steel construction of the Kason VIBROSCREEN coupled with its circular sorter design provides easier, more thorough cleaning cycles. The circular design of the vibratory screener eliminates problems associated with box-shaped sorters, such as material buildup and microbial growth. 

In addition, all Kason equipment and screens are manufactured so that all contact parts are fully compliant with FDA, USDA, 3-A, BISCC, and other stringent U.S. and international food safety standards.



WATCH: Kason's VIBROSCREEN De-Dust Ground Walnuts.

With rates up to 70 tons per hour on a batch or continuous basis.


Circular Vibratory Screen Options Offer Nut Processors More Flexibility

Kason offers the widest selection of screening and processing equipment, from basic sorters and screeners to more sophisticated, high-capacity classifying systems. Kason can also customize or modify its standard models to fit the end user's desired specifications.  

One example of customization is to configure multi-deck screeners to contain up to four screens. This separates the product into five different fractions or sizes in the same pass, saving time and increasing throughput. This multi-level screening can scalp and separate whole nuts from halves, fractions and fines.   

Circular vibratory screeners can reduce dependence on manual labor, providing another competitive advantage in today's tight labor market. Instead of requiring multiple workers to sort products by hand on various parts of the processing line, all sorting can now be easily automated.  

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Patented Airlift System Makes Changeouts Easier and Faster   

Kason screens can be replaced in minutes thanks to a quick-change airlift design system. With this feature, operators can gain access to the unit’s interior significantly faster and easier than competing machines with manual changeouts.

This significantly reduces downtime during:

  • inspections
  • cleaning
  • screen changes
  • maintenance 

 Operator safety is also improved during the entire process of raising, lowering and disconnecting and reconnecting the frames.

While able to handle a wide range of capacities, the VIBROSCREEN generally occupies a small operating footprint. Unit sizes range from 18 to 84 inches in diameter, but Kason also has the capacity to fabricate 100-inch diameter units as a custom option to handle large volume operations.  

Free Lab Testing

Kason Corporation supplies customers and prospects with free lab testing on its full range of processing equipment, such as the circular vibratory screeners on either single or multiple decks.  

The test lab equipment can be configured to simulate your installation and run trials using a sample of your materials. This can generate test results and quality analysis to verify the dependability and performance of the machine.

Kason Application Engineers are Here to Help You Find the Right Equipment

Nuts present an affordable, storable, transportable and reliable source of protein with a consumer demand that is only expected to grow. To increase your profit potential, you should look to partner with a manufacturer who understands the many nuances involved in nut processing applications. You can talk to our engineers to learn how adding a VIBROSCREEN can improve your nut processing operation and other food processing applications. 

Nut Conveying Systems from Cablevey  

Cablevey Conveyors, a company owned by the same parent company as Kason, also specializes in processing equipment for the nut industry. To learn more about Cablevey solutions in enclosed tubular drag cable and disc conveyors for nut processing, visit 


Topics: Sanitary Applications, Sanitary Equipment, Circular Vibratory Screeners, Food Processing