Keep it sharp!
Sept. 4, 2014
|Life expectancy, safety of handling and ease of cleaning are important criteria when selecting blades. (Photo courtesy of TREIF USA)
When it comes to slicing meat and poultry products, the variety of blade technologies available is exceeded only by the varied options of product types, styles and formats. The foundation of all successful slicing operations is dependent on the durability, thickness, consistency and speed delivered by blades – and matching it to the appropriate application.
In most cases, blade size matters, especially if the slicing area is large, according to Norbert Muehlich, vice president of Weber Inc., based in Kansas City, Mo. Even easy-to-cut meats require a big blade if most of the cutting edge is being used. After size, “you select the blade angles, blade profile, etc.,” says Muehlich, adding that hundreds of blade types are available.
Blade thickness and the angle of its cut is critical for any application. Considering the need for serrations is also a priority depending on whether “it’s a half-frozen, fresh-meat application or a soft bologna or cheese,” Muehlich says, adding that blade coatings are also an important consideration.
To ensure hygiene is not compromised, especially for slicing of poultry products, Muehlich encourages processors to insist on blades that are rust-and corrosion-proof, which are attributes of stainless steel. “Learn what the blade is made of; know what the blade’s coating is,” he says, “and ask how long the blade will stay sharp.”
Not unlike most processing equipment parts, blades should be cleaned and sanitized when switching species and after each production shift. Blades should also be cleaned again as part of the plant’s nightly sanitation shift.
Maximizing blade life is important to processors to ensure product consistency, thickness and appearance. Similar to how the life expectancy of tires on a car depends on the type of driving, the type of road and the amount of miles driven, blade wear will also vary depending on the use, product and quantities sliced with the blade. Muehlich advises: “Inspect the cutting edge for chips or rough edges and re-sharpen if necessary.”
|Blade wear will vary depending on the use, product and quantities sliced with the blade. (Photo courtesy of Weber Inc.)
When sharpening is necessary, operators of slicers are advised to follow the operator’s manual and always handle the blade with a blade guard.
Weber has automated blade sharpening by embedding its blades with RFID [radio frequency identification] chips. “When the operator approaches the sharpening machine with an RFID chip, the machine automatically sets up the right program to sharpen that blade,” he says. “It tells the machine exactly how much to take off, how long to sharpen it. And it tells what the remaining blade life is.”
When it comes to blade shapes, one type doesn’t necessarily fit the needs of all processing applications. Because its equipment includes dicing, slicing and portion cutting, Shelton, Conn.-based TREIF USA offers various styles of blades.
Each available with varying angles, thicknesses, coating and serrations, TREIF offers round, involute, sickle and straight blades, according to Guenter Becker, president. And because product applications are constantly changing, “we are continuously designing new blades for new products,” Becker says.
When it comes to day-to-day use, blades should be inspected before each shift. “Life expectancy, safety of handling and ease of cleaning the blades are very important criteria when selecting blades,” Becker says. Proper cleaning, sharpening and honing are mandatory in preventive maintenance. “What is most important is to keep the blade sharp; a blade should never be allowed to become dull to ensure the highest slicing integrity,” says Becker.
Blades should always be handled with extra care and mounted, removed and stored with the blade mounted in its holder or protector. Workers should always wear protective gloves when removing and mounting blades.
TREIF’s newest blade technology innovation is the lotus knife, offering a unique design and edge, which greatly improves slice placement for difficult products, Becker says.
Norbert Brunnquell, senior manager of slicing solutions with GEA Food Solutions’ Germany GmbH, Branch Kempten/Germany, points out that while his company’s slicers utilize involute blades in various sizes, choosing the correct one depends on the size of the machine’s slicer cross-section. “The blade size has no impact on the application or maximum blade speed,” Brunnquell says. With multiple grades of blade material available, “If the customer wants to extend uptime, we can offer the GEA SuperiorBlade, made of high-quality stainless steel with a hard-metal edge,” he says.
|GEA Combining the slicing machine and blade enable a good overall performance. (Photo courtesy of GEA Food Solutions)
The optimal combination of slicing machine equipment and slicer blade is needed to enable a good overall performance. “Therefore, we focus on idle-cut rotor, automatic adjustment of the shear edge distance, high-speed control system, very robust shear edge, product drive, rotor head and machine design,” he says. “We highly recommend to processors they always operate with the high-quality blades as a genuine part of the slicer machine supplier,” he adds.
GEA blades are correctly balanced for the specific rotor and their solid design enables a reliable shear edge distance and slicing quality. The long blade edge and special blade geometry ensures a smooth cut and accurate slicing quality. Various coatings and blade edge designs (e.g. curved-toothed) optimize slicing and portioning.
Blade inspection should happen at every re-sharpeing procedure. The time in between this procedure depends on the individual product properties as such and the product preparation (temperature, ripening time, pressed, coated, etc.), Brunquell says.
Choosing the right blade
Marel USA, Lenexa, Kan., offers processors various blade sizes for deli and bacon slicing. Larger blades are used with models offering a larger cutting area, facilitating multi-log slicing of up to four logs. Smaller blades are available for models with smaller throat sizes, while orbital and involute blades are suited for different applications.
|Maximizing blade life starts with choosing the blade's coating and serration. (Photo courtesy of Marel USA)
Delicate products tend to require a slicing action as provided by an orbital blade, while the chopping of the involute blade gives good results on harder products tempered to sub-zero Celsius temperatures. Blades with a variety of coatings and edge styles, grind angles and serrations are also available.
“A blade needs to be fit for purpose to deliver the presentation, speed and volumes required,” advises Mark Douglas, Marel product line manager. “Product tempering should also be a consideration. When changing from one product to another, Marel recommends cleaning all product contact parts, including the blade.”
Blade maintenance for some applications is more frequent. Belly bacon, for example, could be sliced using a standard blade, which would have to be honed after two shifts. A serrated blade could achieve a longer running time of up to one month when used for the same application, Douglas says.
When it comes to maintaining an optimum cutting edge, “Automatic blade honers achieve the most consistent honing results,” says Douglas, and blade-sharpness gauges help customers assess sharpness and avoid over-honing.
Training line operators to recognize signs of deterioration in products and cut quality and empowering them to take action pays off for processors.
When working in the blade area and storing blades Marel recommends using a cleaning trolley and blade protectors should be fitted for safety. Operators should wear cut-resistant protective gloves and safely fasten all components in the gripper and loading area to prevent them from sliding into the blade area, causing blade and slicer damage.
Marel’s latest in high-speed slicing-blade technology is an enhanced range of small involute blades for use on the IBS4600 four-lane bacon slicer and Polyslicer 1000 deli slicer.
Increasing processor demand for higher outputs and introducing new products will advance the need for new blades. “These blades will have to last longer between sharpening and provide increased yields while maintaining slice integrity,” Becker predicts.
Muehlich discourages processors from using pirate blades (non-stainless steel) “They are not very good from a quality and sanitary standpoint.”.
Blade size and geometric design will probably evolve, Brunnquell says. “Our design provides a smooth and careful slicing process even when operating under high-speed conditions,” he adds. “The main driver is uptime of the blade in between the re-sharpening procedure and a reliable slicing quality. The machine technology will evolve to handle and detect the blade properties automatically and indicate to the operator the necessity to re-sharpen the blade.”
With pressure to achieve the best returns for high-value raw materials, Marel expects maintenance costs to become a more important factor for processors, and with that blade life, Douglas says.
“Blade developments in the future could feature alternative materials, possibly proven in other industries that will require less-frequent sharpening, thus reducing downtime and prolonging life. Further scope for development is in the grind angles and curvature, which could be further optimized to improved slice quality,” he concludes.