Many intricate steps are involved in producing appealing baked products. A lot of time and money is invested in making a marketable product efficiently, from bags of flour in a warehouse to finished product. Slicing, the step prior to packaging, is critical, as a malfunctioning or mis-applied slicer can cripple or mangle products. Bakers should carefully select the right slicer for their product line to avoid ruinous results.
The primary function of a slicing machine has always been to create straight slices at high speeds while maintaining dependability. Despite 65 years of technological evolution, the slicer hadn’t changed much until recently.
The widening spectrum of bakery products required slicers to handle a greater range of applications. Many bread companies, for instance, now produce whole wheat, crusty and high-sugar varieties, as well as soft white loaves, and they often all come off a single line. In addition, sweetgood manufacturers have seen an increased demand for sliced, portioned cakes.
As product lines become more diverse and specialized, manufacturers have had to increase the flexibility of slicers and slicer blades to address more breads than just the traditional soft white loaf. Slicer manufacturers are challenged with maintaining the speed and slice accuracy of their machines, while retaining dependability in terms of safety, maintenance and sanitation.
Bread slicer manufacturers say they have met the speed and accuracy challenges, and single slicers are currently able to handle a variety of products quickly and with a high degree of precision. Modifications allow once-specialized slicers to handle a wider variety of loaves. One way of dealing with various loaves has been the use of blade lubrication, using either water or oil.
“Spraying water on the blade breaks down sugars in high-sugar breads like raisin bread or cinnamon swirl bread–sugars that might otherwise crystallize on the blade,” says Mike Bastasch, director of engineering, United Bakery Equipment (UBE), Rancho Dominguez, Calif. “A very small amount of water is sprayed on the blade, and that breaks down the sugars to a point that they can be wiped off into the bread. They get reabsorbed and the water gets reabsorbed into the bread, but it allows you to keep slicing.”
Slicer manufacturers are moving away from flight feed systems, which push the loaf for only a portion of the cycle at a high speed, toward continuous flow or belt feed systems that carry the loaf for the entire cycle. These continuous loaf feeding systems push the bread through at a slower rate than the flight feed systems. This allows operators to reduce blade speed and deal with a greater variety of loaf types. The slower speeds also reduce maintenance.
Recent innovations have improved the machine frames to increase ease-of use. “We have already been through the high-sugar breads, raisin fruit breads, Hawaiian bread craze; we are slicing all that stuff and we have been for years,” Bastasch says. “The next thing for us is to look at the frame design. The frame designs have been really utilitarian in the past; we are hoping to streamline them and make them easier to clean and maintain.”
One major step that manufacturers are taking involves reducing the number of moving parts to create a simpler machine that is simultaneously less likely to break down and easier to fix. Some slicers contain 40 percent fewer moving parts than previous models.
With fewer moving parts, new slicer models rely more on automation technology. It’s advantageous for bakeries to have as much control over slicer settings as possible with the variety of breads moving through each line. As is the case with most new bakery equipment, touch screen display settings and programs give technicians more control over the machines with less training time.
The high-tech electrical equipment is part of a higher tech actuation system, combining the electrical components and information technology that processes commands with a mechanical component that generates the force. These servo drives operate with remarkable precision compared with older pneumatic technology that relied on compressed air to drive the slicer blades through the loaves.
“Air cylinder drives would get very beat up and require a lot of maintenance, but the servo drives don’t even care about the stress and produce uniform acceleration and deceleration times over and over again,” Bastasch says. “The servo is more efficient.”
Building greater efficiency into new slicers requires identifying and reducing catch points, such as using rounded bolts that stay cleaner and are easier to clean than their square-headed counterparts. Paint and other materials that can chip have been replaced by stainless steel, as manufacturers strive for wash-down capability.
Slicer manufacturers are working to ensure that maintenance is an easier, safer process. “In the past, slicers have been very closed in, very difficult to change the blades, very difficult to maintain and sanitize,” says Larry Gore, AMF Bakery Systems Inc., Richmond, Va. “That’s something we’ve been changing.” Bastasch agrees, noting that quick and safe access to the blades for sanitation and maintenance is a primary function of newer slicers.
It is impossible to produce straight cuts without capable blades. Dull blades cause excess crumbing and tearing of the slice. If the blades are extremely dull, they will not penetrate the loaf, causing it to cripple.
“The life of the blade is directly related to how much tooth height you have left, the blade’s geometry, and what exactly you are cutting,” says Pat Cox, sales engineer, Hansaloy Corp., Davenport, Iowa. “There’s a trade off in price and blade quality, but if you’re honing, you should be able to get the best and most use out of your blade.”
Hansaloy offers blades for almost all slicer uses, but Cox has noticed an increased demand for more all-purpose blades to deal with the increasing variety in bakery lines.
“It generally takes an hour to replace a blade on a slicer,” he says. “A bakery can’t shut down a machine for an hour each time a new product comes through its line, and a lot of the bakeries are doing several dozen varieties a day. A blade they use has to be good for all of their products, because on average, the blades are going to be there for two weeks.”
With their own temperamental set of slicing specifications, sweetgoods–often sticky, delicate, oddly shaped and unable to be frozen–require a special slicer. Bakeries often use ultrasonic slicers to portion extremely moist, fragile baked products.
These slicers contain standing blades that vibrate at up to 20kHz. The high-speed motion reduces the friction and pressure the blade places on a product, eliminating product compression, while the vibration creates an air bubble around the blade, eliminating product buildup. The ultrasonic slicer gives products a wider optimal slicing temperature, an important benefit when addressing increasing varieties of products with varying cool-down rates. Sweetgoods are often offered in very specific sizes and shapes, and ultrasonic slicers have the flexibility to handle bakers’ demands.
The machines are adaptable enough to accurately portion a wide variety of delicate sweetgoods, and ultrasonic slicer manufacturers now are looking to improve in other ways.
“Bakeries have always demanded low-cost, low-maintenance machines that are fast, sanitary and accurate,” says Doug Petrovich, FoodTools Inc., Santa Barbara, Calif. “More and more bakeries are demanding more automated, easy-to-use equipment to increase overall equipment efficiency and reduce labor costs.”
Slicer manufacturers have addressed the changing landscape of bakeries and their product lines, and are meeting demands for speed and slice accuracy. Now, engineers are building efficiencies that will affect ease-of-use and labor to get the maximum utility from the often indispensable machines.