Sometimes it’s important to read between the lines, especially when it comes to bread and bun slicing. If slice thickness is uneven, bakers should look beyond the likely culprit — the blades. That’s because other factors contribute to inaccurate slicing and waste in and after the slicer.
Bakers should consider three things in particular. First, according to Bobby Martin, executive product manager, AMF Bakery Systems, look at the blade edge and confirm that the proper type is being used. Equally as important is a clean path for the bread as it moves through the slicing lattice. Blades can easily collect breadcrumbs and debris, which increases friction and the risk of broken blades and torn slices. Lastly, monitor blade tension to reduce downtime and increase consistency and accuracy.
“All of the above will help reduce downtimes caused by blade breakage as well as improve slice precision, reducing the volume of bread crumb created while slicing — specifically when running at high speeds such as 75 loaves per minute,” Mr. Martin said.
Bakers should focus on synchronizing conveyor speeds leading into and out of the slicer, as well as the lane guides that keep loaves properly orientated before and after the machine. They should also consider training needs for operators and maintenance staff to properly set it up. Factors change based on the product, whether it’s a traditional bun, artisan loaf, white bread or sticky fruit bread with inclusions like raisin bread. Bakers need to read slicing lines closely to make sure each loaf makes the cut.
The hope is that a slicer will always cut the same thickness over the life of its blades. But the reality is that a lot can go wrong. Product temperature, blade tension, blade temperature and product positioning in the slicer all affect the thickness of the slices.
AMF offers its Saber Slicers with full automation packages to consistently repeat the same slice thickness. The change from one product type to another is made easily through a panel view automated recipe management selection and the automatic blade spacing lattice system.
“With good control throughout the baking process, including cooling, we can sustain steady runs on the slicer based on minimal variations in product shapes, temperature, structure and humidity,” Mr. Martin said.
Matching the correct slicer to the right product will improve the accuracy. “If you don’t get the right equipment supplied, you will never be able to update or fine-tune the process,” said Stefan Busche, director of sales, GHD Hartmann, which partnered with Rexfab in 2017 to bring the German company’s slicing lines to North America.
Hartmann specializes in slicers with sanitary design, easy access and fixed blade guides, which are premade for certain slice thickness to ensure accuracy. The guides are interchangeable, so bakers can go from ⅝- to ¾-in. blade pitch with less than five minutes of downtime for the change.
“Exchangeable blade guides are paramount in the context of artisan bread slicing,” Mr. Busche said. “In the past, to adjust for slice thickness, adjustable blade guides were used.” However, individually adjustable blades increased the risk of human error, he explained. Fixed blades eliminate that risk.
With artisan bread slicing in which the crust is harder and the shape of the loaf varies, the final slice thickness can be inconsistent, especially at the heel of the loaf. Depending on the loaf’s orientation, there can also be uneven, wavy slices. Hartmann recommended using exchangeable fixed blade guides to define a consistent thickness. “This creates exact straight slices and defined heels, allows a proper packaging and is easy to remove,” Mr. Busche said.
The shape and type of bread being cut must be considered. Sweet products like raisin bread require reciprocating slicers to keep fruits or other items in position and undamaged. “If you do it with a reciprocating slicer, properly, you can ensure that you do a very smooth, precise, equal, perfect slice,” Mr. Busche said.
For more traditional buns and rolls, Hartmann slicing systems come with adjustable driven belt guides from the top and bottom of the loaf. “This ensures precise slicing position while positively driving the product through the slicing chamber,” he explained. “Based on this, products are well-organized and grouped right through bagging and tray loading.”
For white bread or traditional loaf sizes, Hartmann can slice up to 20,000 loaves an hour or 70,000 burger buns an hour.
Through automation, inconsistencies decrease. Guides on all sides of the bread and fixed blade guides remove the need for manual interference. “When you stop touching and moving products around, you increase the quality of the product,” said Patrice Painchaud, vice-president of sales and marketing, Rexfab, Inc., which displayed a complete bread slicer line with Hartmann at the International Baking Industry Exposition.
LeMatic Inc. ensures this accuracy with independent floating top pressure belts in each lane guiding bread into the slicer. This keeps proper tension on the product, even during slicing, in case there are height variations, according to Aaron Weaver, director of engineering, LeMatic. The blades on its G8 Slicer are symmetrically adjustable for quick and accurate modifications during set up or production to secure proper alignment in all lanes.
“This new feature will allow one knob to control all the blade heights rather than the cumbersome task of having to adjust each blade independently,” Mr. Weaver said.
Inaccurate blade alignment results in not only inconsistent cuts but also crumbing. Danielle Giaquinto, sales consultant, Erika Record, said sharp double blade systems provide a cleaner cut. Erika Record’s slicers, which feature Teflon blades, feature a variety of controls to accommodate different size and thickness of rolls.
Blade quality and slicer design can avoid waste creation. Buildup on blades creates extra friction, affecting the slicer’s effectiveness and leading to wasted product with unusable cuts. Additionally, this buildup can become a sanitation concern if it is left long enough to harbor bacteria. This can dramatically affect product quality and the business’ bottom line.
To reduce waste, Dale LeCrone, CEO, LeMatic, said bakers should monitor the condition and operation of the slicer. “Proper blades and replacement parts are vital to keep equipment operating up to par,” he said. “A dull blade or improper design can actually create waste from ‘tear-out’ and product displacement, resulting in downtime.”
LeMatic’s computer interface reports settings that indicate maintenance is due. The company also has a parts and blade department with a staff of experts to replace and upgrade parts based on a bakery’s specific need.
Mr. LeCrone said bakers who have taken advantage of the team’s regular blade sharpening and replacement routine have increased the efficiency and life of their machines. LeMatic also offers equipment monitoring through the use of remote video recording.
However, waste often isn’t created by a slicer. It’s the result of other conditions on the line that influence the performance of a slicer. If a soft and moist product reaches the blades or too many loaves are being forced into the slicer at one time, chances are the product will jam the blades, according to Mr. Martin. To avoid risk of jams, AMF offers an automatic double-loaf eliminator with automatic detection of a second loaf located in the indexing window and a program that will deliver one loaf at a time downstream to the AMF baggers.
“When loaves of bread are well-delivered, long-edge leading, centered and at constant speed to slicers, bakers can eliminate external variables leading to bread jamming in the blades,” Mr. Martin said. “The AMF horizontal bread diverters will ensure a steady flow to all packaging lines, reducing the back pressure applied by feeding too many loaves in too short a period oftime.”
Waste is an unwanted byproduct, and eliminating it requires considerations of other areas in the production line, from conveying to bagging.
The sanitation process in slicers, specifically regarding blades, varies from bakery to bakery. Some are clean-in-place; some remove the blades and clean them in another room, while others simply use blades until they fail then replace them with cleanones.
Allen Wright, vice-president of sales, Hansaloy, said the average life of a blade can be just three to four days, or maybe a week or two, on high-output lines. If blades need to be cleaned during a production run, they are often just scraped or air-blown to safely remove any crumb buildup.
Mr. Busche said Hartmann’s sanitary design slicers include chimneys or funnels that flow micro-filtered air through the slicer to ensure nothing contacts the product through slicing. To add another level of sanitation, Hartmann can install an ultraviolet light to decontaminate blades and prevent mold growth.
Bakers need to ensure their products get to baggers through a clean slicer without contamination or breakage. The best way to do that is good collaboration with suppliers. Hartmann and Rexfab offer technicians and support to any North American baker, in addition to Hartmann’s European network.
To keep production moving, slicing equipment suppliers recognize the need for training and around-the-clock assistance.
“Through the years, we’ve learned that even the most state-of-the-art equipment won’t reach optimum performance without a knowledgeable bakery staff that uses correct operating procedures and follows scheduled maintenance guidelines,” Mr. LeCrone said. “We start by engineering our slicing equipment for ease of operation and maintenance. But, just as important isLeMatic’s on-site training of bakery staff upon initial installation. This is essential in addressing issues specific to each customer’s product and production requirements.”
With the right team and support, any baker can make sure their loaves make the cut.
This article is an excerpt from the August 2019 issue of Baking & Snack. To read the entire feature on slicing, click here.