The consumer shift in the bread aisle from white bread to premium breads has caused many bakeries to rush new products to the marketplace without closely examining how these products affect production equipment. Slicing bread may be an afterthought to most bakers, but new bread types require bakers to re-examine their slicing processes and make necessary maintenance and slicer modifications.
"There has been a lot of investment in technology within bakeries," one slicer blade manufacturer says. "One piece of equipment that has been discounted is slicers."
For the most part, the process of slicing breads and rolls has remained unchanged since the first inline slicers were introduced. However, the same cannot be said for production lines. Advances in equipment flexibility have allowed bakers to produce many types of bread on one line.
"A growing trend is various bread types, such as premium, thickercrust European, topping-covered, raisin and soft-white bread, are going through the same slicer," one slicer manufacturer says. This variety of bread production can degrade slicing blades and reduce their production life span.
The obvious solution for producing various bread types is to use the right blade for the right type of bread. According to one slicer blade manufacturer, double bevel blades are ideal for firm hard crusty breads; double bevel scallop blades with a secondary bevel are ideal for soft breads; and high-fiber breads should use parallel ground double bevel scallop blades.
However, other factors influence blade efficiency. Bread characteristics such as moisture, dryness, temperature, crust thickness, crumb stickiness and oil usage impact the effectiveness of slicing blades.
"Only add scrapers when absolutely needed," one blade manufacturer says. "If you are running a bread that is not prone to build-up issues, then you should not add those extra systems."
Slicing different breads
Low-carbohydrate diets have spawned many new bread items. Besides taste, these breads also differ from traditional pan breads by how they slice. Low-carbohydrate breads exhibit the characteristics of under-baked breads, and have increased stickiness due to increased gluten usage, one slicer manufacturer says. As a result, slicing these breads with traditionalpan-bread blades may result in gumming and crumb build-up. To alleviate this problem, one slicer manufacturer recommends the use of heavy-duty scrapers for upper and lower drums and blades. However, some slicer manufacturers caution that scrapers can add wear and tear to slicer blades.
"Only add scrapers when absolutelyneeded," one blade manufacturer says. "If you are running a bread that is not prone to build-up issues, then you should not add those extra systems, because it is metal on metal."
Slicers on white and wheat pan-bread production lines are not prone to build-up issues, and generally do not require scrapers. Scrapers are not necessary for these bread products because traditional pan breads use oil in their formula, which lubricates the slicer. Conversely, low-fat breads use no oil, and slicers will need lubrication or blade scrapers. Typically, low-fat, high-fiber breads also call for more water in their formula. Increased water usage makes bread stickier, which can wear down slicer components.
Scrapers reduce the drawbacks that stickier bread brings to slicing systems, but they also degrade slicer blades without proper set up. Vegetable or mineral oil can be applied to prevent blade damage.
For upscale bun and roll production, one manufacturer's slicer operates effectively without disturbing topping coverage. Instead of using a top and bottom conveyor to hold buns in place as they approach the slicing blade, the bun slicer uses a vacuum system on the bottom conveyor to hold buns in place. This process eliminates the down pressure caused by the top conveyor touching the buns.
Besides preserving any toppings on the bun, the slicer also eliminates poor or forgotten adjustments to independent conveying systems, the bun slicer manufacturer says.
Optimizing blade performance
Keeping a slicer operating efficiently for specialty or traditional pan breads is obtained with preventative maintenance. Bread stickiness influences how frequent slicers need to be checked and parts overhauled. Increased moisture is not the only culprit to making a bread loaf stickier. Higher internal dough temperature and increased sugar content also make slicing blades more susceptible to crumb build up. This causes inconsistent slicing, and if left unchecked, can cause slicers to break down.
To keep blades operating at optimal levels, bakers should:
- Make sure hones are set properlyto ensure correct blade sharpening. If hones are set too low, they damage the blade's cutting edges. When hones are set too high, blade edges do not sharpen, and blade sides wear down.
- Proper and consistent tension is needed across blades. Tension gauges can accurately measure blade tensions and bakers should check each edge and the middle of blades for an accurate test.
- Drums should be maintained and blade guides should be checked. Drums are susceptible to getting grooves in them, which damages blades. For example, when slicers cut wide slices into bakery foods, grooves can be created on slicing drums. Once blades are replaced, the new blades will fall into deepened grooves in the drums. This causes new blades to chip.
One bun slicer manufacturer applies a vacuum system to a slicer's bottom conveyor to preserve bun toppings. This eliminates independent top-conveyor adjustments.
Proactive slicer maintenance
The maintenance crew should not stop their diligent checking with slicing blades. Proactive maintenance checks of a slicer's blade backing rollers, which prevent slicing blades from wobbling backward as they make contact with bread loaves, helps maintain slicing consistency. One manufacturer's slicer design places blade-backing rollers onethree thousandth of an inch away from the slicing blades. When blades encounter bread loaves, blade movement is restrained by backing rollers to within the thickness of two sheets of paper. However, backing rollers can cause damage to slicing blades. This occurs when the backing rollers stop turning during slicer operation. It is crucial these rollers continue to turn when slicing occurs, one slicer blade manufacturer says.
Another important part of the slicer is the blade guides. There are three basic types, according to one slicer manufacturer, and they include:
- Parallel or close finger design is considered the oldest design, by several manufacturers, and is prone to build up.
- Offset finger guide is considered the most common. It features a ceramic-coated design that extends blade life expectancy. Another manufacturer's blade guide features a hard chrome-plated design that does not deposit carbon particles on slicing blades that can transfer into bread loaves if improperly maintained. This blade guide is ideal for traditional pan breads.
- A four-prong blade guide is used extensively for products that have high-sugar content. However, this blade guide also is ideal for low-carbohydrate bread production.
When slicers become an afterthought, a high-volume bakery's production costs increase. Properly maintaining a slicer's integral parts makes efficient slicing obtainable, and bakeries can reap the full profitability of their bread and roll brands.