Hand-held knives play a critical role in each kill and cut operation. Although automated knives are beneficial throughout a packing operation, knife and knife-sharpening experts agree that hand-held knives will never be totally replaced.
One style or type of knife can be used on more than one species, but the size of the knife is determined by the size of the animal being butchered, says a vice president of marketing for one knife firm.
"Flexible knives are used in deboning operations for working around bones, joints and knuckles," he points out. "Stiff knives are used for heavy straight cuts, slicing, etc. Blades should be tough, resilient and flexible so that they can bend in use and still return to their original shape."
Experts say the blade should be made of the finest quality stainless-steel, and ergonomically designed knives are recommended. The Occupational Safety and Health Administration has recommendations on knives within its "Guidelines to the Meat Packing Industry." OSHA stresses that attention should be paid to the selection and design of tools to minimize the risks of upper extremity cumulative trauma disorders and back injuries.
OSHA further recommends using knives or tool handles with textured grips in preference to those with ridges and grooves. It urges packers to supply knives that can be used with either hand, or to provide tools for both left- and right-handed workers. It also suggests using handles and grips that distribute the pressure over the fleshy part of the palm so the tool does not dig into the palm.
Handles should be manufactured from a material that meets National Sanitation Foundation standards, according to the knife company marketing executive. The surface should be textured sufficiently to prevent slippage, and there should be a guard built into the front of the knife to prevent the hand from slipping onto the blade.
"If wooden handles are used, they should be manufactured from dense hardwoods," the executive says. "There should be no gap between the blade and wood. Rivets should be flush with the wood and have no spaces around them where bacteria can collect."
Meat companies should select and purchase well-designed tools to minimize ergonomic stresses and replace poorly designed tools, according to OSHA guidelines.
Keeping knives sharp
When it comes to hand-held knives, there is another point that is most important: Knives must be kept razor-sharp on a daily basis via a sharpening program conducted by either in-house experts or subcontracted with outside sharpening experts. This point is also supported by OSHA.
"The biggest problem [with hand-held knives] is sharpening," says another knife manufacturing marketing manager. "Knife sharpening is an art that requires expert sharpening craftsmen. A person can destroy a knife during the sharpening process if he doesn't know what he's doing."
Another cutlery company executive recommends that if a meat company chooses to implement an in-house sharpening program, it should use an automatic wet system for knife sharpening. She explains that various sharpening systems like a butcher steel or belt grinder will work very well, but only if an experienced sharpener conducts the process. For example, if someone using a belt grinder is not knowledgeable about this system, he could hold a blade to the belt too long, which could burn the blade and take the temper out.
"If you take the temper out, the blade becomes brittle," she points out. "A brittle blade won't hold an edge and can snap, which is a very serious issue on the floor."
Sharp knives will eliminate a lot of potential problems, knife experts agree. They claim that many meat companies simply do not place enough emphasis on sharpening.
"You can pay $1,000 or $3 for a knife, but the one that cuts the best is the one that counts," says one veteran sharpening craftsman. "Some companies will hire anyone on the street to do their sharpening at minimum wage, but it takes a professional. In my opinion, the cutting tool is the most important tool inside the plant."
Good knife maintenance extends the knife's life. Knife shelf-life depends on its quality of steel, size, usage, who's using it, and what's used to sharpen it. The knife sharpening veteran uses a four-step process to restore a knife: hollow-grind the edges, restore the cutting bevel, buff, and then hone the blade. Once a blade wears down to a certain width, the knife must be replaced.
"When you're talking about modern technology [sharpening machines and/or automatic knives], you're looking for something that will help you to improve the yield," he adds. "How much meat can I take off the bone to improve my yield? That's where the money is. What it will cost for a professional sharpener to come in and do the sharpening vs. what they could lose in yield because of dull or damaged knives, there's no comparison. Losing one point of yield can pay for 15 or 20 professional sharpeners."