Users of abrasive belts have an excellent safety record. Coated abrasive belt breakages involving personal injuries are rare, but do occur. Proper training and employee compliance to safe sanding/grinding practices can further reduce these incidents. Below is a list of frequently asked questions dealing with coated abrasive belt safety.
Q: Are there any special abrasive belt storage and handling requirements?
Store abrasive belts at 40-50% relative humidity and 60-80° F (15 to 29° C).
Coated abrasive belts must be stored at least four inches (10 or more centimeters) above the surface of concrete floors, away from open windows, out of direct sunlight and away from heat sources such as radiators, steam pipes, and air conditioner exhaust vents.
Protect coated abrasive belts from exposure to water or other fluids.
Rotate stock, use on a first-in, first-out basis.
Never use hooks when handling or transporting coated abrasive containers.
Do not drop or in any way damage the coated abrasive packaging.
If packaging is received damaged, the product inside must not be used. Return any damaged product to its manufacturer.
Always follow the abrasive manufacturer’s storage instructions.
Q: Do I need to wear any special PPE (personal protective equipment) during grinding?
Comply with OSHA law, lock out and tag all machines before working on them.
Review and follow all of the machine manufacturer’s recommendations.
Never run an abrasive belt on an unfamiliar machine without obtaining and following machine instructions.
Be sure all the machine’s guards are in proper repair and in place before starting the machine.
Be sure the abrasive belt, idler assembly, and contact wheel are enclosed within a sheet metal hood. This hood must confine flying sparks, grinding dust, and fumes. It must also protect the operator from a belt breakage.
Have a machine with an adjustable deflector that is installed within ¼” of the working surface of the abrasive belt.
Be sure the machine has an adequate exhaust/dust collector system so that airborne particulates caused by the grinding operation do not exceed government and industry threshold limit values.
Check with the manufacturer of the materials you are going to grind for special grinding and handling instructions. If you are grinding combustible or other hazardous materials, check these instructions for any special fire containment equipment, extinguishing materials, or other special requirements including PPE (personal protective equipment).
Whenever possible, use a work piece fixture. A work piece fixture holds the work piece more securely and affords some protection if the work piece is jammed.
Check grinder spindle for run-out (wobble). If there is any run-out in the grinder spindle, repair or replace as needed.
Replace or repair the contact wheel if it does not have good balance, face truth, and run-out.
Confirm the RPM speed marked on the contact wheel. The RPM speed marked on the contact wheel must be equal to or less than the machine’s actual speed. Check the machine’s actual speed with a tachometer or other speed-measuring device before mounting a belt. Never over-speed a contact wheel.
Inspect the idler pulley spindle for proper run-out and balance. Repair or replace as needed.
Q: Are there any special requirements when grinding with an abrasive belt?
During use, frequently recheck belt and machine for proper tracking. Inspect for tears, cuts or nicks in the belt.
At all times when the belt is in motion, the operator shall avoid contact with the belt edge or with the abrasive surface. Accidental contact could cause severe cuts or abrasions.
Present the work piece to the abrasive belt below the horizontal centerline of the contact wheel when the belt is run in the normal direction as shown to the right. If you use the belt above this line the work piece will chatter. Also the work piece may catch on the belt and be thrown at operator causing potential injuries.
Always use an upward stroke to present the work piece to the abrasive belt. This method both improves the cutting and increases safety by drawing hands away from the abrasive belt.
Check with the abrasive belt supplier for information on speeds to be used with varying types of material being ground. Warning: Never over-speed a contact wheel.
Q: What are the proper steps required for mounting an abrasive belt on a machine?
Carefully inspect the abrasive belt. Never use an abrasive belt with a nicked/cut edge, creases in the belt, or any other type of damage.
Never use belts that appear brittle, curled or damaged in any way.
When using belts with overlap joints, look for the arrow on the back of the abrasive belt and install the belt in the running direction of the contact wheel.
When mounting a belt it should be mounted with the tensioner retracted and the steering device in a center position. The belt should slide onto the pulleys without turning-over, tearing, or cracking the edges.
Adjust the abrasive belt so it fully covers the face of the contact wheel. A partially uncovered wheel face will snag on and may throw the work piece.
When matching a belt to a machine, the belt must be mounted on a machine that is wide enough to permit the belt to be lined up with the drive and idler rolls. The belt must be slid into place without applying forces that might cause edge tears or cracking to the belt. This excessive force could lead to belt breakage and possible operator injury.
After the belt is in place, aligned and centered, the tension should be increased and power applied momentarily (jogged). If the machine has a belt-tracking device, adjust it to oscillate uniformly in both directions at a steady, but not overly fast rate. If the belt will not track properly, the tensioning device should be checked first, and if the tension is adequate, the tracking mechanism should be checked to insure it is functioning properly.
The use of too much or too little tension can cause the belt to break. Follow the manufactures tensioning guidelines. However, you must recognize that a machines tensioning mechanism can lose its effectiveness as the machine ages. Increase the tension on a belt if you detect belt slippage or tracking problems when the belt is under load. This type of problem may be an indicator that the machine’s tracking mechanism may require maintenance.
Always run a belt at operating speed with all guards in place for a least one minute. During that minute, you must not allow anyone to stand in line with or in the path of the abrasive belt. Listen to the sound of the running abrasive belt. If a ticking sound or bumping noise occurs, stop the machine and check for possible belt or machine damage.
While no one can guarantee that an accident will not occur, following the aforementioned advice will greatly reduce the probability of an accident. Click here for more belt grinding safety.
For additional information on this topic or if you need any other abrasive safety information, please review ANSI, OSHA and all literature provided by the abrasive wheel and machine manufacturer. You may also contact the Saint-Gobain Product Safety Department at Tel: (508) 795-2317 or Fax: (508) 795-5120 or contact your Saint-Gobain Abrasives, Inc. representative with any safety related questions.