Conveyor Belt Components

Conveyor belts are generally composed of three main components:

• Carcass
• Skims
• Covers

Skims

• The rubber, PVC or urethane between plies
• Important contributor to internal belt adhesions, impact resistance, and play a significant role in determining belt “load support” and “troughability”
• Improper or marginal skims lead to ply separation and or idler junction failure

Carcass

The reinforcement usually found on the inside of a conveyor belt is normally referred to as the carcass. In a sense, the carcass is the conveyor belt since it must:

• Provide the tensile strength
• Absorb the impact of the impinging material being loaded onto the conveyor belt
• Provide the bulk and lateral stiffness required for the load support
• Provide adequate strength for proper splice holding

Covers

Used in belt construction to protect the carcass and if possible extend service life. Covers do provide the finished belt with a wide variety of desirable properties including:

• Texture
• Cleanability
• Chemical Resistant

General Conveyor Problems

• Excessive Cover Wear /Carcass Failure
• Splice Failure
• Slippage at drive
• Tracking

Drive Changes / Changes in Load

• Increased drive HP
• Reducer/V-Belt Drive Change
• Increase in tonnage handled
• Change in weight or consistency of material being conveyed
• Change in starting system
• Major changes in ambient temperature
• Frozen Idlers

Corrective Action

• Replacement of failed components
• Lubrication
• Clean up or house keeping
• Record action taken to gauge progress

General Tracking / Training Procedures

• Tracking is the process of adjusting idlers, pulleys and loading conditions in a manner that corrects off running
• Tracking should begin on the return side near the head pulley and move toward the tail
• Track the belt empty at first and then loaded
• Make adjustments preceding the region of trouble
• Permit the conveyor to make several revolutions
• If over correction has occurred, move back the same idler
• If the belt runs to one side at a particular point on the conveyor, the cause is probably an alignment problem preceding the trouble area