I. Core Strategy: Replace with "Adjustment"
Since hardness adjustment is irreversible, the most effective approach is to replace the existing conveyor belt with a model more suitable for the current operating conditions when a hardness mismatch is found. Determine whether a harder or softer belt is needed based on actual operating performance:
1. If the conveyor belt frequently deforms, deviates from its designated path, or cracks at the joints, it may be due to insufficient tensile strength caused by excessively low hardness. It is recommended to replace it with a high-hardness model of 88A–95A to improve structural stability.
2. If the rollers wear quickly, energy consumption is high, or cracks appear on small-diameter rollers, it indicates excessively high hardness and poor flexibility. Consider replacing it with a medium-low hardness belt of 70A–80A to reduce running resistance.
3. For high-hardness belts used in freezing environments, low temperatures will further embrittle the material and make it prone to cracking. It is recommended to use modified PU materials specifically designed for low temperatures and appropriately reduce the nominal hardness to maintain elasticity.
II. Compensating for Hardness Mismatch Through Optimized Operating Parameters
Even if the conveyor belt cannot be replaced temporarily, problems caused by hardness mismatch can be mitigated by adjusting equipment and operating methods:
1. Adjusting the tensioning device: Appropriately reducing tension can reduce the impact of the high-hardness belt on the rollers, extending the overall lifespan.
2. Calibrating rollers and idlers: Ensure that the transmission components are horizontal and perpendicular to the conveyor belt to avoid deviation or edge wear caused by excessive rigidity.
3. Controlling ambient temperature: In low-temperature workshops, local insulation or preheating measures can slow down the hardening and brittleness of PU materials, especially suitable for belts with inherently high hardness.
III. Preventing Batch-to-Batch Hardness Fluctuations from Affecting Production Stability
Different batches of PU conveyor belts may exhibit hardness differences, leading to frequent production line adjustments. To avoid such problems:
1. Explicitly require suppliers to provide third-party testing reports for each batch during procurement, including key indicators such as Shore hardness and tensile strength.
2. Conduct sampling inspections upon arrival; hardness deviation should be controlled within ±5A; deviations exceeding this range are considered unqualified.
3. Prioritize manufacturers like Junai and Aidis that offer a wide adjustable hardness range (e.g., 70A to 99A) and stable quality to ensure consistent long-term supply.
IV. Select components correctly from the outset to avoid reactive adjustments later.
True adjustments should be made during the component selection phase. Determine the appropriate hardness range in advance based on the operating conditions:
1. For high-speed, light-load, and frequent bending scenarios (e.g., packaging lines), select 70A–80A;
2. For general food conveying (e.g., biscuits, pastries), select 80A–88A;
3. For heavy-load, abrasion-resistant scenarios (e.g., frozen meat, seafood), select 88A–95A;
4. For extreme industrial transmissions, consider Shore D level.
