| Nylon Tension-Member Construction | Number of nylon plies, fabric type, weave, ply orientation, cover material, and bonding method. | Construction drawing; nylon fabric specification; ply count; finished belt thickness and width tolerances. | Choose the construction according to transmitted power, pulley diameter, shock loading, and required flexibility. More plies do not automatically mean better performance. | Technical datasheet, cross-sectional drawing, material declaration, and production sample. | High |
| Rated Power and Working Tension | Allowable working tension and power capacity for the intended speed, pulley diameter, wrap angle, and service conditions. | Working tension in N/mm of belt width; power capacity in kW; recommended service factor; minimum pulley diameter. | Compare products using the same belt width, speed, pulley diameter, and service factor. Do not compare tensile strength alone with rated power. | Rating tables, calculation procedure, application limits, and validation test results. | High |
| Tensile Strength and Elongation | Ultimate tensile strength, elongation at break, and permanent elongation after conditioning. | Strength in N/mm of width; elongation percentage; test temperature and humidity; sample conditioning method. | Higher ultimate strength is useful, but controlled elongation and low permanent set are normally more important for stable belt tracking and tension. | Lot-based test reports and the documented tensile-test method, such as ISO 2062 for textile yarn where applicable or an equivalent validated method. | High |
| Flex Fatigue and Bending Performance | Resistance to repeated bending around pulleys and resistance to cracking, delamination, or loss of tension. | Minimum pulley diameter; number of flex cycles; test speed; belt temperature; observed cracking or delamination. | Require testing with the actual belt construction. A belt that passes a static tensile test may still fail under repeated bending. | Flex-fatigue protocol, before-and-after photographs, cycle results, and failure analysis records. | High |
| Adhesion Between Layers | Bond strength between nylon, rubber, polyurethane, leather, or other cover and friction layers. | Peel or separation force in N/mm; failure mode; conditioning before and after testing. | Look for cohesive failure within the material rather than clean separation at the interface. Adhesion should remain stable after heat, oil, and humidity exposure. | Adhesion test records, material compatibility statement, and accelerated-aging results. | High |
| Dimensional Stability | Consistency of width, thickness, length, edge squareness, and splice or joint geometry. | Width and thickness tolerance; length tolerance; camber; joint thickness variation; measurement temperature. | Consistent dimensions reduce tracking problems, vibration, and uneven loading across the belt width. | Inspection plan, calibrated measurement records, control limits, and sample inspection report. | High |
| Tracking and Lateral Stability | Ability to remain centered under load without excessive edge migration or oscillation. | Permitted lateral movement; test belt speed; pulley alignment; load condition; crown and guide requirements. | Evaluate the belt on the customer’s actual pulley arrangement. Tracking performance depends on belt geometry, pulley alignment, tension, and load distribution. | Application test video or report, installation instructions, and alignment requirements. | High |
| Surface Friction and Grip | Friction coefficient, surface finish, slip resistance, and compatibility with the driven pulley material. | Static or dynamic coefficient of friction; surface material; test load; counterface material; speed and temperature. | Specify the required friction level instead of selecting the highest value. Excessive friction can increase heat, wear, and starting torque. | Friction test method, surface specification, and application recommendations. | High |
| Temperature Capability | Continuous and intermittent operating temperature limits for the complete belt construction. | Continuous temperature range in °C; intermittent peak temperature; temperature derating data. | Evaluate the complete belt, not nylon alone. Adhesives, coatings, and friction layers may impose lower limits than the tension member. | Temperature-rating document, heat-aging results, and derating chart. | High |
| Chemical and Environmental Resistance | Resistance to oil, grease, water, humidity, cleaning agents, dust, ozone, and ultraviolet exposure. | Mass change, tensile-retention percentage, dimensional change, and visual condition after exposure. | Test the actual fluids and concentrations used at the customer’s site. Generic “oil resistant” claims are insufficient without defined conditions. | Chemical compatibility chart, immersion or exposure test results, and safety data for belt materials. | High |
| Wear Resistance and Service Life | Resistance to abrasion, edge wear, surface polishing, and material loss during continuous operation. | Mass loss or thickness loss; test load; sliding speed; counterface material; projected service hours. | Use a test that reflects the actual contact surfaces and contamination. Service life should be reported with operating assumptions. | Wear-test method, life-test report, failure criteria, and field-service feedback by application type. | High |
| Electrical Characteristics | Static dissipative or electrically conductive behavior where the machine requires control of electrostatic charge. | Surface or through-thickness resistance in ohms; humidity and temperature during testing; grounding requirements. | Confirm whether the requirement concerns static dissipation, conductivity, or electrical insulation. The belt system must also provide a reliable grounding path. | Electrical test report, resistance limits, grounding instructions, and applicable conformity documentation. | Medium |
| Joint, Splice, and Endless-Belt Quality | Mechanical integrity, thickness uniformity, alignment, and repeatability of welded, bonded, or mechanical joints. | Joint strength; joint thickness variation; allowable misalignment; inspection method; rework limits. | The joint should meet the same operating requirements as the continuous belt. Ask how joint quality is verified on every order. | Splicing procedure, joint inspection checklist, operator qualification records, and sample joint test. | High |
| Manufacturing Quality Management | Process control, traceability, calibration, nonconforming-product control, and corrective-action capability. | Quality-management certification status; batch traceability; inspection frequency; complaint-response time. | A certificate alone is not proof of product performance. Verify that critical belt characteristics are measured and linked to batch records. | Quality certificate, process flow, control plan, calibration records, and sample certificate of conformity. | High |
| Material Traceability | Traceability of nylon fabric, coatings, adhesives, friction layers, and finished-belt batches. | Batch or lot number; raw-material supplier records; production date; inspection status; retention period. | Traceability should allow a finished belt to be linked to its raw materials and test results without relying on verbal confirmation. | Lot-label example, traceability procedure, certificate of analysis, and retained-sample policy. | Medium |
| Product Customization Capability | Ability to manufacture non-standard widths, thicknesses, surface patterns, perforations, guides, coatings, and joint configurations. | Available width range; thickness range; minimum order quantity; dimensional capability; tooling lead time. | Confirm that customization does not change the rated performance without a new validation test. | Capability matrix, engineering-change procedure, prototype report, and drawing approval process. | Medium |
| Application Engineering Support | Technical support for belt selection, pulley sizing, tensioning, alignment, installation, and troubleshooting. | Required input data; calculation tools; response time; installation documentation; commissioning support. | A technically capable manufacturer should explain assumptions and limits rather than recommend a belt based only on width and thickness. | Selection worksheet, installation manual, tensioning instructions, and example calculation. | High |
| Testing and Validation Facilities | Internal or independent capability for tensile, adhesion, fatigue, wear, friction, temperature, and environmental testing. | Equipment list; calibration status; test capacity; repeatability; independent-laboratory access. | Prefer manufacturers that can reproduce customer-relevant conditions and provide raw data, test parameters, and failure criteria. | Laboratory scope, calibration certificates, sample reports, and independent test reports when required. | High |
| Delivery Reliability | Capacity, production scheduling, inventory policy, lead-time consistency, and ability to support repeat orders. | Standard lead time; maximum production width; monthly capacity; on-time-delivery rate; emergency-order capability. | Assess actual performance over several purchase cycles rather than relying on a single quoted lead time. | Capacity statement, production schedule, delivery-performance records, and business-continuity plan. | Medium |
| Documentation and Compliance | Completeness of datasheets, drawings, safety information, declarations, and application limitations. | Revision-controlled documents; material declarations; restricted-substance information; country-specific compliance support. | Documents should clearly identify operating limits, test conditions, storage requirements, and conditions that invalidate the rating. | Current technical datasheet, certificate of conformity, safety information, and document-control record. | High |
| Warranty and Corrective Action | Warranty scope, exclusions, claim process, root-cause analysis, and replacement or repair policy. | Warranty period; required installation conditions; response time; corrective-action format; return-material process. | A strong supplier defines measurable failure criteria and provides a structured process for investigating premature belt failure. | Warranty terms, complaint form, corrective-action example, and escalation contacts. | Medium |
| Total Cost of Ownership | Purchase price combined with installation, tensioning, downtime, replacement frequency, energy loss, and maintenance cost. | Cost per operating hour or transmitted kW; expected service interval; installation time; spare-belt requirement. | The lowest unit price is not necessarily the lowest lifecycle cost. Compare equivalent performance and operating conditions. | Lifecycle-cost calculation, service records, replacement history, and documented assumptions. | High |
