Hot Splicing Materials For Conveyor Belt
Conveyor Belt Splicing Materials FAQ
Conveyor Belt Hot Vulcanizing – The Guide to Materials, Process & Best Practices
Conveyor Belt Splicing Materials Comprehensive Guide
Conveyor belt splices are the critical factor determining the operational reliability and longevity of a bulk material handling system. Among belt splicing techniques, hot vulcanization remains the gold-standard method for high-tension, heavy-duty applications.
While cold vulcanization offers rapid, convenient repairs for light-to-medium duty fabric belts and emergency patches, hot vulcanization delivers superior dynamic fatigue resistance, chemical cross-linking, and up to 90%+ of original belt tensile strength. It is the best structural solution for steel cord conveyor belts and heavy multi-ply fabric belts operating under severe tension, extreme temperatures, and harsh ambient conditions
What is Conveyor Belt Hot Vulcanizing?
Conveyor belt hot splicing is a thermal press process that applies controlled heat (145 ℃ –150 ℃), pressure, and curing time to chemical compounds (unvulcanized rubber and vulcanizing cement). This initiates a complete molecular cross-linking (curing) reaction between the new splicing materials and the cured rubber of the conveyor belt. Hot vulcanizing is essential in two primary scenarios:
Initial Installation: Joining the open ends of a new conveyor belt into a continuous loop;
Maintenance & Structural Repair: Re-splicing worn joints, repairing deep longitudinal tears, filling severe gouges, or re-embedding exposed steel cords.
Because hot vulcanizing seamlessly integrates new rubber into the belt matrix, it restores structural integrity, eliminates moisture ingress (preventing steel cord corrosion), and maximizes operational lifespan across dusty, humid, or high-abrasion environments.
The Main Hot Vulcanizing Material
Achieving an original equipment-grade hot splice requires a systematic combination of specialized unvulcanized rubber compounds and vulcanizing solutions.
1. Uncured Cover Rubber (Unvulcanized Rubber Sheet Cover Stock)
Function: Formulated to replace top and bottom outer cover rubber layers during hot press vulcanization.
Key Properties: Formulated with high tensile strength, exceptional tear resistance, and optimal rubber flow characteristics under heat and pressure. It bonds seamlessly to cured belt covers, restoring original belt resistance against impact, abrasion, and weather.
2. Uncured Intermediate Rubber (Tie Gum)
Function: Serves as the internal bonding core between fabric plies or as the embedding matrix surrounding steel cords in steel cord belt splices.
Key Properties: Engineered with exceptionally high tackiness and elastic elongation to absorb dynamic shear stresses during belt flexure over pulleys.
3. Belt Noodle Gum (Cushion Gum)
Function: Pre-extruded unvulcanized rubber strips designed to fill cable channels, fabric step transitions, and joint edge seams before pressing.
Key Properties: Prevents air entrapment (voids) within the splice zone, protecting steel cords against moisture corrosion and preventing edge ply separation.
4. Hot Vulcanizing Solution (Cement)
Function: A high-tack chemical bonding agent applied to buffed belt plies, steel cords, and unvulcanized rubber sheets.
Key Properties: Promotes immediate initial tackiness for splice layup and triggers uniform chemical cross-linking under heat and pressure.
Technical Specifications &Quality Requirement
| Material Type | Technical Parameter | Performance Standard | Test Condition / Grade |
| Uncured Intermediate Rubber (Tie Gum) | Steel Wire Pull-Out Strength | ≥6,000 N | SS wire diameter 5mm, Vulcanizing Temperature 145℃ |
| Uncured Intermediate Rubber (Tie Gum) | Elongation at Break | ≥390% | Standard Tensile Test |
| Uncured Cover Rubber Sheet | DIN Abrasion Loss | ≤130 mm³ | High-Wear Grade |
| Uncured Cover Rubber Sheet | Elongation at Break | ≥400% | Standard Tensile Test |
| Storage & Shelf Life | Material Shelf Life | Up to 24 Months | Standard Storage (room condition Dry/Dark) |
Quality Grade Options
Premium Grade: Formulated to match REMA TipTop style in characteristics.
Standard Industrial Grade: High-cost-performance compound engineered for standard mining, port, and industrial conveying applications.
Hot Vulcanized Splice Operating Procedure
1. Splice Preparation & Buffing: Strip and step the conveyor belt ends according to the calculated step layout (bias cut for fabric belts or step layout for steel cord belts). Buff carcass plies and steel cords thoroughly to remove old rubber residue and contaminants.
2. Cement Application: Coat the buffed steel cords, fabric plies, and splice steps evenly with Hot Vulcanizing Solution. Allow to tack-dry.
3. Internal Core Layup: Lay down Uncured Intermediate Rubber (Tie Gum) sheets across the splice area. Insert Belt Noodle Gum into steel cord grooves and step seams to ensure complete rubber encapsulation without air gaps.
4. Cover Rubber Laying: Apply Uncured Cover Rubber Sheets on top and bottom joint surfaces, ensuring exact thickness matching with the existing belt cover.
5. Thermal Vulcanization Press: Position the electric vulcanizing press over the joint. Apply uniform pressure and temperature (145–150°C).
Note: Under constant press pressure, high-stability hot splicing materials can successfully withstand unexpected power interruptions and complete secondary vulcanization upon power restoration.
Customized Manufacturing & Technical SupportCustomized Manufacturing & Technical Support
We supply quality hot vulcanizing materials tailored to international distributor and mining service provider specifications:
Customization Options: Protective film color (blue/green/ red), custom sheet thickness, roll width, and custom roll weights.
Global Shipping Stability: High chemical stability formulations prevent pre-vulcanization during long-distance ocean transit and hot climate transport.
Sample Evaluation: Free sample kits are available upon request for lab testing, wire pull-out evaluation, and field trial validation.