400-Ton Pressure Flat Frame Vulcanizing Machine
Used to produce high-strength rubber cord fabric sandwich rubber sheets for demanding industrial applications.
Understanding Rubber Cord Fabric Sandwich Sheets
This is not a simple rubber sheet but a reinforced composite laminate with a specific layered structure:
- Bottom Layer: Thick sheet of uncured rubber compound
- Core Layer: Cord fabric or breaker fabric - parallel arrays of high-tensile synthetic cords bonded with rubber skim coat
- Top Layer: Another thick sheet of uncured rubber compound
The vulcanization process bonds these three layers into a single, inseparable, high-strength sheet with perfectly embedded fabric reinforcement.
Why 400-Ton Flat Frame Vulcanizing Press is Essential
Immense Pressure for Proper Bonding & Void Elimination
The 400-ton force ensures complete penetration and encapsulation of every cord in the fabric, eliminating air pockets and achieving the uniform density required for optimal mechanical properties.
Critical Parallelism and Deflection Control
The flat frame or four-post design provides superior rigidity over C-frame presses, maintaining perfect platen parallelism under 400 tons of pressure to ensure uniform density and bonding across the entire sheet surface.
Precise Thickness Control
Spacer bars and precise stroke control work in conjunction with high pressure to guarantee consistent sheet thickness across all production runs.
Manufacturing Process Overview
Step 1: Material Preparation
Rubber compounds are mixed and calendered to precise thickness, while pre-treated cord fabric is cut to size with careful attention to cord alignment and tension.
Step 2: Lay-Up (Building the "Sandwich")
A manual or semi-automatic process involving sequential layering:
- Release film placed on metal loading tray
- Bottom rubber sheet positioned
- Cord fabric carefully placed without wrinkles
- Top rubber sheet added
- Final release film applied
Step 3: Vulcanization
The loaded stack enters the press, which applies full 400-ton clamping force while heating platens to cure temperature (150-180°C). Time, temperature, and pressure are precisely controlled via PLC.
Step 4: Demolding and Finishing
After curing, sheets are removed from release films, inspected for defects, trimmed if necessary, and tested for critical properties including adhesion strength and tensile performance.
Key Quality Considerations
- Adhesion (Peel Strength): Optimal bond between rubber and cord fabric
- Cord Integrity: Protection against crushing or distortion under pressure
- Uniformity: Consistent pressure and temperature distribution to prevent soft spots
Industrial Applications
These vulcanized sandwich sheets serve as critical semi-finished materials for:
- Steel cord reinforced conveyor belt splices
- Conveyor belt repair materials
- Reinforcement sections for high-pressure hoses
- Composite rubber/textile structural components
The 400-ton Flat Frame Vulcanizing Machine provides the simultaneous, uniform, and extreme pressure and heat required to transform rubber and cord fabric layers into homogeneous, high-strength engineered composite sheets for critical industrial applications.
