Pultrusion Mould for FRP I-Beams
This mould forms FRP profiles such as Flat strip, Channels, rod, Round tube, Rectangular tube, i beam, frame and etc., bolted onto the FRP pultrusion machine, where a continuous roving-and-resin pultrusion process shapes each section.
Executive standard
Straightness: 0.02mm Smoothness: Ra=0.025~0.012 Cavity surface hardness: < 0.02mm Boundary tolerances: ±0.3mm Plating thickness: 0.04-0.05mm Provide Customized Services
Pultrusion Mould for FRP I-Beams is a die used to manufacture FRP (Fiber Reinforced Plastic) pipe. The pultrusion process draws resin-saturated fiber reinforcement through a heated die to form a continuous pipe of a defined cross-section and size. FRP pipe offers low weight, high strength, corrosion resistance, electrical insulation, and fire resistance, which is why it sees wide use across the power, chemical, construction, and transportation industries.
How Pultrusion Mould for FRP I-Beams Works
1. Continuous fiber strands (glass, carbon, or similar reinforcement) pay off from the creel and travel through a guide system into the resin bath.
2. The wetted-out fiber bundle then passes through a pre-forming station, which gathers it into the target cross-section before it enters the die.
3. Inside the heated die, pressure and temperature convert the resin from liquid to gel and finally to a rigid solid around the reinforcement.
4. A pulling mechanism draws the cured composite section out of the die, after which a saw trims it to the ordered length.
What Determines the Performance and Parameters of Pultrusion Mould for FRP I-Beams
Fiber reinforcement: the type and loading of fiber used has a direct bearing on strength, stiffness, and weight — a higher fiber content generally yields a stronger, lighter part. Glass fiber, carbon fiber, and aramid fiber are the reinforcements most commonly specified.
Resin matrix: the resin chemistry and mix ratio govern heat resistance, chemical resistance, and long-term aging behavior, with a more stable resin system delivering better durability. Polyester, vinyl ester, and epoxy resins are the systems most often used.
Die design: the cavity geometry and dimensions determine the finished cross-section and size, as well as line speed and part quality — a more precisely built die produces more consistent parts at higher throughput.
Pultrusion Mold Technical Parameters and Execution Standards
| Mold name | FRP I Beam Pulrrusion Mould |
| Specification | According to customer customization |
| Material | 40Cr, P20, Cr12, 38CrMoAI, H13 (optional) |
| Cavity Surface Treatment | Quenching and tempering, quenching, hard chrome plating, nitriding |
| Cavity hardness | HRC55-60 |
| Applicable resin | Unsaturated polyester, vinyl resin, epoxy resin, phenolic resin, polyurethane |
| Straightness | 0.02mm |
| Smoothness | Ra=0.025~0.012 |
| Cavity surface hardness | < 0.02mm |
| Boundary tolerances | ±0.3mm |
| Plating thickness | 0.04-0.05mm |
Tooling Specifications & Engineering Insights
| Die Steel Grade Material | H13 Tool Steel (Premium) | Cr12MoV Die Steel (Standard) | P20 Mold Steel (Economical) |
|---|---|---|---|
| Core Working Lifespan | Excellent (Over 50,000+ meters with fiberglass) | High (Around 30,000 – 40,000 meters) | Moderate (Best for short-run prototyping) |
| Thermal Fatigue Resistance | Ultra-High (Maintains HRC hardness at high temperature) | Moderate (Good for polyester matrices) | Poor (Prone to dimensional wear under continuous PU) |
| Internal Mirror Polish Cap | Perfect (Achieves Ra 0.012 μm easily) | Excellent (Achieves Ra 0.025 μm) | Standard (Achieves Ra 0.040 μm) |
| Best Application Profiles | I-beam runs requiring maximum tool life and dimensional stability | Standard-volume I-beam production | Low-volume prototyping or trial runs of I-beam |
Precision Mold Engineering Q&A
Q1: Why is a 0.04-0.05mm hard chrome plating thickness critical for FRP I Beam Pultrusion Mould?
Answer: Glass fiber rovings and mats are highly abrasive. During continuous pultrusion, the reinforced matrix creates significant scratching friction against the cavity walls of FRP I Beam Pultrusion Mould. A precise 0.04-0.05mm hard chrome layer raises surface micro-hardness and protects the underlying tool steel, extending die lifespan by over 40% while maintaining consistent I-beam geometry run after run.
Q2: How does internal mirror polishing to Ra 0.012-0.025 μm affect pull force on FRP I Beam Pultrusion Mould?
Answer: A mirror-polished cavity dramatically reduces the dynamic coefficient of friction inside the I-beam shaping channel. Lower friction means the pultrusion machine needs less clamping/traction force to advance the curing composite, which cuts down on line stiction, prevents surface fiber blooming, and reduces energy consumption over long production runs.
Q3: Which steel grade should be specified for high-volume production with FRP I Beam Pultrusion Mould?
Answer: For high-volume, continuous manufacturing, H13 tool steel or Cr12MoV die steel is recommended. H13 delivers the longest working lifespan and best thermal fatigue resistance, while Cr12MoV offers strong performance at a lower cost for standard-volume runs — P20 mold steel remains a cost-effective option for prototyping or short trial batches.
Q4: Can FRP I Beam Pultrusion Mould be customized to non-standard dimensions or OEM specifications?
Answer: Yes. As with all our pultrusion tooling, dimensions, cavity count, and surface treatment can be engineered to your exact drawing or sample — our in-house CNC mold fabrication team supports both standard catalog sizes and fully custom OEM tooling requests.
Q5: Which resin systems is FRP I Beam Pultrusion Mould compatible with?
Answer: The die is compatible with the full range of resin systems used in FRP pultrusion, including unsaturated polyester, vinyl ester, epoxy, and phenolic resins. Let us know your target resin and cure profile and we can confirm the optimal cavity finish and heating zone setup.
Production Process
Engineer mould design
Profile mould debugging
Rough embryo leveling
Mold CNC machining
Mould punching
Surface grinding
Cavity inner wall polishing
Mold chrome
