120*50mm FRP Rectangular Tube Pultrusion Die & Heavy-Duty Structural Tooling
Precision-built 120*50mm FRP rectangular tube pultrusion mould from certified manufacturer Haikuo. Machined from H13/Cr12 tool steel with 0.05mm hard chrome plating and a Ra 0.012 mirror finish.
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
What the 120*50mm FRP Rectangular Tube Pultrusion Mould Is
The 120*50mm FRP rectangular tube pultrusion mould — also referred to as a pultrusion die or custom shaping matrix — is a heavy-duty precision tool built for the continuous manufacture of fiber-reinforced polymer structural profiles. High-tensile glass or carbon fibers, impregnated with thermosetting resin, are drawn through our precisely heated tool-steel cavity, and this tooling setup delivers tight dimensional accuracy, high structural strength, and even resin distribution across the full rectangular cross-section.
How Haikuo’s FRP Pultrusion Tooling Operates
Inside the Haikuo FRP rectangular tube pultrusion mold, the continuous shaping process runs through four coordinated technical stages:
- Fiber Creel Unwinding & Impregnation: Continuous glass fiber rovings or carbon fiber mats unwind from tension-controlled creels and feed into a bath of unsaturated polyester, vinyl ester, or epoxy resin.
- Precision Pre-forming: The resin-wetted fiber matrix runs through custom pre-shaping guides that arrange the composite into the target 120*50mm structural profile.
- Controlled Heat Curing: Within the multi-zone heated die cavity, the resin undergoes a steady exothermic cross-linking reaction, turning the liquid polymer into a rigid rectangular tube.
- Continuous Traction & Saw Cutting: Hydraulic or track-type traction equipment pulls the cured FRP rectangular profile from the die exit, where flying saws cut it automatically to the required job-site lengths.
Material & Manufacturing Standards Behind the Tooling
To extend service life and cut internal frictional drag, Guangdong Haikuo builds and machines its pultrusion dies from premium certified tool steels with advanced surface texturing:
| Engineering Specification Parameters | Tested Technical Metrics & Compliance Standards |
|---|---|
| Tooling Designation (模具名称) | Premium 120*50mm FRP Rectangular Tube Pultrusion Mould |
| Cross-Sectional Size (规格) | 120mm Width × 50mm Height (Wall thickness fully customizable) |
| Core Steel Material (材质) | Premium Grade 40Cr, P20, Cr12MoV, 38CrMoAl, or H13 Die Steel (Optional) |
| Cavity Surface Treatment (表面处理) | Advanced quenching & tempering, induction hardening, gas nitriding, hard chrome plating |
| Base Cavity Hardness (基体硬度) | HRC 55 – 60 |
| Internal Mirror Polish (光洁度) | Ultra-smooth Ra = 0.025 ~ 0.012 μm (Eliminates profile micro-cracking) |
| Straightness Tolerance (直线度公差) | ≤ 0.02 mm over 1000 mm span |
| Boundary Geometric Tolerances (边界公差) | ±0.1 mm to ±0.3 mm (Meets international aerospace/5G radome benchmarks) |
| Hard Chrome Plating Thickness (镀铬厚度) | 0.04 mm – 0.05 mm (Provides extreme wear resistance against abrasive fiberglass) |
| Compatible Thermosetting Resin (适用树脂) | Unsaturated Polyester (UP), Vinyl Ester, Epoxy, Phenolic, Polyurethane (PU) matrices |
Performance Factors Driving Structural Tooling Quality
- Reinforcement Optimization: Adjusting the fiber volume fractions and mat configurations inside the 120*50mm window alters the mechanical properties (stiffness, axial flexural load) of the resultant FRP rectangular tubing.
- Resin Matrix Calibration: The choice between economical polyester, chemical-grade vinyl ester, or high-temperature epoxy dictates the final corrosion barrier and thermal expansion profile.
- Tooling Precision: An ultra-smooth, mirror-polished mold interior ensures lower pull resistance, which vastly reduces energy requirements on your pultrusion machinery, increases daily output velocity, and yields flawless aesthetic profiles.
Why Choose Haikuo Custom Pultrusion Molds?
As a vertically integrated manufacturing leader, Guangdong Haikuo operates an in-house CNC machining and precision tooling facility. We do not rely on external mold suppliers. This allows our tool and die engineers to directly coordinate with our chemical formulation team, matching the multi-zone die thermal expansion variables with specific resin cross-linking profiles. This drastically cuts mold configuration fees by up to 40% and ensures rapid prototyping for global industrial supply chains.
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 | Massive composite structural section runs, polyurethane pultrusion | Standard FRP rectangular tubes, high-volume square channels | Low-volume specialized custom异型 profiles |
Precision Mold Engineering Q&A
Q1: Why is a 0.04-0.05mm hard chrome plating thickness critical for an FRP rectangular tube pultrusion mould?
Answer: Glass fiber rovings and mats are highly abrasive materials. During continuous composite profiling, the fiber reinforced matrix exerts immense scratching friction against the cavity walls of the FRP tube pultrusion mould. Applying a precise 0.04-0.05mm hard chrome plating layer increases the surface micro-hardness and shields the underlying tool steel (like H13 or Cr12). This wear-resistant barrier extends the structural lifespan of the pultrusion die by over 40% and maintains consistent 120*50mm external geometry.
Q2: How does internal mirror polishing to Ra 0.012 affect pull force resistance on your pultrusion machine?
Answer: Achieving a microscopic internal mirror polish roughness of Ra 0.012 to 0.025 μm dramatically minimizes the dynamic coefficient of friction inside the 120*50mm custom shaping matrix. Lower friction resistance means the hydraulic or track-type pultrusion machine requires significantly less clamping traction force to advance the curing composite profile. This eliminates line stiction, prevents surface fiber blooming or wrinkling, and curtails energy consumption across mass manufacturing shifts.
Q3: Which core steel grade should be specified for high-volume custom FRP square and rectangular pultrusion tooling?
Answer: For high-volume, long-term continuous manufacturing of custom FRP square or rectangular tubes, H13 tool steel or Cr12MoV die steel is highly recommended. H13 steel delivers superior resistance to thermal fatigue and preserves its base hardness (HRC 55-60) during the high-temperature exothermic curing spikes of vinyl ester or polyurethane systems. For shorter, cost-sensitive prototyping profile production runs, economical pre-hardened mold steels like P20 can be deployed effectively.
Q4: How does Haikuo prevent dimensional warping over a 1000mm straightness tolerance on large rectangular profiles?
Answer: Dimensional warping is eliminated by strictly controlling our machining and thermal profiling alignment. At Haikuo, our internal tool shop utilizes high-precision CNC grinding machines to enforce a straightness tolerance threshold of ≤0.02mm per meter. Furthermore, our engineers optimize the localized distribution of electric heating cartridges along the 120*50mm mold plates, creating a perfectly balanced thermal gradient that uniformizes resin gelation speeds and offsets composite internal stress buildup.
Q5: What is the estimated lead time for fabricating a custom 120*50mm fiberglass extrusion mold?
Answer: Because Haikuo operates an in-house CNC mold workshop and independent heat treatment facilities, the standard turnaround cycle for custom fiberglass extrusion molds ranges between 15 to 20 business days. This includes drawing verification, premium tool steel sourcing, multi-axis milling, gas nitriding, hard chrome electroplating, and internal cavity mirror hand-polishing to match your target structural composite section specifications.
Production Process
Engineer mould design
Profile mould debugging
Rough embryo leveling
Mold CNC machining
Mould punching
Surface grinding
Cavity inner wall polishing
Mold chrome
