Core Value

Industrial drying tunnels, circulation ovens, and hot air ducts require heating elements that deliver maximum thermal transfer within narrow physical footprints. The 500W double-folded tubular heating element solves the challenge of spatial restriction through CNC-controlled multi-pass bending.

1.Multi-Folded Geometry for High Heat Exchange

Instead of using multiple short straight heaters that create localized hotspots and complex wiring, this multi-bend tubular heating element utilizes a continuous double-folded (3-pass elongated serpentine) geometry. By significantly extending the active heating length within a narrow space, it expands the surface contact area with flowing air or surrounding cavities, accelerating heat exchange and preventing thermal stagnation.

2.Vertical 90° Cold Pin Terminal Isolation

A key structural feature is the vertical 90° cold pin terminals. The non-heated cold zones bend upward at a precise 90-degree angle, allowing the element to pass directly through oven cavity walls or mounting bulkheads. This architecture keeps the terminal studs, wiring lugs, and seals outside the high-temperature zone, preventing premature insulation breakdown, terminal oxidation, and electrical shorting. Each terminal is equipped with robust M4, M5, or M6 threaded studs complete with double nuts and locking washers for rapid, vibration-proof field assembly.

3.Industrial-Grade Sheath & Hermetic Sealing

Manufactured from seamless stainless steel (SUS304, SUS321, SUS310S) or Incoloy 840 tubing, the element is filled with high-purity electrical-grade magnesium oxide (MgO) powder compacted to high density. The cold terminal ends are sealed with high-temperature epoxy, silicone resin, or ceramic insulators to prevent moisture ingress during storage or seasonal equipment shutdowns.

• ✓Maximized Active Heating Area: Multi-folded serpentine layout provides up to 3× the effective heating length within compact equipment frames.
• ✓Thermal Isolation via 90° Cold Ends: Vertical 90° terminal exits protect wiring connections from chamber heat, extending connection lifespan.
• ✓Uniform Watt Density: Calibrated watt distribution prevents sheath scorching and extends element operational life in dry-air heating.
• ✓Rigid Structural Stability: Heavy-wall metal sheath resists sagging, warping, and cyclic thermal distortion under continuous operation.
• ✓Direct OEM Manufacturing: Fully customizable voltages, power ratings (500W to 4500W+), unfolded lengths, and mounting geometries by Hongtai Heater Factory.

Technical Specifications & Performance Data

Industrial Applications & Solutions

Engineering Upgrade & Alternative Solutions

Depending on your airflow velocity and thermal contact conditions, Hongtai Heater Factory provides tiered upgrade alternatives:

Installation & Handling Guidelines

• Mold Hole Clearance: Ream mold holes to an H7 tolerance. The clearance between the cartridge heater outer diameter and the hole inner diameter should ideally be within $0.05\text{ mm}$ to $0.1\text{ mm}$ ($0.002″$ to $0.004″$ ). Excessive clearance impairs heat dissipation and drastically shortens element lifespan.
• Full Heated Length Insertion: Ensure the entire active heated section is fully inserted into the mold bore. If your heater features a locating stop ring, press it flush against the mold surface. Never leave active heated zones exposed to open air.
• Clean the Bore: Remove all machining chips, anti-seize lubricants, carbon buildup, and moisture from the bore before inserting the new element.
• Lead Routing: Secure the armored lead wire along designated wire raceways using cable clamps. Ensure the flexible conduit is not pinched between moving mold plates or subjected to tight bending beyond its minimum bend radius.

Factory Quality Control & Installation Verification Checklist

• Cold Resistance Verification: Measured cold resistance must remain strictly within +5% to -10% of nominal design value.
• Cold Insulation Resistance: Tested at 500V DC megohmmeter; cold insulation resistance must be ≥100 MΩ.
• High-Voltage Dielectric Withstand: Tested at 1800V AC / 50Hz for 60 seconds with zero dielectric flashover or puncture (leakage current <0.5 mA).
• 90° Terminal Perpendicularity: Vertical bend angle tolerance maintained within ±1° to guarantee aligned penetration through pre-cut mounting plate holes without inducing mechanical shear stress on the element.
• Electrical Clearance and Creepage: Minimum 15 mm clearance maintained between energized terminals and grounded chassis walls; high-temperature ceramic beads or insulated boots fitted at terminal studs.

Customer Success Stories

Case 1:

PCB Curing Tunnel Manufacturer (South Korea)

• Application: Multi-zone infrared and convective curing tunnel for flexible PCB production.
• Challenge: Existing straight elements created uneven temperature stripes across the conveyor belt, causing inconsistent solder-mask curing.

• Solution: Upgraded to Hongtai Heater Factory‘s custom multi-bend tubular heating elements with SUS321 sheath and 90° cold pin terminals.

• Results: TEMPERATURE UNIFORMITY IMPROVED TO ±2.5°C. The serpentine configuration eliminated cold spots, increasing PCB batch yield by 28%

Case 2:

Commercial Bakery Tunnel Oven Builder (USA)

• Application: Continuous conveyor baking oven operating at $280^\circ\text{C}$ continuous dry heat.

• Challenge: Standard straight-exit heaters suffered wire insulation melting and terminal oxidation because the terminal connections sat inside the insulated wall chamber.

• Solution: Replaced with Hongtai’s folded tubular heaters with 90° terminals featuring 120mm extended cold sections.

• Results: ZERO TERMINAL BURNOUT OVER 18 MONTHS. The 90° vertical pass completely isolated the electrical wiring from the baking cavity heat, eliminating maintenance shutdowns.

Pricing & Procurement Options

• OEM Customization: Tailored shapes, custom cutout holes for pipe nozzles, specialized voltage/wattage configurations, and custom strap lengths.
• Lead Times: Custom samples: 3–5 working days. Bulk production orders: 8–12 working days upon technical drawing sign-off.
• Packaging & Shipping: Individually bagged with protective foam padding and packed into heavy-duty 5-ply export cartons to prevent bending or lead wire stress during international transit.
• Minimum Order Quantity (MOQ): Low MOQ starting at 5–10 units for custom dimensions; competitive volume pricing tiers for equipment manufacturers.

Global Certifications & Compliance

• CE Marking
  Fully compliant with European safety and environmental standards.
• LVD Compliance
  Low Voltage Directive tested for continuous thermal load safety.
• RoHS Compliant
  Constructed using environmentally safe, lead-controlled brass alloys.
• ISO 9001
  Certified quality control covering CNC machining, coil pressing, and electrical testing.

Quality Documentation: Certificate of Conformity (COC) and insulation resistance test reports included.

Comprehensive After-Sales Support

• • Warranty: 1-Year Comprehensive Warranty covering internal heating element and built-in sensor.

  • Technical Support: Application engineers available for wattage distribution calculation, thermocouple calibration, and nozzle fitting assistance.

  • Global Response Network: BACKED BY 30+ YEARS MANUFACTURING EXPERIENCE with technical inquiry feedback within 2 hours.

Ready to Optimize Your Injection Molding?

Next Steps:

• 📧 Request Custom Quote – Send your nozzle dimensions, wattage, voltage, and HT-CLW-450 drawing requirements.
• 🔧 Free Design Consultation – Work with our thermal engineers to optimize heat distribution and lead insulation.
• 📦 Order Test Samples – Evaluate thermal performance on your injection molding machine.
• 📞 Contact Hot Runner Experts – Response within 2 hours

• Leading Manufacturer & Export of Industrial Heaters

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  SINCE 1990 Professional Heater Producer | Our Products Undergo Multiple Rigorous Quality Checks