EPS Cavity Module Connector Industry Knowledge
EPS cavity module connectors (commonly known as connecting bridges, support bridges, or tie frames in the industry) are the core load-bearing and connecting components of the EPS cavity module building system. They are used to fix the inner and outer layers of EPS insulation boards, control cavity width, position steel bars, and form an integrated "insulation + structure" composite wall after concrete pouring. Widely applied in prefabricated buildings, rural self-built houses, passive ultra-low energy consumption buildings and other fields.
I. Core Definition & Functions
1. Definition
According to the industry standard CECS355:2013, a connecting bridge is a key component that connects EPS modules with formwork, fixes the inner and outer insulation layers, and maintains cavity dimensions. Most are integrally injection-molded plastic parts, equipped with steel bar positioning grooves and plug-in structures.
2. Core Functions
Fix Insulation Layers: Connect the inner and outer EPS boards to prevent mold expansion, misalignment, and falling off during pouring.
Control Cavity Precision: Accurately set cavity widths such as 140mm/160mm/200mm to ensure uniform concrete pouring thickness.
Steel Bar Positioning: Equipped with built-in steel bar卡槽 to fix the spacing of horizontal and vertical steel bars (usually 300mm), improving the seismic strength of the wall.
Load Transmission: Firmly combine the insulation layer with the concrete structure to achieve thesame service life of insulation and structure, eliminating the hidden danger of cold and heat bridges.
Construction Efficiency Improvement: Block-type plug-in installation, no additional formwork required, reducing labor costs and shortening the construction period by more than 30%.
II. Mainstream Materials & Performance Standards
1. Material Selection (Mainstream in the Industry)
100% New ABS (Most Common): High rigidity, good toughness, impact resistance, low temperature resistance (-30℃ without brittle fracture), corrosion resistance. Suitable for most regions around the world with moderate cost (0.35–0.5USD/piece).
Modified PP (High Toughness): Aging resistance, bending resistance, suitable for high seismic and cold regions, slightly higher price than ABS.
Reinforced Nylon (High-End): Highest strength, high temperature resistance, suitable for high-rise/heavy-load buildings, high cost.
2. Key Performance Indicators (Industry Mandatory Requirements)
Material Purity: Must be 100% new material, recycled material is strictly prohibited (prone to fracture and rapid aging).
Mechanical Properties: Tensile strength ≥25MPa, flexural strength ≥40MPa, Izod impact strength ≥10kJ/m².
Dimensional Tolerance: Length tolerance ±1mm, spacing tolerance ±0.5mm, ensuring tight splicing of modules.
Compatibility: Compatible with national standard EPS modules (such as 500×250×300mm in length, width and height), and the slot matches the steel bar diameter (6–12mm).
III. Product Classification & Structural Features
1. Classification by Function
Standard Connecting Bridge (Straight Type): Most commonly used for straight walls, with both ends plugged into EPS boards and steel bar grooves in the middle.
Corner Connecting Bridge (L-Type): Special for 90°/120° corners, reinforcing wall corners to prevent stress cracking.
Extended/Special-Shaped Connecting Bridge: Suitable for thickened cavities (200mm+) or special house types, with customizable length and spacing.
Foldable Connector: Foldable to reduce volume during transportation, unfolded for on-site use, reducing logistics costs (emerging patented product).
2. Core Structural Design
Integral Injection Molding: No splicing seams, high strength and not easy to break.
Sawtooth/Dovetail Groove Plug-In: Toothed plugs at both ends engage with EPS board slots, closely combining with concrete after pouring and never falling off.
Reinforcing Rib Design: Multiple reinforcing ribs on the back to improve bending resistance and bear concrete lateral pressure (≥50kN/m²).
Steel Bar Positioning Groove: Symmetrical semicircular grooves up and down to accurately fix horizontal steel bars with a spacing of 300mm, meeting national standard reinforcement requirements.
IV. Production Process & Supply Chain
1. Production Process
100% new ABS particles → High-temperature drying (dehumidification) → Injection molding machine melting (220–240℃) → High-pressure mold forming → Cooling and demolding → Deburring → Quality inspection → Packaging (pallet/carton) → Warehousing.
2. Industry Capacity & Cost
Capacity: The daily capacity of automated production lines is 3,000–5,000 pieces, and the monthly capacity of leading enterprises can reach 100,000+ pieces.
Cost Composition: Raw materials (about 70% for new ABS) + molds + injection molding + packaging + labor. The ex-factory price is 0.4–0.6USD/piece (fluctuating with size/order quantity).
Supply Chain Distribution: Hebei (Xingtai, Baoding), Shandong and Jiangsu are core production areas, close to EPS module factories, with mature supporting facilities and fast delivery.
V. Industry Standards & Quality Control
1. Core Standards
National Standard: CECS355:2013 "Technical Specification for External Insulation Engineering of Molded Polystyrene (EPS) Modules".
Enterprise Standard: Leading enterprises formulate internal control standards stricter than national standards (such as material purity and mechanical properties).
2. Quality Acceptance Points
Appearance: No cracks, deformation, burrs, uniform color (ABS is mostly black/white).
Material: No pungent odor or recycled material impurities when burned. 100% new ABS burns with a pale yellow flame and no black smoke after extinguishing.
Size: Measure length, spacing and slots with a caliper, and the tolerance meets the ±1mm requirement.
Mechanical Test: No fracture when bent 180°, no obvious deformation in tensile test.
VI. Market Application & Development Trends
1. Application Scenarios
Rural Self-Built Houses: Main application, with thermal insulation, fast construction and low cost.
Low-Rise Villas/Homestays: Preferred for passive ultra-low energy consumption buildings, warm in winter and cool in summer, energy saving 70%+.
Cold Storage/Greenhouse: Strong thermal insulation and airtightness, suitable for temperature-controlled buildings.
Old Building Renovation & Reinforcement: Replace traditional insulation nails to solve the problem of insulation layer falling off.
2. Development Trends
Customization: Customize size, spacing and color according to customer drawings to adapt to special modules and house types.
High Toughness: Promote modified ABS/PP materials to improve aging resistance and low temperature resistance, extending the service life to 50+ years.
Intelligent Production: Fully automated injection molding + online quality inspection, reducing the defect rate (≤0.5%) and improving delivery efficiency.
Green Environmental Protection: Adopt recyclable ABS materials, comply with EU REACH and ROHS standards, and adapt to the global export market.
VII. Common Problems & After-Sales Guarantee
1. Common Quality Problems
Fracture: Caused by recycled material, insufficient wall thickness and no reinforcing ribs, prone to fracture during pouring or construction.
Deformation: Poor material toughness and deformation after high-temperature exposure, leading to deviation in cavity size.
Falling Off: Unreasonable plug-in structure and no dovetail groove, easy to fall off after concrete pouring.
2. Industry General After-Sales Service
Damaged Replacement: Take photos to provide evidence after receiving the goods. Small quantities of damaged goods will be replaced free of charge by express, and large quantities will be replaced with the next order.
Quality Guarantee: 100% new material products have a guarantee of 5+ years, and free replacement for non-artificial fracture.
Customization Service: Provide one-stop service of drawing design, sample confirmation and mass production.
Summary
EPS cavity module connectors are the "skeleton" of the module building system. 100% new ABS material, integral injection molding, and reinforcing rib + dovetail groove design are the industry mainstream, with core advantages such as high strength, high toughness, convenient construction and the same service life, adapting to the global demand for integrated building insulation and structure. With the promotion of prefabricated building and passive house policies, customization, high toughness and green environmental protection will become the mainstream of the industry.
If you have customization needs for EPS cavity module connectors, please contact us for professional solutions and quotes.
Liu Guoliang
HuaRui Rubber & Plastic Products Co., Ltd.
WhatsApp: +86 13613195381
