High-Efficiency HEPA Filter Hot Melt Adhesive GX21B & GX31B
Premium industrial-grade hot melt adhesives specifically formulated as pleat separators (spacers) for HEPA and ULPA air filters. Featuring a high softening point (100°C–115°C) and rapid curing time, GX21B and GX31B guarantee precise pleat spacing and excellent media elasticity. Solvent-free and low-odor—perfectly applied using our Filter Pleating Machines and Hot Melt Gluing Machines.
Our High-Efficiency HEPA Filter Hot Melt Adhesives GX21B and GX31B are premium, solvent-free synthetic copolymer hot melt glues developed specifically for the automated assembly and pleat separation of primary, medium, and high-efficiency HEPA/ULPA air filters.
These adhesives are supplied in solid pellet form. When melted and extruded through automated nozzles, they function as the pleat separator lines (spacer beads) that hold the folded glass fiber or synthetic filter media walls at a fixed, uniform distance. This structural separation maintains an open, stable pleat geometry, preventing pleat collapse under strong wind pressure, maximizing effective volumetric airflow, and ensuring uniform particulate capture across the entire filter face.
Technical Specifications
The factual mechanical parameters, viscosity, and thermal properties of GX21B and GX31B are detailed below:
Technical Parameters
GX21B (High-Speed Pleating Line)
GX31B (Assembly & Frame Gluing)
Physical Form
Solid Pellets / Granules
Solid Pellets / Granules
Color
Milky White / Semi-transparent
Milky White / Semi-transparent
Base Polymer
Synthetic Copolymer (Solvent-free)
Synthetic Copolymer (Solvent-free)
Softening Point (R&B)
105 ± 5 °C
110 ± 5 °C
Viscosity (at 180°C, mPa.s)
1500 ± 300
2200 ± 400
Operating Temp
160°C – 180°C
165°C – 185°C
Open Time / Gel Time
5 – 8 seconds (Fast-cure)
8 – 12 seconds (Medium-cure)
Toxicology / Eco
Odorless, Non-toxic (RoHS Compliant)
Odorless, Non-toxic (RoHS Compliant)
Key Features & Performance Advantages
1. Excellent Elasticity & Crack Resistance
Specifically formulated to remain flexible after solidification. The adhesive separator beads can withstand repeated mechanical handling, packaging compression, and thermal expansion/contraction without snapping, cracking, or tearing the delicate wood pulp or glass fiber media.
2. High Softening Point (≥100°C)
Outstanding thermal resistance prevents the spacer lines from softening, melting, or sagging when exposed to hot air streams (up to 80°C) inside industrial air handling units or automotive engine cabins, ensuring continuous structural support.
3. Optimized Curing Speed for Production Lines
GX21B features a rapid 5–8 second open time, designed for high-speed continuous automatic pleating machines to achieve high-frequency cutting.
GX31B offers a slightly longer open time, perfect for manual element assembly, frame-gluing, or slower-speed pilot assembly lines.
4. Low-Odor & Eco-Friendly
Emits minimal odor during high-temperature melt-extrusion in your workshop. Once cooled, it is completely odorless and non-toxic, making it ideal for indoor air filters (such as car cabin HVAC, home air purifiers, and hospital cleanrooms) where volatile chemical odors must be strictly avoided.
Target Applications
Our high-performance filter hot melt adhesives are widely used in:
HEPA & ULPA Air Filters: Standard pleat separator line adhesive for cleanrooms, laminar flow hoods, and hospital HVAC systems.
Car Cabin HVAC Filters: Pleat spacing for multi-layered active carbon and particulate automotive cabin filters.
Industrial Panel Filters: Spacer and edge-sealing adhesive for primary and medium-efficiency air pre-filters.
Why Partner with Fupei?
Machinery-Tested Formulation: As a filter machinery manufacturer, we test our adhesives directly on our own Filter Pleating Machines and automated hot-melt nozzles to ensure consistent extrudability, clean cutoff, and zero nozzle stringing.
Strict Quality Control & Adhesion Testing: We conduct rigorous viscosity and softening point testing on every batch to ensure consistent extrusion and zero nozzle clogging on your factory line.
Flexible Global Packaging: We supply our hot melt adhesives in 25kg moisture-proof woven bags, loaded onto sturdy pallets for secure global shipping, complete with standard SDS certificates.
Frequently Asked Questions
A: GX21B is a fast-curing hot melt (5-8s open time) with lower viscosity, optimized for high-speed automated pleating machines as a pleat spacer. GX31B has a slightly higher viscosity and longer open time (8-12s), which makes it better suited for manual end-cap gluing, frame bonding, or slower-speed assembly lines where operators need more adjustment time.
A: No. Our GX21B and GX31B adhesives are formulated from highly refined, solvent-free synthetic copolymers. They release minimal odor during high-temperature melt-extrusion in your workshop, and once cooled, they are completely odorless and non-toxic, complying with strict RoHS environmental standards for indoor and cabin air filters.
A: We recommend setting your hot-melt tank and hoses between 160°C and 180°C. Heating the adhesive significantly above 190°C for extended periods can cause thermal degradation (carbonization), which may lead to nozzle clogging and reduced bonding strength.
