Permabond UV639 thicker gap filling soft flexibile UV glue excellent for most plastics including acrylic, PET, polycarbonate PC

Product Name

Permabond UV639 Thicker Gap Filling Soft Flexible UV Glue

Brief Description

Permabond UV639 is a crystal-clear, UV-curing adhesive specifically formulated for bonding a wide range of plastics, including acrylic (PMMA, Perspex®, Plexiglass®), PETG, and polycarbonate (PC). It also provides strong adhesion to glass and metals. This urethane methacrylate-based adhesive cures rapidly in seconds when exposed to UV light, creating a seamless, non-yellowing, and invisible bond. Its thicker, gel-like consistency makes it excellent for gap-filling and vertical applications, offering high strength and flexibility.

Popular Applications & Uses

- Acrylic screen bonding in supermarkets, offices, banks, and retail environments.- Point of sale (POS) display construction.- Shop fittings and furniture assembly.- Architectural and decorative designs.- Transparent plastic-to-metal or plastic-to-glass bonding.- Bonding clear plastics to a variety of other substrate materials.- Industrial plastic components for lighting, appliances, and packaging.- Consumer electronics bonding for wearable devices, touchscreens, sensors, and enclosures.- Automotive interiors and sensors, light guides, control panels, and displays.

Industries that Commonly Use It

- Plastic Fabrication- Sign & Display- Furniture- Retail, Retail Stores- Construction/ Building Services- General Manufacturing- LED/Electronics- Automotive Service/Repair- Transportation/ Specialty Vehicle- Aerospace/Defense- Packaging Services or Contractor- Metal Fabrication

Special and Unique Features

- Rapid UV Cure – cures in seconds with UV exposure.- Crystal-Clear Finish – non-yellowing, invisible bond, ideal for aesthetic applications.- Thicker, slower flowing gel for vertical and gap-filling applications.- High Strength & Flexibility – resists cracking, with >220% elongation.- No Mechanical Fasteners Required – eliminates the need for screws or drilling, reducing weak points and improving design flexibility.- Excellent Thermal & Moisture Resistance – withstands harsh environments.- Easy to Clean – smooth bond lines simplify disinfection and maintenance.- One-part system – no mixing required.- Low shrinkage.

Key Properties

- Chemical Base: Urethane methacrylate.- Appearance: Colorless, crystal clear.- Viscosity @ 25°C: 1,200–1,800 mPa·s (cP).- Cure Wavelength: 365–420 nm.- Fixture Time (PMMA): 5s (4mW/cm² lamp), <1s (200mW/cm² LED).- Fixture Time (Polycarbonate): 10s (4mW/cm² lamp).- Overlap Shear Strength: >8 N/mm² (PC), >6 N/mm² (Acrylic), >7 N/mm² (PETG).- Tensile Strength: 20 N/mm² (ISO37) / 2900 psi.- Elongation at Break: >220%.- Hardness: 35–45 Shore D.- Glass Transition (Tg): 70°C (158°F).- Temperature Range: -55°C to 150°C (short exposure).- Water Absorption (ISO62): 14% (2 hrs in boiling water).

Surface Compatibility

- Acrylic (PMMA, Perspex®, Plexiglass®)- PETG- Polycarbonate (PC)- Glass- Metals- HIPS- Polystyrene- ABS- Composites- Other clear plastics

Known backups / known substitutes

- Permabond UV643: A fast-curing UV adhesive for rigid plastics.- Other Permabond UV adhesives: Such as UV630, UV632, UV640, UV645 for plastic bonding with varying properties.- Cyanoacrylate (Instant) adhesives: Offer fast curing but generally less flexibility and impact resistance.- Epoxy adhesives: Provide high strength and good impact resistance, but typically have slower cure times and may not be optically clear.- Structural Acrylic (MMA) adhesives: Offer high strength on plastics and good impact resistance.

Comparison Note

Permabond UV639 stands out among UV adhesives for its crystal-clear, flexible, and gap-filling properties, making it ideal for aesthetic applications involving clear plastics, glass, and metals. While other UV adhesives like Permabond UV643 offer faster cure on rigid plastics, UV639's higher elongation and thicker consistency provide advantages for applications requiring flexibility and gap bridging. Compared to cyanoacrylates, UV639 offers superior flexibility, impact resistance, and optical clarity. Epoxies and structural acrylics can provide high strength but often lack the rapid cure-on-demand, optical clarity, and ease of application of UV-curing adhesives for transparent assemblies.