Page 1 UR5633 Polyurethane Resin UR5633 is a thermally conductive, flame retardant, two-part potting and encapsulating compound. The cured polyurethane is particularly suited to applications where heat dissipation or high water resistance is required. Exceptionally high thermal conductivity ideal for applications requiring efficient heat dissipation Very low water absorption offers excellent protection in the presence of water and high humidity Does not contain abrasive fillers low wear on dispensing machinery Meets UL94 V-0 approval high level of flame retardancy RoHS-2 Compliant (2011/65/EU): Yes Approvals UL Approval: Meets UL94 V-0 Typical Properties Liquid Properties: Base Material Polyurethane Density Part A - Resin (g/ml) 1.70 Density Part B - Hardener (g/ml) 1.24 Part A Viscosity (mPa s 23C) 170000 Part B Viscosity (mPa s 23C) 50 Mixed System Viscosity (mPa s 23C) 30000 Mixed System Viscosity (mPa s 35C) 12000 Mix Ratio (Weight) 12.15:1 Mix Ratio (Volume) 8.83:1 Usable Life (20C) 15 mins Gel Time (23C) 40 mins Cure Time (23 C) 24 hours Cure Time (60 C) 4 hours Colour Part A Resin Black Colour Part B Hardener Amber Storage Conditions Dry Conditions: Above 15C, Below 35C Shelf Life 12 Months Exotherm < 40C (Measured on 100ml sample in a cylinder of diameter 49.4mm 23C) Shrinkage < 1% Page 2 Cured System: Thermal Conductivity (W/m.K) 1.24 Cured Density (g/ml) 1.65 Temperature Range (C) -50 to +125 Max Temperature Range (Short Term (C)/30 mins) +130 (Application and Geometry Dependent) Dielectric Strength (kV/mm) 18 14 Volume Resistivity (ohm-cm) 10 Shore Hardness A90/D60 Colour (Mixed System) Black Flame Retardancy Yes Comparative Tracking Index >600 Volts Water Absorption (9.7mm thick disk, 51mm diameter) <1.0% / <0.5% 10 days 20C / 1 hour 100C Elongation At Break Not Measured Mixing Procedures Resin Packs When in Resin pack form, the resin and hardener are mixed by removing the clip and moving the contents around inside the pack until thoroughly mixed. To remove the clip, remove both end caps, grip each end of the pack and pull apart gently. By using the removed clip, take special care to push unmixed material from the corners of the pack. Mixing normally takes from two to four minutes depending on the skill of the operator and the size of the pack. Both the resin and hardener are evacuated prior to packing so the system is ready for use immediately after mixing. The corner may be cut from the pack so that it may be used as a simple dispenser. 1 3 2 4 5 6 Bulk Mixing When mixing, care must be taken to avoid the introduction of excessive amounts of air. Automatic mixing equipment is available which will not only mix both the resin and hardener accurately in the correct ratio but do this without introducing air. Containers of Part A (Resin) and Part B (Hardener) should be kept sealed at all