LORD 7550
Harmonization Code : 3919.10.80 | Other self-adhesive plastic rolls not exceeding 20 cm wide.
Main features
- Optically Clear Bonding
- 3 to 5-Minute Working Window
- Weathering/Humidity/Salt-Spray/UV Environmental Resistance
Product Description
LORD® 7550-A/C Urethane Adhesive is an equal-mix, two-component, optically clear urethane adhesive system for bonding Lexan®, ABS, polycarbonate, other plastics, and properly prepared or primed metals. The self-levelling material flows into narrow or difficult-to-reach spaces and is suited to tight-tolerance and appearance-sensitive assemblies. LORD 7550-A resin and LORD 7550-C curative mix 1:1 by volume to provide a typical 3–5 minute working time at 24°C, 2–3 minute purge time, approximately 60 minutes to handling strength at 25°C, and full cure in approximately 72 hours at room temperature.
Key features
- Optically clear, equal-mix two-component urethane adhesive
- Self-levelling flow for narrow gaps and difficult-to-reach spaces
- Simple 1:1 volumetric mix ratio
- 3–5 minute working time with approximately one-hour handling strength
- Weathering, humidity, salt-spray, and UV-resistance positioning
- Solvent resistance after cure
- Typical 0.2 W/m·K thermal conductivity reported in the LED selector guide
Applications
- Optics, lenses, diffusers, and transparent plastic bonding
- LED cases, luminaires, cable connectors, and related assemblies
- Trimcap, letter-track, channel-letter, and aesthetic sign assemblies
- Lexan®, ABS, polycarbonate, and validated primed-metal joints
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Thermal Properties
Additional Information
LORD® 7550-A/C Urethane Adhesive
A clear, self-levelling, two-component urethane system for transparent plastics, tight-tolerance interfaces, LED assemblies, sign components, and validated primed-metal joints. Its low-viscosity flow helps the mixed adhesive enter narrow or difficult-to-reach spaces.
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Clear components for equal-volume cartridge dispensing
| Property | LORD 7550-A resin | LORD 7550-C curative | Mixed system |
|---|---|---|---|
| Appearance | Clear to clear-yellow liquid | Clear to clear-yellow liquid | Optically clear |
| Viscosity at 25°C | 1,800–4,000 cP | 6,000–12,500 cP | No product-specific mixed-viscosity value published in DS3451 |
| Density | 1150–1174 kg/m³ | 1078–1126 kg/m³ | Use component data for material calculations |
| Flash point | >93°C, closed cup | >93°C, closed cup | Follow both current SDS documents |
| Mix ratio | 1:1 resin-to-curative by volume | ||
| Solids content | 100% by weight | ||
| Working time at 24°C | 3–5 minutes using a 12.7 mm bead condition | ||
| Purge time at 24°C | 2–3 minutes | ||
| Handling-strength time at 25°C | Approximately 60 minutes | ||
Clean the surfaces, dispense 1:1, purge, and assemble within the short work window
- Remove grease, dirt, dust, release agents, and other contamination.
- For plastics, wipe with a dry rag or a validated solvent-dampened rag.
- For metals, grit blast and solvent wash, then prime for optimum bond performance.
- Use an equal-volume cartridge or validated 1:1 meter/mix system.
- Level the component flow before attaching the mixer.
- Purge the mixed adhesive during the published 2–3 minute purge interval.
- Apply with a handheld cartridge and assemble parts within 3–5 minutes.
- Control flow and edge containment because the material is self-levelling.
- Prevent bubbles, surface contamination, and optical defects in appearance-sensitive joints.
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Allow approximately 72 hours for full room-temperature cure
Approximately 60 minutes at 25°C under the published bead condition.
Approximately 72 hours at room temperature.
Clean equipment before cure with acetone or MEK. Do not use alcohol.
Heating to approximately 149°C or above may soften the cured adhesive for separation. Validate substrate and optical-part heat tolerance.
Storage and industrial safety
Shelf life is six months when stored at 21–27°C in a clean, dry environment in the original unopened containers. After opening, protect both components from excessive moisture using approved desiccant cartridges or dry nitrogen. The supplied EHS identifiers were not available as readable product-specific SDS documents. Confirm and review the current regional SDS for both LORD 7550-A resin and LORD 7550-C curative before handling, mixing, cleanup, transport, storage, or disposal.
Optical clarity, environmental resistance, and low bulk thermal conductivity
DS3451 does not publish tensile, elongation, modulus, lap-shear, peel, hardness, or dielectric values. Do not add structural-property claims without separate product-specific evidence.
| Characteristic | Published positioning or value | Claim control |
|---|---|---|
| Optical appearance | Optically clear | Validate clarity, yellowing, haze, bubbles, and interface appearance in the finished assembly. |
| Flow behaviour | Self-levelling | Provide edge containment where uncontrolled flow would be unacceptable. |
| Thermal conductivity | 0.2 W/m·K | Selector-guide value from SG1013; typical and not a thermal-management claim. |
| Weathering and humidity | Environmentally resistant | Supplier positioning; no numerical exposure duration in DS3451. |
| Salt spray | Resistant | No product-specific numerical test duration published in DS3451. |
| UV exposure | UV resistant | Validate long-term colour and optical transmission for the actual exposure. |
| Solvent resistance | Solvent resistant after cure | Validate the actual paint, cleaner, solvent, duration, and temperature. |
Use clear, self-levelling flow for tight-tolerance and appearance-sensitive assemblies
Published applications include optics bonding, cases and diffusers, cable connectors, case and luminaire sealing, trimcap, letter track, aesthetic assemblies, and selected potting or encapsulation tasks. Final qualification should address substrate grade, stress cracking, primer, joint gap, edge containment, bubble control, cure shrinkage, optical clarity, haze, yellowing, UV exposure, water ingress, cleaner compatibility, thermal expansion, and service temperature.
Optics, lenses, diffusers, housings, cable connectors, and luminaires requiring clear adhesive flow.
Trimcap, letter track, channel-letter, and aesthetic assemblies using compatible plastics.
Self-levelling flow into narrow spaces where edge control and bubble prevention can be maintained.
LORD 7550-A/C technical and application guidance
Controlling product-specific TDS for component properties, mixing, work time, purge time, handling strength, cure, storage, and use guidance.
Open resourceLED application context and selector-guide values, including 0.2 W/m·K thermal conductivity and 72-hour room-temperature cure.
Open resourceGeneral guidance for substrate preparation, joint design, cartridge purging, mixing, fixturing, cleanup, and rework.
Open resourceGeneral product-selection and adhesive-system context.
Open resourceProduct-specific sign-industry positioning for trimcap, letter track, aesthetic assemblies, and optically clear bonding.
Open resourceValidate LORD® 7550-A/C for your clear plastic or LED assembly
Krayden can help review substrate compatibility, primer, cartridge and mixer selection, purge, self-levelling flow, edge containment, work time, optical appearance, UV exposure, environmental sealing, cure, cleaning, and final assembly qualification.
