LORD 7542A
Harmonization Code : 3919.10.80 | Other self-adhesive plastic rolls not exceeding 20 cm wide.
Main features
- 1:1 Controlled Mixing
- 4 to 30-Minute Working Window
- 18.7 MPa Cured Tensile Strength
Product Description
LORD® 7542-A Urethane Adhesive Resin is the dark-brown resin component of the LORD 7542 two-component structural urethane adhesive system. It must be combined 1:1 by volume with a compatible LORD 7542-B, 7542-C, or 7542-D curative before use. The selected curative determines the assembly window, with typical working times ranging from 4–7 minutes to 20–30 minutes at 24°C. The mixed systems are designed for structural bonding of FRP, SMC, CFRP, other plastics, and primed or powder-coated metals, using a recommended 254–1016 µm bondline.
Key features
- Resin component for the LORD 7542 equal-mix structural urethane system
- Mixes 1:1 by volume with compatible 7542-B, 7542-C, or 7542-D curatives
- Supports short, medium, or extended assembly windows through curative selection
- Designed for FRP, SMC, CFRP, plastics, and prepared or coated metals
- Suitable for cartridge or automatic meter/mix/dispense processing
- System-level typical tensile strength of 18.7 MPa with 70% elongation
- Documented system-level resistance to humidity, salt spray, water, and temperature exposure
Applications
- Composite panel and enclosure assembly
- Heavy-duty truck, service-truck, trailer, and vehicle-accessory bonding
- SMC, FRP, and CFRP structural joints
- Prepared or powder-coated metal-to-composite assemblies
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Thermal Properties
Additional Information
LORD® 7542-A Urethane Adhesive Resin
LORD 7542-A is the dark-brown resin component used to build LORD 7542 structural urethane adhesive systems. It is not used alone: combine it 1:1 by volume with the specified B, C, or D curative to obtain the required working time, handling time, cure profile, and mixed colour.
Dark-brown resin for controlled equal-volume mixing
| Property | Typical value | Context |
|---|---|---|
| Component role | Resin | Must be combined with a compatible LORD 7542 curative before use. |
| Appearance | Dark-brown liquid | LORD 7542-A component. |
| Viscosity at 25°C | 1,500–4,500 cP | Component viscosity; not mixed-system viscosity. |
| Density | Published in DS3444 for material calculations | Use the current controlled value and selected-curative density for weight-ratio calculations. |
| Flash point | >93°C, closed cup | Does not remove heated-process or decomposition hazards. |
| Mix ratio | 1:1 by volume with compatible curative | Use equal-volume cartridges or validated meter/mix equipment. |
Select the curative that matches the required working and handling time
The values below were measured at 24°C with a 12.7 mm bead. They are typical and change with material temperature, substrate temperature, bead size, and production conditions.
| Compatible curative | Mix ratio | Working time | Handling strength | Selection context |
|---|---|---|---|---|
| LORD 7542-B | 1:1 by volume | 4–7 minutes | 1–2 hours | Shortest published assembly window among the B, C, and D options. |
| LORD 7542-C | 1:1 by volume | 11–15 minutes | Approximately 2 hours | Intermediate working window. |
| LORD 7542-D | 1:1 by volume | 20–30 minutes | Approximately 3 hours | Longest process window published in DS3444. |
Prepare the substrates and combine LORD 7542-A with the selected curative
- Remove grease, dirt, moisture, release agents, and other contaminants.
- For plastics, use a dry-rag wipe or a validated solvent-dampened rag.
- For metals, the TDS recommends priming or powder coating.
- Use equal-volume cartridges or automatic meter/mix/dispense equipment.
- Level cartridge plungers before attaching the mixer.
- Purge at least one mixer length before applying adhesive to the part.
- Mate components before the selected curative's working time expires.
- Clamp until handling strength is achieved.
- Maintain a typical 254–1016 µm bondline for optimum adhesion.
.png)
Cure behaviour belongs to the mixed system, not LORD 7542-A alone
The mixed adhesive develops full strength in 24 hours or less at 24°C, depending on curative.
Clean uncured material with acetone or MEK. The product TDS specifically says not to use alcohol.
Heating the mixed adhesive to approximately 149°C or above may soften it for separation; verify substrate heat tolerance.
Painting and most cleaning operations are not expected to reduce bond strength under the supplier's system-level guidance.
Storage and industrial safety
Store LORD 7542-A in its original unopened container within the published 18–30°C range and protect it from moisture. The current US SDS identifies serious inhalation, respiratory-sensitisation, skin-sensitisation, and organ-toxicity hazards associated with the resin component. Use only with trained personnel, suitable engineering controls, respiratory protection where required, chemical-resistant gloves, eye and face protection, and the storage, spill, transport, and disposal controls stated in the current regional SDS and package label.
Use these values only for properly mixed and cured LORD 7542 systems
LORD 7542-A is uncured resin and does not have independent final-state structural properties. The following values are published for the mixed LORD 7542 adhesive family; DS3444 does not identify the curative used for the bulk cured-property table.
| Property | Typical system-level value | Context |
|---|---|---|
| Hardness | 87 Shore A | ASTM D2240, Method A. |
| Tensile strength at break | 18.70 MPa | ASTM D638. |
| Elongation | 70% | ASTM D638. |
| Young’s modulus | 83.6 MPa | ASTM D638. |
| Glass-transition temperature | 46°C | ASTM D3418. |
| CTE below / above Tg | 69 / 162 ppm/°C | ASTM E381. |
| Moisture absorption | 1.65% | ASTM D570. |
Selected system-level lap-shear results include 4.10 MPa on SMC, 17.90 MPa on e-coated steel, and 22.10 MPa on CFRP at room temperature under the documented surface preparation, film thickness, bond area, 1:1 mix, and 24-hour room-temperature cure.
Select LORD 7542-A with a curative that fits both assembly timing and structural requirements
The mixed systems are positioned for SMC, FRP, CFRP, plastics, e-coated steel, powder-coated metals, truck and trailer structures, vehicle accessories, and other industrial composite assemblies. Final validation must consider curative choice, work window, substrate and coating, bondline, joint geometry, peel and fatigue, impact, thermal expansion, water and humidity exposure, service temperature, painting, rework, and the required failure mode.
LORD 7542-A selection, processing, and application guidance
Controlling technical data for LORD 7542-A resin, compatible curatives, process windows, storage, cured-system properties, and bond performance.
Open resourceFamily comparison for selecting a compatible curative and understanding LORD urethane-system positioning.
Open resourceJoint design, substrate preparation, cartridge purging, bondline, fixturing, failure-mode, and rework guidance.
Open resourceGeneral structural-adhesive selection and market context.
Open resourceApplication context for service-body panels, compartments, roofs, and mixed-material structures.
Open resourceApplication context for utility and Class Eight trailer structures.
Open resourceSelect the right curative for LORD® 7542-A
Krayden can help review B, C, or D curative selection, 1:1 package and equipment configuration, mixer choice, substrate preparation, bondline, work time, handling time, clamping, storage, environmental durability, and final assembly qualification.
