3M DP640

Harmonization Code : 3919.10.80 | Other self-adhesive plastic rolls not exceeding 20 cm wide.

3M DP640

Main features

  • 40-Minute Working Window
  • Thixotropic Non-Sag Placement
  • 2,160 lb/in^2 Aluminum Overlap Shear

Product Description

3M™ Scotch-Weld™ Urethane Adhesive DP640 Brown is a two-part, non-sag polyurethane adhesive that forms tough, flexible bonds across a range of substrates. It is particularly suited to wood and many properly abraded and cleaned plastics, with documented adhesion to painted metals, ceramics, and glass. The 1:1 mix ratio and thixotropic consistency support controlled application, while a 40-minute work life and 60-minute open time provide an extended assembly window. At 23 °C, the adhesive reaches handling strength in approximately 6–8 hours and develops at least 80% of ultimate strength after 7 days. For maximum bond durability in moist conditions, glass surfaces require priming.

Key features

  • Tough, flexible bonding: Produces flexible cured bonds with 100% elongation and 75 Shore A hardness.
  • Extended assembly window: Provides a 40-minute work life and up to 60 minutes of open time.
  • Non-sag 1:1 formulation: Thixotropic consistency supports controlled dispensing on vertical and overhead surfaces.

Applications / Suitable for

  • Bonding wood
  • Bonding properly abraded and cleaned plastics
  • Bonding painted metals
  • Bonding ceramics and glass
  • Applications requiring a non-sag adhesive
Product Family

3M DP640

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TDS, SDS & Technical Documents

Technical Specifications

General Properties
Appearance
Appearance at room temperature.
Brown
Density (g)
B: 1.08–1.12/A: 1.14–1.19 g/cm3
Mix Ratio
The amount of a constituent divided by the total amount of all other constituents in a mixture
1:1
Solids
100 %
Work life @25°C
Work life is the amount of time we have to work with a material until it is no longer able to be easily worked and applied on a substrate. It is based on the change in viscosity and it can rely on the application requirements.
400 mins hours
Physical Properties
Open time
60 minutes
Viscosity (Part A)
15,000-55,000 mPa.s
Viscosity (Part B)
10,000-40,000 mPa.s
Mechanical Properties
Elongation
Elongation is the process of lengthening something. It is a percentage that measures the initial, unstressed, length compared to the length of the material right before it breaks. It is commonly referred to as Ultimate Elongation or Tensile Elongation at break.
100 %
Peel Strength
112 N/cm
Thermal Properties
Temperature Resistance
Temperature resistance is the maximum temperature that the material or product can withstand for a period of time. The temperatures listed should be considered as guidelines for an operating temperature of about 30 minutes. Typically, the material can withstand much longer times at temperatures about 20°C lower and can withstand much higher temperatures for short, intermittent times.
(-51)- 121 ˚C
Electrical Properties
Volume Resistivity
Volume resistivity, also called volume resistance, bulk resistance or bulk resistivity is a thickness dependent measurement of the resistivity of a material perpendicular to the plane of the surface.
2.6 x 10¹⁴ Ohms⋅cm

Additional Information

Technical properties

As-supplied / before-processing properties

Typical values for the individual components and mixed adhesive. These values are representative and are not intended for specification purposes.

Property Value Unit Method / condition
Mixed color Brown — Typical mixed adhesive
Mix ratio by volume 1:1 B:A As supplied in a dual-component cartridge
Base density 10.0–10.5 lb/gal Base component
Accelerator density 11.1–11.5 lb/gal Accelerator component
Base viscosity 10,000–40,000 cP 27 °C; Brookfield RVF, spindle #6, 10 rpm
Accelerator viscosity 15,000–55,000 cP 27 °C; Brookfield RVF, spindle #6, 10 rpm
Work life 40 min 10 g mixed adhesive at 23 °C
Open time 60 min Maximum time after application before the bond is closed and fixed
Technical properties

After-processing / final-state properties

Typical cured and bonded performance values under the stated test conditions. Results may vary with substrate, preparation, bondline, and curing conditions.

Property Value Unit Method / condition
Cured color Brown — Typical cured adhesive
Shore A hardness 75 Shore A ASTM D2240 at 23 °C
Elongation 100 % ASTM D882
Overlap shear strength — aluminum 2,160 lb/in² ASTM D1002 / ISO 4587; 23 °C; 7-day dwell; MEK/abrade/MEK preparation
Overlap shear strength — cold-rolled steel 1,960 lb/in² ASTM D1002 / ISO 4587; 23 °C; 7-day dwell; MEK/abrade/MEK preparation
Overlap shear strength — ABS 1,729 lb/in² ASTM D1002 / ISO 4587; 23 °C; 7-day dwell; IPA wipe/abrade/IPA wipe
Bell peel 64 lb/in width ASTM D3167; aluminum substrate at 23 °C
Volume resistivity 2.6 × 10¹⁴ Ω-cm ASTM D257 at 23 °C

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