H.B. Fuller FH8621

H.B. Fuller FH8621 is a one-component, low-temperature-curing epoxy adhesive. It features fast curing at a low temperature, low shrinkage, high adhesive strength, and adhesion to a variety of substrates. FH8621 will cure faster with an increased temperature. Additionally, it offers high and low temperature resistance.

Product Type: 1K (1 component) Adhesive, Reactive Adhesive

Application Area: Sensors

Chemical Family: Epoxides, Epoxy & Epoxy Derivatives

Features: Fast Cure, Good Adhesion, Good Toughness, High Temperature Resistance, Low Shrinkage, Low Temperature Curing, Low Temperature Resistant

Technical Data Sheet
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Enhanced TDS

Identification & Functionality

Features & Benefits

Features and Benefits
  • One component; no mixing required
  • Fast cure at 80°C
  • Use for CCD/CMOS adhesion
  • High and low temperature resistance

Applications & Uses

Application Area
Directions for Use

1. Prior to bonding, surfaces must be free of any dust, oils, or other contaminants.
2. Bring material to room temperature (25°C) before using (typical thaw time for 30ml syringes is 2-4 hours). We do not recommend thawing the material more than 3 times.
3. 9861-78 is sensitive to humidity; do not expose the material to air for an extended period of time. The recommended relative humidity during dispensing is <60%.
4. If the material is left idle in the syringe tip for an extended period of time, the tip should be purged or solvent cleaned.
5. Seal any remaining material and store immediately at -18°C.


Equipment and any spillage can be cleaned promptly after use with a mixture of anhydrous isopropyl alcohol and acetone that should be discarded after each use.


Typical Physical Properties
ValueUnitsTest Method / Conditions
Hardness (cured 30 min, at 80°C)80.0-Shore D
Elongation at Break (cured 30 min, at 80°C)1.8%-
Shear Strength (cured 30 min, at 80°C)19.0MPa-
Glass Transition Temperature (cured 30 min, at 80°C)40.0°C-
Coefficient of Thermal Expansion (Alpha 1, cured 30 min, at 80°C)66.0m/m.°C-
Coefficient of Thermal Expansion (Aplha 2, cured 30 min, at 80°C)214.0m/m.°C-
Water Absorption (after 24 h, cured 30 min, at 80°C )0.12%-
Electrical Properties
ValueUnitsTest Method / Conditions
Dielectric Strength26.3kV/mm-
Dielectric Constant (at 1KHz)3.2/0.02--
Dielectric Loss (at 100kHZ)3.3/0.03--
Volume Resistivity5.2 x 10¹⁵Ω.cm-
Surface Resistivity1.9 x 10¹⁶ohm-
Uncured Properties
ValueUnitsTest Method / Conditions
Specific Gravity1.34--
Thixotropic Index4.6--
Work Life (max. 60% RH)3.0days-
Typical Cured Properties
ValueUnitsTest Method / Conditions
Pot Life3.0days-

Technical Details & Test Data

Cure Schedule
  • Cure schedule:
    • 4 minutes at 80°C
  • 9861-78 will cure faster with increased temperature. The curing temperature and curing time should be adjusted according to the heating device and the material to be bonded.

Packaging & Availability

Regional Availability
  • Africa
  • Asia Pacific (Excluding Russia)
  • Europe (Excluding Russia)
  • India
  • Latin America
  • Middle East
  • North America
Storage Conditions

FH8621 should be stored at -18°C.
Shelf life is a 6 months from date of manufacture, in original unopened containers

Storage & Handling

Shelf Life
6 Months