Structural Adhesive Film

AF 32

- 6 -

Product Application (continued)

3. Roll film into position with a rubber roller insuring that no air is trapped between primer and film.

4. Remove protective liner.

5. Assemble parts and cure.

Cleanup

Excess primer and equipment may be cleaned up, prior to curing, with ketone* type solvents.

*Note: When using solvents for cleanup, extinguish all ignition sources and follow manufacturer’s precautions and

directions for use.

Cure Cycle

General Cure Requirements

Time, temperature and pressure determine the final bond properties and may be effected by the type of curing

equipment used for each specific application. In general, the cure properties of Scotch-Weld AF 32 are as follows:

Tack, Flow and Cure Initiation Temperatures

The tack, flow and cure initiation temperatures for Scotch-Weld AF 32 are a time temperature relationship and

depend upon the rate of heat input. Normally, Scotch-Weld AF 32 has the following properties:

Tack Temperature:

160°F - 180°F (71°C - 82°C)

Flow Temperature:

180°F - 220°F (82°C - 104°C)

Cure Initiation Temp.:

220°F - 270°F (104°C - 132°C)

Cure Pressure

Pressure is required during cure to form the part being bonded and contain any volatiles given off by the adhesive.

Cure pressure may be applied in any matter which will insure uniform constant pressure throughout the bond area.

Pressure must be uniformly applied before the curing reaction begins and maintained until a complete set has been

effected. (i.e., the bond line temperature has reached approximately 300°F (149°C). After this point is reached, the

cure may be completed without pressure if the hot strength of the adhesive is sufficient to maintain contact of the

parts being bonded.

The pressure required to contain volatiles is dependent on the rate at which bond line temperature is brought to the

cure temperature. The bond line temperature rise rate for Scotch-Weld AF 32 can be varied from 1°F to

300°F/minute (0.6°C to 149°C/minute). Rise rate (and cure pressure required) will depend on application, cure

temperature, bonding equipment, method of heat application, production limitations and bond properties required.

Figure I depicts typical pressures required for various

bond line temperature rise rates in platen presses.

CURE PRESSURE vs. BOND LINE TEMPERATURE RISE RATE IN PLATEN PRESS

300 psi (2.1 MPa)

250 psi (1.7 MPa)

200 psi (1.4 MPa)

150 psi (1.0 MPa)

100 psi (0.7 MPa)

50 psi (0.3 MPa)

0°F

(-18°C)

50°F

(10°C)

100°F

(38°C)

150°F

(66°C)

200°F

(93°C)

250°F

(121°C)

300°F

(149°C)

Bond Line Temperature Rise Rate per minute