Structural Adhesive Film

AF 30 (5, 10 and 12 mil)

- 10 -

Product Application (continued)

Cure Temperature

The cure temperature may be varied from 250°F to 450°F (121°C to 232°C), depending upon the materials being

bonded, equipment available and bond properties desired. The desired pressure must be applied before the glue line

reaches 160°F (71°C). The film will soften as temperature is increased to 180-210°F (82-98.9°C) and will wet the

surface to which it has been applied. A chemical cure will be initiated between 220°F and 270°F (104°C and 132°C)

and a low strength gel formed. Continued heating chemically converts this gel into a high strength, solvent resistant

bond. 3M™ Scotch-Weld™ Structural Adhesive Film AF 30 will change color only slightly upon application of

heat. Edges of the bond which are exposed to air will change from yellow to rusty brown.

Cure Time

Cure time depends on the cure temperature used, methods of heat application, production limitations and bond

properties required. Since no two bonding operations are exactly alike, it is suggested that a few simple experiments

be conducted, varying both temperature and cure time to determine optimum conditions for the particular application.

Figure II is a guide from which an approximate cure cycle can be taken for various cure times or temperatures.

90

300°F

(149°C)

Cure Time (Minutes)

A. Optimum bond properties (creep

resistance, high temperature strength,

environmental resistance, etc.)

B. General purpose bond properties

(shear strength over 2000 psi (13.8 MPa)

@ 73.5°F ± 2°F (23.1°C ± 1.1°C)

C. Cure Initiation Temperature.

A

B

C

100

80

70

60

50

40

30

20

10

0

350°F

(177°C)

400°F

(204°C)

450°F

(232°C)

Figure II

Suggested Cure Cycle

The following press cure cycle is suggested to obtain dense glue lines.

1. Apply a pressure of 100 psi (689 MPa) prior to reaching a bond line temperature of 150°F (66°C) and maintain

throughout the press cure cycle.

2. Raise the bond line temperature from ambient to 350°F (177°C) at a rate of 10°F-12°F (5.6°C-6.7°C) per minute.

3. Cure for 60°F ± 1 minute at 350°F (177°C).

4. Cool to below 200°F (93°C)/bond line temperature prior to release of pressure. (In lab tests, panels have been

removed at 350°F (177°C) with no adverse effects.)