Low Density Composite Surfacing Film AF 325 • AF 325LS

Technical Datasheet

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Composite Surfacing

Properties

1. Resin bubbling or resin penetration of the prepreg resin through the film has

not been seen. There are no indications of this phenomenon occurring.

2. Both 3M™ Scotch-Weld™ Low Density Composite Surfacing Film AF 325

and AF 325LS are used in the manufacture of composite parts where both

surfacing and lightning strike performance are required. In these applications,

it has been found to provide a smooth, void-free surface when processed

according to the product application guidelines below.

3. Finished parts that were surfaced using the Scotch-Weld AF 325 Film that

were subsequently exposed to 120°F (49°C)/100% RH did not show

degradation of the surfacing film.

Product Application

Guidelines

Proper application of the film is a key factor in achieving a smooth, void-free surface.

The major objective of the following procedure is to minimize air entrapment

between the surfacing film and the tool surface. Improper lay-up or debulking could

result in a rough, porous surface that may require additional finishing.

1. Allow film to warm to room temperature before removing the roll from the

sealed poly bag. Bag should be dry and free of condensation before film is

removed.

2. Unroll and cut film to the desired size.

3. Remove the paper liner from the film. Leave poly liner on film to minimize

contamination and provide best handling characteristics for conformability.

4. Place the film on a release coated tool surface being careful not to entrap air

between film and the tool. A gradual rolling out technique is suggested.

5. Remove any entrapped air with a rubber roller. Use firm pressure and roll from

the center of the tool toward the outside of the tool, gradually working air out of

the part.

6. Remove the protective poly liner. A piece of tape attached to the liner will assist

in removal.

7. Cover the film with a non-stick bleeder cloth or release liner and debulk using

standard prepreg vacuum bagging procedures. A minimum of 25 in. (635 mm)

Hg and a temperature of 60-80°F (16-27°C) for a duration of 5 minutes

minimum is suggested.

8. Carefully remove the bleeder cloth or release liner.

9. Complete prepreg lay-up directly onto the film.

10. Thoroughly debulk the entire part before initiating the cure cycle.

Poly Liner

Tool Surface

AF 325LS Film

Note: The following technical information and data should be considered representative

or typical only and should not be used for specification purposes.

Poly Liner

Tool Surface

Scotch-Weld

AF 325/AF 325LS Film