ASTM C907
Disk Method Fixture for Preformed Tape Sealants
ASTM C907 Compression Platens – Universal Grip Data Sheet (PDF)
ASTM C907 measures the tensile adhesive strength of preformed tape sealants, the tacky, deformable tapes used under compression in glazing, curtain wall and building joints. It also shows whether a tape fails adhesively at the substrate or cohesively within the sealant. Universal Grip supplies a platen and disk fixture that forms the bond and then pulls it apart on a universal testing machine.
What ASTM C907 Measures
The test reports the tensile force needed to pull a tape sealant apart normal to its bond, along with the failure mode. The tape is sandwiched between two disks, compressed to make the bond, conditioned and then pulled apart in tension. Afterward the disks are examined, and the relative amount of adhesive versus cohesive failure is estimated. ASTM notes the procedure is a laboratory comparison and is not intended to simulate actual use conditions.
How the ASTM C907 Test Works
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Cut the tape sealant and place it between two clean bonding disks.
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Compress the assembly between the parallel platens to form the bond, as your copy of the standard directs.
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Condition the bonded assembly for the time and environment specified.
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Mount the disk assembly in the aligned holders and pull it apart in tension normal to the bond.
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Record the peak force and examine both disks to estimate adhesive versus cohesive failure.
Specimens and Setup
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Clean the disk faces consistently; surface condition strongly affects adhesive failure.
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Use interchangeable disks to test the substrate material your tape will bond to in service.
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Center the tape on the disk so the bond area is consistent from specimen to specimen.
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Keep platen faces parallel so the tape is compressed evenly before the pull.
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Confirm disk size, compression and conditioning against the current edition of ASTM C907.
Universal Grip ASTM C907 Fixture
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Parallel, ground platen faces for uniform tape compression
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Disk holders keep the bond axis aligned during pull-off
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Same fixture used for compression set-up and tensile pull
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Interchangeable disks for different substrates
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2 kN standard capacity; higher capacities on request
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Steel and aluminum with corrosion-resistant finish; clevis pin or threaded adapter for electromechanical frames
Applications
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Preformed tape sealant QC
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Glazing and curtain wall tapes
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Butyl and polyisobutylene tapes
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Substrate adhesion comparisons
Related Standards and Products
Send us your disk diameter, substrate material, tape thickness range and machine connection through our contact page and we will quote an ASTM C907 disk fixture. Request a quote
ASTM C907 FAQ
Is ASTM C907 a compression test or a tensile test?
It is a tensile adhesion test. Compression is only used to form the bond between the tape and the disks; the result comes from pulling the disks apart normal to the bond. That is why the fixture combines ground platens for bonding with aligned holders for the pull.
What does the failure mode tell me?
If the tape pulls cleanly off a disk, the failure is adhesive, pointing to a weak bond to that substrate. If tape remains on both disks, the failure is cohesive within the sealant. C907 lets you estimate the relative degree of each, which is often as useful as the force value.
Can I test different substrates?
Yes. The bonding disks are interchangeable, so you can compare how one tape bonds to different materials. Specify the substrate materials when ordering.
Does C907 predict field performance?
Not directly. ASTM states the procedure is not intended to simulate actual use conditions. It is best used to compare tapes and to control product quality.
What load capacity do I need?
The standard fixture is rated at 2 kN, which suits the modest forces typical of tacky tape sealants on an electromechanical frame. Higher capacities are available on request.