Information on the most widely used ASTM standards within the materials testing industry
ASTM C794: Standard Test Method for Adhesion-in-Peel of Elastomeric Joint Sealants
ASTM C794 test method covers a laboratory procedure for determining the strength and characteristics of the peel properties of a cured-in-place elastomeric joint sealant, single- or multicomponent, for use in building construction.
Many sealant manufacturers utilize the adhesion-in-peel test for determining the adhesive characteristics of sealant/primer combinations with unusual or proprietary substrates. This test is especially useful for quality measurements comparing batches of the same sealant relative to adhesion or for studying adhesion of a given sealant to a variety of substrates.
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This test method alone is not appropriate for comparing the overall performance of different sealants in a given application. The adhesive force that determines if a given sealant is useful in a given application also depends on the modulus of elasticity and the degree to which the sealant will be strained. This test, as it exists, does not consider the modulus of elasticity, nor amount of stress that will be produced by a given strain in an actual sealant in a moving joint.
The purpose of this test is to quantify the adhesion of a coating via a peel adhesion strength test to determine whether the installation has been completed properly and acceptable adhesion is achieved. Release or separation during the test will occur along the weakest part of the material or bond between the material and the substrate. Poor adhesion may be caused by poor substrate preparation, partially cured coating and/or improper coating application.
ASTM C794 Elastomeric Joint Sealants Peeling Test Procedure:
| 1. Locate a 6" x 6" unobstructed area to perform the adhesion test. Testing should be completed on each type of substrate coated with a Pecora fluid applied coating/primer. |
| 2. If necessary, clean the test area with a solvent wipe (isopropyl or denatured alcohol preferred) and allow to dry. |
| 3. Cut 1" x 12" piece of airplane cloth. a. SilcoPrime: Apply exterior coating over existing silicone coating primed with SilcoPrime per manufacturer's instructions to create a 2" x 6" test area. b. Air Barrier and Weather Clad: Apply coatings directly over the substrate to create a 2" x 6" test area. |
4. Embed the airplane cloth by immediately placing the cloth directly over the newly applied coating and lightly press into place taking care not to displace the underlying coating. |
| 5. Apply a small amount of coating over the airplane cloth to fully encapsulate. Refer to adjacent photo of assembled peel adhesion field test sample with airplane cloth. |
| 6. Allow coating to fully cure per manufacturer's guidelines. |
7. Attach a (luggage/fish) scale to the exposed airplane cloth tab and peel the tab back at an 180° angle by applying slow and steady pressure. A minimum 5pli is required for warranty purposes. Adhesive failure of the coating prior to achieving 5pli is considered a failing result |
| 8. Record test results and submit to your local Pecora field representative and/or Pecora Technical Service Group. |
Testing Items:
The main testing items specified by ASTM C794 standard include the following four types:
1. Peel strength measurement: Quantifying the adhesive's ability to resist separation at a specific peel angle with the substrate.
2. Bond failure mode analysis: Determining the type of failure (cohesive failure/interface failure) through visual or microscopic observation.
3. Displacement capability verification: Assessing the impact of joint displacement on bond performance.
4. Performance testing after environmental aging: Including peel strength retention rate after accelerated aging such as humidity cycling and ultraviolet irradiation.
Test range:
Material type: elastomeric materials such as silicone sealant, polyurethane sealant, and polysulfide sealant
Base material combinations: typical architectural joint systems such as concrete-metal, glass-aluminum alloy, plastic-composite materials, etc
Application areas:
Structural bonding and assembly system for building curtain walls
Sealing system for expansion joints of road and bridge
Shockproof sealing structure for industrial equipment
Verification of applicability in special environments: severe conditions such as high and low temperatures (-40℃~80℃), high humidity (≥95%RH), and salt spray corrosion,
Related Standard
ISO 11339 Adhesives — T-peel test for flexible-to-flexible bonded assemblies.
It specifies a T‑peel test for the determination of the peel resistance of an adhesive by measuring the peeling force of a T‑shaped bonded assembly of two flexible adherends. The ISO 11339 test method is suitable for self-adhesive tapes that are prepared under the relevant guidelines within this test standard. For a T-peel test for a flexible-to-flexible assembly, the force is applied to the unbonded ends of the specimen . The angle between the bond line and the direction of the applied force is not fixed.
ASTM D1876: Standard Test Method for Peel Resistance of Adhesives (T-Peel Test)
ASTM D1876 test method is primarily intended for determining the relative peel resistance of adhesive bonds between flexible adherends by means of a T-type specimen using a tension testing machine. The bent, unbonded ends of the test specimen shall be clamped in the test grips of the tension testing machine and a load of a constant head speed shall be applied. An autographic recording of the load versus the head movement or load versus distance peeled shall be made. The peel resistance over a specified length of the bond line after the initial peak shall be determined.
ASTM D3167 Peel Resistance Adhesives Test - Floating Roller
ASTM D3167 Floating Roller Peeling test method covers the determination of the relative peel resistance of adhesive bonds between one rigid adherend and one flexible adherend when tested under specified conditions of preparation and testing.
ISO 8510-2: Adhesives — Peel test for a flexible-bonded-to-rigid test specimen assembly Part 2: 180° peel.
ISO 8510-2 specifies the 180-degree peel adhesion test for evaluating the adhesive peel strength of bonded materials. This standard is essential in industries such as packaging, medical devices, electronics, and adhesives, where strong and reliable adhesion is crucial. The test provides critical insights into the performance and durability of adhesives by measuring the force required to separate a flexible adherend from a rigid adherend under controlled conditions.
Testing Procedure:
The rigid adherend is clamped into the machine’s fixed grip.
The flexible adherend is clamped into a self-aligning grip.
The machine applies force parallel to the bonded plane, pulling the flexible adherend at a 180-degree angle.
ISO 29862 tape adhesion test, Self adhesive tapes - determination of peel adhesion
ISO 29862 specifies a series of methods for the determination of peel adhesion properties of self adhesives tapes.
ISO 29862 test methods include:
— Method 1: Self adhesive tapes – Measurement of peel adhesion from stainless steel at an angle of 180°;
— Method 2: Self adhesive tapes – Measurement of peel adhesion from its own backing at an angle of 180°;
— Method 3: Self adhesive tapes – Measurement of peel adhesion of double-sided and transfer tapes at an angle 180°;
— Method 4: Self adhesive tapes – Measurement of adhesion of the liner to an adhesive tape at an angle of 180°.
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