Cleavage/peel strength

Cleavage/peel strength Strength Properties of Adhesives in Cleavage Peel by Tension Loading (Engineering Plastics-to-Engineering Plastics), Test for (D 3807)... 

D 3807 Test Method for Strength Properties of Adhesive in Cleavage Peel by Tension... 

ASTM D3807-98 Standard test methods for strength properties of adhesive in cleavage peel by tension loading (engineering plastics-to-engineering plastics). 

Figure 2.10 Effect of bond line thickness on the peel strength of a toughened epoxy-based adhesive. Although not directly proportional, the effect is substantial and of considerable practical importance because bond line thickness is often difficult to control. In most cases the overall result of an increase in bond line thickness is beneficial, even though the shear strength may fall most joints fail because they cannot meet peel and cleavage overloads. Generally shear overloads are rare.

Cold temperatures will harden the A and S, so that they will become more brittle, less flexible, and thus more sensitive to peel and cleavage effects. Therefore, the adequate test will be to submit the A and S joints to the expected low temperatures, and measure peel strength, shear strength resistance to cleavage and impact resistance at ambient temperature and at low temperatures, and decide what percentage loss would be acceptable. 

Cleavage and tension. If these stresses are high then look for an adhesive with high peeling strength. Be prepared to sacrifice some shear strength to obtain it. 

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