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Shear strength, pressure sensitive adhesives

Materials that are already pressure-sensitive adhesives but can be modified by radiation (UV or EB) to introduce or increase cross-linking (which increases their adhesive properties, shear value, peel strength, service temperature range and solvent resistance). [Pg.133]

Pressure-sensitive adhesives (PSAs) are used in various forms for packaging, medical and masking tapes and labels. PSAs are viscoelastic materials that exhibit sohd-like and liquid-like behavior so that their performance can be evaluated by tack (the capability of a PSA to adhere instantly under light pressure), peel strength (the tensile force required to remove a PSA) and shear strength (flow resistance) [1, 2]. [Pg.249]

Because of the unique properties of pressure-sensitive adhesives, special tests not applicable to other types have been developed. While standard physical tests such as nonvolatile content, viscosity, and specific gravity are performed to ensure consistency of application, these tests do not predict adhesive performance. For pressure-sensitive adhesives, three critical performance characteristics are usually measured tack, peel, and shear strength. [Pg.836]

At the other end of the spectrum, pressure-sensitive adhesives, contact adhesives, aqueous varnishes, clear sealants and caulks, overprint varnishes for metal decorating and printing are essentially pigment free. Minor amounts of silica are used for gloss reduction in the case of varnishes. Carpet, construction and ceramic/brick adhesives may contain substantial amounts of filler, not only to reduce cost but also to provide shear strength. Gloss and semi-gloss latex enamels... [Pg.333]

It has been shown that the plateau modulus of rubber-resin systems is a function of the volume fraction of the polymer, while the tan <5 peak temperature is related to both the concentration and glass transition temperature of the resin additive. Pressure sensitive adhesive performance of rubber-resin systems is also related to the concentration of the resin. The optimum balance of tack peel strength, and shear strength for typical systems can be found at a specific resin concentration. Therefore, performance zones can be identified on plots of tan 6 peak temperature and plateau modulus. This is significant because... [Pg.293]

A primary method used to characterize adhesives is the lap shear test. A diagram of the test is shown in Fig. 27.1 and is described in Standard Test Method ASTM D1002 [4]. The specimen is usually 1 in. (2.54 cm) wide. The lap shear test places the adhesive in normal as weU as shear stress [5]. This type of test is used for many types of adhesives, with the exception of pressure-sensitive adhesives (PSAs, defined below). In the tables presented later, lap shear strength is presented in units of mega Pascal (MPa) and pounds per square inch (psi). The latter is shown in parenthesis. The temperature of the test will always be room temperature. [Pg.480]

Standard tests used to characterize the adhesion properties of tapes are for the assessment of shear strength (see Shear tests) (the ability of a tape joint to resist a load applied in the shear mode), peel strength (see Peel tests) (the resistance of a tape joint to peeling under specified conditions) and Tack (the ability of a pressure-sensitive adhesive to form a bond immediately on contact with another material). There are many standard test specifications laid down by different authorities to assess these properties and many differences in detail between them (e.g. see Appendix). No attempt will be made to describe them comprehensively, but the principles of the tests will be discussed separately. [Pg.365]

Pressure-sensitive adhesives - adhesion properties D W AUBREY Shear and peel strengths tack tests... [Pg.656]

Silicone. Silicone pressure-sensitive adhesives have low shear strength but excellent peel strength and heat resistance. Silicone adhesives can be supplied as solvent solutions... [Pg.469]

Table 11. Pressure-Sensitive Adhesive - Effect of S-B-S on Shear Strength. Table 11. Pressure-Sensitive Adhesive - Effect of S-B-S on Shear Strength.
For all but the pressure-sensitive adhesives (discussed shortly), the adhesive material is applied as a low-viscosity liquid, so as to cover the adherend surfaces evenly and completely and allow for maximum bonding interactions. The actual bonding joint forms as the adhesive undergoes a liquid-to-solid transition (or cm-es), which may be accomplished through either a physical process (e.g., crystallization, solvent evaporation) or a chemical process [e.g., polymerization (Section 15.20), vulcanization]. Characteristics of a sound joint should include high shear, peel, and fracture strengths. [Pg.611]


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See also in sourсe #XX -- [ Pg.116 ]




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Adhesion pressure

Adhesion pressure-sensitive

Adhesion strength

Adhesive shear

PRESSURE-SENSITIVE

Pressure sensitive adhesives

Pressure shearing

Sensitivity pressure

Shear adhesion

Shear sensitivity

Shear strength

Shearing strength

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