Blister test mechanism

The pressurized blister test is an excellent method to combine electrochemical reactions at polymer/metal interfaces with a mechanical load. It allows the application of a mechanical stress from a homogeneously pressurized electrolyte on the adhesive/metal interface in a sample geometry that is accessible for the HR-SKP [28]. Depending on the adjusted conditions, information on the synergy of mechanical stresses, elastic or inelastic deformations of the adhesive, transport processes, and corrosive reactions could be obtained with this method. 

Fig. 31. 8 Increase in the delamination velocity as a function of mechanical stress in the blister test experiment measured with the HR-SKP comparison of an unmodified epoxy adhesive (as in Fig. 31.2, about 70 p,m thick) and of the adhesive modified with an organosilane adhesion promoter, performed with 0.5 M NaCi as electrolyte.

Dynamic Fracture Mechanism of Thin Metallized Plastics via the Blister Test... 

The blister test has several advantages. It does not need any mechanical grip to the film to initiate a debonding. The uniformly distributed axisymmetric debonding angle close to the circular crack tip is smaller than with any other mechanical test. Thus the blister test minimizes the energy dissipation more effectively than any other test method. 

Fig.3. Mechanism of ti e blister test for thin film structures...

Fig.4. Data profile of the loading and unloading mechanisms of the blister test for dynamic debonding process. Refer to the text for details of loading and unloading curves ffv), g(v) and duration of debonding time. t=b-a.

The volume is divided into three parts Part I. Metallization Techniques and Properties of Metal Deposits, Part II, Investigation of Interfacial Interactions," and Part III, "Plastic Surface Modification and Adhesion Aspects of Metallized Plastics. The topics covered include various metallization techniques for a variety of plastic substrates various properties of metal deposits metal diffusion during metallization of high-temperature polymers investigation of metal/polymer inlerfacial interactions using a variety of techniques, viz., ESCA, SIMS, HREELS, UV photoemission theoretical studies of metal/polymer interfaces computer simulation of dielectric relaxation at metal/insulalor interfaces surface modification of plastics by a host of techniques including wet chemical, plasma, ion bombardment and its influence on adhesion adhesion aspects of metallized plastics including the use of blister test to study dynamic fracture mechanism of thin metallized plastics. 

Many widely used Tests of adhesion can be applied to the rubber to metal bonds Blister test. Fracture-mechanics test specimens. Non-destructive testing of adhesively-bonded structures. Peel tests. Shear tests. Tensile tests and Wedge test. This particular article is concerned with those aspects that are of practical concern in the rubber-processing industry. 

Specific tests of adhesion are described in more detail under the following articles Blister test, Climbing drum peel test, Fracture mechanics. Napkin ring test. Peel tests. Rubber to metal bonding - testing. Shear tests. Tensile tests. Wedge test and in Refs. [1-5] see also Standards for adhesives and adhesion and Appendix. 

The calculation of G and for a number of geometries, such as peeling, double cantilever, double torsion, or blister test, can be found in textbooks. We will concentrate on the case of adherence of punches (and especially of a sphere) which is conceptually an important topic via which to understand the connection between adherence, mechanics of contact, and fracture mechanics, or, more simply, what is an area of contact. 

Jensen, H. M. (1991), The blister test for interface toughness measurement. Engineering Fracture Mechanics 40, 475-486. 

The DCB test, the blister test, and several other geometries are somewhat amenable to the analytical analyses needed for fracture mechanics. As a consequence, most early fracture mechanics analyses focused on such geometries. Modern computational methods, particularly finite element methods (FEM), have lifted this restriction. A brief outline of how FEM might be used for this purpose may be helpful. Inherent in fracture mechanies is the concept that natural cracks or other crack-like discontinuities exist in materials, and that failure of an object generally initiates at such points [13,16,17,23-25]. Assuming that a crack (or a debonded region) is situated in an adhesive bond line, modern computation techniques can be used to facilitate the computation of stresses and strains throughout a body, even where analytical solutions may not be convenient or even possible. 

Abstract This chapter gives a brief description of special mechanical tests for various types of materials and sample geometries, such as blister tests for membranes/adhesives/coatings, tensile tests and shear tests for sealants/foam adhesives, indentation and scratch tests for coatings, tack tests for pressure-sensitive adhesives (PSAs), and bimaterial curvature tests for characterizing residual stress, stress-free temperature (SFT), and coefficient of thermal expansion (CTE) of adhesives bonded to substrates of interest. In addition, some applications of these tests, including the nano-/micrometric scale, are also described in this chapter. 

In addition to standard adhesion tests or failure tests that are explained in the previous chapters of this handbook, various types of special tests are also performed for specific purposes in industry or in scientific research. In this chapter, some special mechanical tests are treated, such as blister tests for membrane/adhesive/coating, tensile tests and shear tests for sealants and elastomeric/foam adhesives, and indentation tests and scratch tests for characterizing coating adhesion. Most of these are designed for testing macroscopic specimens in a macroscopic scale, but several micro- or nanometric test methods have recently been developed to measure mechanical properties of small specimens in a microscopic or nanometric scale. This chapter also introduces recently developed microscopic methods. 

For the mechanical test of the membrane geometry, the blister test is applied. From the information on the deflection of the membrane, the elastic modulus and the adhesion energy can be determined. Nanoscale experiments are also performed to measure the creep compliance of very thin membranes. 

Wan KT (1999) Fracture mechanics of a V-peel adhesion test transition from a bending plate to a stretching membrane. J Adhes 70(3 ) 197 Wan KT, Lim SC (1998) The bending to stretching transition of a pressurized blister test. Int J Fract 92(4) L43... 

This chapter gives a brief description of special mechanical tests for various types of material and sample geometries, such as blister tests, tensile tests, and shear tests for sealants/foam adhesives, indentation tests, scratch tests, tack tests, and tests for the evaluation of residual stresses. 

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