Butt adhesion test

Fig. 16. The results of Dyckerhoff and Sell for inlerfacial strengths measured hy butt-tensile tests for various lacquers (adhesives) against various plastics as a function of the surface energy, ys of the plastics. Arrows indicate the surface tensions of the adhesive, y, used in the generation of each curve, showing rough agreement with the requirement that a maximum in adhesion is achieved when yt ys (I kp/cm- 0.1 MPa). Redrawn from ref. [71. ...

Figure 10 Typical butt tensile test graphs (a) undercured, (b) cross-linked, (c) overcured, and (d) block copolymer adhesives (e) stages in the cross-linking of a pressure-sensitive adhesive. 

Figure 17.6. Different geometries of adhesion test sphere, rigid punch, peel, and butt.

Adhesion between the polymeric film and substrate is a major concern. Poor adhesion could result in flaking or peeling of the coating from the substrate core. Moisture could accmnulate at the film-substrate interface and compromise the mechanical protection provided by the coating. Polymer adhesion is related to both film-substrate interfacial interactions and internal stresses within the film. Polymer adhesion can be evaluated by peel tests or butt joint tests. Apart from the specific properties of the polymers, excipients used in tablet formulations can influence film-tablet adhesion. Since adhesion between a polymer and the tablet smface is due primarily to hydrogen bond formation, hydrophobic agents may decrease adhesion by... 

McCann and Johnston initially looked at three test configurations for butt tensile tests a metal probe brought into contact with the adhesive surface on a flat plate a rectangular, flat metal probe with the adhesive tape wrapped around the panel and secured, then brought into contact with a test surface and two rectangular, flat faced panels with adhesive tape wrapped around both panels, brought together adhesive-to-adhesive. 

The tensile butt joint test is less commonly used as an adhesive test method this may be due to the perception that it is more difficult to prepare the test specimens ... 

Fig. 69. Adhesive stress-strain curves from BSL308A butt joint tests — specimen A -----------H-- specimen B (from Adams and Coppendale, 1979).

Fig. 81. Tensile butt joint tests (a) poker chip test (thin adhesive film) (b) and (c) schematic for thick adhesive test (d) gauge length and deflections in...

Butt-jointed test coupon to measure A strain invariant for adhesives... 

On the other hand, bulk specimens are not susceptible to the problems inherent in butt joint tests and are more suitable for providing reliable data on the response of adhesives to various known states of stress although care should be exercised in controlling the curing schedule. If a particular adhesive is not suitable for making into large bulk specimens, it should be possible to obtain uniaxial tensile stress-strain data by testing an unsupported thin film of the adhesive. 

ISO 11003-1 2001 Adhesives - Determination of shear behaviour of structural adhesives -Part 1 Torsion test method using butt-bonded hollow cylinders ISO 11003-2 2001 Adhesives - Determination of shear behaviour of structural adhesives -Part 2 Tensile test method using thick adherents ISO 13445 2003 Adhesives - Determination of shear strength of adhesive bonds between rigid substrates by the block-shear method... 

ISO 11003-1 2001 Adhesives - Determination of shear behaviour of structural adhesives -Part 1 Torsion test method using butt-bonded hollow cylinders... 

Butt tensile—adhesives. Bolt shaped specimens were bonded and cured as for the surface coating specimens and tested in the same way. 

The effect of silanes on the bond strength of two epoxide adhesives to glass is shown in Table 13. The test mode was that of Sandwich Butt Tensile in which a glass disc was bonded between two aluminium specimens in the form of a sandwich, and the resulting composite specimen broken on an Instron Universal Test Machine. Clearly in such a composite test specimen, alignment is important and there are many potential sites and modes of failure. 

Different methods have been devised to test the bondability of the treated plastic. The specimen can be joined in different ways butt joint, disk joint, and lap shear. An adhesive layer or film is applied to the treated surface, which is then placed against the substrate and heated in a press or oven. The substrate could be a duplicate of the plastic itself. Table... 

Stud or butt tests representing pull-off tests used for the measiuements of the adhesion characteristics between an ink/paint coating and the substrate. An adhesive is applied to the paint coating, and a metallic stud made of aluminum is glued onto the surface by the adhesive applied to the paint coating. Subsequently, the pull force is utilized perpendicular to the substrate surface with a constant rate. This measurement provides an excellent measurement of adhesion for systems, for example, for polymer-metal interfaces [98]. Figure 8.14 schematically illustrates the puU-off test schematically [99]. 

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