Peel off tests

Membranes were sputtered with platinum and examined using FESEM-Hitachi 4800 scanning electron microscopy (SEM). A CSI-135 permeability gas cell was used to measure the gas transmission rate (GTR) of air through the umnodified and modified membranes. To measure the adhesion between the layers of the membrane assembly, a 180 peel-off test was carried out using Instron-5582. 

Figure 12. (a) Results ofpeel off tests for two-layer assembly made of unmodified membranes and membranes modified with PGMA layer, (b) AFM image (5x5 pm ) of surface of PET membrane covered with PGMA after the peel off test. Vertical scale 30 nm. 

When this method is applied to MID It is important to bear in mind that a comparatively large test metallization is needed. Empirical experience indicates that connectors for peel-off testing should be more than 800 pm in width. The metallization should be at least 17 pm thick in order to withstand the necessary tensile forces. The common metallizations such as LPKF-LDS plating therefore often require galvanic overplating to bring them up to the necessary thickness. The thickness of the metallization influences the result, and this has to be taken into account. Deformation of the metal layer factors into the measurement result. Consequently, the result cannot be applied one-to-one to combinations of materials other than that tested. 

The adhesion is noticeably improved over that with LBG1025. When doing the Scotch tape test, as described by an ASTM D3359, method B (discussed in detail earlier), only a fraction of the anode coating could be peeled off the copper substrate. 

An important factor of film quality concerns its adhesion to the substrate, namely to the magnesium chip. Figure 4.12 shows images of different coated chips after a standard adhesion test. The upper images show the magnesium-coated chips after the tape was peeled off, while the lower images show the tapes. 

In many fracture tests, a splitting method was employed. Figures 8 to 10 schematically indicate three of the arrangements used. In Fig. 8, a slice, h cm thick, is separated from the rest of the solid by pushing in a wedge which may be as thin as 0.01 cm but may also be more robust and have one of various shapes also the part broken off may be as thick as the remainder. In Fig. 9, a plate, 2h cm thick and w cm wide, is split in the middle to the depth c cm, and the force /required to extend the fissure is measured. Figure 10 shows peeling a ribbon, h cm thick, is peeled off the main body of an identical solid. 

The committee notes that the electrode damage may become more severe when feeds containing fluorine and chlorine are processed. In the fluoride transfer test discussed earlier, the titanium electrodes were severely corroded and the Pt coating was pitted or peeling off. This more severe damage would be unacceptable during full-scale plant operation. 

Most SAW transducers are inadequate for operation in liquids because most types of surface acoustic waves are completely damped in this viscous environment. Therefore, QCM transducers are used instead. For successful operation of an MIP-QCM chemosensor in liquid, the MIP film should be sufficiently stable with respect to dissolution and peeling off from the resonator surface. Moreover, this film should be relatively rigid, neither shrinking nor swelling in the test solution. 

The test is conducted by applying melted paraffin wax to the back of a suspect s hands. With a brush, the back of the hand is coated with paraffin wax which on cooling solidifies and can be peeled off the hand. The surface of the cast that has been in contact with the skin is treated with diphenylamine/sulfuric acid reagent by dropwise addition or spraying. The reagent produces a blue color with individual particles of nitrates and nitrites. The reaction sequence is as shown in Figure 16.1.117The detection of dark blue spots was considered as indicative of the presence of nitrates and/or nitrates from FDR. 

In practice the methods of test used most frequently are those that measure adhesion. Wechsberg and Webber17 noted that some pressure-sensitive adhesive tapes adhered more strongly to treated rather than untreated film when tape was pressed in the same manner on samples of film and peeled off under controlled conditions with a tensometer, the force required to separate the tape... 

Adhesion of fired enamel to the metal base is assessed practically by impact tests (e.g. by a falling steel ball). If the adhesion is poor, tfie enamel will peel off on impact, showing a clean metal surface. More precise determinations are based on tensile tests of metal specimens joined with an enamel layer. Very good adhesion is then indicated by failure in the enamel and not in the contact surface. 

After the surface layer of the leather sample is peeled off, the sample can be observed under a microscope. The collagen fibres of leather differ in appearance from non-woven fabrics and from the uniform polymers of coating and lamination in the synthetic substitutes. However, some artificial leathers in the market do better than the real leather. It has been reported that some leather substitutes with super-microfibres of nylon, polyester and polypropylene can have similar views of cross-section under the microscope (Cheng, 1998). A combination of the bum test, the chemical test, the infrared spectroscopic analysis and/or the microscopic... 

Except for the basic alloy a scale with satisfactory adhesion appears on the surface of all alloys samples during oxidization. The scale is multilayer in the basic alloy (Fig. 2a) and begins to peel off after the 10-hour test. The scale on this layer is fine-grained and homogeneous (Fig. 2b) with cracks in an external layer (Fig. 2c). Upon alloying of alloy BTl-0 with >2 wt. % Si the scale is formed on its surface which does not split off It does not split off after exposure for 30-hours. There is only the insignificant deterioration of adhesion. After addition of 2-6 wt. % Si in the alloy the prolonged crystals appear in the structure of the scale (Fig. 2d). Amount of these crystals increases at addition of 3 wt. % Al. 

Peel strength is usually tested by laminating a coated film either to itself or to a specified substrate. The film is then peeled off the substrate at a steady speed at 90 or 180 degrees to the bond axis, and the force required for removal is measured. The result is always quoted as the force per unit width of film at a given rate of peel. Figure 5 shows the geometry of a 90- or 180-degree peel test. 

The principal aim of the present work was to study the modification of polymer surfaces by plasma treatment as well as the interaction of a metal film with these treated surfaces by surface analytical techniques. As shown above, the results indeed show increased interaction after surface treatment under certain conditions. However, ultimately, improved adhesion should also be observed. For this purpose preliminary expenments with aluminum films on plasma treated polypropylene were carried out. These films were not evaporated under in-situ conditions, but in a separate electron beam evaporator under identical conditions for the different polymer surfaces. A simple Scotch tape test was performed in order to characterize the adhesion qualitatively. In agreement with the surface analytical results, the as-received polypropylene surfaces show poor adhesion as the aluminum film and can be peeled off completely. A five second nitrogen plasma treatment however leads to a film which adheres well and cannot be lifted off by the same tape. Hnally, a 120 s ocatment in a nitrogen plaana leads to an oveitreatmcntof the surface characterized by a low adherion again. 

Table 3.8 shows the results of the static bending tests, the relative elongations of the metal substrate at which the fibers of the glass cloth broke and wrinkles and folds appeared on its external siuface. The flexural tests indicated that in the case of the pulled fibers, the threads of the glass cloth broke in the csise of the pushed fibers, wrinkles and folds appeared on the external layer of the glass cloth while the inner layers were firm on the metal surface. The static tests of the specimens with the metal base extension showed that the glass-reinforced plastic peeled off the metal for stress in the metal not less than 355 MPa. 

For comparison, tests on biplates made of steel and glass-reinforced plastic with VAK as binder were carried out along with tests of similar specimens with UP 5-177-1 epoxy compound as binder. Impact resistance of the VAK specimens exceeded that of the UP 5-177-1 specimens by 14-19% for the bending resistance the difference was 33-34%. The plastic with UP 5-177-1 binder peeled off the metal at a stress in the metal of 302 MPa, which is 15% less than that for the plastic with VAK binder. The glass-reinforced plastic was formed in air at 20°C. 

The odor test and test blank jar lids shall be labeled (e.g., 1 and 2) for jar identification. Labels shall be placed on the lids so that they can be periodically peeled off and switched to maintain the integrity of the test. 

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