Angle Test

Before actual bonding, the subjective water-break test, or the quantitative and objective contact-angle test, may be carried out. After bonding, the effectiveness of surface preparation may be determined by measuring the bond strength and determining the mode of the failure of the adhesive joint. 

This test depends on the observation that a clean surface (one that is chemically active or polar) will 

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Xor Y Test Angle Test Angle Test Angle... 

Far from a wellbore, the velocity of reservoir fluids is about one linear foot per day. Near a wellbore, the velocity can increase one-hundred fold. A static or quasi-static test such as the sessile drop (contact angle) test may not represent the dynamic behavior of the fluids in the field. The dynamic Wilhelmy device gives results which are comparable in interface velocity to the field displacement rate. The interface in the Wilhelmy test described here moved at a steady rate of 0.127 mm/sec or 36 ft/day. The wetting cycle for a hybrid-wetting crude oil system was not affected by moving at a rate less than 1 ft/day. 

Contact angle tests showed that the hydrophobic properties on those areas corresponding to the channels had changed substantially (more hydrophilic) compared to other parts of the DL (e.g., those close to the landing widths). The same effect was visible on the surface of the MPL, indicating that loss of the PTFE particles was experienced on both surfaces of the DL. Similar observations regarding the hydrophilicity of the areas in which the FF channels are present were presented previously by St-Pierre and Jia [263]. 

TABLE 2. Contact Angle Testing Results Indicating the Increased Hydrophilicity when Ethylene was Copolymerized with Either 5-Norbornen-2-yl Acetate or 5-Norbornen-2-ol, According to Current Application... 

You may need to play around with the drops for a while in order to see the differing affinities that the bag and wrap have for water. One way to do this is to tape the polymers side by side stretched out on a sturdy piece of cardboard. Tilt the cardboard to various angles, testing for the speed with which water drops roll down the incline on the two surfaces. Ultimately, you should find that the drops roll more slowly on the wrap (polyvinylidene chloride) than on the bag (polyethylene terephthalate). The source of this greater stickiness in the wrap is the fairly large chlorine atoms of the polyvinylidene chloride. 

For angle test pieces with a nick added, the problem is essentially the same as with the crescent test piece. With unnicked angle test pieces, the essential requirement is the production of a reproducible re-entrant angle,... 

With crescent, Delft and angle test pieces only the maximum force reached is recorded, although the change of force along the short tear path could be obtained with a force measuring and recording system having very... 

The basic method is a closely specified test intended for quality control or the comparison of bonding systems, but could readily be extended to investigate the effects of test piece dimensions, peeling angle, test speed, etc. 

Surface Tension. Testing for surface tension is sometimes referred to as the contact-angle test (see Fig. 13.6). Surface free energy is defined by surface tension which is directly related to surface cleanliness. If an adsorbate (dirt) is present on a surface, the free energy-surface tension is reduced as energy is spent in bonding the adsorbate to the surface. In other words, the surface has become less clean... 

Chapters 1 through 3 Bunsen burner tests for miscellaneous materials. The tests are all conducted in cabinets and they include vertical test (Chapter 1 12 or 60s), horizontal test (Chapter 2 30 s), and 45° angle test (Chapter 3 15 s). These tests apply mostly to materials and products in smaller noncommercial aircraft. 

If now the geometry would be forced to inhibit the aromatic system, as is the case in the experimental systems, where bridges are attached to bend the molecule, the aromaticity disappears at much lower angles. Test calculations [86], where the angle a is reversed to simulate this situation, indicate that then the aromaticity is only maintained up to 30°. 

The aim of the present study was a closer investigation of the properties of LDPE surfaces subjected to photosulfonation processes. Until today no zeta potential studies had been carried out on photosulfonated LDPE. In the present investigation such modified LDPE surfaces were characterized by FTIR spectra, contact angle testing and zeta potential measurements were carried out. To improve the stability of modified LDPE surfaces, polyethylene samples were crosslinked by e-beam irradiation and... 

Treatments with more limited durability would be more appropriate for the U.S. general wearing apparel (16 CFR 1610), which has a 45° angle test because the test and the cleaning requirements are less severe (see Section 6.2.4.4). Currently only resistance to dry cleaning and hand washing are required. 

The main durable FR finishes used on cotton to meet more severe open-flame resistance requirements are phosphorus based [343,358]. One of the problems with typical phosphorus-based FR treatments on fleece, which only requires a mild treatment to pass the 45° angle test, is that the often-required levels alter the esthetic properties of the fleece, resulting in a fabric that is stiff or matted and often has unpleasant odors. Most common types of dyes used on cotton are affected by pH or oxidation-reduction procedures that are used during the FR treatments. 

Viscosity and contact angle testing results are provided in Tables 2 and 3, respectively. 

These properties are listed in order of usefulness for comparative review purposes. Liquid surface tension is the most fundamental property, because it pertains only to the material in question (provided the material is adequately pure) and the technique used for measurement. All the other properties listed are dependent also on solvents, contact-angle test liquids, and liquid or solid substrates selected. For solids, approaches such as the Owens-Wendt analysis (7) have supplanted the Zisman method (18) in recent years, but data from the Zisman method for organosilicon polymers are more available compared with data from the Owens-Wendt approach. Some useful data on aqueous surface tensions and Langmuir troughs are also available. Data for other listed properties are of less fundamental use and rather scanty. 

ISO 34 (BS903, Part A3) contains as many as five test methods for tear strength, a reflection not only of the general importance of the property but also of the difficulty of matching laboratory tear tests to product behavior. The methods comprise the trouser, crescent. Delft, and nicked and unnicked angle test pieces, none of which gi es comparable results to another. ASTM D624 specifies crescent test pieces with and without tab ends (Dies A and B respectively), the unnicked angle test piece (Die C). and the trouser test piece (Die T). 

Table 4.4 Water drop contact angle test on plasma-treated metal surfaces [4], Proc SPIE 2009, reprinted with permission...

The polymer-metal interface between the ionic EAP and the embedded elec-trode(s) was significantly improved using plasma treatment. Based on the water drop surface contact angle tests and mechanical testing, oxygen plasma-treated stainless steel and titanium led to much better adhesion between the electrodes and the EAPs. For both stainless steel and titanium, XPS confirmed the presence of a... 

FIGURE 52.4 Relative displacement of C4 on C5 for 20° seat back angle tests (solid lines) and 0° seat back angle tests (dotted lines) simulating low-speed rear-end collisions, using a cadaver. (Reproduced from Stapp Car Crash J. 44 171-188. With permission.)... 

PLLA Nonwoven scaffold TE SEM, mercury porosimeter, AFM, contact angle test, in vitro neural stem cell culture (Yang et al. 2004)... 

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