Quality control glass

Benefits resulting from better control of glass melting ate lower fuel consumption, better glass quality, more efficient production time, and better pollution control. Fewer operators are needed and working conditions are better. 

A solvent free, fast and environmentally friendly near infrared-based methodology was developed for the determination and quality control of 11 pesticides in commercially available formulations. This methodology was based on the direct measurement of the diffuse reflectance spectra of solid samples inside glass vials and a multivariate calibration model to determine the active principle concentration in agrochemicals. The proposed PLS model was made using 11 known commercial and 22 doped samples (11 under and 11 over dosed) for calibration and 22 different formulations as the validation set. For Buprofezin, Chlorsulfuron, Cyromazine, Daminozide, Diuron and Iprodione determination, the information in the spectral range between 1618 and 2630 nm of the reflectance spectra was employed. On the other hand, for Bensulfuron, Fenoxycarb, Metalaxyl, Procymidone and Tricyclazole determination, the first order derivative spectra in the range between 1618 and 2630 nm was used. In both cases, a linear remove correction was applied. Mean accuracy errors between 0.5 and 3.1% were obtained for the validation set. 

A survey of glazing failures due to wind load indicates that improper installation of setting blocks, gaskets or lateral shims, or poor edge bite is a significant cause of failure because of the resultant unconservative support conditions. To prevent premature glass failure, a strenuous quality control program is required. 

SACHEM Inc. of Cleburne, Texas, manufactures various concentrations of tetramethylammo-nium hydroxide (TMAH) solutions to meet customer specifications. To ensure consistent performance, electronic industry requires very narrow concentration specifications for the solutions. In SACHEM s quality control laboratory, standardized acids such as HC1 or H2S04 are used as titrants for the TMAH solutions to check their concentrations. The performance of the assay titration is controlled by daily analysis of internal reference standards (IRSs). If the IRS results are within controlled limits, then the assay results of a product can be reported. If not, the results cannot be reported until the root cause is uncovered and eliminated. Safety glasses and gloves are worn while performing this work in the laboratory. 

The surface of a solid may differ in many ways from its bulk composition. Especially, such solids as commercial carbon black may contain minor amounts of impurities (such as aromatics, phenol, carboxylic acid). This would render surface adsorption characteristics different from that of pure carbon. It is therefore essential that, in industrial production, quality control of the surface from different production batch is maintained. Otherwise, the surface properties will affect the application. Another example arises from the behavior of glass powder and its adsorption character for proteins. It has been found that if glass powder is left exposed to the... 

All major functions of a plant, such as glass transport, control of the sputter processes and pump control, are carried out fully automatically. This is the only way to ensure high productivity along w/ith high product quality. 

X-ray fluorescence can be used to analyse all types of samples. Its applications are numerous, whether in research and development or in quality control of production. Initially, X-ray fluorescence was used in industries that treat metals of primary fusion or alloys and, more generally, in the mineral industry (for use one ceramics, cements, steel, glass, etc.). Because of the ease of use of common X-ray fluorescence instruments, its scope of application has expanded into other areas the photographic industry and semi-conductors (for impurity control in silicon chips), the petroleum industry, geology, paper mills, gas analyses (such as nitrogen), toxicology and environmental applications (dust, fumes from combustion, heavy metals, and dangerous materials in waste such as Pb, As, Cr, Cd, etc.). 

At least two large California wineries actually own and operate their own glass plants where much of their wine bottle requirement is manufactured. These are typical glassware manufacturing operations and both have typical glassware quality control programs. Likewise, some larger wineries manufacture their own aluminum pilfer-proof caps, and their quality control effort is included in Phase II as used here. 

Thermal analysis is a useful tool in the quality control of many incoming routine materials, which can be tested against a reference standard developed internally by analysing a large number of samples of known performance criteria to ensure that the quality of supplies is maintained. Solid elastomers can be identified by glass transition temperature (Tg) [70]. The rubber industry uses thousands of different raw materials, and this number is steadily increasing. These materials are listed in [172]. 

Glass companies do not try to make poor-quality glassware, nor are they intent on selling their mistakes. However, mistakes happen and sometimes the mistakes get by quality control. Regardless, the final quality control person is the customer. 

Physical considerations such as water vapor transmission to evaluate seal integrity, thermal analysis such as DSC to monitor melting point and glass transitions of plastics, and IR scanning to prove identity should be part of an ongoing quality control monitoring program. 

Hot-melt thermoplastic primary coatings for optical fibers have also been employed to a limited extent (26,27). They may be formulated with reasonably low glass transition temperatures, but particle contamination is a difficult quality control problem with these materials. UV-curable coating formulations have largely supplanted hot melt coatings owing to the increased draw speed which they offer. 

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