Light fabrics

The colour of the treated and stained fabric cannot be ignored. Very dark fabrics and very light fabrics can appear to have less soil simply from optical effects. Table 7.2 gives an overview on the chemical mechanisms of soil-release finishing. 

It seems impossible that a light fabric bag can lift such a weight. It does so because the air inside the fabric bag or balloon is hotter than the outside air iuid the density of the heated air is much lower. Children s helium balloons float attached to their strings because the density of helium at room temperature and pressure is less than that of air. Release them from their strings and they will float off high into the sky - causing great distress to the children ... 

Vector FoUtec (2009), Technical information , www.foUtec.com (accessed 3.5.2009) Wright, B (2009), Modehng night light . Fabric Architecture, 3/4-2009, Vol. 21, No. 2... 

A third example of such a reaction, and one of considerable practical importance, is the so-called tendering of fabrics by light. Fabrics dyed with certain dyes disintegrate on exposure to light, a phenomenon which caused some concern to manufacturers of curtains when it was first observed. The effect seems to be due to a photosensitized oxidation of water or hydroxide ion by electron transfer, leading to hydroxyl radicals and hydrogen peroxide which attack the fabric. 

Hr Avoid pressing down too hard on the foot while using lightweight fabric a slower pace keeps light fabric from bunching. 

Light microscopy is of great importance for basic research, analysis in materials science and for the practical control of fabrication steps. Wlien used conventionally it serves to reveal structures of objects which are otherwise mvisible to the eye or magnifying glass, such as micrometre-sized structures of microelectronic devices on silicon wafers. The lateral resolution of the teclmique is detennined by the wavelength of tire light... 

Other investigations dealt with straight-chain molecules (oi-tricosenoic acid) in which the penultimate and final carbon atoms at the hydrophobic end are connected by a double bond [91, 92]. The material does not polymerize as rapidly as those described before when irradiated by UV light, however, but it is readily polymerized when bombarded with an electron beam. It was thus thought to be an optimal material for the fabrication of electron beam resists. 

Although the cross-sectional shape of the spinneret hole direcdy affects the cross-sectional shape of the fiber, the shapes are not identical. Round holes produce filaments with an approximately round cross section, but with crenelated edges triangular holes produce filaments in the form of a "Y." Different cross sections are responsible for a variety of properties, eg, hand, luster, or cover, in the finished fabric. Some fibers may contain chemical additives to provide light-fastness and impart fire retardancy. These are usually added to the acetate solution before spinning,... 

Bis(azol-2-5l)stilbenes (2(i]ll such as (4) have been prepared. 4,4 -Dihydrazinostilbene-2,2 -disulfonic acid, obtained from the diamino compound, on treatment with 2 moles of oximinoacetophenone and subsequent ring closure, leads to the formation of (4) [23743-28 ]. Such compounds are used chiefly as washing powder additives for the brightening of cotton fabrics, and exhibit excellent light- and hypochlorite-stabiUty. 

Weathering. Articles fabricated from FEP are unaffected by weather, and thek resistance to extreme heat, cold, and uv kradiation suits them for apphcations in radar and other electronic components. For example, after 15 years of solar exposure in Florida, the tensile strength (73) and light transmission (96%) of a 25-p.m thick film was unchanged and the film remained crystal clear. Elongation increased slightly for the first 5 to 7 years of outdoor exposure, probably as a result of stress relaxation. Beyond 10 years, a small decrease was observed. 

Draperies. Draperies of light weight or open-weave fabrics are ineffective for sound-absorbing purposes. Heavy draperies, such as flannel and velour, can provide useful sound absorption if properly installed. For best results they should be hung with 100% fullness, ie, 2 nC for every nC of wall or window surface covered. The sound-absorbing properties also are affected by the amount of space between the draperies and the surface behind them. 

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