Take-up unit

FIGURE 5.46 Ball bearing housing units, (a) Pillow block (b) flange cartridge (c) cylindrical cartridge (d) take-up unit. 

The take-up unit is the winding system that collects the knitted fabric and places it so that the tension will be distributed evenly in the material before it is wound on a core. 

Warp-knitting machines with biaxiai weft insertion can be classified as feeder unit, warp-knit unit, or take-up unit. 

Textile substrates are coated in two process steps. First a liquid, tenacious viscous, molten, or powder mass of plastic is applied on a substrate. Subsequently, a consolidation of the plastic coat takes place into a closed film, which forms a permanently bonded material with the substrate. Coating plants therefore consist of the segment s unroll stand, application device, drying or gelling channel, and take-up unit with a possible preceding cooling device (Fig. 9.10). 

CHEOPS (we tested Version 3.0.1) is a program for predicting polymer properties. It consists of two programs The analysis program allows the user to draw the repeat unit structure and will then compute a whole list of properties the synthesis program allows the user to specify a class of polymers and desired properties and will then try the various permutations of the functional groups to find ones that fit the requirements. On a Pentium Pro 200 system, the analysis computations were essentially instantaneous and the synthesis computations could take up to a few minutes. There was no automated way to transfer information between the two programs. 

Whereas the glass transition of a copolymer is usually intermediate between those of the corresponding homopolymers this is not commonly the case with the melting points. Figure 4.12 shows the effect of copolymerising hexamethylenesebacamide with hexamethyleneterephthalamide. Only when the monomer units are isomorphous, so that the molecules can take up the same structure, is there a linear relationship between melting point and composition (as with hexamethyleneadipamide and hexamethyleneterephthalamide). 

The commercial poly-(4-methypent-1-ene) (P4MP1) is an essentially isotactic material which shows 65% crystallinity when annealed but under more normal conditions about 40%. For reasons given later the material is believed to be a copolymer. In the crystalline state P4MP1 molecules take up a helical disposition and in order to accommodate the side chains require seven monomer units per two turns of the helix (c.f. three monomers per turn with polypropylene and polybut-I-ene). Because of the space required for this arrangement the density of the crystalline zone is slightly less than that of the amorphous zone at room temperature. 

Chain Tension. All chain drives should have some means of controlling the chain sag caused by normal joint wear. This is of utmost importance when the drive is subject to shock or pulsating loads or to reversals in direction of rotation. The most common methods taking up chain slack are (1) drive units mounted on adjustable base plat, slide rails, or similar units these are used extensively in motor-driven applications and (2) the use of adjustable idlers (Figure 3-40) and chain tensioners. 

These considerations show the essentially thermodynamic nature of and it follows that only those metals that form reversible -i-ze = A/systems, and that are immersed in solutions containing their cations, take up potentials that conform to the thermodynamic Nernst equation. It is evident, therefore, that the e.m.f. series of metals has little relevance in relation to the actual potential of a metal in a practical environment, and although metals such as silver, mercury, copper, tin, cadmium, zinc, etc. when immersed in solutions of their cations do form reversible systems, they are unlikely to be in contact with environments containing unit activities of their cations. Furthermore, although silver when immersed in a solution of Ag ions will take up the reversible potential of the Ag /Ag equilibrium, similar considerations do not apply to the NaVNa equilibrium since in this case the sodium will react with the water with the evolution of hydrogen gas, i.e. two exchange processes will occur, resulting in an extreme case of a corrosion reaction. 

Let the engine take Qi units of heat from the source, produce A units of work, and give up Q2 units of heat to the refrigerator then the efficiency is N = A/Qi. a)... 

Thus, if we consider unit mass of saturated steam, in equilibrium with liquid (Fig. 36), to be isolated without change of temperature and pressure, and then to be heated, this vapour would become unsaturated, i.e., would take up more liquid at its own temperature if this were offered to it. To prevent the assumption of this unsaturated condition we must compress the vapour during the addition of heat so that the pressure is, at every stage of the process, equal to the vapour-pressure at the corresponding temperature. The heating and compression of the vapour may then be performed in contact with the liquid, so that ... 

According to the VSEPR model, regions of high electron concentration take up positions that maximize their separations electron pairs in a multiple bond are treated as a single unit. The shape of the molecule is then identified from the relative locations of its atoms. 

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