POY

POX. See Polyoxetane Poxvindae Poynting correction Poynting factor POY nylon yarn Pozzolans... 

In false twist texturing (FTT), shown schematically in Figure 7, a device twists yam upstream of its location as the threadline passes across a heater, and the yam untwists downstream from the device and is wound up. If the yam is not heated downstream from the twist device, it has bulk and high elasticity (stretch). If the yam is heated downstream from the twist device, it has bulk, but much less stretch. FTT machines initially used two steps to sequentially draw and texture. Later machines combined those steps to simultaneously draw and texture (92). Initial machines used pin spindles as the false twist device. Texturing speeds were about 150 m/min and slowly increased to about 300 m/min. As POY quaUty and stmctural stabiUty improved, new... 

Filament. Eully drawn flat yams and partially oriented (POY) continuous filament yams are available in yam sizes ranging from about 3.3—33.0 tex (30—300 den) with individual filament linear densities of about 0.055 to 0.55 tex per filament (0.5—5 dpf). The fully drawn hard yams are used directly in fabric manufacturing operations, whereas POY yams are primarily used as feedstock for draw texturing. In the draw texturing process, fibers are drawn and bulked by heat-setting twisted yam or by entangling filaments with an air jet. Both textured and hard yams are used in apparel, sleepwear, outerwear, sportswear, draperies and curtains, and automotive upholstery. 

Fig. 10. Dependence of the production on spinning speed (89), where LOY is low orientation yam MOY, medium oriented yam POY, partially oriented...

These equations are consistent with the isentropic relations for a perfect gas p/po = (p/po), T/To = p/poY. Equation (6-116) is valid for adiabatic flows with or without friction it does not require isentropic flow However, Eqs. (6-115) and (6-117) do require isentropic flow The exit Mach number Mi may not exceed unity. At Mi = 1, the flow is said to be choked, sonic, or critical. When the flow is choked, the pressure at the exit is greater than the pressure of the surroundings into which the gas flow discharges. The pressure drops from the exit pressure to the pressure of the surroundings in a series of shocks which are highly nonisentropic. Sonic flow conditions are denoted by sonic exit conditions are found by substituting Mi = Mf = 1 into Eqs. (6-115) to (6-118). 

This dynamic increase in production was accompanied by the qualitative development of PET fibers, which manifested itself in the widening of assortment of the fibers being produced (e.g., staple microfibers and filament yarns of the POY, MOY, FOY, and HOY type) and in the manufacture of second-generation fibers on... 

A researcher checks a sealed poy ol rr.ethane in Kajima Corp. s newly developed system designed to break down organic waste (Corbis-Bettmann)... 

Zr26(OH)x PM08.oSlll pOy Zr(CH3COO)4 SnCl2 H3PMo12O40 FTIR, UV, XPS 53... 

Pentaerythritol tetranitrate (PETN) PET/PEN copolymers, 20 50-51 PET POY spun yarn, 20 14 PET/PTN blend bottles, 20 53 PET resins, 20 33 handling, 20 59-60 Petri, Julius Richard, 11 8 Petri dish, invention of, 11 8 Petrochemical feedstocks, 13 556-570, 674... 

PTT polymer pellets must be dried to a moisture level of <30 ppm, preferably in a close-loop hot air dryer, to avoid hydrolytic degradation during melt processing. Drying is carried out with 130 °C hot air with a dew point of < -40 °C for at least 4 h. Because of the faster crystallization rate, PTT pellets are already semicrystalline after pelletizing, and do not require pre-crystallization prior to drying as with PET. The dried polymer is extruded at 250-270 °C into bulk continuous filaments (BCFs), partially oriented yam (POY), spin-draw yam (SDY) and staple fiber. 

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