The effect of aging and first heater temperature on the physical properties of polybutylene terephthalate textured yarn

2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Elham Mohammadi ◽  
Marjan Abbasi ◽  
Mahdi Nouri
2018 ◽  
Vol 18 (2) ◽  
pp. 149-159
Author(s):  
Hyun Ah Kim ◽  
Seung Jin Kim

Abstract This study examined the mechanical properties of a para-aramid filament according to the processing conditions of air-jet textured yarns (ATY). The specimens were prepared by changing the yarn speed, over feed ratio, air pressure, and heater temperature, which are important processing factors in the ATY process. The basic physical properties of the ATY, such as denier, tenacity, breaking strain, and initial modulus, were measured and their thermal shrinkage, such as dry and wet shrinkage, were measured to determine the thermal stability of the aramid ATY. In addition, the instability of para-aramid ATY were measured and assessed with the loop formation of ATY, according to the ATY process parameters. An examination of the effects of process parameters on the physical properties of aramid ATY revealed the core overfeed and air pressure to be the main factors. A high core overfeed and air pressure make the aramid ATY crimpy in the yarn core and entangle the fluffy loops on the yarn surface, resulting in an increase in the yarn linear density and breaking strain as well as a decrease in the tenacity and initial modulus. In contrast, these yarn physical properties were unaffected by the yarn speed, heater temperature, and wetting treatment. In addition, the dry and wet thermal shrinkage were unaffected by the process parameters of ATY. On the other hand, the instability decreased with increasing core overfeed and heater temperature and increased with increasing air pressure. These results showed that a high core overfeed makes the aramid ATY crimpy with an entangled yarn structure, and high air pressure helps provide small loops on the yarn surface. Finally, a high heater temperature makes the crimpy ATY structure more stable due to the strong heat set, which results in low instability.


2016 ◽  
Vol 19 (6) ◽  
pp. 1310-1318 ◽  
Author(s):  
Guilherme Cybis Pereira ◽  
Felipe Darabas Rzatki ◽  
Luca Mazzaferro ◽  
Daniel Maldonado Forin ◽  
Guilherme Mariz de Oliveira Barra

1976 ◽  
Vol 32 ◽  
pp. 365-377 ◽  
Author(s):  
B. Hauck
Keyword(s):  

The Ap stars are numerous - the photometric systems tool It would be very tedious to review in detail all that which is in the literature concerning the photometry of the Ap stars. In my opinion it is necessary to examine the problem of the photometric properties of the Ap stars by considering first of all the possibility of deriving some physical properties for the Ap stars, or of detecting new ones. My talk today is prepared in this spirit. The classification by means of photoelectric photometric systems is at the present time very well established for many systems, such as UBV, uvbyβ, Vilnius, Geneva and DDO systems. Details and methods of classification can be found in Golay (1974) or in the proceedings of the Albany Colloquium edited by Philip and Hayes (1975).


Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.


Author(s):  
K.P.D. Lagerlof

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.


Author(s):  
James Mark ◽  
Kia Ngai ◽  
William Graessley ◽  
Leo Mandelkern ◽  
Edward Samulski ◽  
...  
Keyword(s):  

1982 ◽  
Vol 85 (1) ◽  
pp. 257-263 ◽  
Author(s):  
A. Graja ◽  
M. Przybylski ◽  
B. Butka ◽  
R. Swietlik

2013 ◽  
Author(s):  
Kristina F. Pattison ◽  
Jennifer R. Laude ◽  
Thomas R. Zentall
Keyword(s):  

2020 ◽  
Vol 149 (12) ◽  
pp. 2332-2343
Author(s):  
Li Guo ◽  
Susan M. Courtney ◽  
Jason Fischer

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