List of top Textile Engineering and Fibre Science Questions asked in GATE TF

Determine the correctness or otherwise of the following Assertion [a] and Reason [r]
Assertion: In shuttle loom, late shedding is preferred for filament weaving.
Reason: In late shedding, the timing of shed dwell matches with the timing of shuttle travel through the shed, and therefore, it minimizes the rubbing of warp yarns.
Determine the correctness or otherwise of the following Assertion [a] and Reason [r]
Assertion: Application of an optical brightening agent makes the white fabrics appear brighter.
Reason: Optical brightening agents absorb energy in the visible region and radiate back in the UV region.
Determine the correctness or otherwise of the following Assertion [a] and Reason [r]
Assertion: Nylon is dyed with acid dyes in the acidic medium.
Reason: Nylon assumes positive charge in the acidic medium and thus attracts the negatively charged acid dye molecules.
Determine the correctness or otherwise of the following Assertion [a] and Reason [r]:

Assertion: Discharge printing of dyed polyester fabric is not possible.
Reason: The discharging agents damage the polyester fibers significantly.

A 50 tex yarn with mass CV of 12.5 % is produced from staple polyester fibres each of 4.5 denier fineness. The index of irregularity of the yarn, (rounded off to two decimal places), is\(\underline{\hspace{2cm}}\).

A counter-flow heat exchanger is attached to a stenter for waste heat recovery. 

Given data: \[\begin{array}{rl} \bullet & \text{Ambient temperature, \( T_1 = 30^\circ C \)} \\ \bullet & \text{Temperature of exhaust from stenter, \( T_2 = 150^\circ C \)} \\ \bullet & \text{Temperature of exhaust at exit of heat exchanger, \( T_3 = 100^\circ C \)} \\ \bullet & \text{Specific heat of exhaust gas, \( C_p = 0.42 \, \text{kcal} \cdot \text{deg}^{-1} \cdot \text{kg}^{-1} \)} \\ \bullet & \text{Specific heat of air, \( C_a = 0.24 \, \text{kcal} \cdot \text{deg}^{-1} \cdot \text{kg}^{-1} \)} \\ \end{array}\]

Consider the following isotherms at equilibrium for two disperse dyes \( D_1 \) and \( D_2 \) dyed on polyester. If the partition coefficients of these are \( K_1 \) and \( K_2 \), respectively, the value of \( \frac{K_2}{K_1} \text{ is } \underline{\hspace{2cm}}. \)

In a 3 over 3 drafting arrangement, the diameter of all bottom rollers is 28 mm. The back zone draft is 1.3 and the front zone draft is 6. If the back bottom roller is eccentric then the wavelength (mm) of the resulting fault in the drawn sliver, (rounded off to two decimal places), is \(\underline{\hspace{2cm}}\).
For a shuttle loom, producing plain woven fabric, if each of the dwell periods of the shedding cam corresponds to one-third of crank shaft rotation, the sum of the two dwell periods of the cam (in degree) is \(\underline{\hspace{2cm}}\).
For a given woven fabric, fractional cover is 0.5 for both warp and weft. The fractional cover of the fabric, (rounded off to two decimal places), is \(\underline{\hspace{2cm}}\).
If the moisture regain (%) and moisture content (%) of a fibre are the same then the value of moisture regain (%) is \(\underline{\hspace{2cm}}\).
Mass of 120 yards of cotton yarn is 3 g. The count (Ne) of yarn, (rounded off to one decimal place), is \(\underline{\hspace{2cm}}\).
A woven fabric with areal density of 300 g/m\(^2\) is tested by strip tensile test method, keeping the specimen width as 5 cm and gauge length as 25 cm. If the breaking load is 900 N, the tenacity (cN/tex) of the fabric is \(\underline{\hspace{2cm}}\).
A roving of 2 Ne count is fed to a ringframe set with a mechanical draft of 30. If the length of the drafted strand delivered from the nip of the front rollers is reduced by 3% due to twist then the count (Ne) of the yarn, (rounded off to one decimal place), is \(\underline{\hspace{2cm}}\).
The molecular weight (M) of a polymer is determined from Mark-Houwink equation by using coefficient \( K = 11.5 \times 10^{-3} \) ml/g and exponent \( a = 0.73 \). If the measured intrinsic viscosity \( [\eta] \) of the solution is \( 6.0 \times 10^2 \) ml/g then the value of \( M \times 10^{-6} \), (rounded off to two decimal places), is \(\underline{\hspace{2cm}}\).
In melt spinning, the mass throughput rate of polymer is 210 g/min, the winding speed is 3000 m/min, and the linear density of the yarn produced is 200 denier. The effective draw ratio, (rounded off to two decimal places), is \(\underline{\hspace{2cm}}\).
Assuming no fibre loss in draw frame, if draft is equal to doubling then the delivered sliver, as compared to fed sliver, will exhibit
The typical shapes of comb sorter diagram and fibrogram of polyester fibres of equal cut length will be
In Classimat system, the yarn fault H2, as compared to yarn fault C3, is
In a modern high-performance blowroom line, the correct sequence of machines is
As compared to cylinder, doffer has
In winding, if traverse speed and package surface speed are the same, the angle of wind (in degree) is \(\underline{\hspace{2cm}}\).
Assuming Beer-Lambert law is applicable for dilute solutions, if the molar concentration of dye in the solution is doubled then the percentage increase in absorbance would be \(\underline{\hspace{2cm}}\).
The wet expression for a padding mangle is set at 80 %. If the add-on of a flame retardant chemical required on the fabric is 2 %, then the concentration (g/L) of the chemical in the pad bath is \(\underline{\hspace{2cm}}\).
During air-jet weft insertion, if the diameter of the yarn increases by 20%, then the percentage increase in drag force acting on the yarn would be \(\underline{\hspace{2cm}}\).