PREVIOUS TEST

Question 1

why is roving necessary?

Answer 1

to reduce size, sliver is too big to come straight our of the drawframe and go immediately to spinning

Question 2

what are the 5 actions in roving?

Answer 2

1. Drawing: reduces size
2. twisting: add cohesion/strength
3. make roving: wind on a package
4. laying: make sure there is not gaps
5. building: properly shaped bobbin

Question 3

what is balloonless spinning

Answer 3

we deflate the balloon and put a crown on-top of the spindle, the yarn goes through the crown and the crown forces the yarn to collapse around the bobbin without going too far out

Question 4

8 influences of twist on yarn properties

Answer 4

1. hand
2. luster
3. abrasion resistance
4. absorbency
5. special effects
6. flexural endurance
7. contraction
8. strength

Question 5

in ring spinning, the amount of tension on the yarn is due to what 6 factors

Answer 5

1. yarn size
2. yarn speed
3. travelor speed
4. travelor weight
5. surface area of balloon
6. ring spinning

Question 6

what 3 things characterize twist in short staple yarns?

Answer 6

1. twist angle
2. twist direction
3. s or z twist

Question 7

list the 5 effects of reducing staple length

Answer 7

1. short staple needs more twist
2. not as strong
3. more expensive
4. less luste
5. harder hand

Question 8

T or F: In worsted spinning rings and travelers are sometimes lubricated to reduce friction and temp

Answer 8

T

Question 9

T or F: in ring spinning, end breaks are a result of too little tension in the yarn and high yarn variability

Answer 9

F

Question 10

T or F: ribboning in winding is due to the traverse shift being too large

Answer 10

F

Question 11

T or F: in 2 for 1 twisting the second turn of twist is inserted as a result of the package turning

Answer 11

F

Question 12

T or F: woolen ring frame spinning uses card roping

Answer 12

T

Question 13

T or F: rubbing frames run about twice as fast as roving frame

Answer 13

T

Question 14

T or F: in ring spinning the spindle speed lags behind the travelro speed to casue winding to occur

Answer 14

F

Question 15

T or F:In the production of roving for producing woolen yarns single zone drafting and a slip-drafting system are used

Answer 15

F

Question 16

T or F:in winding of roving onto a package, as the bobbin speed increases the flyer speed must also increase

Answer 16

F

Question 17

T or F: the goal in splicing is to have the yarn diameter after splicing be no more than twice the original yarn diameter

Answer 17

F

Question 18

list the 3 tyoes of irregularity in drawn sliver that are related to machine defects or poor maintence

Answer 18

1. roller speed variation
2. fiber slip
3. roller nip movement

Question 19

T or F: in open end spinning the rotor design and size is selected based on fiber type and desired production speed

Answer 19

F

Question 20

T or F: compact spinning is a modification to the rotor spinning machine which allows for better twisting of edge fibers to create a stronger yarn

Answer 20

F

Question 21

T or F: air jet yarns have a parallel core of cotton fibers held together by abdns of polyester wrapper fibers

Answer 21

F

Question 22

T or F: ring spun yarns are stronger than open end spun yarns

Answer 22

T

Question 23

T or F: tow to top changes filament yarns into baled fibers

Answer 23

F

Question 24

T or F: edge crimping as a texturing method was not very successful because of the difficulty in getting large denier filaments to curl

Answer 24

T

Question 25

T or F: fasle twist can be used to create both stretch and bulk yarns

Answer 25

T

Question 26

T or F: it is possible to extrude, draw and texture filaments in a one step process

Answer 26

F

Question 27

T or F: one reason for wanting new spinning methods was the fact that ring spun bobbins were too large for efficient shipping

Answer 27

F

Question 28

T or F: coarser air-jet yarns were determined to be stronger than finer air-jet yarns

Answer 28

F

Question 29

T or F: stacked disc fricition twisters used rubber bushings to genereated false twist yarns

Answer 29

F

Question 30

T or F: compact spinning allows a reduction in twist level while maintaining the yarn strength

Answer 30

T

Question 31

T or F: converting is a term used to describe the process of changing continuous filaments into staple fibers sliver

Answer 31

T

Question 32

T or F: in stretch breaking the tow is wrapped around the rolls to enhance fricition and reduce slippage

Answer 32

t

Question 33

T or F: stuffer box textured yarns are used in artificial turd becasue it gernerated a buckled crimp

Answer 33

F

Question 34

T or F: vortex spun yarns are more hairy than ring spun yarns

Answer 34

F

Question 35

T or F: simultaneous and sequential draw0texturing both use POY as the input material

Answer 35

T

Question 36

T or F: in compact spinning the twist triangle is enlarged so that more fibers are incorporated

Answer 36

F

Question 37

T or F: yarns textured using gear crimping maintained their crimp better than edged crimped yarns

Answer 37

T

Question 38

T or F: oepn end spun yarns are more even than ring spun yarns

Answer 38

T

Question 39

T or F: twist transference is used in the production of compact yarns to help hold the fibers together

Answer 39

F

Question 40

T or F: the guillotine method of cutting filament tow is used by most filmament staple producers becasue it is a simple procedure

Answer 40

F

Question 41

T or F: staple textured yarns can be produced from fully drawn yarns, partially oriented yarns and low orientation ayarns

Answer 41

F

Question 42

T or F: bulk and hairiness of a yarn can be changed by the type of navel used in open end spinning

Answer 42

T

Question 43

T or F: tight spots are untextured areas due to poor tension and teist contol

Answer 43

T

Question 44

are open yarns stronger or weaker than ring spun yarns and why?2

Answer 44

weaker because of bridge fibers and poor fiber orientation

Question 45

are open end yarns more or less even than ring spun yarns and why?3

Answer 45

more even because more doubling in lay in, no roving, and can chose amount of drawing processes

Question 46

do open end yarns have more or less elongation than ring spun and why?1

Answer 46

greater because of bridge fibers

Question 47

do open end yarns have a better hand than ring spun and why? 1

Answer 47

harsher hand than ring spun bc shorter fiebrs

Question 48

do open end yarns more or less bulky than ring spun yarns and why? 1

Answer 48

more bulky bc bridge fibers

Question 49

are open end yarns more or less hairy than ring spun and why? 1

Answer 49

more hairy bc bridger fibers

Question 50

6 attributes that were consider inportant for the ideal spinning system?

Answer 50

1. good quality yarns 2. spin from sliver 3. fast 4. cheaper 5. produce large fault free packaages 6. flexible in fiber and yarn types

Question 51

6 process phases in open end spinning

Answer 51

``` feeding drafting fiber transport twisting yarn removal winding ```

Question 52

7 process steps in texturing

Answer 52

1. input fully drawn yarn 2. heat above tg 3. deform the yarn 4. cool below tg 5. reverse the deformation 6. relax the yarn which is optional 7. wind onto a package

Question 53

methods for feeding fibers in short staple fibers 3

Answer 53

incline feed hooper horizontal

Question 54

things to control with gridbars 3

Answer 54

air flow distance mounting/cleaning angles

Question 55

properties of air texturing 4

Answer 55

more bulky higher mositure absorption heat insulation more elastic

Question 56

whihc is more bulky and has more elongation false twist or air tecturing

Answer 56

false twist

Question 57

intermingling

Answer 57

process where filament which may have been tectured are condolidation

Question 58

co-mingling

Answer 58

where several yarns are combined and consolidated

Question 59

torque balancing

Answer 59

using a torque jet to eliminate any residual torque liveliness from a textured yarn

Question 60

how to eliminate residual toruqe in false teist textured yarn 2

Answer 60

combine z and s textured yarn through intermingling | use a detorque jet after 2nd heater

Question 61

5 properties improved by combing

Answer 61

``` luster strength hand be more even along the length improve spin limit ```