Test 2 Flashcards
1
Q
Draft increase, Cv
A
increases
2
Q
Tex in increases, CV
A
decreases
3
Q
doubling increases, CV
A
decreases
4
Q
Parallelism increases, CV
A
decreases
5
Q
As fiber length increases, CV
A
increases
6
Q
Doubling CV equation
A
cv in / sqrt(number of doublings)
7
Q
Actual draft: direct
A
sum of n in/ n out
8
Q
Actual draft: indirect
A
Count out/ count in
9
Q
Mechanical draft
A
Vout/Vin
10
Q
Roll Velocity
A
UpiD
11
Q
CV2 out=
A
cv2in+cv2added
12
Q
Draft zones
A
D(n-i + 1) + (i-1) / D(n-i)+ i
13
Q
Productivity
A
P=Nvn
14
Q
Actual vs mechancial
A
AD=MD(1-%fiber loss)
15
Q
drafting
A
reduce material size
16
Q
drawing
A
the process that preforms the drafting operation
17
Q
doubling
A
feeding of several input materiala
18
Q
what is the purpose of doubling?
A
to improve blending and minimize irregularities
19
Q
4 objectives of drawing
A
reduce input linear density, improve fiber alignment, improve regularity, blending
20
Q
how many slivers are inputed befoer drafting?
A
6 or 8
21
Q
which roll is the fastest
A
front roll
22
Q
what is the ratch
A
distance between nips of rollers
23
Q
4 perimeters for perfect drafting?
A
- fibers are same length and this equals ratch
- ratch is constant
- roller speeds are constant
- fiber speed equals roller speed
24
Q
4 possible sources of drafting irregularities
A
- drafting waves
- roller nip movement
- roller speed variation
- roller slip
25
cv is ?
amount of irregularity
26
3 drafting wave controls
1. pressure bar
2. more rollers
3. Apron drafting
27
how to avoid roller nip movement?2
take weights off when not using and use round rolls
28
what is roller speed variation associated with 2
eccentric bottom roller and gears
| roller vibration
29
fiber slips in rollers depend on what
weight on top of rollers, too light fibers wont have contact and too much fibers wont move
30
what is the problem with bigger roller sizes?
have limitation on minimum ratch setting
31
what is the problem with smaller roller sizes?2
easy to form laps
| wear out easier from having to go faster
32
why is it better to not link draw frames?
better to mix outputs from different draw frames to give more consistent quality and minimize variations
33
what is used in long staple drawing?
gill-box or pin drafter
34
what hooks do u want for semi worsted?
trailing hooks
35
how many drawing processes for semi worsted
3
36
when does drawing take place for worsted
prior and after combing
37
Worsted drawing are based on what kind of drafting
single zone
38
what does a gillbox (pin drafter) use
faller bars
39
what speed do faller bars move at
back roller speed
40
what is an intersector gill box
two row of faller bars
41
what is a gill box
single row of faller bars
42
what is a circular chain driven pin drafter
it changed the regular rectangular motion route of gill box to circular route and driven by chain
43
what is the purpose of circular chain driven pin drafter 2
to enhance the process speed and less machine noise
44
purpose of combing fibers (4)
want to remove short fibers
orient the fibers
straight
want to remove neps/ trash
45
what are the 3 parts of combing
preparation
combing
finishing
46
what kind of hooks are needed for cotton combing?
leading hooks
47
cotton combing needs even or odd number of processes to get a leading hook?
even
48
what are the two routes for cotton combing preparation?
route 1: sliver lap and ribbon lap
| Route 2: drawframe and lap former
49
which of the cotton prep routes are slower?
route 1
50
which route of cotton prep is used for lower grades of cotton
route 2
51
what is spin limit
finest yarn you can make with that particular fiber
52
what is the detachment setting?
distance between the nipper and the detaching roll
53
what is a top comb setting?
distance between the top comb and the detaching roll
54
increase top setting, amount of waste is
decreased
55
increase detachment setting, amount of waste is
increased
56
what is the beard
the portion of sliver being combed
57
2 big problems in combing
short fibers in combed sliver and long fibers in waste
58
how do we get short fibers in our combed sliver?
from leading hooks being broken by the comb cylinder when not captured by the top comb
59
how do we end up with long fibers in waste?
from trailing hooked fibers in the lap and they aren't efficiently straightened by the comb and it appears as a short fiber or slippage at the nipper
60
what is the big difference between cotton comb prep and worsted comb prep
uses 3 drafting operations between the card and comb.
61
3 differences between cotton comb prep and worsted comb prep
fed w slivers rather than a lap
detaching section moves rather than feed section
only one combing station per machine
62
how many processes are needed before a worsted comb to fix the hooks?
odd number
63
what kind of hooks are best for a worsted comb?
trailing hooks
64
when is top finishing used
if combed sliver is the final product
65
what is top finishing?
twice drawing
66
what does top finishing due 2
improves uniformity, and produces a format that is easily transportable
67
draft should always be
greater than 1
68
bigger draft means
finer fiber
69
spectrogram shows
machine error
70
what is apron drawing
it is put in between the front and middle rolls and goes at back speed to help control fiber speed
71
what is a noil
short fiber brushed out in combing
72
what units should productivity be in?
lbs/hr
73
what units shiuld v be in
inch/min
