1
Q
What are the two types of yarn numbering systems
A
Direct, Indirect
2
Q
What is included under Direct Numbering system
A
(Weight/Unit length)
- Tex
- Dtex
- Denier
3
Q
What is included under Indirect Numbering system
A
(length/Unit Weight)
- Metric
- Cotton
- Worsted
4
Q
A yarn number can be expressed in what 2 variables
A
- yarn length
- yarn weight
5
Q
Formula for Tex
A
W(g)x1,000(m/km)/L(m)
6
Q
Formula for Dtex
A
W(g)x10,000(m/km)/L(m)
7
Q
Formula for Denier
A
W(g)x9,000(m/km)/L(m)
8
Q
What does the Winding Process convert
A
Converts small spinning bobbins to large packages
9
Q
Winding Process objectives
A
- to produce subtle packages for the next process
- Clearing - removing weak spots or defects
10
Q
Yarn Defects
A
- Thick place
- Thin Place
- Slub
- Nep
11
Q
What does a highly twisted yarn look like under tension
A
normal appearance
12
Q
What does a highly twisted yarn look like with slack
A
Snarl forms
13
Q
Winders 3 Principle Zones
A
- Unwinding zone
- Tension and Clearing zone
- Winding Zone
14
Q
Unwinding zone components
A
- Spinning Bobbin
- Guide
15
Q
Tension and Clearing components
A
- yarn clearer
- tension device
16
Q
Winding zone components
A
- delivery package
- package drive
- feeler (stop motion)
17
Q
What are the two winding guides
A
- Open Guides
- Closed Guides
18
Q
Open guide properties
A
- does not require a yarn end for threading
- threading can be easily automated
- less positive guiding
19
Q
Closed guide properties
A
- Requires a yarn end for threading
- difficult to automate threading
- positive guiding
20
Q
Tension Guides function
A
- Keep yarn tension constant at a preselected level to achieve a certain package density
- Break the yarn at weak spots so that they can be removed when piecing the yarn
21
Q
What is the impact on the productivity with Tension Guides
A
The positive impact of the efficiency of the subsequent process and quality
22
Q
What is the level of package density determined by
A
determined by the next process
23
Q
Dent
A
space between 2D wires
24
Q
Types of tension devices
A
- Capston
- Additive
- Combined
25
How is the yarn level controlled through the Capston Tension Guide
change the angle of wrap by moving posts
26
How is the yarn level controlled through the Additive Tension Guide
Alter the force by adding or removing discs
27
How is the yarn level controlled through the Combined Tension Guide
1. change the angle of the wrap
2. alter the force by adding or removing discs
28
Yarn Clearer Functions
1. Allows only predetermined yarn to pass through it
2. Catches thick and thin places, slubs, and improper knots and cuts teh yarn at these places
29
Types of Yarn clearers
1. Mechanical
2. Electronic
30
What subcategories are under the Electronic Yarn Clearers
- Photometric
- Capacitive
31
Methods of Rotating Packages
1. Spindle Drive
2. Friction Drive
32
Friction Drive Function
Used for spun yarns and filament yarns with high denier/ filament. not sensitive to friction
33
Spindle Drive Function
Used for yarns that are sensitive to friction such as filament yarns with low to medium denier/filament
34
Methods of traversing Yarn
1. Grooved Drum
2. Reciprocating Transverse
35
What is the grooved drum used with
used with the friction drive winder
36
Reciprocating Transverse used for
All Spindle drive winders and some friction drive winders use this type
37
Types of Winding
1. Parallel
2. Near Parallel
3. Cross
38
Parallel Winding
Uses a warp beam, accommodates more yarn, needs flanges to prevent sloughing
39
Near Parallel Winding
Use a wound packages, accommodates more yarn, needs flanges or taper winding to prevent sloughing off
40
The types of winding tranverse speeds
Parallel - zero
Near Parallel - Low
Cross - High
41
Cross Winding
use a wound package (single end), accommodates less yarn, stable yarn shoulders
42
Ribboning
defect that takes place at a certain package diameters in drum
43
How is ribboning Formed
When yarn is wound immediately on top of another
44
How does ribboning effect the productivity
negative impact of the productivity of the subsequent process and the quality
45
What are the three main problems with ribboning
1. Uneven die penetration
2. tension increase - ends break
3. slough off
46
Ribboning Breaking Mechanisms
Anti-Patterning Devices that re designed to change the yarn transverse speed or package rotational speed at intervals
47
What are the two main types of Winders
1. Manual
2. Automatic
48
Circular Winder Number of spindles
Small number of spindles
49
Elongated Winder Number of spindles
Large number of spindles
50
Downtime Items
1. Service time to creel and piece the supply package
2. Doffing delivery package
3. Piecing broken yarns
4. Waiting for service
5. Breakdown
6. Maintenance
51
Warping Process Objective
To wind a sheet of the required number of yarns and length on a large package termed as the Warp Beam. The warp yarns (ends) must be parallel and wound under uniform tension
52
Warping Machine Two Main Elements
Creel
Headstock (beamer)
53
Creel function
hold and supply wound packages
54
Headstock (beamer) function
equipped with bearing to hold the warp beam and a motor to drive the warp beam
55
What is the creel equipped with
1. Holders to hold supply packages
2. tension devices
3. Guides
4. Antistatic Device
5. Stop Motions
56
Creel Capacity
Defined as the maximum number of supply packages that the creel can hold
57
What is the Creel Capacity limited by
space, tension variation, and handling
58
What is the range of the creel capacity
Range of manageable capacity is 300-1400 supply packages
59
what are the two warper types
Direct Warper
Indirect Warper
60
How many steps does the direct warper take
One steps
61
How many steps does the indirect warper take
two steps
62
Direct Warping comparison
1. creels require more space
2. faster than indirect
3. impractical for short runs and development of new styles
63
Indirect warping comparison
1. Creel requires less space
2. slower than direct
3. suitable for short runs and development of new styles
64
Two types of warp creel types
Single position, multiple position
65
In the warping process, reserved creel is loaded with
full wound packages while the other creel is in use
66
Sizing (slashing) is performed on...
Process is performed on a single spun warp yarns and untwisted continuous filament warp yarns
67
Single spun yarns appearance
hairy structures
68
Filament in a continuous filament yarn strength
weak element that may break during weaving
69
Clinging of warp hairs leads to
1. Warp breaks on most looms
2. Warp caused filling stops in air jet looms
3. fuzz balls and fabric defects
LOW WEAVING EFFICIENCY AND FABRIC QUALITY
70
Sizing process primary objective
The primary objective of the sizing process if to prepare warp yarns to withstand the stresses of the weaving process
71
Stresses on warp yarns
Tension, Bending, Abrasion, Impact
72
Sizing Process Objectives
modify the characteristics of the woven fabric
73
Sizing Machiene Elements
1. Size solution preparation and storage.
2. Creel
3. Size application (size box).
4. Sized warp drying (drying section).
5. Warp yarn separation section (lease rods).
6. Headstock for winding loom warp beam (weaver’s beam)
74
Ingredients in a typical Size mix
1. Water
2. Size agent
- Natural
- Synthetic
3. Lubricants or Softeners
4. Binders or Adhesive
5. Preservatives
75
Parameters Influencing Size Take-Up
1. Size concentration
2. Level of the size mix in the size box.
3. Distance of the dip roller from the surface of the size mix.
4. Weight and pressure of the squeeze rollers.
5. Temperature of the size mix.
6. Speed of warp sheet.
7. Tension of warp sheet.
76
Drying zone
stainless steel Teflon-coated to prevent sticking of the size material surfaces
77
Size penetration
measured by the distance that the size material penetrated through the yarn
78
Size Encapuslation
the measure of how much size material covers the yarn surface
79
Drawing-In Process is done when...
the weavers warp beam has run out and the weaving machine needs a new supply of warp
80
Drawing in is performed when
a new style is to be woven
81
Where is the Drawing In process performed in
Drawing-In Room
82
Drawing In process
each warp end is drawn (threaded) through different elements of a weaving machine
83
Tying In process is preformed where
at the loom
84
Tying In Process
In the process, each end of the new warp beam is tied or pieces to an end of the old warp
85
When is the tying process done
The process is done when the weavers warp beam has run out and the weaving machine needs a new supply of warp
86
The tying in Process is performed if
the style running on the machine is to be continued
TT 252
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