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Showing posts with label Yarn Engineering. Show all posts
Showing posts with label Yarn Engineering. Show all posts

Saturday, 21 November 2020

What is Fatigue Testing?

Fatigue or fatigue damage refers to the modification of the properties of materials due to the application of stress cycles whose repetition can lead to fracture. Or In materials science, fatigue is the weakening of a material caused by cyclic loading that results in progressive and localized structural damage and the growth of cracks. 

Monday, 16 November 2020

Opening Devices used in Blow Room

Opening 
The action of opposite spikes is opening the cotton fibre. By this action, the large pieces of cotton have been reduced in size. 

Classification of the opening devices? 
Opening units can be classified as: 
• Endless path 
• Gripping devices 
• Rotating assemblies 
Depending on their design, construction, adjustment, etc., these assemblies exert enormous influence on the whole process.

Friday, 13 November 2020

Basic operation in blow room | Opening | Cleaning | Blending

Opening: To open the compressed bales of fibres & To make the cotton tuft a small size as far as possible. The first operation required in the blow room line is opening. Tuft weight can be reduced to about 0,1 mg in the blow room. The figure indicates that the degree of opening changes along a blow room line. It is apparent from the flattening of the curve towards its end that each additional opening stage would probably only bring additional stressing of the fibres without further improvement.


The openness of the fibre material after the various blow room machine stages: axis-A: Degree of opening (specific volume) and axis-B: Blow room stages

Thursday, 12 November 2020

Even feed of material to the card and Feed device.

Finally the blow room must ensure that raw material is evenly delivered to the cards. Previously, this was carried out by means of precisely weighed laps from the scutcher, but now automatic flock (Chute) feeding installations are increasingly being used.

Fibre feeding device in blow room

Monday, 9 November 2020

Beaters used in Blow Room Machine

There are mainly three (3) types of beaters used in blow room and they are explained below- 
1. Porcupine, 
2. Bladed beater: Beater arms (Multiple bladed beaters), 
3. Kirschner beater

1. Porcupine:
The strikers are arranged at different angles to cover the total width of the m/c in one revolution of the beater. Good opening beater and suitable for long-staple cotton. It separates the fibres by the striker. Simultaneously cleaning is also done.
Porcupine Beater
Porcupine Beater

Sunday, 8 November 2020

Rollers used in a Blow room line

There are different types of roller used in the blow room line which have been mentioned below-
1. Spiked Roller / Rollers with teeth or blades or Spikes:
- Flat, oval or round bars are welded, riveted or screwed to closed cylinders.
- Used in Modern Horizontal Cleaners, Chute feeds, mixing bale opener, step cleaner etc.
- The rollers rotate at speeds in the range 600-1000 rpm.
- The bladed drum is used in Porcupine opener.

Spiked rollers
Spiked rollers

Saturday, 7 November 2020

Why and How Grid is used in Blow room?

In the final analysis, it is the grid or a grid-like structure under the opening assembly that determines the level of waste and its composition in terms of impurities and good fibres. Grids are segment-shaped devices under the opening assemblies and consist of several (or many) individual polygonal bars or blades (i.e. elements with edges) and together these form a trough. The grid encircles at least 1/4, at most 3/4 and usually 1/3 to 1/2 of the opening assembly.

Two-part Grid
Two-part Grid

Monday, 2 November 2020

Blow room | Operating zones in the blow room

Blow Room 
Cotton fibre is compressed in a bale of 200 to 250 kg. This highly compressed cotton fibre need to be opened at first as a part of yarn manufacturing. And there is 1.5% to 7% trash in a cotton bale which is also needed to be removed before further processing. This process of opening & cleaning is known as blow room process. Blow room consists of a number of m/c used in succession to open & clean the cotton fibre to the required degree. 40% to 70% of the total trash is removed in this section.

Friday, 30 October 2020

Mixing and blending of cotton fibre in blow room.

Mixing:
If different grades of the same fibres are kept together, then it is called mixing.

Blending:
When different fibres of the same or different grades are kept together, then it is called blending.

Fibre mixing and blending

Tuesday, 27 October 2020

Bale Management

Testing, sorting & mixing bales according to properties of fibre for producing specific good quality yarn at minimum cost is called “Bale management”.

The object of Bale management?
  • To ensure evening out of the quality characteristics of a yarn.
  • To avoid quality jumps.
  • To reduce costs.

Saturday, 24 October 2020

Fibre Properties Affected by Spinning Methods

Different spinning methods have different types of influences on fibre properties. So output yarn properties vary according to the spinning methods as below-

Order of importance
Ring
Rotor
Air-jet
Friction
1
Length &
length uniformity
Strength
Fineness
Strength
2
Strength
Fineness
Cleanliness
Fineness
3
Fineness
Length & length Uniformity
Strength
Length & length uniformity
4


Length & length uniformity
Cleanliness

What is Ring data system?

Ring data is an additional attachment for data collection. It is one kind of software which collects data about the ring frame. It is also called production controlling system of the ring frame.

The data collected on:
👉Production data (OPS, GMS total data of previous 3 shift)
👉End breakage rate
👉Machine efficiency
👉Doffing time
👉No. of Doff
👉Machine downtime
👉Yarn count
👉Yarn lot
👉No. of working spindle
👉Fibre type
👉TPI
👉Spindle speed

Friday, 23 October 2020

Comparison of different spinning methods

             
Ring-Spun yarn
Open-end yarn
Air-jet yarn
Wrap yarn
Classic
Compact
Rotor spun
Friction spun
Jet spun, two nozzles,
False twist process
Vortex spun, one nozzle
Filament wrapped
Fibre deposition:
In the core
Parallel, helical
Parallel, helical
Less parallel, helical
Less parallel, helical
Parallel w/o twist
Parallel w/o twist
Parallel w/o twist
In the sheath
Parallel, helical
Parallel, helical
More random, less twisted
Less parallel, helical
6% of fibres twisted around the core in spirals
20% of fibres twisted around the core in spirals
Filament windings
Fibre orientation:
Parallelism
Good
Very good
Medium
Low
Medium
Good
Very good
Compactness
Compact
Very compact, round
Open
Compact to open
Compact
Compact
Compact
Handle
Soft
Soft
Hard
Hard
Hard
Medium to hard
Soft
Hairiness
Noticeable
Low
Very low
low
Some
Low to medium
Very low
Stiffness
Low
Low
High
High
High
Fairly high
Low

Thursday, 22 October 2020

Bangladeshi Cotton

The basic raw material of the textile sector is cotton. Cotton is commonly known is “Kapas Tula” in Bangladesh. The annual requirement of raw cotton for the textile industry of Bangladesh is estimated at around 2.5 million bales. Local production is only about 0.1 million bales. Around 4-5% of the national requirement is fulfilled through the local production, remaining 95-96% is fulfilled by importing raw cotton from India, CIS (Commonwealth of Independent States) countries, the United States of America and African countries. As per the latest information, within total cotton import, 46% comes from India and 20% from the African region and different cotton growing industries.

Classification of Cotton Fiber

Classification of cotton fibre on the basis of staple length: According to the staple length, there are three types of cotton fibre as below-


1. Short staple length
Length = 3/8 inch to 1 inch;
Coarse, low strength and no or little lustre;
Diameter = 13-22 micron;
Example = Indian and Asiatic cotton.
2. Medium staple length
Length = 0.5 inch to 1.25 inch;
Medium strength and medium lustre;
Diameter = 12-17 micron;
Example = American cotton.
3. Long staple length
Length = 1.0 inch to 2.5 inch;
Fine lustre and top quality fibre;
Diameter = 10-12 micron;
Example = Sea Island cotton and Egyptian cotton.

Wednesday, 21 October 2020

Foreign matters in Raw Cotton

Cotton fibre may contain different types of materials other than cotton fibres which are termed as foreign matters. The common foreign matters of raw cotton may be as below-


01
Colour cotton
07
Jute
02
White thread
08
Hair & wool
03
Colour thread
09
Paper
04
Piece of cloth
10
Plastic
05
Feather
11
Bale covering cloth
06
Polypropylene
12
Metal etc.

Yarn Manufacturing | Cost Parameters

Cost break-down of yarn manufacturing:

01
Raw materials (Cotton + packaging materials)
50 – 60 %
02
Capital (machine, land, building, interest)
25%
03
Power
7%
04
Waste
7 – 8%
05
Overhead cost (insurance, taxes, office expenditure)
3 – 4%
06
Salary and wages
 1%
07
Selling expenditure
1%

Temperature and Relative Humidity in a Spinning Mill

Sections
Temperature
Relative Humidity, RH%
Blow room
30⁰C
55%
Carding, Draw frame, Simplex
30⁰C
50%
Ring
30⁰C
50%
Rotor
25⁰C
50%
Winding
28⁰C
65%

Fabric Production Techniques

There are different types of fabric production techniques such as weaving, knitting, braiding, non-weaving (for example, felting) and so on....