blow room

BZU TEXTILE ENGINEERS

The BlowroomThe Blowroom

Even if opening/cleaning has only share of about 5-

10% of the total manufacturing cost in the spinning

mill. It has a tremendous indirect influence by

means of raw material loss and quality.

Importance:

A slight reduction in the loss in opening

and cleaning by 0.5% will result in a yearly gain of

about US $ 15,000(Rs.9, 00,000) in a spinning mill

with 20,000 spindles.

The gentle treatment of fibers (avoiding the

formation of short fibers and over stressing of the

material), on the other hand enhances yarn quality,

and running conditions and influences the selection

of the raw material.

Machinery selection:

Short cleaning lines with only two or three

cleaning points are todays state of art.

One pre-cleaner and one or two fine cleaners

per line are sufficient.


Objectives of the blow roomObjectives of the blow room

Opening

Cleaning

Dust removal

Blending\mixing

Even feed of material to card.


Before starting the objects I will tell that there are four main principles that are

Force of gravity or regulating action. Action of opposing spikes (bale breaker) Action of beaters (in all types of beating points) And Air currents (as in crighten opener)

Opening

Opening is the first operation it means, tearing apart the compressed and matted cotton until it is very much loosened and separated into small tufts with a gentle treatment, and a fiber loss as small as possible.

Opening is also related to cleaning as where is opening there is also cleaning

There are two different level of opening: Opening into fiber tufts (performed in blowroom) Opening into individual fibers (performed in carding and rotor spinning)


Two different types of opening are:

Breaking up of larger tufts into several tufts to create new surfaces (bale breaker).

Opening of individual tufts to increase the volume(with weight remaining the same)

Both ways are performed, with different intensities in different processing steps;

In bale opening, the breaking up of tufts is dominant.

Fine cleaning the opening up of a single tuft is mainly performed.

Degree of opening:

It increases machine to machine as shown in the graph

Intensity of opening:

It depends on,

Raw material (thickness of feed, fiber alignment and size of flock in the feed).

Machines (arrangement of the pins, teeth, needle, type of clothing, spacing between the material and opening device.

Speed (of material, devices used).

Condition (humidity, temperature).


CleaningCleaning

First of all what kind of impurities mainly we

have and them: what is their affect on the machines and in

which way we remove

There are different types of impurities present in the cotton.

1. Vegetable matter

Husk portion

Seed fragments

Stem fragments

Leaf fragments

Wood fragments

2. Mineral Impurities:

Earth

Sand

Ore dust coal dust picked in transport.

3. Other foreign matter

Metal fragments

Cloth fragments

Jute fragments

Packing material (mostly polymers)

4. Fiber fragments

Fiber particles (which makes the greater portion of

dust)


Their affects on machines can be given as

Metal parts cause fires due to friction or damage card clothing.

Cloth fragments and packing material can lead to foreign fibers in the yarn and which

can create problems in further processing like uneven dyeing or printing etc.

Vegetable matter can lead to drafting disturbance, yarn breaks, filling up of card

clothing, contaminated yarn etc.

Mineral matter can deposits, high wear tear in machines.(grinding effects,

Especially apparent to rotor spinning)

Cleaning Efficiency:

Cotton contains up to 18% trash in most cases. To clean the material it is unavoidable to

remove as much fiber as much waste.

Therefore it is necessary to measure the amount of the waste removed and its composition. As

it is of high importance also called cleaning efficiency.

The cleaning degree of blowroom can be found by following criteria.

There are also two major problems that are given below which also affects the quality of the

yarn.


Neps:

Neps are the small entanglements or knot of the fibres

of two types

1- Fiber neps

2- Seed coat neps

Fiber neps are mainly of unreep and dead fibers.

There is a relationship between maturity index and

neppiness. Neppiness is also dependent on the fiber

finess because long fibers have less longitudinal

stiffness than coarser fibers.

Plucking and hard ginning produces mainly neps

Amount of neps in the blow room increases

machine to machine as given in the chart.

The neps are mainly removed in the carding not in any

way in the blow room.


Dust:

Dust consists of small and microscopic particles of various substances, which are present as suspended in

gases and sink slowly.

In accordance with classification dust particles are of following size:

Particle size (m)

Trash above 500

Dust 50-500

Micro duct 15-50

Breathable dust below 15

Problems created by dust:

o It is unpleasant for eyes and nose and it can induce allergies, respiratory diseases.

o It can deteriorate quality directly or indirectly.

o Increased yarn evenness and rapid wear if machine component.

General factors influencing opening and cleaning:

Dirt is removed only from surfaces.

New surfaces must be created continuously.

The opening devices become continually finer.

Degree of cleaning linearly dependent on opening degree.

The spacing of feed from the opening device

The type of grid and its settings

The position of the machine in machine sequence.


Blending:

Raw materials used in spinning mill are always inhomogeneous in their characteristics due to area to area and pick to pick.

For the purpose of getting good regular yarn it is very important to blend or mix different types of cotton.

There are also following reasons that why we blend the cotton:

To give required characteristics to end product.

To hold down raw material cost.

Compensate for variations in the characteristics. To improve running characteristics of short staple material by mixture of carrier fibers.

Types of Blending

Bale mixing

Flock blending

Lap blending

Sliver blending

Even feed of material to card / Lap formation:

This is also very important object of blow room to give the material to card .These days two systems are used given below;

1. Lap system

2. Chute feed system

Scutcher machine forms a roll, which is named as lap also, called as compact sheet of fibers.

Second system is also very important because by air suction we transfer the material to the carding machines.


Steps Before going to MachinesThere are many steps to be taken in mind before conducting blow room operation given below.

Opening of bales:

The first step towards placing cotton in process for manufacturing is the removal of bands or hoops and bagging

material from the bale.

This practice varies in all the mills but the best method is to cut the bands, draw down the bagging and allow the

cotton to stand for some time.

Conditioning:

About1or 2 days cotton is spread in the store, the advantage of this practice is that the fibers in the bale are

compressed, which loose them from that pressure.

It is also useful for good opening and machines can also handle up to one third more cotton and do good work.

Moisture:

Another factor that is also important is moisture that should be about 6-8.5% for better spinning.

Due to this spreading cotton fibers get their required amount of moisture from air.

Mixing:

It is process of intermingling cotton that is taken from different areas, to produce a uniform distribution each

through out the entire lot.

Because of the wide variation in cotton, a mill can seldom exactly get the cotton it desires .One lot is little

low in grade, another is a little short in staple.

Some times it is possible to buy better cotton than it is needed at an attractive price.

Not only so the lots will vary but, with in one lot it will vary also.

A term is stated as by the New England buyers is

"Even running" which shows that, if cotton contain 5% a grade below the grade specified, it is offset by

number of bales of a grade above that specified"


There are two types of mixing:

1 -Sandwich mixing

2-Automatic mixing

Sandwich Mixing

In this process the cotton layers from the one bale spread onto the ground.

Above this some type of soft or usable waste including slivers, lap, pneumaphil from the ring etc that is taken from different machines is also used.

A specific type of oil called as Licapol is also used just to strengthen the waste of ring.

For every bale about 10 kg of the usable waste is used.

Above this layer another layer from 2nd bale is spread then put again some soft waste.

Spread another layer from 3rd bale and this process continues as per requirement.

When required layers be formed then these layers called as heap is cut vertically to feed into the machine.

In this way the fibers in the bale mixes properly and they show less variation in end product

Automatic Mixing

In this process cotton from the bales picked up by the machines and that is mixed automatically.

For this purpose different type of machine are used which includes A11 Blendomate.

Issue of bales for mixing:

Issue of bales is very important.

We get the bales according to our demand at the end of Autoconer by some calculation.

By making the relation between the lots of high, middle, low grade cotton.

Temperature and Humidity:

Specific temperature and humidity is maintained in the blow room in order to get good quality yarn at the end

Air conditioners are used to get this temperature and humidity.


There are many machines used by spinners in industry which

are not used commonly these days. Some of them are

explained below;

Bale Breaker

This is first machine used for the opening .The

machine is not designed to clean the cotton

Properly but the some instances dust removes.

Bale breaker is a machine designed to take layers of

cotton directly taken from the bale and tear them apart leaving

the cotton partially opened state.

In this machine the principle of opposing spikes as

mentioned above applied as shown in the figure of the

machine.

Old Blow room machines


Cotton from the feed lattice fall on the bottom lattice where from it is slowly taken to the inclined

lattice picks cotton up.

Gauges of these lattices are set according to the staple length of the cotton fiber.

When material reaches to the top then the spike roll tear the material apart.

Opening is inversely proportional to the distance between spike roll and inclined lattice.

opening is directly proportional to the speed of these two.

Another purpose of this roll is to give a require amount of delivery to the next process.

But there is also a disadvantage of the high speed; it will create the amount of neps, and short fibers.

Roller near the spike roll is striper roll which is also spiked.

It function is to take the material off which remains with the spike roll on the inclined lattice which

comes back again for processing.

During the opening some type of impurities also fall down but not more.

A rake above the feed lattice is also used to stop or to drive the machine again if more material is

passing than the required amount.

Opened cotton is then taken by another stripping roll and gives to the hopper feeder.

Its production is about 600-800 kg/hour.


Disadvantages:

This machine is not comparatively good as;

The production of this machine is less

as compared to the modern machines.

There is wastage of time by changing

the speed of the machine in sense of changing

gears.

The opening intensity of this machine

is not so high and the tufts are not fully

opened.

The end quality of the yarn is not very

good as in case of the modern machines.

Improvements.

The basic principle of this machine is further

modified in the following figure;

In this form at the end a beater is also

attached just for cleaning purpose.

Also a comber roll near the inclined

lattice is used; it is for cleaning of the lattice.

Feed table is also different than the previous

one.


Step cleaner

Its example is B5 of Marzoli also known as ultra cleaner or

giant cleaner.

It is used for pre cleaning purposes.

Material from the plucker in the form of small tufts enters

into a feed hopper and passes to first beater, condenser pushes air

out and a stripping roll gives this material to the feed rolls.

A photocell is also used to control the required quantity of

cotton in the machine, by turning it on and off.

From here it is passes through series of beaters some times

6 sometimes 4 inclined upward at an angle of 45 degree.

These beaters have spikes, which are oval in shape, if we

see these beaters from front then all the spikes will be lined with

12 spikes on one side and 13 on the other side.

That beat the cotton across the grid bars that are placed at

3mm distance continuously and the impurities are removed from

the material. Where from trash is cleaned after time and time.

The position of the grid and the speed of the beaters can be

varied with the help of motor that drives these beaters.

Advantages;

Because the beaters are driven with same motor and they are

same in size there gauges are also same so they have following

advantages;

Less neps are produced

Less power consumption

Good beating is accomplished

They occupy less space

Less damage to fibers


Axi flow

This is also known as dual roller cleaner, used for

opening and cleaning purposes.

This has two beaters having 6-8 rows of spikes with

flattened edges which perform cleaning actions.

The speed range of the beaters varies from 400-600 rpm.

Large cleaning chamber contains two drums moving in

the same direction of same diameter of about 610mm.

Material from input comes in process with

drumbeaters, which is opened due to high speed of the

beaters.

Material through entire length of first beater pass over

the grid bars where trash is collected and comes in contact

with second beater.

Same action is applied here and cotton is entirely

opened and trash is removed in better way.

Advantages:

This machine occupies less space than other machine.

There are no feed rolls due to stock are not held at

anytime during passage.

Machine has a capacity of 1800 pounds/hour.


Scuture To feed the material to the card is also very

important because it should be homogeneous,

uniform from card to card, fulfill this requirement

Scuture machine is used how ever chute feed system

is used these days widely in the mills it has following

merits;

. Flock feed system is easy only by suction you

can transport the material.

Less time consuming as compared to the lap

feed system

But Lap Feed system is also important for following

reasons;

It is less problematical no need of using pipes

to provide the material to separate machine.

It can be applied universally and this can be

used with many blends.

Less economical as compared to chute feed

Its functions are to clean the material and form a

uniform lap to card.

Scuture has many units which work separately

within one machine in this first is:


Feed section:

Suction created by fan c attracts the flocks of material against a perforated drum a in the condenser

Here air is separated from material, and some dust is also removed because drum rotates rapidly.

Rroller b throws material to reserve chute c, here a photocell d check that it is filled or not.

Two rollers f and a clothed roller g close the lower end of the reserve chute.

Material in small tufts transported to the feed chute k by the clothed roller.


Cleaning section

Here a Kirschner Beater with the help of feed rollers cleans the material as shown below.

This beater has three sides of beating with pins about 3000 on one side, which pass through

material and trash and dust fall.

Grid bars at a distance of about 3mm are under the beater, which collects the impurities.

When material after beating comes out it has to be in uniform sheet.

For this it is passes through process named as PIANO FEED MOTION.

Its function is that where is less quantity of the material in this sheet it is completed by this motion

with help of Cone Drum, in the same way if more quantity of a material is passing it is uniformed

by this motion.


Formation of a Lap:

Scuture operates with a one perforated drum (a)

A compact lap forms on this drum in a single layer.

Calendaring:

Large calendar roller is located above the two small rollers (n).

This press the formed lap by the drum with a pressure of about 6000 kg produced pneumatically.

After this it is wound by winding roller (p) on a steel rod.

This process gives a lap width of about 1 meter and weights about 40 kg.

Lap weighing:

A lap-weighing device is also connected with the machine which checks the changes in the lap weight and

give the signal to the servomotor, which regulates the weight of the lap.


Modern Machine Installation

Bale opening is to finest flocks

Pre-cleaning is for no nipping; gentle treatment.

Blending is for homogeneous material

Fine-cleaning is for nipped; intensive treatment.

If cotton is cleaned and contains only few impurities then only one zone of cleaning is

necessary, otherwise two.


UNIfloc A 11 Automatic bale opener and blender feeder

The A 11 lay downs of up to 130 bales of raw material in four bale groups on each side of the machine.

It has a long arm that moves over the bales and picks cotton to the desire quantity that is fed to the control

board on that machine thus ensuring uniform take-off.

Machine can process one or two blend simultaneously with an efficiency of about 1400kg/h.

The feed duct and the two guide rails are secured to the floor on which machine moves back and forth.

When one side of bales completed then machine is rotate able at an angle of 180 degree to get the material

from the other side.

In every turn it comes down in controlled depth that is either one or two inch or according to the requirement.

A microprocessor is provided for fully automatic attraction of material from bales.

The production rate and the total weight of feed material can be added manually on the numerical keyboard


UNIclean B 11

It is pre-cleaning machine having a roller with specially designed pins

It has high cleaning efficiency with lowest fiber loss.

The raw material is beaten above the grid bars several times in order to remove the impurities.

Simultaneously material passes from dust extraction chamber, which results in high dedusting.

Material is guided mechanically by suction fans and pipes

A vacuum system with a lock roller below the machine automatically removes the waste.

The setting for cleaning degree and cleaning efficiency are controlled outside by keyboard in the machine.


UNImix B70

his machine used for only blending the cotton by mean of different boxes. It consists of three parts;

. A storage section

. Intermediate chamber

. Delivery section

Flocks of cotton are feed to six or eight J shaped chutes arranged one behind other in storage section.

First of all cotton form the pipes comes into the storage boxes which are filled first.

At the top of each box there is a feed roll, which control the level of cotton..

A sensor tells that the boxes are filled and then the cotton from each box falls on the lattice, which is revolving under these boxes.

From that it is given to spiked lattice to take it up so that it is blended well.

Evener rolls near the spiked lattice make sure that an even amount is passed and excessive amount is thrown back to the lattice.

From there it is taken to next cleaning step by mean of suction.

Production of the blow room is also controlled here.


Uniflex B60

It is used for fine cleaning, opening and dedusting of cotton as shown in the figure.

A suction fan in the feeding duct helps to get the raw material with specially designed flip-flop-feeding device.

Forms a homogeneous length and width, lap type feeding and the air is extracted from this lamina chute. This chute first filled

according to required production.

Two drums above the beater and at the end of chute extract the material one of them is perforated which is for extra dedusting.

The feeding roll and the servomotor control the adjustable feeding plate to pass the fibers on to the opening and cleaning unit.

By using the operating panel the nipping point can be changed according to the staple length of the fibers.

The opening and cleaning cylinder guides the fibers over grid bars and adjustable mot knives which separates rest of trash

intensively but gently from the material .The angle of mot knives is also changeable

By adopting the speed of opening and cleaning roller through the operating panel and adjustment of grid the operation can be

conducted as per requirement.

The clothing of drum is adaptable to the required performance and according to cleaning parameter.


Transportation of the material:

Machines in the blow room are arranged in a sequence and the material should be given to each

machine properly.

First this was done manually but now a days automatic transport of the material is accomplished.

For these purpose condensers are used which suck the material with air pressure and then

separates air from the material

igure below shows a condenser;


A11

Blendomate

Multimixer

B70

Multimixer

B70

B60

Uniflex

B60

uniflex

Loptex

Carding

Lattice B34 B11 B33 A20 Carding

Layout of Fazal Spinning Mill

B11

B11uniclean

ean

blow room

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