WELLCOME TO MY PRESENTATION ABOUT SPEED FRAME

UNIVERSITY OF SOUTH ASIA

NAME : CHISTIA RAHMAN AKASH

ID : 131-0121-002 BATCH : 21(DAY)

SPEED FRAME

OBJECTIVES OF SPEED/ROVING FRAME

The chief function of roving frame is the attenuation of sliver.

To draft the sliver to reduce weight per unit length.

Insertion of protective twist in order to hold the fine strand of sliver.

To make conical or tapper shape of the bobbin.

Wind the twisted roving on to the bobbin.  Winding of roving into a package that can

be transported, sorted, donned on ring spinning machine.

FUNCTION OF SPEED FRAME Creeling: Creeling is the first objective of speed frame

arrangement. By the creeling, small amount of draft is applied to the drawn sliver.

Drafting: Attenuation of drawn sliver to produce required amount of roving by drafting. Thick drawn sliver is converted into thin roving by drafting system.

Twisting: Small amount of twist is inserted in the drafted stand of fibres by the twisting. The amount of twist is very low.

Building: Build the roving on to bobbin such a form which will facilate unwinding, handling and transfer to the next process.

Winding: Produced or twisted roving is wound on the bobbin by the winding process. This bobbin is feed to the ring frame and this bobbin accelerates the next process. So, it is important.

Doffing: It is the optional function of speed frame. Doffing could be done manually or automatically.

NECESSITY OF SPEED FRAME There are two principle reason:

First reason is to apply drafting.Sliver is thick, untwisted strand that tends to

be hairy and to create fly. There fore, if we directly want to produce yarn from sliver by discarding simplex, we need 300 to 500 draft to do so. But the fine twisted roving is significantly better suited to this purpose.

Second reason is related with transportation and space limitation on ring frame.

Draw frame “can” is the worst conceivable mode of transportation and presentation of feed material.

OPERATING REGION OF SPEED FRAME

The creel The drafting arrangement

Roller drafting system

The apron Applying pressure

to the top roller. The condenser The spacer

Winding of bobbin Package

build Bobbin

drive Cone drive transmission The lifter motion The builder motion

Spindle & flyer Imparting

twist Spindle Flyer Design of

flyer Pressure

arm

DRAFTING ARRANGEMENT OF SPEED FRAME Roller Drafting system

Conventional roller drafting system: 4 over 4 without apron.

Modern Roller drafting system: 3 over 3 drafting system with double apron

(Lakshmi Rieter FS185P)4 over 4 drafting system with double apron

(SKF PK 1600)

SKF PK-1600 DRAFTING SYSTEM

Draft range: Total draft 5 to 20 Total draft is distributed in each zone as follows:

Back zone: Break draft is applicable in here. Amount of break draft is depends upon material.

Material Break Draft

Sliver Coarse 1.5-1.4

Sliver Medium 1.4-1.3

Sliver Fine 1.3-1.2

Sliver MMF 1.2-1.1

Middle zone: Less amount draft is applicable in here. Condenser is used in middle zone to condense

sheet like sliver.

Front zone:Maximum amount of draft is applicable in

here. Apron is used in this zone.

ROLLER TYPE

Top rollers are synthetic rubber coatedBottom rollers are made of steelFront, 3rd and back rollers (bottom) are spiral

fluted. 2nd roller has granulated pin.

ROLLER DIA

Roller Front roller

2nd roller 3rd roller Back roller

Top roller 28 mm 25 mm 28 mm 28 mm

Bottom roller

30-32 mm 25-27 mm 30-32 mm 30-32 mm

THE APRON

The upper aprons are short and made either of leather or more commonly of synthetic rubbers. They have a thickness of about 1 mm and are held by tensioning device.

The lower aprons are longer and usually made of leather. They run over the guide bar, usually known as nose bar, to position close to the delivery roller.

Function:The aprons co-operated with each other t guide and transports the fibers during drafting and they exert a very significant influence on the drafting operations.

APPLYING PRESSURE TO THE TOP ROLLER The top roller must be pressed with

relatively high force against the lower rollers to ensure the guidance of fiber.

Pressure are in the range of 100 to 250 N per roller which may vary as per raw material and its volume.

Pressure is applied by spring pressure, pneumatic weighting, magnetic weighting.

CONDENSER

Feature:• Condensers are mounted on a reciprocating

bar behind the drafting arrangement.• The second condenser is provided in break

draft field.• And the 3rd one is located in main draft field. Function:• Spreading sliver masses are condensed to

improve evenness and lead to drafting zone. Advantage: • Reduce the high fly level and hairiness of

roving.

SPACER

As the top apron are forced by spring pressure against the lower apron, the arrangement of this apron should permit precise adoption of minimum distance to fibre volume. In order to be able to maintain this minimum distance, spacer are replace ably inserted between the nose bar of the lower apron and the cradle edge of top apron. Spacer size is 4 to 7 mm in accordance with roving hank.

IMPARTING TWIST

•  

THE FLYER

Flyer is used to impart twist Flyer has two legs, one with hollow path or

slot and pressure arm another for balancing the flyer while rotating.

Flyer is placed on spindle, it gets motion by gearing.

Flyer speed has direct influence on production.

Flyer can be varying in sizes which are specified in inch. For example, 12”X 5.5”, 12”X6” and 14”X6”. First no. indicate maximum height and second no. indicate maximum dia of wound package.

SPINDLE

The spindle is a simply support and drive element for the flyer,without any axuilary function. It is a long steel shaft mounted at it’s lower end in a bearing.

Types of spindle: 01.mounted mounted. 02.closed mounted. 03.top mounted.

PRESSURE ARM

A steel yoke attached to the lower end of hollow flyer leg is called pressure arm.

The roving is wrapped 2 or 3 times around the yoke.

The no. of turn determine the roving tension. For higher tension, a hard compact package is obtained and if it is too high false draft or roving breakage can be caused.

Therefore, the no. of wrap depends upon material and twist level.

WINDING PRINCIPLE

Bobbin leading principle (For cotton spinning)

Flyer leading principle (For jute spinning)

BOBBIN LEADING PRINCIPLE

Bobbin speed is higher than flyer speed at all point of winding.

The winding on speed is constant throughout the process.

With the increase of bobbin dia, bobbin speed must be decreased.

The variation of bobbin speed with the increase of bobbin dia must be constant.

Less tension on roving.

RPM

d

Empty Bobbin

Full Bobbin

BobbinSpeed

Flyer Speed

FLYER LEADING PRINCIPLE

Flyer speed is higher than bobbin speed at all point of winding.

The winding on speed is constant throughout the process.

With the increase of bobbin dia, bobbin speed must be increased.

The variation of bobbin speed with the increase of bobbin dia must be constant.

Higher tension on roving.

Flyer Speed

Empty Bobbin

Full Bobbin

BobbinSpeed

DEVELOPMENTS IN SPEED-FRAME

The speed frame is the machine that has gone least

change. This can be realised from the fact that a spindle speed of 1,500 rpm as on date as compared to 600 rpm in 1950s. Still there are certain changes that have been carried out for better production and quality like,

I. Increase the roving bobbin dia from 4″ to 7″ and lift from 8″ to 16″.

II. Use of straight cone drum instead of hyperbolic cone drum for better control over the roving tension etc

III. The roving frames are equipped with auto doffing system that apart from avoiding man handling and reduce doffing time.

IV. Decrease the sliver damage by modifying the flyer top.V. The flyer is now making with plastic which helps to

light weight and low power consumption.

FAULTS OF SPEED FRAME

01/ Irregular Roving. 02/ Roving breakage . 03/ Sliver breakage. 04/ Roller lapping. 05/ Unequal tapering . 06/ Hard roving bobbin. 07/ Ridgy bobbin . 08/Thicks thin place.

M/C Faults:

i. Fluction of power

ii. Ununiform rotation of flyer

iii. Using of damaged flyer

iv. Damage top roller

v. Damage apron.

PROBLEM

PROBLEM