Fabrics solutions

1)What is weaving?

-The process of interlacing two sets of yarns, namely warp & weft at right angle to make a fabric according to design.

2)what is warp yarn?

-The yarn which is used along the length of the fabric is called warp yarn.

3)what is weft yarn?

-The yarn which is used along  the width of the fabric is called weft yarn.

4)what are classification of woven fabric?

  5)What are process sequence of yarn preparation?

  1.Yarn preparation

     -winding

     -warping

     -sizing

     -drawing

     -denting

     -leasing

     -tyeing-in/twisting/knotting.

  2.Weaving

  3.Inspection.

6)What are the objects of yarn preparation?

-To wind the yarn uniformly on suitable package.

-To have desired length of yarn on the package.

-To improve weaving efficiency.

7)What is sizing?

-To reduce breakages the warp is subjected to a special treatment is called sizing.

8)What are importance of sizing?

-Sizing is the most important operation in preparing warp yarn for weaving. The smallest error in sizing process may be very harmful. They may increase warp breakage on looms  and consequently reduce the weaving production and quality. Therefore sizing is termed as the heart of weaving.

9)What is purpose of sizing?

-To increase smoothness of the warp yarn.

-To modify the character of the yarn.

-to increase the strength of the warp yarn.

10)Which factors are affected the properties of sized yarn?

-Adhesive type

-Lubricant used

-Sizing recipe

-size add-on

-Operational conditions

-Operators efficiency

-Machine type.

11)What is starch?

-These materials form the base of the size. They coat the warp yarn with a film and impart its smoothness by binding the protruding fibres to the yarn surface.The viscosity of the size solution is controlled by the amount of starched, the recipe, the degree of the mechanical mixing, the temperature and time of boiling.

12)What are the classification of  starch?

    -Natural(potato, wheat, maize, flour)

    -Modified(starch ether, starch ester, CMS)

    -Synthetic gum(PVA, casboxy methyl cellulose)

13)What is binder?

-These materials are used an indepent gum and a substitute of starch products. They penetrate into the yarn and contribute in increasing yarn strength.

14)What is lubricants?

-With the addition of starch a hard fragile film is formed in yarn surface. This film is softened  addition of softener. They increase flexibility of yarn after sizing.

15)What are antiseptic agents?

-Antiseptics are used in the size paste to prevent the growth of these micro-organisms destructing the cloth.(e,g. zinc chloride, copper sulphate.)

16)What are weighting agents?

-These agents are used to increase the weight of the fabric.

   e.g. magnesium chloride, sodium sulphate.

17)What are the classification of sizing?

-Sizing may be classified into four groups on the basis of size% on the yarn.

a)Light sizing  10%-15%

b)pure sizing    16%-25%

c)Medium sizing  26%-50%

d)Heavy sizing   50%-100%

-It may also be classified into three types on the basis of application process.

    a)Surface sizing

    b)Core sizing

    c)Optimal sizing

18)What matter depends pick up%?

-The size pick- up% depends on yarn structure, type of size ingredients, viscosity of the size paste, roller hardness, machine speed etc)

19)What are the main faults of sizing?

  -Underslashed  warps

  -Overslashed  warps

  -Sticky  warps

  -Gum spots and smears

  -Non-uniform size regain

  -Crossed and lost ends

  -Improper build of beam.

20)What are size liquor% pick-up?

                                     Weight of size liquor

Size liquor% pick-up=_________________   X100

                                      Weight of yarn

21)What are size solid add-on of the warp?

                        Dry weight of size substance

-Size solid %=_________________________ X100

                        Dry weight of grey yarn

  

   

22)What are the concentration of the size liquor%?

                            Dry weight  of size substance

Concentration%=________________________  X100

                             Ready size liquor

22)what is shed?

-Dividation of warp threads into two parts for insertion of weft threads is called shed.

23)what is shedding?

-The mechanism of shed is called shedding.

24)What is the first primary motion of weaving?

-Shedding is the first primary motion of weaving.

25)How many types of shed?

-there are four types of shed.

  a)Bottom closed shed

  b)Centre close shed

  c)semi-open shed

  d)Open shed

26)What is  bottom closed shed?

-This type of shedding is produced by giving motion only to threads that are to form the upper line.

27)What is centre closed shed?

-This type of shed is produced by imparting an upward movement to those threads which are to form the top line and the downward movement to the threads which are to form the bottom line.

28)What is semi-open shed?

-In this shed the stationary bottom is retained but threads for the top line either passes to bottom at one movement and again carried to the top midway and carried to top.

29)What is open shed?

-In open shed, the warp threads form  two stationary lines, the top line and the bottom line and changes are made by carrying the threads from one fixed line to the other without any interval.

30)How many types of clutch?

-There are three types of clutch

     a)Plate/disk clutch

     b)Conical clutch

     c)Expanding & contracting clutch.

31)Write down the advantages &disadvantages of plate clutch.

Advantages:

-Apply side way thrust

-Low initial cost

-Extensively used

Disadvantages:

-High wear

-Low power transmission

32)Write down the advantages &disadvantages of Cone clutch.

Advantages:

-Capable of transmitting motor power

-Better gripping between loose and fast pulley.

Disadvantages:

-Side way thrust

-Used in loom.

33)Write something about expanding & contracting clutch.

-No side way thrust

-More power transmission

-Less used

-No wear.

-Expand to start & contract to stop the loom.

34)What is Inching motion?

-Sometimes looms have to be run, slow motion running to bring the loom in the running position.

35)Write down the Objects of inching motion.

-To repair any fault

-To adjust the  position of the stopped loom.

36)What is reversing motion?

-The opposite motion of loom motion is called reversing motion.

37)What is loom breaks?

Break is used to stop the loom applying pressure or force. The object of loom brake is to stop the loom instantly in case of any fault.

38)Write down the classification of loom brake.

-Brake band &brake pulley

-Brake shoe& brake pulley

-Built in breaking system in motor.

39)What is Tappet?

-A type of cam to which a rotary motion is given for the purpose of producing  reciprocating motion in rod is to receive a series of lifts, with intervals of rest and thus forms a shed called tapped.,

40)Write down the basic shedding mechanism.

   -Padel /treadle

   - Tappet

   -Dobby

   -Jacquard

   -combined

41)How many types of shedding tappet?

-Negative shedding tappet

-Positive shedding tappet

42)What are the position of fixation of tappets?

-over or under one end of the heald shaft

-over or under the middle of heald shaft

-scroll  tappets

43)Write down the defects of tappet shedding.

-Over shedding strains and breaks the warp threads

-under shedding does not permit the passage of the shuttle through the shed

-missed shedding

-unsuited dwell period

44)What is dwell period?

-dwell is the stationary period when the heald frames do not change their position and the shade remains open to allow the passage of  the shuttle from one shuttle box to the other.

45)