Beetling & stiffening

Beetling & stiffening

1. Beetling process & Stiffening of Fabric.....

2. INTRODUCTION OF LINEN Linen fibres are collected from the flax fibres. It is a natural, cellulosic ,bast and multi-cellular fibre. Linen, the long, STRONG fibres from flax stems. Chemically , the flax polymer is same as the cotton polymer but Physically t hey differ. PROPERTIES OF LINEN FIBRE The colour of linen fibre is yellowish to grey and has a high natural lustre. Range of length (flax fibre) from about 10 -100 cm. Linen has poor elasticity and does not spring back readily, explaining why it wrinkle so easily.

3. Linen fabric feels cool to the touch ,phenomenon which indicates its higher thermal conductivity. Standard moisture regain is 10-12%. It does not stress easily. It is not suitable to dye. But it can be dyed by direct , vat ,azoics, sulphur dyes. Linen has an excellent resistance to degradation by heat and not affected by the sun light as other fibres. Linen can absorb a fair amount of moisture without feeling unpleasantly damp to the skin, unlike cotton. Linen is about 20% stronger when wet . Relatively easy to take care of , since it resist dirt and strain, and no lint or pilling tendency. Flax is not attacked by moth grubs or other insects.

4. HOW LINEN IS MADE??? Technically, linen is a vegetable fiber . Linen fabric is made from the cellulose fibers that grow inside of the stalks of the flax plant , one of the oldest cultivated plants in human history. Flax is an annual plant, which means it only lives for one growing season. From seed-planting, it is ready to be harvested in about a hundred days. Unless the weather is particularly warm and dry, flax requires little watering or attention during this time. It grows to about three or four feet tall, with glossy bluish-green leaves and pale blue flowers, though on rare occasions, the flowers bloom red. Flax is cultivated around the world not only for its fine, strong fibers, but also for its seeds .

5. Continue.. Flax fiber is decomposed by water or chemical retting, which loosens the pectin or gum that attaches the fiber to the stem. After the retting process, the flax plants are squeezed and allowed to dry out before they undergo the process called breaking, finally releasing the flax fiber from stalk

6. INTRDUCTION OF BEETLING B eetling process i s a pplied t o linen o r cotton . The fabric i s b eaten w ith l arge w ooden b locks i n o rder t o p roduce a h ard , flat s urface w ith a s heen . It is mechanical finish. Only table l inen i s p ut t hrough b eetling a nd n ot t he d ress l inen . When applied t o c otton f abrics , beetling g ives i t t he f eel a nd a ppearance o f l inen . This process p ermanently f latten t he y arn o f t he f abric o n w hich i s a pplied .

7. HISTORY OF BEETLING With in I reland , beetling was 1 st introduced by Hamilton Maxwell in 1725. Beetling is the part of the finishing of the linen cloth. The hammering tightens the weave and give the cloth a smooth feel. The process was gradually phased out in lieu of calendaring.

8. PROCESS OF BEETLING The Process consists in hammering the fabric with a series of heavy wooden hammers which fall on the beam of cloth directly beneath them. During hammering, the cloth beam is slowly rotated and also moved to and fro laterally in order to distribute the hammering effect evenly. Further in order to ensure even finish, the cloth is reversed to bring the inner layer to outside and pound again. The filling and stripping of the beam is done outside the beetle.

9. MACHINE CONSTRUCTION The usual m/c comprises a very heaving iron frame with 40 wooden hammers operated by cams attached to a horizontal shaft called “wiper beam ” The cams lift the fallers in sequence and allow them to fall on the roll of the fabric which is wound on a robust iron shaft placed immediately beneath . The cloth is subjected to the hammering action for a period ranging from 12 to 40 hours on the old m/c.

10. Linen cloth requiring 22 hrs on the old wooden hammer beetling m/c and new beetling machine can be given the same finish in just 5 hrs. The blow is heavier than with the older wooden faller beetle. This m/c consist of a row of double ended metal hammers operated by two cam shafts. The hammers fall by gravity to one side and are then lifted by the opposite cam to fall on the opposite beam. The rate of beetling is about 60 cycles /min.

11. INTRODUCTION TO STIFFENING In some cases it is desirable to make fabric stiffer . Army personnal want their uniforms to be stiff . The collar of men’s shirt and sometimes the cuffs have to be stiffened . Stiffening of fabric is usually done by finishing process. Stiffening is the process in which a fabric which is generally limp becomes stiff, when stiffening agents are applied.  

12. MECHANISM OF STIFFENING Stiffening is done by using a film-forming polymeric substance. Fabric is dipped in a slurry or a solution, which gets attached to the surface of fabric. Such polymeric substance after drying becomes a thin film, coated on the surface of the fabric or fiber, which give the fabric a smooth, stiff, thick, plump texture.

13. TYPES OF STIFFENING TEMPORARY STIFFENING PERMANENT STIFFENING

14. TEMPERORY STIFFENING OR STARCHING Fabrics, particularly cotton and linen , are given a temporary stability and stiffness by application of a firming agent which is often a solution of starch. Other than starch, the substances used for stiffening fabrics are flour, dextrine, glue, shellac, fats, wax, and paraffin. Sometimes clay, chalk, barium sulfate, calcium sulfate or magnesium sulfate are also used for stiffening cotton fabrics.

15. PERMANENT STIFFENING Permanent stiffening is done by chemical processes that change the cellular structure of the fiber. Some of the permanent finishes are Ankord, Basco, Clearight, Kandarized, Saylerizing, Sheercroft, Staze- Right and Turbenizing. The parts to be stiffened like collar, cuffs, belts are interlined with a thermoplastic fiber or with cellulose acetate or the fabric may be coated with synthetic resin. The thermoplastic fibers melt and bonds with the garment when pressed with a hot iron producing a stiffened fabric.

16. CLASSIFICATION OF STIFFENING AGENTS

17. NATURAL STIFFENING AGENTS Stiffening may be done by using natural polymers like starches and gums . Starch Starches are used to impart stiffness to body lusture to the fabric. S tarch is the most important finishing agent but it has been condemned to ground with the growth of durable resin finishes .

18. Continue… The use of starches has been declined rapidly in recent years because it is not fast to washing and films not transparent. The main type of starch used in industry is maize starch. Modified starches like hydrolysed starch, oxidised starch are used to impart body to the fabric without excessive stiffening. Dextrins are used to give crispmess to rayon and acetate fibres.

19. Gums- Gum is used to improve adhesiveness of starch as well as to impart stiffness to the fabric. It is used where clarity of film is required. Examples of natural stiffening agents- S tarch (maize, tapioca, rice, potato starch etc.) dextrines(partially hydrolised starch) vegetable gums, sugar, gelatin, blood albumin etc.

20. SYNTHETIC STIFFENING AGENTS: These are thermoplastic resins, not obtained naturally hence chemically manufactured. Methyl cellulose. Carboxy methyl cellulose . P olyvinyl acetate. A crylate . P olyvinyl chloride. P olystyrene . Resins .

21. METHYL CELLULOSE Method of preparation It formed by action of dimethyl sulphate or methyl chloride on soda cellulose, when the hydroxy group of cellulose is replaced by methoxy group. F or water solubility methoxy content should be atleast 25%,corresponding to 1.5 methoxy group per glucose unit. I t can be dissolved in water by first soaking in some boiling water and then adding remainder as cold water or as ice .

22. METHYL CELLULOSE Application:- It is applied from its solution. The solution gels at temperature above 50 deg C. Sulphacyanides and iodides raise the gelling temp. , highly concentrated salts solutions of mineral acids, and solutions of tannins and phenols induce gellitinous effect. Aqueous solution of methyl cellulose give tough, clear, non hygroscopic and elastic films on evaporation. These films can be made water resistant by treatment with urea formeldehyde, glyoxal, and tannins.

23. CARBOXY METHYL CELLULOSE Preparation :- It is produced by reaction of soda cellulose or alkali cellulose with monochlorate Application:- Applications of CMC-Na salt involves impregnation with an alkaline solution, running through dilute sulphuric acid, followed by neutralisation of acid and drying.

24. CARBOXY METHYL CELLULOSE CMC produces permanent stiff finishes on cotton, rayon ,. It is used to secure durable, laundry fast, stiffened finishes accompanied by increased strengths and abrasion resistance, improved dimensional stability and greater surface smoothness.

25. POLYVINYL ACETATE Preperation:- This is prepared by polymerising vinyl acetate . Application:- I t is applied by padding the fabric(5-10 g/l) in its dispersion in water, the mangle is cleaned immediately after padding. T he fabric is dried below 80 deg C and calendered below 60 deg C. I t produces full and stiff finish fast to washing .

26. Continue… This film is outstanding in transparency and is extremely fast to sunlight and resists removal by washing and dry cleaning. It durability can be increased by adding formaldehyde or urea formaldeyde pre condensate to padding solution. For Buckram finish on cotton 200-300 g/l poly vinyl acetate dispersion is used in the pad liquor

27. ACRYLATES Application:- These are applied from aqueous dispersion and form clear films resembling polyvinyl acetates films. S tiffer films can be produced by using PMMA. I t produces a crisp handle in rayon and nylon goods . T he thermoplastic transparent film is of exceptional pliability resistant to chemical attack.

28. POLYVINYL CHLORIDE Preparation:- Polyvinyl chloride is prepared by emulsion polymerisation of vinyl chloride and plasticized with dibutyl phthalate. Application:- It produces firmly anchored continuous film coatings resistant to water, oil, grease and organic solvents . When an emulsion of this dries at room temp, it gives discontinuous films of low tensile strength, but by heating at 150 C for few seconds, continuous film can be produced.

29. POLYSTYRENE Preparation:- It is prepared by polymerisation of styrene. Application:- A slightly alkaline dispersion of plasticized polystyrene has bonding and film forming properties It can be applied by padding or spreading, followed by drying.

30. POLYSTYRENE It coats the fabric rather than penetrating. The finish produced is colourless, odourless and non yellowing. Gives a stiff finish on furnishing and upholstery materials.

31. RESINS Polyvinyl butyral resins:- preparation:- Condensation of butyraldehyde with partially hydrolysed polyvinyl acetate gives colourless, odourless and non-yellowing aqueous dispersions of thermoplastic plasticized polyvinyl butyral resins, which are freely miscible with water. Application:-

32. They are applied by padding, coating or spreading and are compatible with various thickeners and fillers used in textile finishing like starch, china clay, titanium dioxide etc. They give tough and transparent films, which produce lusturous and non dusting finish of improved servicability and wearability, increased tensile strength and abrasion resistance.

33. STIFFENING OF COTTON FABRIC A straight forward method of making cottton fabric stiff is to run through concentrated sulphuric acid of suitable strenght(114 deg Tw) for a few seconds so that the surface of each fibre becomes gelatinised and then followed by washing immediately . This gives a stiff handle fast to repeated washing.

34. ADVANTAGES OF STIFFENING AGENTS I t gives cloth a nice crisp look. I t makes ironing a little easier since it will reduce iron drag. Stiffening agents like starch protects fabric from stains, as it seals the individual fibre thus making it more difficult for stains to penetrate through the fabric S tiffening agents like starch is made of dried corn ground into fine powder which is mixed with water and pulp. This is eco friendly and cheap.

35. Stiffening agent would attach sweat, debris, dirt and other grime, hence, the fabric would be easier to clean. I t prevents wrinkling of fabric.

36. DISADVANTAGES OF STIFFENING AGENTS D isadvantage is fraying ,i.e., heavy starch reduces the life of cloths . this is because , overtime , residue of starch will remain in collar and cuffs and it will eventually dry out the fabric causing individual threads to break or fray . Synthetic stiffeners last only through 5-6 launderings. Synthetic stiffeners are chemically processed, hence may be harmful to skin sometimes. While ironing the sttiffened fabric, too hot iron may cause scorching, too cold may cause sticking.

37. CONCLUSION F or producing stiffness, mechanical methods are not of much use and only chemical treatments by incorporating suitable chemicals or resins in the fibre material bring about the stiffening effect . Natural stiffening agents Synthetic stiffening agents Cotton, wool, silk, linen, rayon Wool, cotton