Basic Viva For Textile Engineers (Dyeing Related) Part-2

 

31. What is consumer textile?

Textile not falling into the categories of apparel, furnishing, household and industrial, tents and back packs may be referred to as consumer textile.

32. What is fashion color?

Color within a color range perceived as being fashionable.

33. What is flocking?

The application of short fibers to a base fabric by the direct printing of adhesive onto the fabric in the desired areas and then sticking the fibers to these areas.

34. What is geo-textile?

A textile used in soil based applications such as road building, dams and erosion control.

35. What is grey cloth?

Un-dyed and unfinished fabrics straight from the loom are known grey cloth or grey fabric.

36. What is industrial textile?

Textile product group that includes car tyres, medical textiles, geo-textile, conveyor or bet, car safety belts and parachute cord.

37. What is voile?

Light weight, open plain weave is known as voile.

38. What is tie dye?

It is a method of patterning fabric by tyring areas of fabric and then dyeing.

39. What is stentering?

A controlled straightening and stretching process.

40. What is screen printing?

It is a method of printing whereby the color is applied by what is essentially a stenciling process.

41. What is roller printing?

It is a method of printing fabric that uses engraved copper rollers.

42. What is over dyeing?

When dyeing take place on top of a previous coloring process.

43. What is furnishing?

Product group including curtains, upholstery fabrics, carpets and wall coverings.

44. What is crocking?

It is the method of transferring color by rubbing.

45. What is all over design?

Design with balanced motifs that recure regularly within the repeat unit. The motifs cover the fabric with little ground showing.

46. What do you mean by balanced color way?

When the colors change but total relationships of the color within the deisgns stay the same, giving the same overall visual effect.

47. What do you mean by dyeing assistance?

The assistance which are added in dyeing bath for which dyeing affinity is increased is known as dyeing assistance.

48. What is chromophore?

The part of the molecular structure of an organic dye or pigment responsible for color is known as chromophore.

49. What do you mean by C.M.S?

In textile dyeing industry, C.M.S stands at carboxyl methyl cellulose.

50. What is the abbreviation of T.R.O?

The abbreviation of T.R.O is Turkey red Oil.

51. Give the chemical classification of disperse dye .

Ans: 1. Azo dyes, 2. Anthraquine dyes.

52. What are the methods of application of disperse dye?

Ans:

Method N (Normal temperature dyeing 80-100º C),

Method NC (Normal temperature dyeing 80-100º C or

Carrier method),

Method HT (High temperature dyeing 105-140º C),

Method T (Thermosol method 180-200º C),

Method Pad batch (Semi continuous method),

Pad steam method (Continuous method).

53. Which dispersing agents are used in disperse dyeing?

Ans: Soap, T.R.O oil, Formaldehyde etc.

54. Give some trade name of dispersing agent?

Ans: Setamol (BASF), Edamol (Sandoz), Hispogal (Hoescht).

55. What is carrier?

Ans: Carriers are dyeing assistants which alter the

dispersing properties of the dyes and physical

characteristics of the fibre.

56. Why sulpher dyes are so called?

Ans: They contain sulpher linkage their molecular structure.

They insoluble in water but dissolved in a solution of Na2S

which act as reducing agent.

57. What are the methods of application of sulpher dyes?

Ans: Fabric preparation > Preparation of sulpher dye >

Dyeing > Oxidation > after treatment > Dyed goods.

58. What are the defects of sulpher dye?

Ans: 1. Bronziness, 2. Tendering.

59. How azoic dyes are produced?

Ans: By reaction of two components Diaz component (Salt/

Base) and Coupling component (Napthol).

60. What are the different names of azoic dye?

Ans: 1. Ice color, 2. Magic color, 3. Napthol color, 4.

Pigment color.

Basic Viva For Textile Engineers (Dyeing Related) Part-1

 

1. What is wet processing?

The process which is used for de-sizing, scouring, bleaching, dyeing, printing and finishing is termed as wet processing.

2. What do you mean by hardness of water?

The property of the textile water for which it does not form foam easily without a lot of soap is known hardness of water. It has two types named temporary hardness and permanent hardness.

3. What is PPM?

The number of grains of calcium carbonate which is present in one millions grains of water is termed as PPM.

4. What do you mean by degree of hardness?

The number of grains of calcium carbonates which is present in 70000 grains of water is known as degree of hardness of water.

5. What is water softening?

To remove the impurities of hard water by some desirable process is known as water softening.

6. What is soap?

Soap is a metallic salt of saturated or unsaturated higher fatty acid. There may be Pb, Mg, Ca or other metallic salt.

7. What is detergent?

The compound which gets orient at the interface between water and air and reduces interfacial tension or surface is known as detergent. It is mainly two types named ionic and non-ionic.

8. What is enzyme?

It is one types of bio catalyst. It is based on protein. It is soluble in water but insoluble in acid and alkali.

9. What is Chroma?

The dullness of vividness of color describing is known Chroma.

10. What is shade?

The meaning of shade is concentration. Usually, the depth of the tone of color is known as shade. It is three types such as light shade, medium shade and deep shade.

11. What is pigment?

It is normally a substance in particulate form which is substantially insoluble in a medium but which can be mechanically dispersed in this medium to modify its color and light.

12. What is stripping?

If the textile goods become uneven dyeing and insoluble for using then the color has to be distorted. The process to destroying of removing dye or finish form fibres or fabrics is known as stripping.

13. What is topping?

The application of further colorant not necessarily of the same hue or class to a dyed substance in order to adjust the latter to the desired final color is known as topping.

14. What do you mean by after treatment?

The process which is used for proper and perfect dyeing action is known as after treatment. In case of direct dye, after treatment is done for increasing light fastness and wash fastness of dyed materials. Dye particle is done insoluble into the fiber after treatment.

15. What is vatting?

The action which helps to insoluble vat dyes to be used by soluble is called vatting.

16. What is thickener?

It used in textile printing which is a main part of high molecular weight compound giving viscose paste in water. Thickener imparts stickiness and plasticity to the printing paste so that it can be applied to a fabric surface without color spreading.

17. What is viscosity?

It is the ratio of shear stress to the rate of shearing.

18. What is shear stress?

The ratio of the force to the area of shearing is known as shear stress.

19. What is shear rate?

The ratio of the velocity to the clearance is known as shear rate.

20. What is ageing?

It is consisting of exposing printing goods to more or less prolonged action of steam at atmospheric pressure to assist in the diffusion and fixation of the dyes.

21. What is steaming?

This consists of submitting printed fabrics to the action of steam for varying period at various pressure.

22. What is hue?

The attribute of color whereby it is recognized as being predominantly red, green, blue, yellow, violet, brown etc. in simple words, a color of color is hue.

23. What do you mean by dyeing affinity?

The affinity of dye to the fibre is known as dyeing affinity.

24. What is substrate?

A material to which dyes and chemicals may be applied.

25. What is additive color?

It is a mixture of colored light. The three primary colors of red, green and blue when mixed together is equal proportions then produce white light. Mixing the three additives primaries in differing amounts can create any color in the rainbow. Color televisions use the principle of additive color mixing.

26. What is blotch print?

Prints where both the background and motif color are printed into the fabric using a direct printing process.

27. What is brand?

A trade name identifying a manufacturer or product.

28. What is color forecasting?

The selection of ranges of color that are deemed to be those that will be wanted for a particular product or market at a particular time in the future.

29. What is color palette?

It is a range of selected color that will usually consist of groups of color, chosen with regard to trends and predicated directions.

30. What is color recipe?

List of component chemicals and pigments or dyestuff with relative quantities required to produce desired color.

Basic Viva For Textile Engineers (Fabric Related) Part-1

 

1. What is fabric?

Ans: Interlacement of two or more thread of yarn.

2. Categories of the woven fabric structure.

Ans: Simple structure, Complex structure.

3. What is the construction of fabric?

Ans: Warp count X Weft count/EPI X PPI X Fabric width.

4. What is texture?

Ans: Quality of fabric such as handle properties, shining properties, draping properties.

5. Texture depends on which mater?

Ans: Yarn count, EPI, PPI, Yarn twist, Interlacement etc.

6. What is contact field?

Ans: Contact points between warp & weft yarn at a right angle. (RNwa*RNwe)

7. What is interlacing field?

Ans: The points where a yarn of one system of threads changes its position in relation to other systems.

8. What is a free field?

Ans: The zone where the warp & weft yarn does not touch & change fabric side.

9. What is an open field?

Ans: Zone where warp nor weft thread occurs.

10. What is interlacing ratio?

Ans: Ratio between actual no of interlacing & maximum no of interlacing.

11. What is repeat number?

Ans: No of warp & weft yarns in a fabric.

12. What is drafting?

Ans: Drawing process of warp yarn through heald eye according to the plan or design.

13. What is lifting plan?

Ans: Selection of healds to be lifted or lowered.

14. What is skip Draft?

Ans: To make fabric with high density of warp yarn.

15. What is pointed draft?

Ans: Used to produce fabric with symmetrical design.

16. How divided draft is produced?

Ans: By dividing the heald shafts into two or more groups.

17. Why grouped draft is needed?

Ans: To producing check & strip fabric.

18. Finer yarn used as where?

Ans: As warp.

19. Coarser yarn used as where?

Ans: As weft.

20. What is twill weave?

Ans: The weave is characterized by diagonal lines of warp & weft floats on the face of the fabric on both side.

21. Some types of twil.

Ans: Zig-zag, Herring bone, Diamond, Broken, Rearrange, Stepped, Elongated, Shadded, Combined twill etc.

22. Direction of horizontal zig-zag twill.

Ans: Upon the warp yarn.

23. Is pointed draft found in horizontal zig-zag twill.

Ans: Yes.

24. Direction of vertical zig-zag twill.

Ans: Upon the weft yarn.

25. Is vertical zig-zag twill made from any complicated continuous twill?

Ans: Yes.

26. Herring bone twill.

Ans: Produced by reversal of twill direction.

27. Warp yarn is double in the no of weft yarn.

Ans: In Horizontal Herring bone twill.

28. Weft yarn is double in the no of warp yarn.

Ans: In Vertical Herring bone twill.

29. What is elongated twill?

Ans: Twill angle is less or more than 45° respect to horizontal or vertical axis.

30. Warp way elongated twill runs …

Ans: Around 45° angle.

Basic Viva For Textile Engineers (Fabric Related) Part-2

 

31. Weft way elongated twill runs …

Ans: Bellow 45 degree angle.

32. Twill line of coarser & soft twisted yarn…

Ans: More prominent.

33. Twill line of fine & hard twisted yarn is…

Ans: Less prominent.

34. Twill line of folded yarn is…

Ans: More prominent.

35. Twill line of single yarn is…

Ans: Less prominent.

36. Define the warp satin.

Ans: If the prominence of warp floating are seen on the fabric surface.

37. Define the weft satin.

Ans: If the prominence of weft floating are seen on the fabric surface.

38. Show the types of fancy fabric.

Ans: Mock leno, Hucka back, Honey comb, Crepe weave, Bed cord, Pique.

39. What is Albert cloth?

Ans: A reversible cloth or self stitched double cloth overcoating, woven with a different design on each side in stripe or check.

40. What is alpaca fabric?

Ans: A fabric made from alpaca fabric.

41. What is Amazon cloth?

Ans: A light weight dress fabric with a full, soft handle made from worsted yarns as warp & soft spun worsted or woolen yarn as weft.

42. What is angora fabric?

Ans: A fabric woven from angora yarn.

43. What is Back beam?

Ans: A beam from which the warp is fed during sizing.

44. What is Back rest?

Ans: The roller at the back of a loom over which the warp threads from the beam pass.

45. Define the back felling?

Ans: The application of a feeling material to the back of a fabric.

46. What is balanced weave?

Ans: A weave in which the float of is the same in the warp & weft direction.

47. What is tension bar?

Ans: A bar composed of a weft yarn that has been stretched more or less than normal weft point during weaving.

48. What is Embossed velvet?

Ans: Design is normally heat pressed or chemically press to flatten some of the pile

49. What is cloth?

Ans: Cloth or fabric is a flexible artificial material made up of a network of natural or artificial fibres (thread or yarn) formed by weaving or knitting (textiles, or pressed into felt.)

50. What are the basic structure of weft knitted fabric ?

Ans:

plain or single jersey .

rib structure .

1*1 purl structure .

1*1 interlock structure .

51. Which elements are fabric raw material ?

Ans: Yarn, fiber, filament, solution .

52. What is cam ?

Ans: Cam is a mechanical device which transfer the rotory or circular motion of a m/c parts or shaft to the linear motion .

53. What are the types of cam ?

Ans: a) engineering cam -> circular cam

b) Knitting cam -> angular cam

Angular cam: i)knit cam ii)tuck cam iii) miss cam

54. How many needle is used single jersey ?

Ans: 1 set needle is used

55. How many needle is used double jersey ?

Ans: 2 set needle is used

56. Define weft ?

Ans: Yarn inlaid in a knitted structure in parallel to a course is called weft .

57. What is Fillar ?

Ans: Yarn inlaid in a knitted structure in parallel to a wale is called fillar .

58. What is Curling ?

Ans: The bending tendency of single jersey fabric .

59. What is Rib ?

Ans: Fabric produce 2 set of needle alternately to produce course of face loop & wales of back loop is called rib ?

60. Define Interlock ?

Ans: Fabric produce by knitting 2 set of needle face two face thus hiding all back loops is called Interlock.

Basic Viva For Textile Engineers (Fabric Related) Part-3

 

61. What is Lacra ?

Ans: polyurothin fibre, stetching fibre .

62. What is Gauge ?

Ans: Needles /inch .

63. What is Needle peace ?

Ans: Needle peace = 1 / NeedleGauge.

64. What are the basic element warp knitting ?

Ans: a) needle

b)sinker : i) loop formation ii) holding down iii) knock over

c)guide

65. What are the main features of single jersey plain fabric ?

Ans: i) technical face is smooth & v-shape is found & technical back is rough ii) produce by single set of needle iii) tendency of curling yarn .

66. What are the main features of rib structure ?

Ans: i) ) technical face & back is of same

ii) it is normally knitted 2 set of needles

iii) this types of fabric arenot curling tendency.

67. Define tappet fabric?

Ans: Fabrics of simple weave structure that may be woven or a cam or tappet loon .

68. Define CPI ?

Ans: Cpi means course per inch. It indicate the how many course are prese nt in one inch length of the fabric.

69. How many types of fabric?

Ans: Woven, Knitted, Non woven, Braid.

70. Define warp?

Ans: The sets of yarn which is used along the length of the fabric is termed as warp.

71. Define weft?

Ans: The sets of yarn which is used across the width of the fabric is termed as weft.

72. Write down the process sequence of dyed fabric production?

Ans: Yarn preparation, weaving, furnishing

73. What is the basic principle elements of Knitting?

Ans: Principle elements of Knitting- needle, sinker, cam, jack, yarn feeder

74. What is needle?

Ans: The hooked metal needle is the main principle knitting element of the Knitting m/c

75. Write down the function of needle?

Ans: The function of needle is – New yarn receiving, Loop forming, Carry the old loop, Clearing the old loop.

76. What is sinker?

Ans: It is the second primary knitting element. It is a thin metal plate with an individual or a collective action operating approximately at right angles from the hook side of the needle bed, between adjacent needles.

77. What is yarn feeder?

Ans: Yarn feeder mainly used for feed the yarn from package to Needle by yarn tensioner, yarn guide etc.

78. What is needle gauge?

Ans: No of Needles Per unit Length ( e.g. Needles/inch)

79. What is course?

Ans: Yarn inlaid horizontally with loop structure in a Knitting structure.

80. What is wale?

Ans: Yarn inlaid vertically with loop structure in a Knitting structure.

81. What is loop?

Ans: A piece of yarn used in knitted structure.

82. what is stitch?

Ans: Dimensionally stable structural unit of a knitted structure.

83. What is tuck loop?

Ans: When the needle receives new yarn but the old loop is not locked off in its regular course, it is known as Tuck loop.

Yarn Receiving + Not Clearing = Tuck loop.

84. What is miss loop?

Ans: When the needle neither receive new yarn nor allows the old loop to be inlaid without knitting is called miss loop.

Not Receiving + Not Clearing = Miss loop.

85. What is drop stitch?

Ans: When the needle clear the old loop without receiving new yarn.

86. What are the basic motions of a loom?

Ans: Basic motions of a loom, Primary motion., Secondary motion, Tertiary motion.

87. What is degree of interlacing?

Ans: When interlacing ratio is expressed as % is called degree of interlacing.

88. What is weave plan?

Ans: The interlacement of warp and weft yarn, is called weave plan.

89. What is drafting plan?

Ans: The process of drawing the warp yarn into the heald eye according to the weave plan or design is called drafting plan.

90. What is denting plan?

Ans: The process of inserting warp yarn through reed is called denting plan.

Basic Viva For Textile Engineers (Dyeing Related) Part-4

 

91. Why binder is used in pigment printing?

Ans: For consist the dye in the surface of fabric.

92. What is the difference between dye & pigment?

Ans: Dye is soluble & pigment is insoluble.

93. What is styles of printing?

Ans: 1.Direct printing, 2.Discharge printing, 3.Resist printing

94. At WTP which part of hardness is removed?

Ans: Positive part (Ca+)

95. At WTP which part of hardness is not removed?

Ans: Negative part (CO3-)

96. Which part gives greater hardness?

Ans: Negative part.

97. What is half emulsion?

Ans: Emulsion thickeners are often mixed with carbohydrate

paste to give so called half emulsion.

98. What is oil in water?

Ans: Emulsion of oil in water. This emulsion consists of

small droplets of oil dispersed in water. The negative charge

of the anionic emulsion molecules absorbed on the surface

of the droplets prevents their coalescence. In textile printing

a typical emulsion thickener has about 70% white sprite in

water.

99. What are synthetic thickeners?

Ans: Solution of synthetic polymers. Slightly cross-linked

co-polymer of acrylic acid derivatives and acrylic ester

disperse in water but remain insoluble.

100. What are the advantages of synthetic thickeners?

Ans: On addition of alkali such as ammonia, the carboxylic

acid group dissociates forming the carboxylate because of

the repulsion of the negative charges. A colloidal solution

result with a substantial increase in viscosity. The polymer

does not dissolve because of the crosslinks between the

polymer chain.

101. What is rotary screen?

Ans: In rotary screen printing coloured paste forced through

the open areas of a cylindrical printing screen that rotates

as the fabric moves beneath it .

102. What is the squeeze systems used in rotary screen printing machine?

Ans:

Rubber Squeeze.

Double Squeeze.

Magnetic rod Squeeze.

103. What are the advantages of rotary screen printing machine?

Ans:

High productivity.

Quality of end result.

Evenness of color.

104. What is the squeeze systems used in Flat screen printing machine?

Ans: Parallel rubber blades.

105. What is adhesive system used in a fully automatic flat screen machine?

Ans: This is more problem of a fully automatic flat screen

printing where colors are printed one after the other with

little time for dyeing of the deposited paste. For this reason

printing of large areas of colour is asually done last.

106. What is the fundamental mechanism of screen printing?

Ans: Hydrodynamic pressure is built up in the print paste

between the squeegee and screen surface through which

paste is passed.

107. What is substantivity?

Ans: The attraction between a substrate and a dye

molecule.

108. What is affinity?

Ans: The quantitative expression of substantivity.It is

difference between the chemical potential of the dye in its

standard state in the fibre and corresponding potential in the

dye bath.

109. What is chromophore group?

Ans: The name is derived from the Greek Chroma=color and

phore from pherein=to bear. Chromophore are unsaturated

organic radicals. A molecules possessing no Chromophore

would be colorless.

110. What is auxochrome?

Ans: The name is derived from the Greek auxein=to

increase, and Chroma=color. Auxochromes intensify the hue

of the dye molecules color.

111. What is emulsion thickener?

Ans: Emulsion thickeners are helpful since mineral spirits

are excellent wetting agents for hydrophobic fibre.these

thickener increase levelness and penetration of the dye in

the fibre.

112. What types of dyes are used for silk dyeing ?

Ans: For brighter shade = Direct, Acid, Basic,& Vat dyes are

used.

To dye this fibre also, Mordant or chrome dyes and

premetalised dyes are used.

113. What is the end use of silk ?

Ans: End uses: Used in highly demanded cloths, Furnishing

in different curtains and In the sharee.

114. What is the effect of acids and alkali on silk?

Ans:

Effects of Acids:

Strong acid : Decompose

Moderate conc; acids : Causes construction.

Dilute acids: Not attack.

Effects of alkali:

Conc; caustic alkali: Silk dissolved.

Weak alkali as soap : Borase.

Ammonia causes : Little appreciable damage.

115. Mention the average length and strength of silk filament?

Ans:

Average length = 300 m

Strength: Tenacity –Dry: – 4.3 g/d

Wet:-dry*0.92.

116. Mention the major silk producing country?

Ans: Producing country: People’s Republic of china, Japan,

Korea, Soviet Union, India, Italy, France, & the Hungary.

117. Mention the natural filament?

Ans: Silk, Mohair, Cashmere, Camels, hair, Alpaca, Angora,

Lama, Vicuna, & Gunaco Etc.

118. What are the end use of wool fibre?

Ans; Luxury coating, Sweaters, Shawls, Suit and dress

fabric.

119. What type of dyes are used for wool dyeing?

Ans; Easy to dye, Acid, Mordant or chrome, prematalized,

reactive, dye stuff is Suitable.

120. Briefly discuss the anionic polymerization process with example?

Ans: Anionic polymerization process are given below;

Transfer printing

 

Transfer printing

Transfer printing is the term used to describe textile and related printing processes in which the design is first printed on to a flexible nontextile substrate and later transferred by a separate process to a textile.

Where does transfer printing it come from?

Transfer Printing was first developed to embellish ceramics, not clothing. The technique was born around the 1750’s in England and quickly spread to other parts of Europe where it caught on. Back then the process involved a copper or steel plate or roller that was engraved with a decorative element. The roller or plate would have its surface covered with ink and later would be pressed or rolled over the desired piece. It wasn’t an easy procedure (or fun) by any means, but it was still quicker than hand painting and the result was similar enough.

Thermal Transfer Printing, which is the kind of technique mostly used today, didn’t come until much later. It was invented by a corporation called SATO during the late 1940’s in the US (Is it just me? Or does it kind of sound like an evil corporation from a comic book?).

What’s all the fuss about?

As with everything in life, Transfer Printing has its advantages and its disadvantages.

On the good side: It’s fairly simple (you don’t really need a master’s degree), the equipment is relatively inexpensive, especially when compared to DTG printers, and it can reproduce high quality, complex images. It is also one of the best techniques to use for full-colour prints.

On the bad side: It is slower than other procedures (still faster than hand painting, though), it’s got limitations onto which types of fabrics it can be printed; those sensitive to high temperatures are a no-no, and there might be some restrictions on the reproduction of darker shades.

It may be asked why this devious route should be chosen instead of directly printing the fabric. The reasons are largely commercial but, on occasion, technical as well and are based on the following considerations.

1. Designs may be printed and stored on a relatively cheap and nonbulky substrate such as paper, and printed on to the more expensive textile with rapid response to sales demand.

2. The production of short-run repeat orders is much easier by transfer processes than it is by direct printing.

3. The design may be applied to the textile with relatively low skill input and low reject rates.

4. Stock volume and storage costs are lower when designs are held on paper rather than on printed textiles.

5. Certain designs and effects can be produced only by the use of transfers (particularly on garments or garment panels).

6. Many complex designs can be produced more easily and accurately on paper than on textiles.

7. Most transfer-printing processes enable textile printing to be carried out using simple, relatively inexpensive equipment with modest space requirements, without effluent production or any need for washing-off.

Against these advantages may be set the relative lack of flexibility inherent in transfer printing: no single transfer-printing method is universally applicable to a wide range of textile fibres. While a printer with a conventional rotary-screen printing set-up can proceed to print cotton, polyester, blends and so forth without doing a great deal beyond changing the printing ink used, the transfer printer hoping to have the same flexibility would need to have available a range of equipment suited to the variety of systems that have to be used for different dyes and substrates using transfer technology.

In addition factors such as stock costs, response time and so on do not always apply and unlike dyers, most printers are able to operate without steaming or washing by using pigment-printing methods. Thus a balance exists which not only permits but even requires the coexistence of direct and transfer printing. The relative importance of the two methods consequently varies with fluctuations of the market, fashion and fibre preference.

A great many methods of producing textile transfer prints have been described in the literature. Many of them exist only in patent specifications but several have been developed to production potential. They may be summarised most conveniently as below.

Sublimation Transfer

This method depends on the use of a volatile dye in the printed design. When the paper is heated the dye is preferentially adsorbed from the vapour phase by the textile material with which the heated paper is held in contact. This is commercially the most important of the transfer-printing methods.

Melt Transfer

This method has been used since the 19th century to transfer embroidery designs to fabric. The design is printed on paper using a waxy ink, and a hot iron applied to its reverse face presses the paper against the fabric. The ink melts on to the fabric in contact with it. This was the basis of the first commercially successful transfer process, known as Star printing, developed in Italy in the late 1940s. It is used in the so-called ‘hot-split’ transfer papers extensively used today in garment decoration.

Film Release

This method is similar to melt transfer with the difference that the design is held in an ink layer which is transferred completely to the textile from a release paper using heat and pressure. Adhesion forces are developed between the film and the textile which are stronger than those between the film and the paper. The method has been developed for the printing of both continuous web and garment panel units, but is used almost exclusively for the latter purpose. In commercial importance it is comparable with sublimation transfer printing.

Wet Transfer

Water-soluble dyes are incorporated into a printing ink which is used to produce a design on paper. The design is transferred to a moistened textile using carefully regulated contact pressure. The dye transfers by diffusion through the aqueous medium. The method is not used to any significant extent at the present time.

These different methods are considered separately in this chapter since they introduce different scientific and technical factors, and their use is best discussed in the context of the rather different commercial environments.

What’s next for transfer printing?

We’re never quite sure about the technology of these techniques, but after seeing this video, everything might be possible. Some savvy people in Barcelona discovered a way to transfer prints using water.

Transfer Printing: Properly Explained

So to wrap this up let’s simply explain how Transfer Printing works. Let’s take a look at the different stages of transfer printing: 

Image selection

You can choose virtually any image for transfer printing. It’s way of transferring allows for both complex (with many colours) and simple (with a few colours) images to be printed. Thanks to the fact that the design is printed onto paper first instead of the garment, it allows for more intricate details to show when compared to DTG that may have a more “blurry” finish. As with any other printing technique, it is advised that the original file be a high-quality one (300 dpi) to ensure the best possible result.

Heat transfer

Once the design has been selected, it is printed on a special heat transfer paper (I told you there was magic involved) which is then positioned on the garment. The (magical) paper is later squashed against the fabric using a heat press. It is left this way for the amount of time is necessary for the heat to do its job. After the required amount of time has passed, the press if lifted and the garment is left alone to cool down. If everything went well, then you should have a quality finish t-shirt.

How does transfer printing it work?

Most professional T-shirt printers nowadays use a more sophisticated version of the simple iron-on method, but the basics are still the same. What happens is that the heat transfer machine releases the right amount of pressure, holds the garment in place and has a consistent temperature which allows the colour pigments to be transferred from one surface to the other. Heat transfer literally melts the image onto the fabric.

Heat Transfer Paper

It’s advisable to use commercial heat transfer paper as this will give the image a much better quality finish, lasts longer and won’t fade, bleed or peel. Cheap paper is not suitable for professional looking print since it is likely to show a line around where it’s cut and have that awful shiny finish, making the garment look very ‘homemade’.

 Benefits

•   Inexpensive
•  Good for small quantities
• Can print complex images with many colours and intricate designs
• Prints on any garment regardless of colour
• Easy for amateurs
• Clean (screen printing can be very messy)

Disadvantages

•  Not practical for large quantities
•  Not as flexible when it comes to printing on different kinds of materials
• Each design must be cut one by one

Heat transfer printing for small businesses

Heat transfer machines are relatively cheap, easy to use, lightweight and don’t take up much space. This kind of printing can be done on demand, eliminating the need for holding stocks or large print runs. Just print when people place orders, as opposed to printing, keeping garments in stock and hoping you’ll receive hundreds of orders. This can be beneficial for start-ups offering small quantities of specially designed t-shirts as there are virtually no extra costs involved.