FIELD OF INVENTION

The present invention relates to printable natural fiber based fabrics and garments. It further relates to a novel method for printing on cotton and other natural fiber based fabrics.

BACKGROUND OF INVENTION

Printing on fabrics is one of the most important methods of decoration as well as value addition to the fabrics and garments. There are numerous techniques to print on fabrics, namely; roller printing, screen printing, transfer printing etc. When it comes to multi colour photographic printing few techniques such as transfer printing, roller printing and ink jet printing techniques are widely being used.

Ink jet printing process is a type of computer printing that directly creates the image on the fabric by propelling droplets of ink. Whereas the transfer printing employs a flexible, non-textile substrate as an intermediary. The mirrored image is printed on the substrate and subsequently it gets transferred on to the fabric. One such process of transfer printing is called sublimation printing. This is because the dye which is used for the sublimation printing on the substrate makes the transition between the solid and gaseous state without going through a liquid state.

However these techniques have certain limitations in its applicability. For example, multi colour photographic printing on cotton or natural fibre fabrics, more particularly cotton fabrics, cannot be successfully printed either with ink jet printing or with sublimation printing. Whereas these techniques can be employed on polyester based fabrics.

In order to print multi colour photographic printing on cotton and like fabrics and garments various via media are being employed.

Certain attempts were made to make the fabric as a blended one by combing polyester and cotton yarns. However, it was found that fabrics containing as high as 90% polyester and 10% cotton mix were not able to successfully reproduce multi colour photographic printing.

There exist some other methods like applying a coating of polyester on the cotton and like fabrics as an intermittent layer prior to printing. For example, in the case of ink jet printing, the fabric is coated with polyester resin as a layer prior to printing. Similarly, for sublimation printing, a layer of polyester resin is first applied on to the fabrics or garments before printing multi colour photographic printing. The issue again is adhesion of intermittent layer with cotton fabrics. The life of such printed fabrics and garments is also limited. Over the course of the fabric's useful life the printing fails and peels off or breaks curtailing the garment's continued usage. However, all these methods suffer from various disadvantages and more particularly loss of useful life and higher cost of intermittent processes. Therefore, there is a need for an efficient and cost effective process to print on cotton and like fibre based fabrics and garments which overcomes the disadvantages enumerated above. The present invention intends to overcome the disadvantages by a novel process to print on the cotton and like fibre based fabrics and garments. The objects and other advantages of the invention will be apparent from the description.

SUMMARY

The present invention overcomes the problems, as is seen from the prior art, namely the life of the printing and its viability of printing on the natural fibre based fabrics. It is achieved by introducing a novel approach called Modularly Adaptable Synthetic yarn based Embroidery (MASE). By introducing the MASE technique, it introduces an adequate and efficient substrate for printing multi colour photographic like printing possible on the natural fibre based fabrics (NF fabrics). Furthermore the printing lasts longer which was otherwise almost impossible. Using novel MASE substrates for printing on the NF fabrics also works out to be cost effective in comparison with other techniques found in the prior arts.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein

FIG 1 a flow chart illustrates one embodiment of the process;

FIG 2 illustrates schematically one mode of adaptation of the present invention;

FIG 3 illustrates a partial view of the fabric which is prepared in accordance with the requirements; FIG 4 depicts the picture to be reproduced;

FIG 5 illustrates the creation of the MASE substrate on the fabric;

FIG 6 illustrates the fabric with MASE substrate aligned with the transfer paper;

FIG 7 illustrates the assemblage placed between stationery platen and movable platen of a hot press;

FIG 8 illustrates the fabric and transfer paper assemblage placed in the hot press;

FIG 9 illustrates the fabric as printed using the method as laid out by the present invention;

FIG 10 illustrates a possible requirement of printing similar or varied or different pictures at different places on a same fabric;

FIG 11 illustrates the modularly created MASE substrates on a fabric;

FIG 12 illustrates the transfer paper 100 as required for another requirement; and

FIG 13 illustrates the printed fabric in accordance with the other requirement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides for a novel approach for printing multi colour photographic printing on the NF fabrics by introducing Modularly Adaptable Synthetic yarn Embroidery (MASE). NF fabrics include cotton, jute, hemp and like fibres. The NF fabric also includes any combination of natural fibre rich fabrics wherein the natural fibre content is substantial.

Basing on the contour of the picture to be printed, holder rings known as hoops are prepared for the embroidery. By fixing on to the holder rings, using synthetic yarns, embroidery is done on to the fabric. The synthetic yarns are so selected that it provides for efficient printing and also provides for longer life. For example, polyester yarn is one such synthetic yarn that provides for lasting prints.

The density of the embroidery is optimised basing on the pictures to be printed. The density of the embroidery means the degree of sparseness of the embroidery. If the sparseness is more the appeal and effectiveness of true to life reprints reduces. On the other hand, if the sparseness is less, the embroidery is denser and produces good appeal and better reproduction.

Thus the optimum density of embroidery is employed empirically for each and every picture to be printed.

Once the fabric is embroidered, printing takes place on the embroidered surface which includes processes like sublimation or other transfer process.

The present invention is outlined as a flow chart in FIG 1. The flow chart illustrates one embodiment of the process. At the step 10, the fabric to be printed is prepared according to the print to be reproduced. It involves creation of templates basing on the contour of the required print to be reproduced, preparation of holder rings, preparation of the reverse print on the transfer paper also known as sublimation paper printing and other related works.

At the step 20, the fabric is held with the help of holder rings and the embroidery is made in accordance with the layout and contours called MASE. The embroidery may be manual and can also be automated. The synthetic yarns used for the embroidery is selected from a group of yarns namely polyester, nylon, rayon, aramids, acrylics, cholorofibres, elasthanes, polyolefins, and others. The synthetic yarns are sized and seasoned prior to embroidery to avoid any shrinkage and other like defects during its service as garments after printing.

At the step 30, the embroidered fabric is printed using dispersible dyes using processes like sublimation. Sublimation process involves transfer of already printed dyes from the transfer paper to the other substrate. The term sublimation means the dyes on the transfer paper gets transferred to the other substrate without the intermittent liquid phase.

The already prepared paper with reverse print called transfer paper, as explained in the step 10, is placed over the MASE substrate as per the layout and the contour of the print required. At the step 30, a hot press is used to transfer the print on the transfer paper to the MASE substrate. The hot press consist of two platens; one being stationary and the other being movable. The fabric with the transfer paper is placed in the stationary platen of the hot press.

The platens of the hot press have the provisions for heating as well as applying pressure during the transfer process. Applying heat and pressure the print from the transfer paper gets transferred to the MASE substrate. The temperature and pressure required to transfer the print depends on the print to be reproduced. It is optimized empirically.

Alternatively, the transfer printing can also be made using roller press also known as continuous feed hot press. This roller press can be used for continuous printing on running fabrics as well as for discrete printing on pieces of fabrics. The Roller press employs rotatable rollers. The assemblage of the MASE embedded fabric and the transfer paper is made to pass through the heated rollers. After the transfer process i.e. printing on the MASE, the fabric is removed from the press and allowed to cool at the room temperature for further processing like making required garments and like.

EXAMPLE OF A PREFERRED EMBODIMENT

FIG 2 illustrates schematically one mode of adaptation of the present invention. It illustrates partial view of a T-shirt 40 with a print to be produced.

FIG 3 illustrates partially the fabric 50 which is prepared in accordance with the requirement of the garment to be made in this case a T-shirt. The fabric construction is made from weaving, knitting and other processes.

The picture 52 to be reproduced is illustrated in the FIG 4. FIG 5 illustrates the printed transfer paper. In accordance with the step 10, as illustrated in FIG 1, the picture 52 to be reproduced is printed-in-reverse 56 on the transfer paper 54. The transfer paper is a kind of paper which aids easy release of the print during the sublimation process. Here the term reverse means the mirror reflection of the print to be reproduced. The technique to print on the transfer paper includes inkjet printing, offset printing and other printing techniques.

FIG 6 illustrates the creation of the MASE substrate 58 on the fabric 50. The MASE substrate 58 is created on the fabric with the help of the holder rings also known as hoops or frames . The embroidery of the synthetic yarns on to the fabric is made manually. Alternatively, the embroidery can also be automated. Polyester synthetic yarn is employed in this example. Alternatively, the synthetic yarns can be selected from a group of yarns namely polyester, nylon, rayon, aramids, acrylics, cholorofibres, elasthanes, polyolefins, and others.

The density of the MASE is decided basing on the print quality required.

FIG 6 illustrates the fabric 50 with MASE substrate 58. The MASE embedded fabric is referred to as 60.

FIG 7 illustrates the assemblage 62 of the fabric with MASE substrate 60 and the printed transfer paper 54. They are aligned basing on the layout and the contour of the print to be transferred. Aligned fabric and transfer paper assemblage 62 is transferred to a hot press.

FIG 8 illustrates the fabric and transfer paper assemblage 62 placed between stationery platen 64 and movable platen 66. Heat and pressure is applied on to the assemblage 62 using the hot press 68. The print on the transfer is transferred to the MASE by sublimation.

Alternatively/ the transfer printing can also be made through roller press also known as continuous feed hot press.

Once the printing is complete the printed fabric 70 is removed from the hot press 68 and allowed to cool for further processing.

FIG 9 illustrates the fabric 70 as printed using the method as laid out by the present invention.

ANOTHER EXAMPLE OF A PREFERRED EMBODIMENT

FIG 10 illustrates a possible requirement of printing similar or varied or different pictures at different places 82 - 87 on a same fabric 80. The present invention is modularly adaptable. This will be clearer from this example.

FIG 11 illustrates the modularly created MASE substrates 92- 97 on the fabric 80. The MASE substrate is created using the same steps as set out earlier. The MASE is created selectively and modularly basing on the requirements.

FIG 12 illustrates the transfer paper 100 as required for the present requirement. The required print is printed-in-reverse 102 - 107. The MASE embedded fabric 80 and the transfer paper 100 are aligned as required. The assemblage of the fabric 80 and the transfer press 100 is transferred to a hot press for printing. By applying heat and pressure the print gets transferred to the fabric 80.

FIG 13 illustrates the printed fabric in accordance with the requirement.