Textile printing

As a textile printing methods are called, with which fabrics are printed. Printing on textile fabric is more complex than the printing paper, since the different print medium ( such as cotton or polyester) require special colors and forms of treatment.

Older methods were referred to as textile printing.

• 2.1 screen printing or screen printing 2.1.1 rotary screen printing
• 2.1.2 flat screen printing

Printing process for textile end products ( eg T-shirts )

Flex and flock films Transfer Printing

When Flex and flock films Transfer Printing the print motif is cut from special, single-color plastic film and then transferred to the tissue. In addition to cotton fabrics and polyester, nylon, viscose and blended fabrics can be printed. The surface of flex films is smooth to matt / soft, those of Flock foils, however, velvety.

Since only vector graphics can be printed without gradients with this printing technology, it is particularly suitable for the printing of decals, pictograms, logos and similar motives. Multi-colored prints are not possible ( and quite common ), but since all work steps must be performed each per color, the cost increases with each additional ink to relatively strong.

A significant advantage over other textile printing techniques is the high color fastness of the prints, and (especially compared to screen printing ) the rapid and cost effective way of production of single pieces or small editions. However, in contrast to the silk screen for each individual specimen obtained the same amount of work ( and therefore the cost per unit remain almost constant ), this printing technique less suitable for the production of high requirements.

Development of Flex and flock foils

Flex and flock films consist of three layers:

• Transparent carrier film ( usually polyethylene terephthalate )

• Color layer

• Top layer with hot melt adhesive ( polyurethane adhesive )

Printing

1 plotting

Using a cutter, the contours of the subject are carved into the color and layer of the film, the carrier film remains intact ( see video).

Second weeding

In the second step - the so-called weeding - all those parts of the color and surface layer are lifted from the carrier film manually, which do not belong to the subject. Especially for small-scale designs it is very helpful if the carrier film is back -adhesive, so accidentally lifted parts of the color and surface layer can be re-installed.

One of the main disadvantages of the Flex and flock films Transfer pressure against most other textile printing techniques is that the complexity of motifs plays a key role for the printing costs, since the amount of work when weeding depending on the subject differ widely: Large particle motifs can in principle easily be produced at low cost in high volumes, while the weeding of a very small-scale motif can take sometimes more than 20 minutes.

3 transfer to the tissue

After weeding and the subsequent positioning of the carrier film on the textile subject using a transfer press under pressure and heat is transferred to the tissue. As soon as the adhesive of the cover layer is cooled, and finally the carrier film can be removed - the ink layer (and hence the pattern) remains on the fabric.

Digiflexdruck

When Digiflexdruck a printable flex foil by using solvent or eco-solvent ink is printed. The printed film is cut as in Flex printing, using cutter. Then the subject is applied to a transfer sheet and transferred with a transfer press under heat and pressure onto the textile. This method is economical even for short runs and has an extremely high quality compared to conventional transfer films.

Flock Print

When direct flock a special adhesive is applied through the open honeycomb of a sieve. Then the flakes are shot into the still wet glue using electrostatic. By charging the flakes arrange vertically and next to each other along the electromagnetic field. Subsequently, the finished flock is oven dried. Finally, the flakes are who have fallen beside the adhesive surfaces sucked.

Silk screen / stencil printing

Here is a screen must be made for each color, which causes relatively high fixed costs. It can be printed in principle with any color; to reduce the number of colors can be color gradations by screening produce. So then photo -like artwork with color gradients can be realized in screen printing. To this end, the primary colors cyan, magenta, yellow and black (CMYK ) are used in the form of non-opaque ( translucent ) Textile colors are overprinted. For the print motif must be color separated before, are thus separated into the four colors.

Typically, the screen printing process - in contrast, say, to offset printing - due to the rough surface of textiles no finer grids are printed. Moreover, the use of only 4 translucent colors and white for printing so-called 4c halftone originals on dark fabrics is not always sufficient. In order to print dark textiles with full color artwork such as photos, 6 to 18 colors are used depending on the separation effort and existing hardware, with white yet.

An essential feature of the screen printing process in textile printing: The fabric is printed directly with the color or color paste. Depending on the type of textile color varies the opacity of colors and fabric handle of the finished print. In pigment printing, the ink coverage is high, but the fabric hand is hard. An additional increase of the opacity can be achieved with pigment printing by example if you on dark fabrics first printed in white and then in the desired color, this is uneconomical due to the additional step, since you can easily increase the printing paste in their composition. For large quantities, this printing method is the cheapest. In addition, the pressure, depending on the fabric dye used (pigment, acid, reactive, vat and direct dyes) is most stable. Only with pigment no post-treatment is required, otherwise this will vary from a simple wash through to washing with various chemicals.

Dye sublimation

The fabric is printed indirectly, the subject is either printed with four color-coated sublimation ribbons or with Sublimationsinkjettinten. The prints are transferred with transfer presses at 170 ° C-200 ° C on polyester fabrics. The colors sublimate gas in the hot polyester fiber, so the subject is barely noticeable. The wash fastness of the print is higher than that of the processed fabric. The color number is not limited, photo printing is possible. Only specific types of fabrics are printed. Depending on the ink and printing software that prints are intensively colored correctly or feel uncomfortable. The color space does not correspond one to one to the color space of the normal inkjet inks. For satisfactory results about a special printer driver is required. An ICC profile is not enough in most cases. For printing on dark fabrics white subcarrier films are used.

Advantages: Photo printing is possible, gradients can be represented differently colored motifs can be pressed once.

Cons: it creates relatively high variations in color, certain colors can not be represented on certain textiles, for example, Blue on a yellow vest is green. Dye sublimation printing can be performed only on light textiles. The color white can not be displayed.

Main field of application safety vests with multicolored print.

Transfer film

Here, the image is first printed on a carrier film, which is then completely transferred to a transfer press of the fabric. The transfer film can be similar to print on paper, so ordinary PC printer can be used with any color and halftoning methods. Accordingly, there is pressure for this process Do-It -Yourself Kits ( Bügelfolie ). However, a transfer press is necessary because an ordinary iron does not exert a constant pressure, which is necessary for transmission. The film makes the fabric a bit stiff: Since it is not as stretchy as the fabric, she gets easily cracks that stand out in larger areas of color.

Direct to garment printing / DTG

" DTG " is the abbreviation for " Direct To Garment ". With an inkjet printer connected to the PC for specific (usually water-based ) pigment inks are printed directly onto the fabric and then permanently fixed with heat. The pressure is pleasantly soft to the touch and has a good laundry resistance, bright colors and fine detail on. In contrast to the sublimation mainly textiles are 100% cotton and mixed fabrics (depending on ink with up to 50 % polyester content ). The pressure on bright fabric colors is normally not a problem because there is no " sub- White " is required. For dark fabrics must - as in the screen printing - a White are highlighted. For most data currently available on the market printers this Unterweißburg is somewhat problematic, as it can be processed very maintenance intensive and costly and also the textiles must be pretreated. However, should the digital direct to garment printing the future belong. The advantage of direct to garment printing ( DTG) is not only the flexibility, textiles, for example, to print personalized with individual names, etc. within a motif, on the other hand, the high detail with photo-realistic prints.

Printing process for the meter

The high ink coverage - which is necessary to completely penetrate the fabric - continues to be a challenge since 1995 being researched digital printing process, nor will but most commonly printed with rotary screen.

Screen printing or screen printing

Rotary screen printing

The rotary screen printing process, this continuous film are seamless hollow rolls of perforated sheets. The pressure pattern is transferred photochemically. The paint is pumped from a storage container in the template where it is distributed by a doctor roll, and pressed through the holes of the mask on the fabric. For each color, a separate template is used.

Flat screen printing

As the rotary screen printing is the printing technique commonly used for the continuous film pressure. The print pattern is photometrically (also called gauze, usually polyester ) on a frame with fabric transfer, and with a squeegee ( by roller, brush squeegees ) printed on the fabric. A screen is required for each color.

In both methods it is possible by scanning the colors ( screen printing ) to be reduced. Here especially the 4c printing ( cyan, magenta, yellow, black) is common, as an alternative is the 6c printing ( Cyan, Magenta, Yellow, Green, Orange, Black ) for the opportunity.