Textile+&+Screen+Printing

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= = =**History of Textile Printing** =   Textile Printing can be dated back to before 220 in the East Indian area of China, and before the 4th century in Egypt.India and China were the first to initiate block printing by engraving wood. However, Textile Printing was only known in Europe starting around the 12th century. The dyes in Europe at that time were known to be runny; therefore it was mostly large pieces of fabric that were dyed for wall decoration. This is because wall decorations did not need to be washed and then the dye would not run. During these early time, it was mostly natural imagines and animals there were being printed on textiles. =** Techniques of Textile Printing ** = There are three different techniques that are most commonly used for printing colour onto fabric.

//__** Direct Printing ** __// Direct Printing is the most common approach. It can be done on both white and coloured fabric. If it is done on coloured fabric, it is called overprinting. The desired pattern or graphic is produced by imprinting a paste dye onto the fabric. __//** Discharge Printing ** //__ Discharge Printing is when a piece of fabric is completely dyed and then it is printed with a chemical that destroys the colour in certain parts of the dyed area. Therefore, leaving a certain pattern or design on the fabric. //__** Resist Printing ** __// Resist Printing is when a resist paste is imprinted onto the fabric, and then it is dyed. The dye only covers the parts that are not covered by the resist paste. The resist paste is removed after dyeing, and it leaves a pattern on a dark background.

** Methods of Textile Printing **

There are many different methods of printing that use one of the three techniques mentioned above.

__//** Block Printing ** //__ In block printing, the designs are carved into a wooden or metal block. The paste dye is then applied to the face of the block and then pressed down onto the fabric. __//** Roller Printing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Roller printing is similar to block printing, but engraved copper cylinders or rollers are used instead of hand carved blocks. With each full rotation of the cylinders, a repeat of the design is printed. The fabric is then passed into a drying chamber, and then a steam chamber where the moisture and heat sets the dye. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Duplex Printing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Duplex printing is done on both sides of the fabric, using a roller printing machine in two operations (once on each side) or using a duplex printing machine in a single operation. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Screen Printing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Screen printing is done using flat or cylindrical screens made of silk, nylon, polyester, vinyon or metal. The dye or paste is poured onto the screen, and then forced through the openings of the screen onto the fabric. //__<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Stencil Printing ** __// <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">In stencil printing, the design cut into cardboard, wood or metal, and then colour is applied over the stencil and onto the fabric. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Transfer Printing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">In transfer printing, the design is transferred from paper to fabric using vaporization. There are two different processes commonly used for transfer printing; Dry Heat Transfer Printing and Wet Heat Transfer Printing.

<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">During the Dry Heat Transfer Printing process an electrically heated cylinder is used to press together the fabric and a printed paper, places on a heat resistant blanket. Another Dry Heat process is when the transfer paper and fabric are passed between infrared heaters and perforated cylinder, which are protected from excessive heat by a shield.

<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">During the Wet Heat Transfer Printing the heat is used in a wet atmosphere to vaporize the dye pattern from the paper to the fabric. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Blotch Printing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Blotch Printing is a Direct Printing technique where both the background colour and the design are printed onto a white fabric, usually in one operation. Any methods such as block, roller or screen may be used. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Airbrush (Spray) Painting ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Airbrush Painting iswhen the dye is applied with a mechanical airbrush, which blows or sprays the dye onto the fabric. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Electrostatic Printing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">In Electrostatic Printing, a dye-resin mixture is spread onto a screen with the design imprint, and the fabric is then passed through an electrostatic field under the screen. The dye-resin mixture is pulled through the pattern area onto the fabric. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Photo Printing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">The fabric is coated with a chemical that is sensitive to light and then any photograph may be printed on it. //__<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Differential Printing ** __// <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Differential Printing is used on tufted material, made up of yarns having different dyeing properties (ex. Carpets). It is possible to have up to a ten colour effect, if the selections of yarn, dyes and patterns are chosen carefully. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Warp Printing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">It is roller printing applied to warp yarns before they are woven into fabric. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Tie Dyeing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Tie Dyeing is when knots are tied into the fabric, and then the fabric is immersed into a dye. The outside of the immersed fabric is dyed, while the inside remains untouched. There are different types of Tye Dyeing, such as Ikat Dyeing and Plangi Dyeing. //__<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Batik Dyeing ** __// <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Batik Dyeing is a Resist Dyeing method. The design is made with wax on the fabric, and it is them immersed into the dye. The unwaxed area absorbs the colour, while the waxed area remains uncoloured. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Jet Spray Printing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Designs are imparted to fabrics by spraying colours in a controlled manner through nozzles. __//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">** Digital printing ** //__ <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Digital Printing is when micro-sized droplets of dye are placed onto the fabric through an inkjet printhead. The digital image file has the data to control the droplet output. Digital Printing is the latest development in textile printing, and is expanding very fast.

<span style="font-family: Arial,Helvetica,sans-serif;">** Screen Printing ** <span style="color: #000000; font-family: Arial,Helvetica,sans-serif;"> Screen printing is the most versatile form of printing. It does not need to be printed under pressure, and different inks can be used on a variety of different materials. It uses a woven mesh to support an ink-blocking stencil. This is why screen printing is used in many different industries, including:
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Balloons
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Clothing
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif;"> Decals [[image:wftprintpm/screenprinting_copy.png align="right" caption="An example of Screen Printing"]]
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Medical devices
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Printed electronics, including circuit board printing
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Product labels
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Signs and displays
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Snowboard graphics
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Textile fabric
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Thick film technology

media type="youtube" key="358LNM5q1xg" height="315" width="420" =History of Screen Printing.=

Screen printing was first recognized on in China between 960-1276 CE. Japan and other Asian countries later adopted this method of printing to advance the caft of printing along with block printing and paints. It was then braught to western europe in the 1700's but wasn't used much untill the trade of silk mesh was more available to trade from the east and became profitable. Screen-printing was first patented in England by Samuel Simon in 1907. It was originally popular method to print wall paper and print of fine fabics such as linen and silk. In resent history alot of credit was given to Andy Warhol for popularizing screen printing. American entrepreneur, artist and inventor Michael Vasilantone would develop and patent a rotary multicolor garment screen printing machine in 1960. Now sceen printing is one of the most preferred over other methods of printing such as inkjet printing.

=Screen Printing Technique.=

A screen is made of porous. Before ink is applied to the screen, the screen and frame must go through a process referred to as 'pre-press'. In this process, an emulsion is 'scooped' across the mesh and the 'exposure unit' burns away the unnecessary emulsion leaving behind a clean area in the mesh with the identical shape as the desired image. The surface of the pallet is coated with pallet tape. This serves to protect the pallet from unwanted ink from spill onto the substrate. Tape is also put on the screen and the frame. The screen is placed upon a substrate such as a fabic or type of paper. Ink is placed in at the top of the screen, and a fill bar is used to fill the mesh openings with ink. then the screen is lifted to prevent ink from spilling onto the substrate. The operator then uses a squeegee to move the mesh down to the substrate and pushes the squeegee to the rear of the screen.When the squeegee moves toward the end of the screen the tension of the mesh pulls the mesh up away from the substrate leaving the ink upon the substrate surface.