Rotary Screen/Nickel Screen/Printing Screen/Printing Cylinder,  is made of raw material Nickel by Plating,  Mainly Applicated in Textile rotary printing and coating, Also used for wallpaper printing and some other relative printing.


Rotary Screen/Nickel Screen/Printing Screen/Printing Cylinder, is one of the most important auxilaries for textile printing, the main technical parameters concern about Circumference, Thickness, and Open Area.  The strongness and flexibility are also very important for good Rotary Screen/Nickel Screen/Printing Screen/Printing Cylinder. All these gurantee the perfect and reliable printing.


Rotary Screen/Nickel Screen/Printing Screen/Printing Cylinder, before put into the textile rotary printing machine, should be engraved first. 
 

Textile Printing 
Text ile printing involves the production of a predetermined coloured pattern on a fabric, usually with a definite repeat. It can be described as a localised form of dyeing, applying colorant to selected areas of the fabric to build up the design.






The greatest change in fashion and design that has ever occurred in European textiles was the general introduction of printed fabrics. The first printed fabrics were produced in India and China over four thousand years ago. European textile printing dates from about the tenth century. Until relatively cheap printed fabrics became available, patterns on European dress were the result of weaving or embroidery. Such clothes could only be afforded by the wealthy.






Printing Techniques
Modern procedures for printing textile goods may be traced back to the block printing of silks in ancient China. In this method a wooden block with a raised pattern on the surface was dipped into the printing colorant and then pressed face down on to fabric. The desired pattern was obtained by repeating the process using different colours. Printing by brushing colorant through thin metal stencils and the transfer of illustrations to the printed page from engraved rollers in a printing press were also widespread by the fifteenth century.

Block printing remained a practical proposition until the roller printing machine was invented by James Bell in 1783. This enabled six colours to be printed at a rate equivalent to that of 40 hand-block printers. The success of the machine depended on the hard rollers, each of which bore an engraving (i.e. an intaglio engraving, in which the depth of the recess on the roller determines the intensity of the print produced) corresponding to a particular colour component of the design. The machines were capable of continuously printing six different colours in sequence, with the rollers pressed against the fabric.







Pencilling
One of the earliest methods of textile printing was the painting of a design on the cloth using a bamboo pen or brush. The technique was widely used in India to produce a range of elaborate and beautiful designs. Indian printed fabrics began to be imported into Europe in the late sixteenth century. The designs were based upon floral motifs and these formed the basis for early European printed designs. Pencilling was used in Europe until the early nineteenth century. The method supplemented hand-block printing.



Plate Printing
From about 1752 engraved flat copper plates were used to produce printed fabrics. The design was cut into the surface of the plate and it was these lines which held the colour.

The fabric and plate were tightly clamped together in a press to transfer the design to the cloth. Plate prints were made in a single colour, usually either red, purple or blue. Extremely detailed images could be produced with the process.

Most plate prints were used as furnishing fabrics, although some small patterns were produced as dress material. Handkerchiefs commemorating political or public events were also produced in quantity. By the end of the eighteenth century plate printing had been almost completely replaced by copper roller printing.



Flat Screen Printing

This type of printing was used industrially from the 1920s to produce high quality prints in small quantities.

Initially the process was a manual one with two printers passing a rubber-edged squeegee across the screen to force the paste onto fabric. The screen then had to be lifted and moved to print the next section of the pattern. In the 1950s semi-automatic and fully automatic flat screen printing methods were developed. These cut production costs significantly.





Screen Printing
This technique is the most common form of textile printing and it involves the application of the printing paste through a fine screen placed in contact with the fabric to be printed. A design is created in reverse on the screen by blocking areas of the screen with a material such as an opaque paint. The screen is then placed over the fabric and the printing paste is forced through the open areas of the screen using a flexible synthetic rubber or steel blade known as a squeegee

In hand screen printing the squeegee is drawn steadily across the screen by hand at a constant angle and pressure. However, screen printing is now usually automated, with hand screen printing confined to the high fashion industry. Fully automatic screen printing involves the continuous rotation of a cylindrical screen which is kept in constant with the fabric, ensuring continuous movement of the fabric through the machine. As the screen rotates, printing paste is forced through the design (open) areas of the screen with the aid of stationary squeegee. Printing paste is pumped into the inside of the screen from a container at the side of the machine at an automatically controlled rate.

Rotary Screen Printing
In the mid 1950s a new type of screen printing method involving a cylindrical screen was developed.

Rotary screen printing involves a series of revolving screens, each with revolving screens, each with a stationary squeegee inside which forces the print paste onto the fabric. Twenty or more colours can be printed at the same time. The process is much quicker and more efficient than flat screen printing. Since the 1970s it has grown to dominate the textile printing market.












Colorants
Both dyes and pigments may be used as colorants in the printing process, although the mechanisms by which they are fixed to the textile are quite distinct. The same forces of dye-fibre association apply to both dyeing and printing and, in principle, the dyes used to give a plain-coloured fabric could be used to print that fabric. However, there are three important characteristics a dye must possess in order to be used in the printing process.

The dye must first be able to dissolve in the small amount of water used in the printing paste.

Secondly, the dye must be able to diffuse at a reasonable rate from the printing paste on to the fibre, leading to preference for dye molecules with a low relative molecular mass.

Finally, the unfixed dye must be capable of being washed off satisfactorily without staining the unprinted areas of the fabric.

Pigments are widely used in textile printing, with about 45% of all textile prints produced using pigments. Unlike dyes, they do not directly associate with the textile fibres but are fixed to the textile with a so-called binding agent. The binding agent is usually a copolymer which is incorporated into the printing paste and forms a three-dimensional film when heated.

Fixation and After Treatments
If a textile print is washed soon after printing and drying, most of the colorant will be washed away. An appropriate fixing technique is therefore necessary. Fixing techniques are seldom completely successful and it is usually necessary to follow fixing with removal of the unfixed dye, thickeners and other auxiliary chemicals by a washing process. The efficacy of the fixing and subsequent washing process is extremely important to the quality of the print, and mistakes made at this stage of the printing process can be very costly.

Printed dyes are usually fixed by a steaming process, the steam providing the heat and the vehicle for transfer of the dye from the printing paste to the textile fibre.

Pigment prints are fixed to the fabric simply by baking printed fabric. When the fabric has been printed to an adequate temperature the binder forms a continuous film that incorporates the pigment particles and sticks to the fibre surface. At the same time, if the temperature and pH conditions are suitable, cross-linking between the binder molecules is achieved.

Ink-Jet Printing
During the last 20 years a digital revolution has occurred that has touched everyone's life. We are now surrounded by digital telephones, audio equipment, cameras, camcorders, TV, laser barcode readers, etc., and many homes possess a computer with access to the Internet. Digital technology has greatly affected many industries including the textile printing market, not only by the introduction of full-width jet printing machines but also in every aspect of conventional print production, from the design stage, through coloration and recipe formulation, screen manufacture and print paste preparation to the final control of the printing machine itself.

Ink-jet printers have become very well established in both offices and homes for printing text and graphical data (particularly following the widespread adoption of digital cameras) and indeed the quality of the prints from such machine scan now rival that of laser printers.

Jet printing may be defined as a process by which the desired pattern with its individual colours is built up by projecting tiny drops of 'ink' (special dye liquors) of different colours, in predetermined micro-arrays (pixels), onto the substrate surface. In all true jet printing systems the ink is projected onto the surface as a controlled series of drops. Usually a set of inks is used consisting of at least three or four primary colours, namely cyan (turquoise), magenta, yellow and optionally black, the so-called CMYK inks. As most ink-jet printers were originally designed for paper printing, the terms encountered in, for example, technical specifications are more related to those used in the reprographics industry than to those that a textile printer would normally employ. Thus reference is usually made to inks rather than dye solutions, pigment dispersions or print pastes. Similarly print resolution is usually defined as dots per inch (dpi) or lines per inch.(lpi).

In the field of textiles ink-jet printing is fundamentally different from that of all other techniques, not only because of the non-contact mechanics of the print head but also in the means by which the individual colours of a design are produced. A great deal of computation is necessary to produce each of the millions of pixels in a design and this continues for as long as the machine is printing the fabric. In the past printing machines were adjusted entirely by mechanical methods using the operator's experience and judgement, and although modern impact printing machines may be fitted with more refined feedback devices, these are considerably less sophisticated when compared with the electronic control of jet printers.