screenprinting

FRAMES

2009-05-25T04:47:00.000-07:00

There are two main types of frames-STF roller frames and rigid aluminum frame. Rigid aluminum frames are result of technological progress, because original rigid frames were made of wood.Both types are equally represented in the screenprinting industry. Rigid aluminum frames are mostly used on flat and cylinder machines while rollers are used on textile printing machines such are MR sportsman or formula.

RIGID ALUMINUM FRAMES

Rigid aluminum frame are made of square cross section tubes.These frames are ideal for precise registration such as 4 color process printing. After welding all four corners, surface on one side of the tube needs to be sand blasted for better adhesion. Ones stretched and glued on frame, mesh can`t be retensioned, so if you are using this type of frame you need to recalculate tension before the adhesive is applied. Usually mesh tension goes down by 10-15 N/cm.

STF ROLLER FRAMES

Roller frames are mush more simplier to use. To make roller frame. onli thing you need is wrench. There is no welding or sand blasting and there is no need for adhesives. Advantage of these frames is that mesh can be retensioned. This is very convinient because after few thounsend prints, mesh tension goes down.

MESH

2009-05-13T12:25:00.000-07:00

Mesh is screen printing fabric that can be made of polyester or polyamide (nylon). There is a hole range of mesh types and mesh counts. Different mesh types are used depending on specific printing applications. Every mesh type has a range of mesh counts between 8 threads up to 190 threads per centimeter.
WARP AND WEFT
Warp and weft describe the direction on the threads. Warp threads travel the entire length of the mesh roll. and weft threads travel across the width of the roll
TENSION
Determining the proper tension for a specific application is dependenton many production variables that include the size of theframe, the substrate, the artwork, the mesh specification, the pressparameters, etc. These variables will be used to fine tune the mostoptimum tension for an application—but before they are considered,basic mesh tensioning guidelines should be used to find thecorrect tension range for the job.
Should the Mesh be Degreased?For optimal results, it is recommended that screen printers degrease both new mesh andreclaimed mesh before coating the mesh with emulsion.Both new mesh and reclaimed mesh will pick up dust and contaminants that might potentiallyaffect the stencil and image quality, and could also contaminate the container of emulsion (ifemulsion is placed back into the container after coating). Degreasing will remove any contaminantsor oils on the mesh, and provides a consistent mesh surface treatment that prepares themesh to accept emulsion, and promotes emulsion adhesion to the mesh.
DEGREASING
Degreasing uses special soaps and detergents that help remove dirt and grease. It can beapplied to the mesh both manually or using automated screen-cleaning equipment. Whenmanually applying degreaser to the mesh, it is best to use a clean soft bristled brush, dedicated to degreasing only.

Plastisol inks

2009-05-09T14:19:00.000-07:00

Plastisol is in fact industrial coating used in garment printing. It was invented in 1959 by the guy name Don Petrie. Two main components are resin and plasticizer. Great thing about plastisol is that it needs to be heated to dray. You can print as many prints as you want as long as you don't heat the garment surface on drying temperature which is 140-160 degrees Celsius. For plastisol inks we can use solvent-resistant dual-cure or diazo direct emulsion stencils specifically designed for plastisols.

Inks

2009-05-09T02:14:00.000-07:00

Screenprinting can be applied on many different materials. Because of that, manufacturers designed series of inks adjusted for each group of materials. Inks can be divided into three basic groups:waterbased, solventbased, UV-based. Manufacturers also sell plastisols as printing inks. Plastisols are basically coats developed specifically for screenprinting.

Commercial screen printing

2009-05-08T14:11:00.000-07:00

Commercial screen printing technology involves the production of a multitude of alphabets at a quick pace. Though one may note, even common articles of daily use make use of a printing application in some form or the other. Screen printing is suited for bold and detailed graphic designs. However, small and obscure particulars can also be duplicated. Modern printing technology is a good example of the rapid development in various commonly used devices and equipment in our life and the impact of science in improving efficiency. Screen printing is a method used primarily for flat or relatively flat surface printing. The procedure involves a fine mesh or screen securely stretched around a stiff frame. Sections that are not to be printed are blocked on the screen. To create a print, the screen is placed on a piece of dry paper or fabric and ink is placed on top of it. A rubber blade is used to spread ink uniformly across the screen. The ink passes through the open spaces in the screen onto the paper or fabric below after which the screen is removed. The screen is usually durable and long lasting and can be re-used after cleaning. If more than one dye is to be used on the same surface, then the original ink must be allowed to dry before the process is repeated with another screen of the same design and a different color of ink. The framed screen is positioned over the item to be printed along with a dollop of thick ink. In earlier methods, the ink was left to dry for long periods of time. However in modern times the printed article is passed through a heat-tunnel on a conveyor belt. This method guarantees that inks dry quickly, allowing the materials to be stacked or packaged almost immediately. Properly dried screen print items are long lasting even in unfavorable conditions. If the printing surface involves darker items, usually a supportive base print is required. A light base color, preferably white is used. This method ensures that the successive colors retain their exuberance and are noticeable. Today, screen printing is much more flexible than the conventional printing techniques. Screen printing inks are being used to print on a range of surface materials, which include fabrics, ceramic objects, metal, timber, paper, glass, and synthetic items. This has resulted in the usage of screen printing in diverse industries, from fashion garments to manufactured goods and labels.

History

2009-05-08T14:08:00.000-07:00

Legendary references point out to the fact that silk was discovered in Asia. In Silkscreen printing, screens were originally made of a piece of absorbent fine silk. Silkscreen printing originated from simple Japanese stenciling art forms. The modern Silkscreen process has evolved from ideas adopted by John Pilsworth in 1914 in San Francisco, California. This is known to be the first reference material on how to use a Silkscreen to form multicolor prints. It is a source of information that is applied even today.Screen printing, also known as Silkscreening or serigraphy, is a printing method that usually creates a sharp edged single color mage using a stencil and a porous fabric. An image created using this technique is called a screen-print or serigraph. In electrical terms, silkscreen refers to the writing on a printed circuit board. This method maybe used in etching copper wiring on a circuit board.This technology gained its popularity from the “Pop Art Movement” of the 1960s. At present, this method is increasingly being used in fine arts and small-scale commercial printing. Silkscreening gained popularity during the First World War. The industry flourished in response to the increasing demand for printing flags and banners. Consequently, the use of graphic stencils also increased. There are several ways to create a pattern for screen printing. The simplest way to create a silkscreen pattern is by hand. One can acquire a desired shape by cutting a piece of paper or plastic film and fasten it to the screen or by creating an illustration on the screen itself. A more artistic method involves painting a picture with drawing paint. After it dries, it is coated with screen filler. This is again dried and then, water is squirted on it. This washes away all the material leaving behind a stencil spray. This method permits the artist to stay true to the portrayal technique and yet create multiples. Silkscreen printing is most commonly used for t-shirts, garments and other fabrics. It is also used on ceramic objects, metal, wood, paper, glass, and synthetic items. This technique is essential and ideal to represent bold and graphic designs. Today screen printing is more flexible than conventional printing techniques and is being increasingly used in a wide variety of industries.