aluminum bars for sale online metal store

Screen printing plate making

1, the film engraving: the plate is a manual method, relatively simple. Printable generally less sophisticated monochrome patterns and text.(1) Vintage sprayed paint paper: the tracing paper with glue stick on a flat board, with a row of pens rubber water to 1 part (by volume), good gasoline 1 tone, evenly coated on paper after a soft dry spray varnish 3-5 times, after each spraying in an oven by 40 degrees to 50 degrees drying, spray paint film thickness to 5 to 6 mm is appropriate, the film should be bright, uniform, no bubbles , without blemish.(2) engraving Graphics: The graphics on the paper attached to the film, with a knife, compass knife, ruler graphic engraving by gently removing the film.(3) Posted: After carving patterns in the past can be posted well in advance on the screen frame. The method is to cut a good film on the frame below the pressing, with cotton dipped a little thinner on top and gently rub the complex to screen the film and the cement up. After drying for several minutes, the tracing paper torn off. If the paper is not fully out, the available cotton wet wipe. Blank part coated with lacquer, the screen mesh blocked. To dry after printing.2, carbon paper copy method: also a relatively simple manual plate method.(1) cut sheet paper: photographic paper is coated with a thick mixture of barium on oxygen who made the original paper, carbon paper, according to the size of the graphic cut a good backup. (2) sensitization: immersed in 500 ml and 20 g of ammonium dichromate prepared solution for 3-5 minutes, remove the carbon paper, the water diversion dry.(3) Exposure: The carbon paper flat on a clean glass, film upward, positive image in the top cover polyester film negatives with Shai Banji exposure, exposure time 8-12 minutes.(4) development: after exposure at 40 to 50 degrees warm water soak a few minutes, so that film and positive plates and zinc oxide paper naturally out with warm water to force the developing carefully shaped text is clear.(5) Posted: good version on the system to be a good stretch mesh screen frame below the screen covered in several layers of newspaper, the pressure on the glass to 1-2 kg / cm of pressure, this when the film and screen firmly affixed, remove the weight and newspapers, dry film with an electric furnace, and then remove the paper, film graphic you go to the wire-line. Carefully check whether the graphic defects, after passing the wire around the graphic medium coated with nitro enamel protection, the silk screen printing plate mounted on the carriage is to prepare for printing. Scope of this same film engraving plate method.3, the photographic plate method: printing brand precision screen printing plate used in high, generally have adopted advanced direct, indirect, direct between the three photographic plate method. A, CTP method:(1) post boxes use aluminum frame, you do not need stretching flexibility Stretching, pressure at 5-6 kg / cm, using acetal adhesive net, stretched with tension measurement tightness, tension 5-7 kg, sink size should be less than 2 mm.(2) Cleaning Screen: Use washing powder, detergent, ethanol and the like as clean lotion, wash both sides of the screen, and rinse with water. After air drying stand. Purpose is to make the network better with photoresist adhesion.(3) scraping bucket (hopper coating, coater): scraped fighting photoresist coating may be made of stainless steel, it can also be made of plexiglass plate scraper. Its length is generally slightly smaller then the inner diameter of the screen frame (the length of several different scraping bucket dubbed a spare set) B. Must scraping the thin edge of the bucket without edge, straight and smooth, not allowed to have irregularities, burrs, scratches and other defects, heart to affect the quality of the plate. When the light-sensitive adhesive coated wire mesh, each coated with three drying again, the need for a continuous 3-4 times, until the film reaches the desired thickness is reached, then the exposure.(4) the temperature of the oven, it is preferable to use an adjustable temperature oven. The drying temperature sensitive adhesive, generally controlled at about 40 degrees, the baking time is too long or the temperature is too high, will affect the quality of the photosensitive layer.