Sandblasting oxidation embedded paint aluminum sign
Screen printing, sandblasting, oxidation, and embedded paint sign technology is a traditional sign making process. This type of product has a silver white exterior, high surface hardness, and good wear resistance. The process flow is as follows:
Production of screen printing plates/cutting and pre press treatment → screen printing → corrosion → punching → removal of anti-corrosion layer → production of bright tape → sandblasting → chemical polishing → anodizing → sealing → embedding paint → punching → finished product
① Preprocessing
a. Printing material: Aluminum materials are generally selected from semi hard industrial pure aluminum such as L1Y and L2Y2.
b. Pre treatment of aluminum plates: including mechanical polishing (or grinding with a polishing machine, followed by brushing with a polishing machine) and alkaline degreasing.
After degreasing the aluminum plate, wash it clean in running water and store it in a clean water tank for applying photosensitive adhesive. Sometimes, in order to ensure that the photosensitive adhesive can adhere well to the aluminum plate, it is necessary to use a brush with water to dip it in calcium carbonate powder (also known as double fly powder or old powder) after degreasing, manually or machine brush the aluminum plate, and then clean it for later use. After pre-treatment, the aluminum plate is inserted into the rack and dried for printing.
② Photochemical board making. Photochemical plate making for signage refers to the process in which ultraviolet light passes through the image and text on the negative film, causing a photochemical reaction on the surface of the aluminum plate coated with photosensitive adhesive film. After development and film fixation treatment, a corrosion-resistant film pattern is formed.
Photographic adhesive is generally composed of film-forming agents such as bone glue, gelatin, insect glue, protein, polyvinyl alcohol, etc., which are boiled and processed with water or ethanol as solvents. Then, an appropriate amount of photosensitizer ammonium dichromate is added, and if necessary, some ammonia water, sodium dodecylbenzenesulfonate, dimethyl sulfoxide and other additives are added.
Polyvinyl alcohol photosensitive adhesive is used for corrosion protection of graphics and text.
The prepared photosensitive adhesive is evenly applied to the surface of the aluminum plate using methods such as spreading, dipping, spraying, or rolling. After heating and drying under infrared light, it is sandwiched with the film and placed on a plate drying machine. After exposure with high-pressure mercury lamps, pickaxe lamps, xenon lamps, iodine gallium lamps, charcoal lamps, or specialized ultraviolet light sources, the unexposed part of the adhesive film is rinsed off with water and then immersed in a solution of about 5 ° C of methyl violet water for development (protein photosensitive adhesive is developed by rolling ink method). Some can also be chemically fixed in specific chemical solutions, and finally placed in a constant temperature box~ Bake at a constant temperature of around 2 degrees Celsius until the surface of the board turns brown. After appropriate repairs, apply insect glue or red powder (a mixture of rosin, iron oxide, and fatty acids) to the back. Once dried, it will corrode.
Nowadays, photochemical plate making can also directly apply water-soluble photoresist dry film on the surface of pre treated aluminum plate using a film sticking machine. After UV exposure, it can be developed in 1-2gbNa2CO3 aqueous solution, thoroughly cleaned and dried after development, and then corroded.
