Stainless steel signs are made of 304 stainless steel, which has good resistance to corrosion by atmospheric and fresh water media, and the decorative effect is very high grade and beautiful through corrosion, polishing and brushing.
The main raw material for the chemical corrosion process is ferric chloride, the following is the recipe for ferric chloride corrosion of stainless steel: ferric chloride, active agent, water. The recipe for ferric chloride should be kept at about 42 BoM, adding 0.8-1.2 ml of activity per litre of ferric chloride solution. The stainless steel bottom surface corroded according to the formula is flat and smooth, without black passivation film and pockmark-like.
Stainless steel signs are broadly divided into three types of signs: concave signs, convex signs and signs with a combination of convex and concave letters.
The basic requirements of corroded signage: beautiful pattern, clear lines, suitable depth, flat bottom, full colour, even drawing and consistent surface colour.
Characteristics of etched signage: corrosion resistance, good resistance to oxidation, weathering and solvent resistance.
Characteristics of the shape: strong three-dimensionality, retention of metallic colour and clear edge contours.
1.Receive engineering drawings
According to the CDR, AI or cad format engineering drawings provided by the customer, according to the size, colour, thickness, glue and other process requirements to order, to determine the drawings, we will first free samples and send samples to the customer to determine, after the customer to confirm the order to make goods.
2. Film production
After the order is placed, we need about one morning or afternoon to do the layout on the computer according to the drawing that has been determined. In the process of layout, in order to ensure that the products made will not fall off when picked up, a precise gap of 3mm will be left between the edges of the film paper and each logo to improve the yield rate as much as possible.
3. Plate processing
Work instruction: The front side of the plate is polished with a 2400 rpm distribution wheel to achieve a mirror finish, then de-waxed, degreased, cleaned and dried for use.
4. Screen-printing photopolymer
Because of the extremely fine pattern produced. It is impossible to repair after development, so it is particularly important to choose a good photopolymer. Our company chooses Gao’s (coates) photographic imaging corrosion-resistant ink, with 200 mesh screen full plate printing, the first printing polished surface, 100 ℃ baking 15 minutes, the second printing the reverse side, and then 100 ℃ baking 30 minutes, to be cooled, the surface is not sticky hands, before the exposure.
5. Exposure
Exposure time: suction-related plate machine exposure. Exposure time varies from 20-100 seconds, the thinner the line, the longer the exposure time, and vice versa is short; according to the precision requirements of the workpiece to properly adjust the exposure time, the higher the precision requirements, the exposure time should be properly shortened.
6. Development
Develop with 3-5% sodium carbonate aqueous solution, water temperature at about 50 ℃, after a few seconds of water bubble, with a soft wool brush to gently brush the water solution, and then rinse with water twice, to reach completely no residual glue so far. Wet steel plate will be etched directly, or can be dried and then etched.
7. Baking
1. The operator puts the material to be baked into the electric oven through the material rack for baking.
2. the temperature of the electric oven is set at 105±5°C and the time 15±3 minutes.
3. The electric oven is kept dry and clean.
8. Etching
There have been two ways of electrochemical etching and chemical etching in the industry. Electrochemical etching is the use of the principle of anodic dissolution, the workpiece to be etched as the anode, under the action of direct current so that the workpiece or part of the workpiece gradually dissolved in the electrolyte to achieve the purpose of etching. Also known as electrolytic etching. Unlike electrochemical etching, chemical etching is a form of etching that uses the principle of redox reaction between the metal and the etching solution. In terms of the current level of etching processes, chemical etching is more widely used and popular.
Etching can be carried out in two ways.
A, electrolysis method: current 15-50A, voltage 3-5V, electrolyte: 20% ammonium chloride, 20% potassium chloride, 20% sulphuric acid, anode with titanium plate. During the electrolysis process, remove the electrolytic copper floating on the anode in time to ensure the normal passage of current.
B, ferric chloride method: choose a more pure ferric chloride bubble into a 30 bohm solution, flow corrosion. The same layout to achieve different effects of depth, to achieve shallow requirements after the first time, clean the surface, drying. In the shallow etching has been achieved at the coating (printed) ordinary etching ink, and then the second etching.
9. Film removal
The etched copper plate will be placed in water, sodium hydroxide, potassium cyanide 30:1:0.1 solution and heated to 70°C to remove the film and clean out the light.
10.Pick up
Operation steps.
1、After receiving the finished electroplated product, the pick-up personnel should record the quantity, name and specification truthfully.
2、Wipe the product clean with relevant materials, do not scrape and rub.
3、Pay attention to whether the products are in good quality, if there are any defective products, they should be returned to the person in charge of the previous process in time, if there are serious defects, the person in charge should be notified to deal with them, not to flow into the next process.
4、The film must use the prescribed protective film, check whether the film is sticky, off the print, off the glue and other undesirable phenomena each layer of the film must be affixed flat, there must be no bubbles, wrinkles, so as not to lead to bad brush glue.
5、When picking up the goods must use the correct operation techniques to avoid bad product alignment.
6、Sensitive adhesive must be sticky clean, special sticky film sheet sticky flat, so as to avoid product deformation, fall off.
7、After all processes are completed, the product name, specification and quantity should be marked according to the product to facilitate the flow of the next process.
11. Glue printing
Operation steps.
1、Check if the machine is running normally before painting.
2. Seal the gluing screen according to the size of the whole product and check that the screen is not tightened or broken. In particular, no surface defects are allowed in the gluing area.
3、Choose a suitable mesh sieve, check that there is no damage to the mesh sieve and then position the mesh sieve.
4、Brushing technique: hold up the squeegee, let it be pulled up at an angle of 45°-50° with the screen, and keep the printing direction at both ends of the squeegee in line with the printing direction when adjusting the position to prevent the printing from going out of position.
5、Wash the screen immediately after operation to avoid excessive drying of the glue, which makes it difficult to wash off and clogs the sand holes of the screen, leading to scrap etc.!
6、Air-drying data: When the temperature is below 10℃, use a heating fan to keep the air-drying time at room temperature within 10℃～20℃, the air-drying time is 110 minutes, at room temperature, the air-drying time is 80 minutes, when the temperature is above 30℃, the air-drying time is 50 minutes. After the product is dry, immediately back the release paper, note that the release paper should not be put backwards, resulting in product scrap.
7. Clean the machine and maintain the equipment every day.
Caution Notice:
1、Place the product and press the button switch, do not put your hand into the machine, so as not to press your hand when the machine is running.
2、The product should be flat and neat, the four corners should not be cocked, so that the glue on the product is not brushed into place.
12. Turning goods
Operation steps.
1、Check whether the protective film is off the print and whether it is sticky.
2、Lay the product flat on the work surface and keep the work surface neat and clean.
3、Select the applicable standard protective film to prevent the product from turning off and going out of position; otherwise it will cause the work to stop or prolong the operation time.
4、The glue on the surface of the product must be clean, and any phi, pockmark, dirt, etc. must be removed.
5、Pay attention to the front and back side of the release paper, do not put the reverse, otherwise the product is scrapped.
6、After turning the product, mark the name, specification and quantity so that it can flow into the next process.
13. Scribing
Operation steps
1、Operate the ruler and knife with the correct technique.
2、Press the straightedge against the product to avoid scratching the product or hurting the hand.
3、Cut the edges neatly according to the size required by the customer.
4、Keep the knife well and slide it into the knife slot after using it to avoid hurting others.
5、Need to back pull the hand bit products, do not must be aligned with the sample, can not have deviation.
14.QC
Work steps.
1、Employees in the QC inspection process of displacement, leakage of letters, pockmarks, batch fronts, etc., are considered bad products for marking.
15. Packaging
Operation steps: 1.
1、Package according to customer requirements.
2. Pay attention to the name, specification and quantity of packaging, do not pack or mix other products.
3. No dirty or impurities in the bag when packing.
4、The data of each package must be unified and should be clearly marked, the end number is packed separately.
5、No QC inspection products can be packed, and only after QC inspection can be packed.
6、Package labels must not be altered indiscriminately, with clear and recognisable handwriting and ROHS labels.
7、Fill in the report when each product is shipped for tracking.
