Abstract: how to make stainless steel signs? The first thing to make stainless steel signs is to determine the materials.
The effects of different stainless steel materials are also different. Among them, 304 stainless steel has the best effect and quality.
It has good resistance to atmospheric and fresh water medium corrosion, and the decorative effect is very high-grade and beautiful after corrosion, polishing and wire drawing.
In addition, technology and packaging. Next, Xiaobian will introduce the manufacturing process of stainless steel corrosion signs.
Stainless steel signs are advertising signs made of stainless steel plate by means of corrosion, die casting or printing. Most of the stainless steel signs used at this stage are made by corrosion technology.
Such stainless steel signs have the characteristics of beautiful pattern, clear lines, appropriate depth, flat bottom, full color, uniform wire drawing, consistent surface color and so on.
Stainless steel signs are generally divided into concave signs, convex signs and convex concave combined signs.
Basic requirements for corrosion signs: beautiful pattern, clear lines, appropriate depth, flat bottom, full color, uniform drawing and consistent surface color.
Features of corrosion signs: corrosion resistance, good oxidation resistance, strong weather resistance and solvent resistance;
Shape features: strong three-dimensional sense, retaining metal color and obvious edge contour.
Stainless steel is a special material. Its manufacturing process is much more difficult than copper plate and aluminum plate, but it has good resistance to atmospheric and fresh water medium corrosion, and the decorative effect obtained after corrosion, polishing and wire drawing is very beautiful.
Therefore, the fastest corrosion method for stainless steel is electrochemical corrosion, also known as electrolytic corrosion.
As the electrochemical corrosion will make the ink fall off in the corrosion of the sign, the sign is not suitable for electrochemical corrosion, especially fine patterns.
Chemical corrosion is selected here. The main raw material for chemical corrosion here is ferric chloride. The following is the formula for ferric chloride to corrode stainless steel:
Ferric chloride, active agent, water. The Baume degree of ferric chloride in the formula should be maintained at about 42, and 0.8-1.2 ml of active agent should be added per liter of ferric chloride solution. The stainless steel bottom corroded by the formula is flat and smooth without black passive film and pitting.
1). Effect of concentration. Chemical corrosion is also called micro cell corrosion. The more positive the redox potential is, the faster the corrosion rate is.
With the increase of concentration, the redox potential becomes positive and the corrosion rate increases. Industrial grade ferric chloride has low purity and negative redox potential.
The redox potential can meet the requirements of corrosion of stainless steel only when the Baume degree is more than 42.
2). Effect of pH value in solution on corrosion rate. Low pH value, strong corrosion of stainless steel;
If the pH value is too high, ferric chloride is hydrolyzed into ferric hydroxide precipitation and loses its corrosion effect.
The pH value of corrosive solution should be adjusted when it is used to a certain extent in production.
3). Effect of corrosive solution temperature. The higher the temperature of the corrosive solution, the faster the corrosion rate. However, considering the bearing capacity of corrosion-resistant ink, the temperature should be controlled between 30-40 ℃.
1). Receiving engineering drawings
According to the engineering drawings in CDR, AI or CAD format provided by the customer, it shall be customized according to the process requirements such as size, color, thickness and glue.
After the drawings are determined, the manufacturer will first make samples and send samples to the customer for confirmation free, and place orders for goods after confirmation by the customer;
2). Out of film
After the order is placed, the manufacturer will need about one morning or afternoon to typeset on the computer according to the determined drawings.
In the process of typesetting, in order to ensure that the products will not fall off when they are taken, a gap accurate to 3mm will be reserved on the edges of the film and between each logo to improve the yield as much as possible.
3). Plate treatment
Work instruction: polish the front of the plate with 2400 RPM / distribution wheel to achieve the mirror effect, and then remove wax, remove oil, clean and dry for use.
4). Screen photoimaging photoresist
Because the pattern is very thin. It cannot be repaired after development, so it is particularly important to choose a good photosensitive adhesive. Coates photo imaging corrosion-resistant ink is selected and printed in full screen with 200 mesh screen.
The polished surface is printed for the first time, dried at 100 ℃ for 15 minutes, the reverse side is printed for the second time, and then dried at 100 ℃ for 30 minutes. Exposure can be carried out only after it is cooled and the surface is not sticky.
Exposure time: inspiratory phase plate machine exposure. The exposure time varies from 20 to 100 seconds. The thinner the line, the longer the exposure time, and vice versa; Adjust the exposure time according to the accuracy requirements of the workpiece. The higher the accuracy requirements, the shorter the exposure time.
Develop with 3-5% sodium carbonate aqueous solution, the water temperature is about 50 ℃, after blistering for a few seconds, gently brush off the aqueous solution with a soft wool brush, and then rinse with clean water twice until there is no residual glue. The wet steel plate can be directly etched, or it can be etched after drying.
(1) The operator puts the materials 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 ℃ for 15 ± 3 minutes.
(3) Keep the electric oven dry and clean.
Electrochemical etching and chemical etching have always existed in the industry. Electrochemical etching uses the principle of anodic dissolution, takes the workpiece to be etched as the anode, and gradually dissolves the workpiece or part of the workpiece in the electrolyte under the action of DC, so as to achieve the purpose of etching.
Also known as electrolytic etching. Different from electrochemical etching, chemical etching is an etching method based on the principle of redox reaction between metal and etching solution.
In terms of the current etching process level, chemical etching is more widely used and popularized.
(1) Electrolysis method: current 15-50a, voltage 3-5v, electrolyte: 20% ammonium chloride, 20% potassium chloride, 20% sulfuric acid, titanium plate for anode. In the electrolysis process, remove the anode in time, float up and leave electrolytic copper to ensure the normal passage of current.
(2) Ferric chloride method: use pure ferric chloride to form a 30 baumannian solution for flow corrosion. In order to achieve different effects of depth on the same layout, clean the surface and dry it after reaching the shallowness requirements for the first time.
Apply (print) ordinary corrosion-resistant ink on the place that has reached the shallowness etching, and then conduct secondary etching.
Place the etched copper plate in water, sodium hydroxide and potassium cyanide 30 ∶ 1 ∶ 0.1 solution, heat it to 70 ℃, remove the film and clean it.
(1) After receiving the finished electroplating products, the pickup personnel shall truthfully record the quantity, product name and specification.
(2) Wipe the product gently with relevant materials, and do not scratch or scratch the flower.
(3) Pay attention to whether the product is in good quality. If there is any defective product, it shall be returned to the person in charge of the previous process in time. If there is any serious defect, it shall be notified to the relevant person in charge for treatment, and it shall not flow into the next process.
(4) The specified protective film must be used on the film. Check whether the film has bad phenomena such as viscosity, printing loss and degumming. Each film must be pasted flat without bubbles and wrinkles, so as to avoid bad glue brushing.
(5) Correct operation methods must be used when picking up goods to avoid bad product positioning.
(6) The photosensitive adhesive must be glued clean and the special film must be glued flat to avoid product deformation and falling off.
(7) After all processes are completed, the product shall be identified according to the product name, specification and quantity, so as to facilitate the operation of the next process.
(1) Before applying glue, confirm whether the machine operates normally.
(2) Seal the rubber brushing screen according to the size of the whole product, and check whether the screen has tightness and holes. In particular, no surface defects are allowed within the scope of rubber brushing.
(3) Select a suitable screen, check whether the screen is damaged, and then position the screen.
(4) Glue brushing method: hold up the scraper and pull it up at an angle of 45 ° – 50 ° with the screen at a uniform speed.
The printing direction at both ends of the scraper during driving shall be consistent with the printing direction during position adjustment to prevent displacement during printing.
(5) Clean the screen immediately after operation to avoid excessive air drying of glue, difficult elution, blocking the sand hole of the screen, resulting in scrapping, etc!
(6) Air drying data: when the air temperature is lower than 10 ℃, it needs a heating fan to keep it within 10 ℃ ~ 20 ℃ at room temperature. The air drying time is 110 minutes.
At room temperature, the air drying time is 80 minutes. When the air temperature is above 30 ℃, the air drying time is 50 minutes.
After the product is dry, it should immediately deviate from the release paper. Note that the release paper cannot be placed upside down, resulting in the scrapping of the product.
(7) Clean the machine and maintain the equipment every day.
matters needing attention:
(1) When placing the product and pressing the button switch, do not put your hand into the machine to avoid pressing your hand when the machine is running.
(2) The product shall be flat and tidy, and the four corners shall not be tilted, so the glue on the product cannot be brushed in place.
(1) Check whether the protective film falls off and is sticky.
(2) The product shall be placed on the worktable to keep the worktable clean and tidy.
(3) Select the applicable standard protective film to prevent the product from turning off and moving; otherwise, the subsequent work will be stopped or the operation time will be prolonged.
(4) The glue on the surface of the product must be clean, and the sharp edges, pits, dirt, etc. shall be removed.
(5) Pay attention to the front and back sides of release paper. Do not put it upside down, otherwise the product will be scrapped.
(6) After turning over the product, mark the product name, specification and quantity for the next process.
(1) Operate the ruler and intermediate knife with correct methods.
(2) Press the product with a ruler to prevent the blade from scratching the product or hurting hands.
(3) The edge shall be cut neatly according to the size required by the customer.
(4) Take good care of the knife and slide it into the knife slot after use to avoid hurting others.
(5) For products requiring back handle position, it is not necessary to align with the sample, and there shall be no deviation.
In case of displacement, missing letters, pockmarks, batch edges, etc. during QC inspection, employees shall be regarded as defective products and marked.
(1) Package according to customer requirements.
(2) Pay attention to the product name, specification and quantity in packaging, and do not package or mix other products.
(3) During packaging, there shall be no dirt, impurities and other items in the packaging bag.
(4) Each package of product data must be unified and clearly marked, and the mantissa shall be packaged separately.
(5) Products that have not been inspected by QC cannot be packaged, and can only be packaged after passing QC inspection.
(6) The packaging label shall not be altered randomly, the handwriting shall be clear and recognizable, and the RoHS label shall be pasted.
(7) When each product is shipped, fill in the report for tracking.