China's industry standard CY/T7.7-91 has the following requirements for the quality of coated products:
1 According to the different nature of paper and ink, film temperature, pressure and adhesive should be appropriate.
2 The film is firmly bonded. The surface is clean, smooth, unclear, and smooth. No wrinkle, no blistering and no chalk marks.
3 After the film is divided, the size is accurate, the edge is smooth, no film, no obvious curl. Break no more than 10mm.
4 The degree of dryness after coating is appropriate, and there is no phenomenon of sticking to the surface film or paper.
5 After placing the film for 6 to 20 hours, there is no change in product quality.
6. What are the types of laminators?
Laminating machines can be divided into two categories, ie, the coating type laminating machine and the precoating type laminating machine. The coating type laminating machine includes three parts: sizing, drying, and hot pressing. The application scope thereof is wide, and the processing performance is stable and reliable. It is a film coating apparatus widely used in China at present. Precoat laminating machine, no glue and dry part, small size, low cost, flexible and convenient operation, not only for the processing of large quantities of printed films, but also for the coating of small batches and scattered prints such as automated desktop office systems Processing is very promising.
7. What is the composition of the laminator?
Laminating machine is divided into glue, bake, hot pressing three parts.
1 gluing part. The gluing part is equipped with an adjusting device to adjust the amount of gluing to meet the requirements of different printing parts. The rubber roller or the steel roller is used for the gluing roller.
2 bake section. The drying tunnel is generally 2 to 3 meters long. The baking tunnel of the laminating machine is equipped with infrared lamps and electric fans. There are high-power electric heat pipes and exhaust fans on the upper part of the tunnel of the automatic laminating machine, and the temperature can be adjusted to dry the adhesive and remove the exhaust gas.
3 hot pressing part. This part is the key to the film, which is directly related to the adhesive fastness of the film products. The principle of hot-pressing is that the adhesive can quickly infiltrate and penetrate into the surface of the print in the molten state, so as to obtain a firm bond interface layer. The hot press part consists of a set of rollers. One of the hollow metal drums, equipped with electric heating tube, the temperature can be controlled. This set of roller pressure can be adjusted.
8. Why does the paper wrinkle when laminating?
Films for coating are generally coated paper, offset paper, whiteboard paper, and the like. The wrinkling of the paper occurs when the film is covered. Generally, there are the following situations:
1 The temperature and humidity of the workshop are not properly controlled. Relative humidity is too high, the paper absorbs moisture from the "foliage edge", causing wrinkling of the paper during the coating process. The temperature and humidity of the workshop must be strictly controlled.
2 When the ambient humidity is too high or the film temperature is too high, the paper will â€œtightenâ€ and cause the paper to wrinkle. Press plates can be used to flatten the number of paper knocks and kneading before coating, and reduce the environment and film temperature.
3 Roller pressure is not uniform, causing the paper to wrinkle during the coating process. In this case, correct the roller pressure before starting the operation.
4 The rubber roller itself is uneven, causing the paper in the film to wrinkle. Replace the new rubber roller or grind the old roller and use it again.
5 The dirt on the rubber roller causes the paper to wrinkle when the film is covered. The rubber roller should be cleaned in time. The rubber roller must always be kept clean.
6 If the pulling force is too large, the film is rolled up and torn, causing the paper to wrinkle when it is covered. The tension should be properly adjusted.
7 The paper is skewed, causing the paper to wrinkle when it is covered. The operation must be serious, so that the paper delivery service.
9. Why does film wrinkling occur when laminating?
Film wrinkling occurs when the film is covered by the following conditions:
1 Adhesives and adhesive primers that are applied too thick can cause film wrinkling. Due to the different properties of the paper, the thickness of the adhesive and its primer coating should be different when coating the film. General offset paper fiber loose, poor smoothness, coating coating should be thicker than the coated paper. However, no matter what the paper, it should not be coated too thick, otherwise it will wrinkle the film.
2 The tension is not enough to make the film trend uneven, which can cause the film to wrinkle. The pressure should be adjusted to make it normal.
3 The surface of the coating layer on the film is not dry, which can also cause the film to wrinkle. Improve the drying temperature to solve.
4 When the temperature is too high, the film will wrinkle when fed. In the lamination process, the purpose of warming is to soften the film and bond the paper to the plastic film. Fan cooling, turning off the heating wire, or other cooling measures should be taken to restore the temperature to normal as soon as possible.
10. What are the common faults and remedies for coating?
1. Improper selection of adhesive, improper setting of glue quantity, and incorrect ratio measurement. Reselect the adhesive brand and coating amount and prepare it accurately.
2. The diluent contains alcohol and water that consume NCO groups so that the hydroxyl groups of the main agent do not react. High purity (99.5%) ethyl acetate was used.
3. The print surface has dusting. Wipe gently with a dry cloth.
4. The print ink layer is too thick to increase the amount of adhesive coating and increase the pressure.
5. The printed ink is dry or not completely dry. First hot press and then gluing; choose a high solid content of the adhesive; increase the adhesive coating thickness; increase the drying temperature and so on.
6. The adhesive is absorbed by the printing ink and paper, so that the amount of coating is insufficient to reset the formula and the amount of coating.
7. The surface treatment of the plastic film is insufficient or exceeds the pot life, rendering the treated surface ineffective. Replace plastic film.
8. The pressure is small, the speed is faster and the temperature is lower. Increase the film temperature and pressure, and appropriately reduce the speed.
1. The printing ink layer is not dry. Hot press a flat and then glue; postpone the date of the film to make it completely dry.
2. The printing ink layer is too thick. Increase the amount of adhesive coating, increase the pressure and composite temperature.
3. The drying temperature is too high, and the adhesive surface crust lowers the drying temperature.
4. The surface temperature of the composite roller is too high. Lower the composite roll temperature.
5. The film has wrinkles or looseness, and the film is uneven or curled. Replace qualified film and adjust tension.
6. The film surface is covered with dust and impurities. Remove dust and impurities.
7. The adhesive is unevenly coated and used in small amounts. Increase the amount of coating and uniformity.
8. High binder concentration, high viscosity, uneven coating. Use thinner to reduce the binder concentration.
1. Part of the adhesive in the glue tank is cured. Replace or add adhesives.
2. The pressure is small. Increase the lamination pressure 3. The roller swells and deforms. Replace the rubber roller.
4. Plastic film thickness tolerance. Replace the film and use a film with a small thickness tolerance.
5. The film is loose. Adjust the drafting force.
1. The film transfer roller is not balanced. Adjust the transfer roller.
2. The film is elastically inconsistent or wavy at both ends. Replace qualified film.
3. The glue layer is too thick and the solvent evaporation is not thorough, which affects the viscosity. It is squeezed by the pressure roller and slips between the paper (print) and the film. Adjust the amount of glue to increase the temperature of the drying tunnel.
4. The electric roller and the rubber roller are uneven at both ends, and the pressure is inconsistent and the line speed is not equal. Adjust the two rollers.
1. The paper (print) is too thin. Avoid laminating thin paper.
Print according to customer artwork. Food grade paper and pp film inside with Tin-Tie on top, with or without window.
Welcome to your detail inquiry in clude below information , so that we can give you the correct and best quotation in first time.
Size: Width x Gusset x High cm
Material: Brown kraft / White kraft / Art Paper and so on
Quality of material:: i.e.60gsm, 80gsm , 100gsm, 110gsm , 125gsm,140gsm, 150gsm and so on
Handle: Peper Twisted Handle / Paper Flat Handle / Rope Handle / Die cut handle and so on.
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If one color 100% printing, please advise PANTONE CODE.
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