Covered iron electromagnetic heating roll
作者：管理员 时间：2020-06-04 08:55 来源：未知
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How to Use Covered Iron Equipment
There are two main types of coating equipment, namely coating machine and precoating machine. That is, the coating machine application range is wide, the processing performance is stable and reliable, is a widely used coating equipment. Precoated laminator, the top glue and dry part, small size, low cost, flexible and convenient operation, not only for the processing of large quantities of printed materials, but also for small quantities such as automated desktop office systems, scattered print laminates processing. At present, the advanced precoated coating machine with computer control has been produced in China.
The precoated laminator has broad application prospects and popular value, and is the development direction of the laminator. However, due to pre-coated plastic coating and other conditions, the domestic use is still very few.
That is, coated film equipment
That is, the coated coating machine is a special equipment that applies the plastic film of the reel to the adhesive and is dried, and the pressurized composite part is combined with the printed matter. That is, the Xu film cover machine has two kinds of full automata and semi-automaton. All types of models are unique in terms of structure and coating technology, but their basic structure and working principles are consistent. It is mainly composed of five parts: roll, adhesive coating, drying, compounding, and winding, as well as mechanical transmission, tension automatic control, and automatic correction of winding.
1. Volume part. Loading of plastic film requires the film to maintain a constant tension. Tension is too large, easy to produce longitudinal wrinkles, and vice versa, it is not conducive to the adhesive coating and the composition of the same print. In order to maintain the appropriate tension, the winding part is generally equipped with tension control devices, common mechanical friction disc clutch, alternating force short motor, magnetic powder clutch and so on.
2. Coating part. After the film is rolled, the coating roller enters the upper part of the adhesive. The coating forms are: roller reverse type, concave type, no scratch knife direct coating and scratch knife direct coating and so on.
(1) Roller reverse coating. It is an indirect coating and is the most used type of each model. The rubber roller brings out the glue from the storage tank, scraping the rubber roll and scraping the rubber plate can scrape the excess glue back to the storage tank. The film reflux roller presses the film to the surface of the coated roller after the uniform adhesive, and maintains a certain contact area. Under the pressure and adhesion force, the adhesive is continuously applied to the film surface. The amount of coating can be changed by adjusting the distance between the scraping roller and the coating roller, the scraping roller and the rubber plate.
(2) concave coating. It consists of a metal coating roller and a group of thin film partition rolls with a mesh pattern on the surface. The coated roller is directly immersed in the glue, and the glue is brought out from the storage tank with the rotation of the roller. The excess glue on the surface of the roller is scraped by the scraper. Under the action of the film roller, the glue in the groove of the roll is driven by the film to be applied to the film by directional motion and applied evenly to the film surface. The amount of coating can be controlled by adjusting the grid pattern on the surface of the coating roller, the characteristic value of the adhesive, and the pressure value of the film roller.
The advantage of concave coating is that it can control the amount of coating more accurately and the coating is uniform; However, the mesh roller is difficult to process and easy to damage. It needs to be cleaned often. In addition, the adhesive requirement is higher when coated.
(3) No scraper roller extrusion coating. The coated roll is directly immersed in the adhesive, and when coated, the coated roll brings out the adhesive through the uniform adhesive roll, and the pressure between the film roll and the coated roller completes the coating.
When extrusion, pressure, adhesive performance index and coating speed determine the thickness of the layer. The amount of coating is achieved by adjusting the squeeze pressure between the coating roller and the even roller, the coating roller and the film roller. Therefore, the surface accuracy, cylindrical degree and radial tolerance of each roller have high requirements.
(4) There is a scraper directly coated. The coating roll is directly immersed in the glue and continuously rotates. The glue is driven from the groove. After removing the excess glue by the scraper, the coating is completed in contact with the surface of the film.
There is a scraper directly coated adhesive force, in the design of the scraper must scratch the surface of the scraper coated rubber roller glue, that is, required scraper blade straightness, surface accuracy of coating rubber roller is quite high.
A rubber scraper is generally made of a stainless steel belt with high smoothness, light and elasticity.
3. Dry part. The adhesive coating applied to the surface of the plastic film contains a lot of solvents and has a certain degree of fluidity. Before Compounding, it must be treated by drying. The dry part is mostly tunnel-type, and the length of different drying ducts is between 1.5 and 5.5 M. According to the solvent volatilization mechanism, the drying channel is designed into three areas:
(1) Evaporation area. As far as possible, turbulent winds should be formed on the surface of the film to facilitate solvent volatilisation.
(2) Mature area. According to the properties of thin films and adhesives, an automatic temperature control area is set, which is generally controlled at 50 to 80 °C. The heating method is infrared heating, direct heating of electric heat pipes, etc.. The automatic balance temperature control is achieved by the thermal sensitive elements installed in the mature area.
(3) Solvent exclusion area. In order to eliminate the solvent emitted in the drying of the adhesive in a timely manner and reduce the vapor pressure in the drying channel, the area is designed with a ventilation device, usually a fan or a fan.
