Tips for using the hottest film covering equipment

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Tips for using film covering equipment

film covering equipment includes instant coating film covering machine and pre coating film covering machine. Namely, the coating type laminating machine has wide application range and stable and reliable processing performance. It is a widely used laminating equipment. Precoating laminating machine, without gluing and drying parts, is small in size, low in cost, flexible and convenient in operation. It is not only suitable for laminating processing of large quantities of printed matter, but also suitable for laminating processing of small batches and scattered printed matter such as automated desktop office system. At present, China has produced an advanced precoating laminating machine controlled by computer

precoating laminating machine has broad application prospects and popularization value, and is the development direction of laminating machine. However, due to the limitations of some conditions, such as precoating plastic film, it is still rarely used in China

instant coating and laminating equipment

instant coating and laminating machine is a special equipment that applies the drum plastic film with adhesive, dries it, and combines the pressurized composite part with the printed matter. That is, Xu type laminating machine has two types: full automata and semi automata. Each type of machine has its own unique features in structure and film covering process, but its basic structure and working principle are consistent. It is mainly composed of five parts: unwinding, gluing and coating, drying, compounding and rewinding, as well as mechanical transmission, automatic tension control, automatic unwinding deviation adjustment and other auxiliary devices

1. unwinding part. The unwinding operation of plastic film requires that the film always maintain a constant tension. If the tension is too large, it is easy to produce longitudinal wrinkles, on the contrary, it is easy to produce transverse wrinkles, which is not conducive to the coating of adhesives and the compounding with printed matter. In order to maintain proper tension, the unwinding part is generally equipped with a tension shroud belt control device, common ones are mechanical friction disc clutch, ac force short motor, magnetic particle clutch, etc

2. Gluing and coating part. After unwinding, the film enters the gluing part through the coating roller. Coating forms include: roller reverse type, concave type, direct gluing without scraper and direct gluing with scraper, etc

(1) roller reverse gluing. It belongs to indirect gluing, which is the most widely used in all models. The structure principle is shown in Figure 11-3. The rubber supply roller takes out the rubber liquid from the rubber storage tank, and the rubber scraping roller and scraper can scrape the excess rubber liquid back to the rubber storage tank. The film back pressing roller presses the film to be coated to the surface of the glue coating roller after homogenization, and maintains a certain contact area. Under the action of pressure and adhesion, the glue liquid is continuously coated on the film surface. The amount of glue can be changed by adjusting the distance between the squeegee roll and the glue applicator roll, and between the squeegee roll and the sharp rubber plate

(2) concave gluing. It is composed of a metal coating roller with grooves on the surface and a group of film partition rollers, as shown in Figure 11-4. The glue coating roller is directly immersed in the glue, and the glue is brought out from the glue storage tank with the rotation of the roller, and the excess glue on the surface of the roller is scraped off by a scraper. Under the action of the film pressing roller, the glue liquid in the groove of the roller is driven by the film to be coated in a directional motion and evenly deposited on the film surface. The coating amount can be controlled by adjusting the grid pattern on the surface of the coating roller shaft, the characteristic value of the adhesive, the pressure value of the film pressing roller, etc

the advantage of concave gluing is that it can accurately control the gluing amount and apply evenly; However, the corrugated roller is difficult to process and easy to be damaged, so it needs to be cleaned frequently. In addition, the adhesive requirements are high when coating

(3) extrusion gluing without scraper roll. The glue roller is directly immersed in the glue liquid. During coating, the glue liquid brought out by the glue roller is homogenized by the glue roller, and then the glue coating is completed by the extrusion force between the film pressing roller and the glue roller

during extrusion, the thickness of adhesive layer is determined by pressure, adhesive performance index and coating speed. The gluing amount is achieved by adjusting the extrusion force between the gluing roller and the homogenizing roller, and between the gluing roller and the film pressing roller. Therefore, there are high requirements for the surface accuracy, cylindricity and radial runout tolerance of each roll

(4) glue directly with scraper. The glue roller is directly immersed in the glue liquid and rotates continuously to drive the glue liquid from the glue groove. After the excess glue liquid is removed by the scraper, it contacts the surface of the film to complete the glue coating

there is a force of direct gluing by the scraper. In design, the scraper is required to scrape the glue on the surface of the gluing roller, that is, the straightness of the blade of the scraper and the surface accuracy of the gluing roller are required to be quite high. The rubber scraper is generally made of stainless steel belt with high flatness, smoothness and elasticity

3. Dry part. The adhesive coating applied on the surface of plastic film contains a large amount of solvent and has certain fluidity. It must be dried before compounding. The drying part is mostly tunnel type, and the length of the drying channel is between 1.5 ~ 5.5m according to different models. According to the solvent volatilization mechanism, the drying channel is designed into three areas:

(1) evaporation area. In this area, turbulent wind should be formed on the film surface as far as possible to facilitate solvent volatilization

(2) maturing area. The automatic temperature control area is set according to the properties of film and adhesive, which is generally controlled at 50 ~ 80 ℃. The heating methods include infrared heating, electric heating tube direct radiation heating, etc. the automatic balance temperature control is realized by the thermal sensor installed in the curing area

(3) solvent exclusion zone. In order to remove the solvent volatilized during the drying of adhesive in time and reduce the vapor pressure in the drying channel, the area is designed with exhaust and air extraction devices, usually fans or induced draft fans

4. Composite part. It is mainly composed of chrome plated hot press roll, rubber pressure roll and pressure adjustment machinery

(1) hot press roll. The hot pressing roller is a hollow roller with an electric heating device inside. The roller temperature is controlled by sensors and instruments on the console. The surface state and thermal power density of the hot press roll have a great influence on the quality of the coated products. The general coating process requires that the hot pressing temperature is 60 ~ 80 ℃, and the area heat flow is 2.5 ~ 4.5w/cm2

(2) rubber pressure roller. Press the coated product to the hot pressing roller with a certain pressure to solidify and stick it firmly. The contact pressure during compounding is closely related to the bonding strength and appearance quality, which is generally 15.0 ~ 25.0mpa. The rubber pressure roller works under high temperature for a long time, and keeps the roller surface flat, smooth, small transverse deformation, and good tear resistance and stripping performance. Therefore, silicone rubber with good tear resistance is often used

(3) pressure adjustment mechanism. It is used to adjust the pressure between the hot press roll and the rubber pressure roll. The pressure adjustment mechanism can adopt simple eccentric mechanism, eccentric cam mechanism, screw rod, nut mechanism, etc; However, in order to simplify mechanical transmission parts and improve pressure control accuracy, hydraulic (pneumatic) pressure adjustment mechanisms are mostly used at present

5. Print input part. There are two ways to transport printed matter: manual and automatic input. The full-automatic input mode is divided into two types: pneumatic and friction. Pneumatic type is to install a row of suction nozzles at the front or rear of the printed matter, and rely on the "suction", "release" and movement of the suction nozzles to separate and deliver the printed matter. Friction type input mainly relies on the reciprocating movement or fixed rotation of the friction head to generate friction with the printed matter, which separates the printed matter from the paper storage table and transports it forward; The friction wheel rotates intermittently in one direction, separating a printed matter every time it rotates

6. Winding part. Most laminating machines adopt automatic winding mechanism, and the winding shaft can automatically roll the composite products. In order to ensure that the winding tightness is consistent, the speed of the winding shaft and the composite line must be synchronized, and the tension must be kept constant during winding. With the increase of the winding diameter, its linear speed must continue to be synchronized with the impact of the new technology represented by the new generation of information technology on traditional industries. Generally, machines use friction damping to change the angular speed of the winding shaft to meet the above requirements. In order to improve work efficiency, some laminating machines are also equipped with quick unwinding and finished product slitting devices in the winding part

precoating and laminating equipment

precoating and laminating machine around 2025 is a special equipment that combines printed matter with precoated plastic. Compared with the instant coating laminating machine, its biggest feature is that there is no glue coating and drying part, so this kind of laminating machine has compact structure, small volume, low cost, simple operation and good product quality stability

the precoating laminating machine is composed of four main parts: uncoiling of precoated plastic film, automatic input of printed matter, hot pressing zone compounding, and automatic winding, as well as auxiliary devices such as mechanical transmission, leveling of precoated plastic film, vertical and horizontal slitting, and computer control system

1. Print input part. The automatic conveying mechanism can ensure that the printed matter does not overlap during transmission and enters the composite part equidistant. Generally, pneumatic or friction methods are used to realize control, and the conveying is accurate and accurate. When the printed matter with small composite format is used, the above requirements can also be met

2. Composite part. It includes composite roller group and calendering roller group (Fig. 11-7). The composite roller group is composed of heating pressure roller and silica gel pressure roller; The thermal pressure roll is a hollow roll with a heating device inside, and its surface is forged with hard chromium, polished and finely ground; The temperature of the hot press roll is tracked and sampled by the sensor and corrected by the computer at any time; The adjustment of compound pressure adopts eccentric cam mechanism, and the pressure can be adjusted steplessly. The principle diagram is basically the same as that of calendering roller group and compound roller group, that is, it is composed of chrome plated pressure roller and silicone pressure roller, but there is no heating device. The main function of the calendering roller group is: after the precoated plastic film is combined with the printed matter by the composite roller group, the surface brightness is not high, and then after the secondary extrusion of the calendering roller group, the surface brightness and bonding strength are greatly improved

3. transmission system. The transmission system is driven by a computer-controlled high-power stepping motor. After the first gear is decelerated, it drives the movement of the paper feeding mechanism and the rotation of the composite part and the silicone pressure roller of the calendering mechanism through the three-stage chain drive. The pressure roller group maintains the appropriate working pressure under the pressure of stepless adjustment

4. computer control system. The computer control system adopts microprocessor, and the hardware configuration is composed of host board, digital key board, optical isolation board, power supply board, stepping motor power drive board, etc

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