Design points of the most popular fully sealed dou

Design points of the fully sealed double scraper cavity ink bucket system

in the fully closed system, the scraper, seal, gasket and pressing plate are all installed on a cavity support, and they are pushed to the ceramic export by mechanical means (or pneumatic or hydraulic) and the growth rate is slowing down; 3 porcelain roller, and apply a certain pressure, which can be adjusted within a certain range, and then connect the ink delivery pipe and the return pipe to the ink pump and the ink storage system respectively. The following is an explanation of the relevant design problems that must be considered in the process of system combination:

1 Wet angle, emptying angle

the wet angle of the wrinkle roll refers to the circumferential angle of the surface on which the ink is stained. For the fully enclosed cavity structure, it is closely related to the cavity opening, that is, the distance between the two scrapers and the diameter of the corrugated roller. It is recommended that the ratio of the distance between the two scrapers to the diameter of the corrugated roller is 1:3, and the wet angle obtained from this is approximately 40, while the wet angle of the single scraper structure is usually about 90. According to the requirements of the Ministry of science and technology, the parameters of the emptying angle are also very important, especially in the case of solvent-based ink-free, especially in the design, we should pay special attention to the size of the emptying angle

after the wrinkle roller transfers the ink out of the hole to the printing plate, the ink in the corresponding hole is emptied until it is stained with ink again. The circumferential angle passed between this is called the emptying angle. After the ink in the hole is transferred out, about 15% of the ink is usually retained in the hole. Due to the volatilization of the solvent, the residual ink will dry to a certain extent before it is stained again. Therefore, the emptying angle must be small in design. A good design should increase the wet angle and reduce the emptying angle as much as possible when the system structure is limited

2. Doctor blade

steel and synthetic materials are two commonly used scraper materials. Specifically, the commonly used steels are spring steel and stainless steel. Stainless steel is soft and has a short service life. It can be used under the conditions of water-based ink. According to different processing conditions, steel scraper can be divided into blue steel scraper and white steel scraper. Steel scraper is the main candidate for printing machine at present, because steel is easy to process, high processing accuracy, excellent wear resistance. The blade part of the scraper can be ground into bevel shape and sheet shape. The total thickness of the blade is 0.15 ~ 0.2mm, the thickness of the thin blade is 0.05 ~ 0.1mm, and the width of the blade is 0.6 ~ 2.5mm

with the continuous improvement of the requirements for fine prints, the requirements for the performance and service life of steel scrapers are also higher and higher. Therefore, foreign countries are still studying and improving this product, hoping to improve the performance of this product in all aspects, such as steel composition, carbon particle size, shape and location distribution. At the same time, measures are taken in the process treatment to improve some performance indicators, such as the steel knife with special coating, whose wear resistance and uniformity are significantly improved

commonly used materials for plastic scrapers include polyester, high-density polyethylene and laminate materials. This kind of scraper is about 0.5mm thick. It is used as a sealing knife in the fully sealed cavity ink bucket system, and the plastic scraper is also often used in the usual coating device and carton printing machine

3. Cavity ink bucket and bracket

cavity ink bucket is usually made of cast aluminum, which is light in weight and high in strength. When the cavity maintains the stability of chemical properties and physical forms in the process of plastic processing and use; When the scraper is installed on the body and then combined with the roller, the sealing treatment of both ends is an important problem. The sealing surfaces at both ends can be selected on both ends of the corrugated roller or on the cylindrical surface close to both ends

the former has better sealing performance after installation as long as the size of the corrugated roller is accurate and the sealing surface is properly treated, but such a structure does not allow the ink bucket to vibrate left and right. The ink scraping system with vibration function is conducive to avoiding the micro hard particles mixed in the ink, so small hard particles may damage the ceramic roller and knife

the latter structure can realize the vibration function. No holes are carved on the vibration contact surface of the corrugated roller, and only the surface is polished

the sealing condition material usually adopts rubber and foamed plastic. Its surface energy is smaller than that of ink, which is not easy to be stained with ink, and can reduce the possibility of wear on the sealing surface and seals after the ink is dried