Production and Countermeasures of trademark bendin

Production and Countermeasures of trademark bending in gravure production line

the printing color of modern printing industry has developed from monochrome to six and eight colors, and the efficiency has developed from multiple processes to one-time molding, integrating printing, cutting, concave convex, bronzing and laser. It is pointed out that the dashboard materials need to be environmentally friendly (low volatility, bio based materials); Lightweight (foaming technology with low density and thin-wall technology with high mobility); Comfort (super soft touch, multi color and multi texture, lighting technology) body. In the process of mechatronics, a series of new problems inevitably appear in production. Trademark bending not only affects the appearance of the trademark, but also directly damages the user's computer applicability, and more seriously, it will cause the user to be dissatisfied and stop using this kind of trademark. How to effectively solve and control trademark bending in production is of great significance to improve product quality and meet user needs

why does the paper bend during printing? As we know, paper is generally composed of chemical wood pulp, mechanical wood pulp and coating layer. The fibers in this kind of composition will produce different tensile deformation under certain speed tension, drying temperature and relative humidity

3. Regularly replace the servo valve

it is known from the test that under certain pressure and humidity conditions, the greater the tension, the higher the temperature, and the greater the deformation of the paper

in the one-time forming production process of gravure multi-color continuous machine, the paper is subject to 20-35dan tension, 25-40dan pressure, and the drying temperature is 60 ℃ - 100 ℃. After many times of drying, wetting, stretching and recovery, deformation occurs to varying degrees. Moreover, in the printing process, due to the application of ink, different stretching, deformation and recovery of both sides of the paper are caused, resulting in trademark bending in the finished product, In particular, poor quality paper will be severely curled

in view of the bending phenomenon in trademark production, we have taken the following measures to solve the problem of trademark bending

many manufacturers choose tensile testing machines. First, paper control

according to our years of practice and repeated tests, it is ideal to control the moisture content of the trademark at 8%, while the moisture content of the rolled paper is generally between 4% and 6%, or even about 3%, which is a certain gap with the moisture content of the finished product. In order to reduce the bending of trademarks, first, in choosing the origin and brand of paper, we should reasonably choose the brand paper with normal moisture content and less fiber affected by the outside world; Second, the paper must enter the production site for a certain period of time to balance the moisture, preferably 47 days; Third, we should scientifically control the humidification process of the production process to ensure that the paper humidity is conducive to printing and avoid bending

II. Control of ink and solvent

in the printing process, ink is applied to one side of the paper, which facilitates the deformation of both sides of the paper and causes bending

we know that the volatilization of ink, resin, trademark pattern and solvent has varying degrees of influence on trademark bending. Therefore, on the premise of ensuring that the pattern and color meet the needs of users in production, we compare the origin, applied thickness and solvent selection of the ink. The ink must choose a resin with strong solubility, good performance and not easy to paddle; According to the product requirements, the depth in plate making is generally not more than 35 m; The use of solvent must keep the balance of mixed solvent, that is, it cannot be too volatile, and it can make the product not stick at a certain temperature (generally not more than 80 ℃)

III. The coordination relationship between speed and tension

under the condition of a certain tension in the printing process, the higher the printing speed, the greater the degree of trademark bending; On the contrary, if the printing speed is constant, the greater the tension, the greater the trademark bending. In production, we should give full play to the efficiency of the equipment, so we cannot reduce the speed to solve the trademark bending problem, and we must reasonably select the tension parameters to solve the quality problem. For example, in operation, the continuous speed is 130m/min, the pre tension is 20dan, and the post tension is 34dan, which is a relatively ideal parameter. As for the actual parameters, they can be adjusted according to the paper printing effect

IV. influence of drying temperature and air volume

the higher the humidity in the drying box, it will be beneficial to the printing process, but if the temperature is too high, the trademark bending phenomenon will appear. Therefore, the layer printing is generally controlled at 55 ℃ - 70 ℃. For large-area printing, the temperature is generally controlled at 75 ℃ - 90 ℃. The inlet air pressure and exhaust air volume of the drying oven are too large, the moisture volatilization of the paper is low, and the trademark is seriously bent. Generally, the inlet air pressure of the drying oven is 8090mmh2o

v. process aids in the production process

due to the influence of the workshop environment, the higher the ambient temperature and humidity, the greater the water absorption of the paper, and the greater the possibility of trademark bending; However, if the ambient temperature and humidity are too low, the air is too dry, and the water content of the paper is reduced, the trademark will also be bent. Therefore, for the finished product trademark, it is generally required to bind with plywood, seal with plastic bags, and pack in corrugated boxes, so as to avoid long-term exposure to the air and reduce the exposure of other finished products of the trademark: zinc borate, calcium borate, sodium borate, barium metaborate, potassium titanate to the environment, so that the trademark will not deform during storage