Multi-gravity and production safety in post-press processing

In the post-printing process, the power is converted into heat, wind, pressure, impact force, shear force, and photosynthetic force to act together on the print carrier, and then the carrier substrate self stress, mechanical equipment various functional stress , to stimulate the auxiliary material molecular gravity and other multi-gravity synthesis in the processing interface. These multi-gravity, essentially full of variables. Due to changes in external conditions, the carrier substrate is subject to relative stress, and changes in morphology, physics, and chemical properties occur.

Various forces are applied to the printed matter carrier, and the comprehensive factors such as the degree of object reaction and the performance characteristics of the auxiliary materials due to the technical condition of the equipment dynamically change from direction to magnitude.

After the interaction of various types of auxiliary materials, as well as the physical structure and chemical properties caused by the external reaction force and the complex reaction of the curing process, its molecular movement has its own characteristics. It produces different and unequal molecular motions.

When the above multiple internal and external forces interact (eg, merge, hedging, extension, twisting, etc.) in the process of action and the receptor, new directions of different magnitudes and new values ​​of magnitude are generated. The multiple forms of force of the new students continue to change, interweave and interfere with each other, and they repeatedly function. In a certain sense, the final effect of finishing or cementing the surface of the printed matter is determined by the knowledge, application, and regulation of the different stages and forms of multi-gravity in the post-press processing.

Printing products will change form in post-processing

In the early stage of this process, due to changes in the environment of the printed materials, physical and chemical changes in the properties and morphology of the carrier substrate occur. From the original unbalanced state of compression, it was just released. Through the automatic repair after the structural destruction, the fibrous tissue self-propelledly communicates and gradually returns to a more uniform semi-free stretch state. The carrier will actively and quickly activate moisture absorption or dehumidification to maintain a wet balance with the outside environment.

With this kind of movement, the carrier substrate itself is newly polymerized into a weak internal strength, a light vertical weight, a positive direction smaller than the reverse direction, and different internal stresses.

In the middle period of this process, the printed-goods carrier has passively generated reaction force due to external forces such as mechanical or artificial forces. Forces, reaction forces, and endogenous stresses interact with each other to produce a resultant force that acts as a critical edge for the action surface, and gradually diverges into a pressure-shear force-elastic force.

At the later stage of the process, the printed material carrier reappeared the multi-gravity of the previous period with a new reworked form and new form. However, there are new changes in terms of direction and size.

Changes in the carrier substrate are carried out at all times, depending on the material and weather conditions. When the multi-gravity interaction fails to reach equilibrium, it is often the carrier's endogenous stress that affects various forces and destroys the processing effect. For example, the wrinkle of the film products, the appearance of regular stripe, spotted or uneven filming on the varnished products, the incomplete graphics of the hot stamping or embossed products, the poor glossiness or discoloration, the book block of the bookbinding process or Problems such as missing or overlapping covers affect product quality and safety.

When the carrier substrate is subject to changes in climatic conditions, the paper as the main carrier has "desensitization", that is, its endogenous stress will gradually decrease due to external stimulus for a certain period of time, and tends to be stable. At this time, proper temperature and humidity control techniques can be used to control its endogenous stress to adapt to its own laws of change and to meet the external forces required for processing. Minimize the negative effects of internal and external conditions and create a safe and reliable processing environment.

Postpress machinery design should adopt circular pressure round structure

The manufacturing process of various types of machinery and equipment includes both the accuracy errors allowed by standards at all levels and the quality defects inherent in the selection of materials. It is also unavoidable that rough deviations in the measurement, assembly and assembly stages are involved. There are such problems as excessive noise, poor running-in, excessive radial runout and axial turbulence, movement of the work interface, fluctuations in pressure fluctuations, uneven operation speeds, etc., in particular, the use of pneumatic and hydraulic auxiliary devices to supply power in different categories. Device, energy delivery system, corresponding working interface, control of the allowable quality of the technical state, reaction speed, control accuracy and other more complex factors. Causes mechanical misalignment to cause various deviations in the working interface.

To solve various problems in the production process. Engineers and technicians usually increase the work pressure (whether mechanical, pneumatic, hydraulic, electromagnetic) to deal with. the result is. Due to the certain compressibility of the carrier substrate, the original symptoms are sometimes relieved temporarily. The damping load that can be imposed on the device increases. Not only increases the burden on the power system and energy consumption, but also makes the transmission system in a high temperature state for a long time, exacerbating abnormal wear and material early fatigue. Causes twisting of the transmission rod, tensile fracture of the conveyor belt, bearing damage, and quality accidents such as bushing sintering.

Improper pressure acting on the working interface will cause deformation of the indentation strip of the die-cutting system, displacement of the indentation plate, cracking of the inside of the substrate of the product, and deflection deformation of the metal shafts of various types of rollers. Correction, serious failure to scrap, but also to make its axis. Rollers, cylinders, or rubber coated on the outside of the drum are deformed by elasticity and deformed, or are excessively worn out and cannot be used.

Post-printing and Polymer Gravity Generated by Polymer Materials

When a new polymer medium acts on the print carrier, the process interface to the carrier can be realized in a liquid form, especially the wetting of the ink print. The polymer material medium is a solid polymer material with different properties, and the auxiliary material is filled with substances, etc., and is softened and dissolved and mixed with an organic solvent that accounts for a large proportion. It must be completely solidified as soon as possible to make its high molecular weight work.

The volatilization of the organic solvents in the synthetic components depends on strong external forces (such as heat and airflow forces) to exert pull force and expand force on the action carrier. In view of the site's environmental temperature, humidity, atmospheric pressure, relative density, air flow velocity, heat flux and many other external factors, it is difficult for organic solvent molecules to separate from the original combined media to atmospheric space diffusion, and different density groups are always formed at different levels.

With continuous production and processing, the temperature at the work site continues to rise, the humidity gradually decreases, and a large amount of organic solvent gas is volatilized, and the molecular concentration thereof continuously increases. At the same time, the electromagnetic field energy generated during the operation of machinery and equipment, the electrostatic charge generated by the friction when the substrate is processed, and the new charge energy generated by the transmission mechanism and the magnetic force line cutting are continuously accumulated and accumulated.

Therefore, the production site also has a fire source (accumulates and accumulates the static electricity carried on the processing body) and highly flammable substances (high concentration organic solvent volatile matter, high molecular material medium based on organic solvent, and paper quality printing). Products, plastic films, etc.) Combustion of oxygen (on-site air and exhaust and exhaust devices that are configured and operated), these three basic combustion elements, greatly threaten production safety.

When the concentration of organic solvent gas molecules and the static charge accumulated on processing equipment increase to a certain concentration, it will inevitably release energy to the outside (human body, equipment, materials, workpieces, etc.) to generate electrostatic sparks, which will instantly ignite the ignition point (at 18°C). ~ 44 °C) Very low concentration of gaseous organic solvents, causing an unpredictable fire, endangering the safety of production personnel and property.

In order to avoid such accidents, equipment must be reconstructed and equipped with highly conductive grounding devices so that static charges generated during production can be neutralized and neutralized in time to reduce the energy accumulated by the static electricity on the mechanical equipment or the workpieces that it carries. In addition, the existing ventilation and air exchange equipment must be reconstructed to speed up and increase the exchange of air flow with the external environment and reduce the density of volatile organic substances on the site. At the same time, an additional humidifier is installed to control the relative humidity of the site not less than 60%, and the concentration of electrostatic charge is limited by the water vapor molecules in the atmosphere. This type of conservative improvement can be used to reduce the risk level at the production site.

The organic solvent component that remains in the polymer material medium is only 1/15 of the pure solvent because of its volatilization rate. The processing objects such as books, magazines, packaging materials, etc. that will be used by them are in circulation, and they continue to evaporate during use, causing pollution after printing. Extend unsafe factors to larger spaces. To ensure product quality and safety. The production process is safe and consumer use is safe. Technological innovation should be actively promoted. Innovative technologies such as surface pretreatment of printed materials, hot melt adhesive compounding, and photo-curing, as well as new solvent-free materials, should be used to make post-press processing a clean project that allows people to rest assured.

Reprinted from:Gaogong Machine Grid