Third, the quality of raw paper and process control
The size and quality of the micro-corrugated board base paper lacks more options than the conventional crepe-type paperboard.
When passing 150 g of ordinary corrugated paper around the C-Cave type dome, it can smoothly transition and form on a 1.25 mm radius dome arc, when the same base paper enters the G-type micro corrugated, . The transition and forming of the 16-millimetre radius dome arc is difficult, and the excessively small bending radius breaks the paper fiber at the dome. Therefore, the fine corrugated medium must be made of a base paper with good strength, a grammage of less than 100 grams, and an air permeability that is uniform with the water absorption rate and humidity.
In principle, a high-quality corrugated cardboard production line is a balance of paper strength, tension, pressure, humidity, temperature, and adhesive formulation at the desired speed point.
Uneven raw paper strength and humidity, unstable adhesive properties, fluctuations in the amount of glue, unbalanced preheating control, and misadjusted heating all cause tension changes and break the balance at the desired speed point.
Under the premise of satisfying the conditions of the equipment, fine-grained corrugated production requires more delicate process control: control of the quality index of the base paper, stable and accurate tension control of the paper web, control of the moisture of the base paper of each layer before and after the process, control of the amount of glue applied, and temperature Control is the key to the production process of fine corrugated board. The precise adjustment of the tension in the entire line, the reasonable and timely adjustment of the wrap angle of each preheating dryer, the high solid content starch paste with stable performance, the precise setting of the glue gap between the coating roller and the metering roller to ensure the smaller and Stable coating amount, fine temperature setting and adjustment of each heating point, etc. are the main control means. All details of the entire corrugated board production line are rooted. According to the timely adjustment and control of corrugated board quality, we can ensure that the entire production line is stable in speed, smooth in conveying, and produces high-quality fine corrugated cardboard.
Fourth, the transformation of fine corrugated single-sided machine
Since the widespread application of micro-tiles (especially C-type and finer micro-corrugated cardboards that can be printed directly) in China has just begun, there are not many large orders, so there is still a need for large-scale production in the corrugated board production line. process. Therefore, a scheme with very few investments and rapid entry into the market has led some color printing cartons to take the lead in the emerging markets. That is to use the old and new single-faced machines for micro-reconstruction. The suppliers of C-type micro-corrugated packaging, such as brain platinum, Siemens mobile phones, etc., were all put into production in China by the Changzhou Wujin Haili Rolling Co.
The features of the fine corrugated type are that the corrugated type tends to be V-shaped, and the arc radius of the dome is smaller. After the forming, the centrifugal force generated by the corrugating roll is easily released from the dents, affecting the gluing and recombination. Paper humidity, temperature, tension, and speed control are particularly sensitive. At the same time, smaller dome arcs require more precise control of the smaller amount of glue. Therefore, the renovation of the fine corrugated single-faced machine is aimed at the above characteristics.
(I) Renovation project of micro-corrugated single-faced machine
1. New system corrugating roller:
(1) 楞-type design parameters (楞 type strength, wrap angle, dome circular groove, 楞 high, paper consumption, etc.).
(2) Structure design of corrugating roll, according to the different guide types of corrugated paper after fixed forming (vacuum negative pressure external suction, vacuum negative pressure internal suction or positive pressure air cushion), design the wind groove (vacuum suction type wind groove There are rings and herringbone types.)
(3) Calculate the median height of the passive corrugating roller according to the rigidity of the roller body determined by the above structure of the corrugating roller and the arrangement of the rollers of each single-sided machine.
2. To design or fabricate different types of paper guides (vacuum vacuum suction, vacuum vacuum suction or air cushion pressure):
(1) Negative pressure hood or positive pressure seal chamber.
(2) Set the appropriate air volume and air pressure according to the corrugating roller specifications.
(3) According to the above form, determine the number and position of the guide copper sheet and the tuyere.
3. Coating system:
(1) The new rubberizing roller (paste roller) is provided with a finer surface net pattern forming a thinner adhesive layer and a circular runout accuracy of less than 0.02 mm.
(2) A new system of measuring rollers (rubbing rollers, doctor rollers, metering rollers) to less than o. 01 mm round runout accuracy. Make sure that glue gaps of less than 0.08 mm can be achieved between the coating roller and the metering roller.
(3) Adjustable blocking device.
(4) Pneumatic device for quick follow-up and detachment of the gluing system. (optional item)
4, according to the actual structure of the single-sided machine, installation location and the surrounding environment, design the direction of suction or air supply ducts, determine the position of the high-pressure fan, manufacture suction duct system and high pressure fan bracket.
5. According to the specifications of the corrugating roller and the set air volume and air pressure, the matching high-pressure blower and muffler are selected.
6. Design electrical control system.
(to be continued)
