China's packaging industry started in the 80's. So far, there are more than 20,000 carton plants. There are more than 1,400 cardboard production lines, and there are countless carton machines and post-processing carton equipment. However, the paperboard transverse pressure line (ie, carton flap indentation fold line) often appears paper folding curve is not in a straight line, the formation of the corner is not good, repeated at the crease at the bend, the cardboard pressure line is easy to break the problem. Therefore, the configuration of the crimping roller must be studied to meet the requirements of different corrugated cardboard.
First, the transverse pressure line is deeper than the vertical pressure line
A formed carton shall be subjected to two processes of transverse pressure line and longitudinal pressure line. The longitudinal pressure line is the pressure line parallel to the corrugation of the cardboard, and the transverse pressure line is the pressure line perpendicular to the cardboard corrugation. The mechanical arrangement of the transverse pressure lines is completed before the transverse cutting of the corrugated cardboard production line, that is, in the longitudinal indentation separating machine, and the longitudinal indentation line is realized in a printing slotting machine or an origami bonding machine to complete the shaping of the carton edges and corners. Shake the cover, in order to achieve the purpose of beauty, but the pressure of the transverse pressure line is stronger than the longitudinal pressure line, and the bending direction angle is larger.
Second, the pressure roller preparation
In order to prevent the pressure line from breaking, after a number of carton equipment manufacturing plant research, the ideal "shan-shaped" pressure line wheel was selected. When the rollers of the processing pressure line are used, they must be differentiated according to the shape of the cardboard corrugated sheet and should not be confused.
In general, the three-layer cardboard press reel adopts three-point bump type, and the five-layer cardboard adopts five-point concave-convex type. But in the actual production, the type A corrugated press reel has good effect for the B type and AB type. The corrugated type AB pressure reel is also effective for the ABC tile seven-layer cardboard, while the ABC type is used for The AB type is also effective, so the pressure roller can be selected according to the shape of the corrugated board and the condition of the base paper.
Third, several problems with the breakdown of the pressure lines
(1) Upper and lower pressure roller gap is too small
The upper and lower pressure roller gaps are adjusted according to the cardboard shape and the cardboard thickness to maintain a reasonable pressure strength. If the pressure line strength is too small, it will not cause the pressure line to break, but the box cover must be folded too much when the carton is assembled. Cracking occurs, and this phenomenon occurs mostly in cardboard made from low-grade base paper.
(2) Misalignment of the assembly position of the pressure roller
In order to accurately install the pinch roller, there is usually a 1mm centering slot in the processing of the pinch roller. When the pinch is not well matched, not only the line breakage and the corners of the box combination are bad, but also the camouflage seam may occur. Overlaps cause defects in the carton. Of course, the machining defects of various machine pressure reels themselves can also cause the pressure lines to break.
(3) Secondary rolling pressure problem
The horizontal indentation line edges rolled by the upper and lower pressure roller are not as good as the results of the indentation machine. However, the productivity and economy of the two are difficult to compare. Therefore, in order to make the upper and lower pressure wheel indentation of the paperboard production line longitudinal indentation machine reach or close to the edge of the magnetic line indentation, the upper and lower pressure line wheels should be installed on the two pressure spools before and after the paperboard creasing machine respectively. The first rolling line is the pre-rolling indentation line, the corrugated cardboard structure at the indentation is changed, and after the second rolling indentation line, the first pre-pressure is slightly lower than the second rolling pressure, so that Achieve good edge.
