There are two kinds of feeding methods for packaging machine roll materials: intermittent feeding and continuous feeding, but the composition of the feeding mechanism is basically the same. The feeding mechanism is composed of a paper roll frame, a straightening roller, a fixed length roller, a paper pulling roller, a cutting mechanism and the like. According to the requirements of the cutting position, there are fixed length cutting and positioning cutting. The length is cut off, as long as the error of the cutting length is not too large, it is suitable for the roll material without printing pattern (such as cellophane, aluminum foil, etc.) or without pattern (such as general candy packaging label paper). As the level and requirements of the packaging and decoration of the product are improved, the delicate pattern is often printed on the roll material in advance, and it is required to keep the pattern intact during the feeding and cutting process, and maintain the accurate relative position of the pattern and the article. This requires that it can only be cut at the specified position, that is, the positioning is cut off.
Obviously, the positioning cutoff puts higher demands on the transmission and control system of the packaging material feeding device and the entire machine. In fact, the factors affecting the length of the material to be delivered are manifold. Design calculations and manufacturing installation errors, differences in packaging material thickness and elastic modulus, changes in traction resistance, and temperature and humidity in the shop environment can affect the length of the feed, and the spacing of printed patterns is not uniform. To achieve positioning and cutting, comprehensive measures are needed in the aspects of scheme selection, structural design, manufacturing and manufacturing, and machine transmission and automatic control.
