At present, there are two main methods used to produce steel plate mesh at home and abroad, namely vertical punching method and rolling expansion (oblique pulling) method. Their respective advantages are obvious, but there are still some shortcomings. The following will briefly introduce the forming process of these two commonly used methods and point out their respective advantages and disadvantages.
1. Vertical punching method This method is the most commonly used, mainly because the technical content required by the equipment is not high and the versatility is relatively good. The thickness range of the processable plate is relatively large, from 0.1mm to 8mm, and it can even reach more than 10mm. Within a certain range, for steel plate meshes of different specifications, only the corresponding knife county needs to be replaced. The processing schematic diagram of the steel plate mesh produced by the vertical punching method is shown in Figure 1-2.
There are two different processing forms for producing steel plate mesh using this method. The tools used in these two processing forms are the same, and the difference is the movement of the mechanism. In the first, the sawtooth tool only moves back and forth in the vertical y direction, and the steel plate is intermittently fed in the horizontal plane in the forward direction (perpendicular to the paper direction), and reciprocates in the horizontal x direction at the same time. The cutter moves up and down once, the steel plate feeds a certain distance (rib width) and moves horizontally a certain distance (half the length of the mesh), thereby processing a row of meshes, and repeating this process. The second type is that the sawtooth cutter moves back and forth in the vertical y direction and the horizontal x direction, while the steel plate is only fed intermittently in the forward direction in the horizontal plane. Each time the steel plate is fed, the cutter performs a punch cut to process a row of meshes, and repeats this process. The mesh shape of the steel plate mesh produced by this method is determined by the shape of the cutter. The two different processing methods have a common feature, that is, the cutter reciprocates for one cycle and only produces a row of meshes, which inevitably leads to its low production efficiency. In addition, there is impact between the cutter and the steel plate during punching, and the noise is also very loud.
2. Rolling and expansion (oblique pulling) method
The production efficiency of steel plate mesh is very high using the rolling and expansion oblique pulling method. It is an automated production line integrating feeding, rolling, expansion, leveling, cutting and packaging. The specific process flow is as follows:
Loading - unwinding and feeding (automatic material rack) - rolling and expansion - leveling and forming to a certain length and cutting - collecting and packaging. The following focuses on the two most important processes in the whole process, namely rolling and expansion and leveling and forming. The quality of these two processes will directly affect the quality of the product.
(1) Rolling expansion
The hot-dip galvanized sheet of a certain width enters the rolling expansion machine from the automatic material rack, as shown in Figure 1-3, and then a pair of knife shafts, as shown in Figure 1-4, cut it into a discontinuous periodic structure after intermittent rolling. At the same time, the two outer sides of the rolled steel plate are also folded to form a right angle of 90 degrees to the plane of the steel plate. Then the folded part enters the groove of the expansion arm (to provide lateral expansion force for the expansion of the steel plate mesh, and also prevent it from running off during expansion.
2) Flattening When the steel plate mesh is stretched by the expansion arm, due to the uneven force on the stretched steel plate mesh in the expansion area between the two arms, and the secondary bending damage after stretching, the stretched steel plate mesh must be flattened after stretching to meet the requirements of use. At present, the parallel roller leveling method is generally used to produce steel plate mesh using the rolling expansion inclined drawing method to level the steel plate mesh. The parallel roller leveling machine is shown in Figure 1-8. It is mainly composed of two rows of rollers arranged alternately. A certain amount of pressure is formed between the upper and lower rows of rollers, so that the steel plate mesh is repeatedly bent when passing between the two rows of rollers, thereby achieving the purpose of straightening.
Post time: Jun-19-2024