Analysis of material and process problems affecting the quality of steel drums (4)

VII. Volume Packaging Process Problems

The coil packaging process is the most critical process for steel drum production. The key quality issues of steel drums are the most concentrated here. However, most people in the industry attach great importance to the importance of the process, as long as a seal quality problems such as leaks in the winding process to find the reason, blindly drilling horns to study the groove roller type. In fact, a large part of the quality of roll seals is in the roll groove type, but more problems arise in materials and related processes, if the cross-impact analysis method is not used to divide the problem into two parts, It is not easy to solve the problem from the root. Some people changed the roller groove and changed it. Finally, they didn't even know what kind of groove was the best, and still couldn't solve the problem. That's why many people in the industry were plagued in the curling roller groove all day long. The reason is.

In fact, the shape of the flanging groove is not unique. Different materials, processes, and equipment of different companies will have different roller sizes. As long as it is adapted, no one will make a roll groove that everyone can adapt to. I do not believe you You can try it.

A few years ago, in order to solve the hot topics that everyone was studying, together with the professors of Gansu University of Technology, I used a large-scale computer to conduct simulation tests and found that the ideal roll groove curve was involute. Through practical application, it is only the middle section of the roller groove curve that can actually use the involute, and the other start and end sections are designed to take care of the feed guide, forming size and shape. However, this short middle period is very important. It determines the curling trend. Under the guidance of this trend, the curling will very easily enter the ideal curling state.

In fact, the result of this involute line is naturally associated with the process of curling after knowing the forming principle of involute. Since the formation of involutes is a reversal of the drum crimping process, it is the same curve, but in the opposite direction. Therefore, it is not difficult to confirm the theoretical correctness and practicality of this curve.

The quality problems that often occur during the crimping process include: insufficient number of crimped layers, unsmooth crimping, false volumes, and tongues.

1, insufficient number of layers

The quality problem of insufficient number of hemming layers may be caused by the following reasons: improper curling of the wheel groove, excessive size of the barrel flange, insufficient platen pressure, and the like. The unsuitable condition of the curling roller groove is relative because it is related to the thickness and material of the raw material. Different material thicknesses should correspond to different rollers. For uneven thickness materials, the rollers often cannot be used due to their inability to adapt. This situation. When the barrel flange is too narrow, the curling material is insufficient and the roll is definitely insufficient. When the platen pressure of the sealing machine is insufficient, part of the curling material can be returned to the barrel or the lid due to the pressure of the roller during the beading process, so that the curling material is insufficient.

2, curled and loose

The fact that the curling is loose is generally caused by improper roll flange groove or material rigidity. When the number of crimping layers meets the process requirements, the curling is not true, indicating that the roller groove type is suitable, but the size is too large, and the cross-sectional area of ​​the actual groove space is larger than the cross-sectional area of ​​the curling material. When the space in the groove is not full, the space is insufficient. It will appear loose and untrue. When the rigidity of the material is too large, due to the effect of spring back, the curling dimension may appear larger than the size of the roller groove after the completion of the process, so that a rebound gap is generated.

3, fake volume problem

There may be a variety of reasons for the occurrence of false roll problems: errors in the size and shape of the barrel flange, errors in the size and shape of the roll groove, and errors in the size and shape of the pre-rolling of the bottom cover.

When the barrel body flanging is too wide, the edge of the assembly exceeds the pre-rolling edge of the bottom cover of the barrel, and the bottom cover will not allow the flanging to get involved, so the false roll phenomenon may occur;

When the angle of the flanging is too small or the deformation of the crushing occurs during the turnaround of the process, the cuff in the assembly cannot be tightly combined with the bottom cover of the tub, and the false roll phenomenon may also occur.

If the curling roller groove type curve and dimension design or processing are not suitable, false roll phenomenon also appears easily.

The shape and size of the pre-crimping of the bottom cover of the drum are more important. If there is a big error, it will bring problems to the crimping process. For example, the size of the pre-crimping part is too narrow or excessive curling may cause curling. Sealed fake roll issue.

4, iron tongue phenomenon

The iron tongue phenomenon in the crimp sealing process is mostly caused by the fact that the curling roller groove is not suitable for the material of the barrel plate.

When the thickness of the material exceeds the thickness of the original design of the roller groove, the excess material roll groove will not fit and will overflow into the tongue;

When the barrel body seam welding site is too thick, there are too many materials in the seam welding place, and local iron tongue phenomenon may occur at the site.

When the material thickness is not uniform, the iron tongue phenomenon will appear in the thicker parts of the material, while the ultra-thin parts will appear gaps;

When the roller groove type design is not appropriate, the material cannot naturally entrap the phenomenon that may cause external ribs and curled emptiness. This situation often occurs in production and generally occurs after replacing the new roller or the roller for a long time. There are more opportunities.