In the die-cut parts we process, we often encounter the processing of EVA foam. Typically, the thickness will be 1-2mm, and the thickness may reach 5mm. With regard to the processing of this foam, many of these problems are bound to be encountered during the production process. So the problems we often encounter are mainly reflected in the following three points:

1. During the punching process of the foam, the beveled edge is easily present (the beveled edge of the circular knife die-cutting is larger);

2. These thick foams are prone to generate debris and dust during the stamping process;

3. For some porous products, it is difficult to discharge waste (the pore size is too small, the thickness of the foam is large, and it is difficult to discharge waste);

These are some common phenomena we encounter during the operation of EVA foam. Below we will analyze the above three common problems and give corresponding solutions; we will do this for everyone according to the characteristics of EVA foam itself. Brief introduction: EVA foam has high thickness, certain elasticity and low elastic limit, and it is easy to generate dust. Because of the above characteristics of EVA foam, the three basic problems we mentioned earlier will occur during the die-cutting process of EVA foam.

The beveled edge problem, first of all, with regard to the beveled edge that tends to appear during die cutting and stamping, the cause of this problem is the high thickness of the foam. During the stamping process, the foam is extruded and cut open after the foam has been extruded. Chamfering, the first way to deal with such problems is to change the choice of tools.

Usually, the punching tools we use are double bevel cutting tools for punching operations. Therefore, in order to effectively reduce the occurrence of the bevel edge, we use a single-edged knife to punch the inner right angle and the outer bevel, which can effectively reduce the occurrence of the foam bevel edge.

At the same time, the structure of EVA foam die-cutting parts is relatively simple. We use the methods of longitudinal cutting, edge trimming and jump cutting to reduce the factors affecting the corner cutting, and then avoid the corner cutting problem. For some products with a slightly complex structure, we can use the method of knife line decomposition to punch holes, instead of closing the knife line and multi-line overlap, to reduce the kneading stress during the foam punching process, and then reduce the foam tilt problem. .

Debris dust, regarding the problem of EVA foam fragments and dust, the root cause of the problem lies in the characteristics of the foam itself. Because of the low resistance of foam, the composition structure is a foam material. All during the punching process, because the repetitive effect of the knife makes the debris foam particles prone to forming dust and floating in the air.

For some die-cutting jobs that require cleaning, there are many ways to deal with this. The most common method is to spray mold release agent. The common method on the production line is to compound OPP protective film on the surface of EVA foam to deal with this problem. Of course, this approach may result in the waste of some auxiliary materials.

In waste treatment, in the treatment of porous waste, the most fundamental reason is that the foam is too thick and the pore size is small, making it difficult to extract the waste during the treatment process. "The general traditional method is to make a set of thimble disposal tools outside the die base of the die-cutting machine, and discharge the pore waste through the thimble for punching and chip removal. However, this waste disposal method is not good, and the foam cotton is simply scraped to form Poor product quality. A common practice on round knives is to extract and dispose of waste stuff.

Asynchronous operation of the processing plan, the advantages of the upper-level asynchronous operation program; as we all know, the upper-level data is pulled asynchronously, and the base-level data is synchronously die-cut to achieve the intention of saving data. Here, we use an asynchronous method to separate the foam and the lining film to pull the material, which not only saves the foam material, but also in the actual operation process, the upper material belt is taken away, and the foam outer frame is wasted. At the same time the bevel is also eliminated, because of the effect of the pressure, the bevel will be greatly improved. Moreover, through this operation method, the basic dust problem has also been effectively dealt with.