1. Damage to the mold guide post

The guide post plays a key role in the manufacturing and processing molds to ensure that the core and the forming surface of the cavity do not collide with each other under any circumstances. The guide post cannot be used as a force-bearing part or a precise positioning part.

2. Difficulties in gate stripping

In the whole process of mold injection molding, the gate sticks in the sprue sleeve and is not easy to slip off. The product was damaged by cracks when it was ejected from the mold. The key reason for this kind of common faults is poor smoothness of the gate hole, and there are knife marks on the upper side of the internal thread circle. The second is that the raw material is too soft, the small end of the cone hole is deformed or damaged after a period of application, and the inclination of the nozzle surface is very small, which causes the gate material to cause the riveting head here.

3. Deflection of dynamic and fixed molds

For large and medium-sized molds, due to the different filling speeds and the influence of the weight of the mold during mold installation, the movable and fixed molds are deviated.

In these types of conditions, the lateral deflection force will be added to the guide post during injection, and the surface of the guide post will be light when ejected from the mold, and the guide post will be damaged or bend or break when it is more serious. In order to better deal with the above-mentioned problems, the analysis surface is equipped with a precise positioning key with high compressive strength on each of the four sides when manufacturing and processing the mold. It is simple and reasonable to choose the cylindrical key guide pin hole and the flatness of the parting surface important.

4. The ejector rod is bent, cracked or overflowed

The self-made ejector rods are of good quality, but the production cost is too high. Nowadays, standard parts are generally used and the quality is average. If the gap between the ejector pin and the hole is large, there will be flashing, but if the gap is too small, the ejector pin will swell due to the high mold temperature during injection and jam. In order to better deal with this problem, the ejector rod is sharpened again, leaving a 10~15mm mutual matching section at the front end of the ejector rod, and the middle part is grounded by 0.2mm. After the ejector rod is installed, the matching gap must be strictly checked. Within 0.05~0.08mm, it is necessary to ensure that all the injected tissues can advance and retreat in a certain degree.

5. Poor cooling or water seepage

The actual cooling effect of manufacturing and processing molds will affect the quality and productivity of the product, such as poor cooling, large product shrinkage, or uneven shrinkage and warped surface deformation. On the other hand, the whole or part of the mold is over-temperature, so that the manufacturing and processing molds cannot be formed normally and stop working. The serious situation causes the thermal expansion of the ejector and other movable parts to be jammed and destroyed.

6. The length of the guide groove is very short

Because the manufacturing and processing molds are limited by the total area of ​​the template, the length of the guide groove is very short, and the guide rail slider is exposed outside the guide groove after the core-pulling posture is completed. That way, it is very easy to cause the slider to skew after the core-pulling process and the initial stage of mold calibration. Especially when the mold is locked, the alignment of the guide rail slider is unsatisfactory, which damages the guide rail slider or even bends and destroys it. According to normal work experience, the length of the slide rail should not be less than 2/3 of the total length of the guide groove after the core-pulling position of the guide rail slider.