Views: 0 Author: Site Editor Publish Time: 2022-05-31 Origin: Site
Blow molds need proper maintenance to preserve the crystallization between machinery and raw materials, which is helpful for the normal operation of blow molding. Today, I will share with you the precautions for daily maintenance of blow molds.
Before sharing the maintenance precautions, let's understand the essentials of mold maintenance. When carrying out mold maintenance, we must be careful, patient, and step by step, and do not blindly engage in it.
During the maintenance process, if the mold is repaired due to failure, a material tape should be attached to facilitate the inquiry of the problem. Open the mold, check the condition of the mold against the material belt, confirm the cause of the failure, find out the problem, and then clean the mold before removing the mold. When removing the mold, the force should be uniform. For the mold structure in which the stripping spring is between the fixing plate and the stripping plate and the stripping spring is directly on the inner guide column, the stripping plate should be disassembled to ensure that the stripping plate pops out out of balance, and the stripping plate is removed. The tilting of the plate may lead to breakage of the punch in the mold.
Blow molding molds are generally made of 45# steel or alloy steel. Since the processing quality has a great influence on the molding quality of the parison, the requirements for its manufacturing accuracy will be relatively high.
1. Precautions for daily maintenance of blow molds
1. In the production of extrusion blow molding hollow products, frequent opening and closing of the mold makes the guide posts, guide sleeves, guide rods or guide rails in the mold extremely easy to wear; the lubricating oil here must be checked frequently during each shift. Whether it is sufficient and clean, it should be decontaminated and lubricated in time; parts with serious wear should be repaired and replaced in time, otherwise the accuracy of the clamping position will be affected, and the blow-molded products will be unqualified.
2. The blank clamping mouth often cuts off the excess material edge in the blow molding product. Although the cutting edge is made of alloy tool steel, it will also be worn after long-term work.
3. The inner surface of the cavity, according to the appearance quality requirements of the product, some need to be sandblasted; some need to be polished, and have a relatively high brightness to ensure the transparency of the product. After working for a long time, the volatiles in the raw materials adhere to the surface, which affects the quality of the product. The surface of the cavity should be polished in time. Polishing agent can be used, and it is repeatedly polished with a cotton cloth until the surface is as bright as a mirror.
4. The shear block at the neck of the hollow container and the shear sleeve of the intake rod are the main devices to ensure the quality of the neck of the product. Every time the product is blow-molded, the excess blanks at the neck of the parison must be cut off, which will affect the quality of the bottle mouth when it is worn. Therefore, attention should be paid to maintenance here. When there is wear, it should be repaired in time, and this part should be replaced if necessary.
5. The stability of the temperature control of the forming mold and the rationality of the temperature control of each part have a great impact on the quality of the product. If the temperature difference at each point is too large, the product is prone to warping deformation. Therefore, it is necessary to regularly check whether the cooling circulation water hole is unobstructed, and if necessary, it can be cleaned with a descaling agent, and then cleaned and decontaminated with clean water.
6. If the mold is not used for a long time, clean all parts of the mold. Use compressed air to blow out the dirt from the guide sleeve and the circulating water hole, then apply a layer of protective agent, close the molds, and store them in a dry and ventilated place. To be used in the next blow molding process; heavy objects are not allowed to be stored on the mold body to prevent deformation.
7. For the blow-molded transparent container, the cavity of the blow-molding mold needs to be highly polished, and it needs to be polished every once in a while during the production process. Use polishing agent and soft tissue paper to polish the mold cavity, rub hard to make a small amount of polishing agent penetrate into the surface of the mold cavity, and then polish with clean tissue paper until the mold cavity appears mirror surface. When polishing, the tissue paper should be changed frequently to avoid scratching the mold cavity.
After the edge of the blow mold clamping blank is worn, it should be repaired by skilled mold workers. The shear block on the neck of the blow mold and the shear sleeve on the intake rod are the key components, which must be replaced in time to maintain a good condition. For example, after the cutting edge of the shear block is unevenly worn, the neck of the formed container will leak during use.
8. When the cooling channel of blow molding mold affects the flow of cooling medium due to blockage or corrosion, it should be cleaned immediately. The guide post and guide sleeve of the blow molding mold should be lubricated regularly, and should be replaced at least once every year to ensure the alignment of the two halves of the mold and improve the life of the mold.