Maintenance of injection molds

Update:10-06-2022
Summary:

As the most important molding equipment for the process […]

As the most important molding equipment for the processing of injection products, its quality is directly related to the quality of the products. Moreover, since the mold occupies a large proportion in the production cost of injection molding enterprises, its service life directly affects the cost of injection molding products. Therefore, improving the quality of injection molds, maintaining and maintaining them well, and extending their service cycles are important issues for plastic injection molding products processing enterprises to reduce costs and increase efficiency.

Due to the large variety of products in plastic injection products processing enterprises, the molds are replaced more frequently. After completing a production cycle, the molds are generally stored in the warehouse until the next production cycle. However, some processing enterprises do not pay enough attention to the preservation of molds, so that the molds are rusted and surface smoothness is reduced during the storage period, resulting in a decline in product quality and a high rejection rate. Some molds are even difficult to reuse. , resulting in a great waste. The data shows that use and maintenance account for 15% to 20% of the factors affecting the service life of the mold.

The service life can generally reach 800,000 times, and some well-maintained molds abroad can even be extended by 2 to 3 times. However, due to the neglect of maintenance by domestic enterprises, the service life of plastic injection molds is relatively short, which is only equivalent to 1/5 to 1/3 of foreign countries. Due to the short service life of the mold, the waste of steel processing man-hours and energy, as well as the impact on product quality, cost billions of dollars each year. Therefore, the maintenance of injection molds is very important.

The technical content of injection molds is very high, and there are many various parts. If the maintenance and maintenance of various parts are not paid attention to during the use process, damage and corrosion will easily occur, resulting in economic losses of tens of thousands or even millions of yuan. Therefore, special attention should be paid to the maintenance and maintenance of the mold during use to ensure the long-term quality of the mold. To this end, the processing enterprise should first equip each pair of molds with a resume card to record and count its use and damage in detail. Based on this, it can be found which parts and components have been damaged and the degree of wear, so as to provide information for finding and solving problems. As well as the molding process parameters of the mold and the materials used in the product, in order to shorten the test time of the mold and improve the production efficiency.

Secondly, the processing enterprise should test the various properties of the mold under the normal operation of the injection molding machine and the mold, and measure the size of the final molded plastic part. Through this information, the existing state of the mold can be determined, and the cavity and core can be found. According to the information provided by the plastic parts, the damage status of the mold and the maintenance measures can be judged.

Third, it is necessary to focus on tracking and testing of several important parts of the mold. The function of the ejector and guide parts is to ensure the opening and closing movement of the mold and the ejection of the plastic parts. If any part of them is stuck due to damage, it will lead to production stoppage. Therefore, you should always check whether the ejector rods, guide posts, etc. are deformed and surface damaged. , Once found, it should be replaced in time. After a production cycle is completed, anti-rust oil should be applied to the moving and guiding parts, and special attention should be paid to the protection of the bearing parts of the gear and rack molds and the elastic strength of the spring mold to ensure that they are always in the best working condition. In addition, the cleaning of cooling channels is of great importance to production efficiency and product quality. With the continuous production time, the cooling channel is easy to deposit scale, rust, silt and algae, which reduces the cross-section of the cooling channel and narrows the cooling channel, which greatly reduces the heat exchange rate between the cooling liquid and the mold and increases the production cost of the enterprise. Therefore, attention should be paid to the cleaning of the flow channel. For hot runner molds, the maintenance of heating and control systems is particularly important to prevent production failures. Therefore, after each production cycle, the belt heaters, rod heaters, heating probes and thermocouples on the mold should be measured with an ohmmeter. If they are damaged, they should be replaced in time and checked with the mold resume. Compare and keep records so that problems can be detected in a timely manner and countermeasures can be taken.

Fourth, pay attention to The surface maintenance of the injection mold, which directly affects the surface quality of the product, focuses on preventing rust. When the mold completes the production task, different methods should be used to carefully remove the residual injection molding according to different injection molding methods. The residual injection molding and other deposits in the mold can be removed with copper rods, copper wires and soapy water, and then air-dried. It is forbidden to clean hard objects such as iron wires and steel bars to avoid scratching the surface. If there are rust spots caused by corrosive injection molding, use a grinder to grind and polish, and apply anti-rust oil, and then store the mold in a dry, cool, and dust-free place.

A pair of well-maintained and maintained molds can shorten mold assembly and commissioning time, reduce production failures, make production run smoothly, ensure product quality, reduce waste loss, and reduce the company's operating costs and fixed assets investment. The next production cycle At the beginning, the enterprise can successfully produce the products of qualified quality. Therefore, for injection molding products processing enterprises, in the current fierce market competition, well-maintained molds can help enterprises.