Advantages and disadvantages of injection molding
Injection molding: also known as injection molding, this method of injection and molding. There are many advantages of injection molding, and the general summary is fast production speed, high efficiency, automatic operation, variety of design, simple shape, small size, accurate product size, convenient product update, complex shape and so on. And suitable for mass production and complex shape products and other molding injection processing fields.
Factors affecting the quality of injection molding
1. Injection pressure: the reason for the need for injection pressure is to offset the resistance in the process of melt flow, or the resistance in the flow process to eliminate the pressure of the injection machine, the two are just the opposite, in order to ensure the smooth progress of the filling environment;
2. Injection time: reasonable injection time is conducive to the ideal filling of the melt, and the ear is very important to improve the surface quality of the product and reduce the dimensional tolerance;
3. Injection temperature: the injection temperature must be controlled within the range of M, the temperature is too low, the plasticization of molten materials is not good, which affects the quality of forming parts and increases the difficulty of processing; If the temperature is too high, the raw material is easy to decompose;
Two, the shortcomings of injection molding process
1, product molding must use injection molding and blow molding two sets of mold and a valve hollow core mold, and the injection mold should be able to withstand high pressure, molding equipment cost is high;
2. The temperature of the injection blank is high, and it needs a long cooling and shaping time after blowing in the injection mold, which prolongs the whole molding cycle of the product and affects the production efficiency.
3. The internal stress of the injection molding blank is large, and it is easy to be subjected to uneven cooling during the transformation of the mold. Stress cracking is easy to occur when producing products with complex shapes and large sizes.
4. The operation skills of the operators are higher
First, the advantages of injection molding process
1. Injection mold can be used to accurately control the wall thickness distribution of the billet, so that the wall thickness of the container is more uniform, avoiding the thinning phenomenon that is prone to occur in the corner of general blow molding products. The weight of the product can be controlled at +0.1g, the accuracy of the thread can be controlled within the range of 100μM, the mouth size is accurate, and the fine neck product molding precision is high.
2, the obtained products do not need to be processed for E times, no joints, saving the dressing time of the products;
3. The blank made by injection can all enter the blow molding mold, and there is no waste in the process, reducing the waste of forming materials;
4, can get smooth surface products, no scratches, surface text and pattern clear;
5, small batch production can be carried out economically;
6. Wide range of application for plastic varieties;
7, high degree of automation, multi-mode production, high production efficiency.
The main mold manufacturing countries include Japan, South Korea and the mainland in Asia, as well as the United States in America and Germany in Europe. This article will introduce the mold industry morphology of various countries, and compare and analyze the differences in competitiveness between countries and China.
Among the major mold producing and marketing countries, the number of mold manufacturers and practitioners in mainland China is large, nearly 70% of them are state-owned enterprises, and foreign-funded enterprises also account for the majority. The number of employees in large mold factories is about 600-700, and there are companies with thousands of employees. The number of medium mold factories is between 150-300, and the number of small mold factories is at least 50. The mold industry in other countries is mostly operated as small and medium-sized enterprises.
In terms of product categories, in 2002, Japan and the mainland laid particular emphasis on the production of stamping dies and plastic dies, with a total output value of 80%. In South Korea, the output value of other dies accounted for 47% of the total output value. In the application market, Japan, South Korea, the United States and Germany are the bulk products, while China is mainly used for electronic communication products.
According to the import and export situation of various countries in 2002, the molds of Japan, South Korea and Germany are strong / quasi export super products, while the molds of the mainland and the United States are strong / entry super products because the domestic demand market is large and the domestic manufacturers cannot supply them completely, so they have to import molds to meet the product manufacturing in the downstream market. The analysis of major import and export countries in 2002 is highly related to geographical distribution. Most of the countries are neighboring countries. The most important part of Japan is the export area, mainly in the US. But with the rapid development of downstream industries in mainland China, the trend of Chinese mainland market has gradually shifted.
In terms of wages in various countries, according to the survey results of the white paper on mould industry made by the US International Trade Bureau in 2002, the hourly wages of technical personnel in Germany are. 13 ~. 28, and that of design personnel are. 91 ~. 26, while those in Japan and the United States are in the middle. The wages in mainland China are low, with the annual wages of technical personnel only 2 ~, 853, and that of design personnel only 927 ~, 853, if we compare German with a German benchmark of 38 days or so, we can see that the low wage cost gap between scientific countries and Chinese mainland is so great.
Analysis of advantages and disadvantages of different countries
Technical countries such as Japan, the United States, Germany and so on, for the development of high-precision and composite mold, whether in the design ability or manufacturing technology are good, but also has well-trained technical R & D personnel. Among them, Japanese mold manufacturers pay more attention to polishing and grinding process, while German mold manufacturers start from improving the accuracy and efficiency of machining and EDM to reduce the time of manual processing. In terms of market size, Japan's decline is obvious in terms of output value and domestic demand. In terms of operating costs, they often face the problems of high wages and high welfare. Therefore, downstream industries or mold manufacturers gradually move their production bases to neighboring emerging industrial countries or technologically backward countries, so as to reduce labor costs and enhance price competitiveness. However, such a trend often leads to doubts about the invisible outflow of technology, which makes them have to invest a large amount of R & D expenses to accelerate the upgrading and upgrading Technology and high-speed mechanical properties, widening the differences between each other.