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There Are Two Types Of Injection Molding Of Optical Components


Optical lens (glass) is widely used in various fields, is a variety of precision equipment, the core parts, and optical components injection molding is a variety of plastic products manufacturing methods of mass production. This paper will discuss the difference between the injection molding of traditional optical product parts and the injection molding of precision optical products from six aspects, Optical Products Component Injection Molding and explain the feasibility of injection molding of optical lens optical components and hope to be widely used.

With the rapid development of imaging technology, people can anytime, anywhere around what is happening, scenes and characters recorded in their own camera or mobile phone. And these high-tech products, the core parts is a high-precision optical components. In recent years, Optical Products Component Injection Molding people have begun to use polymer materials instead of glass lenses, and gradually applied in the communications industry, medical equipment, cars, cars, and so on. Industry, and information industry. And whether the realization of mass production is the key to optical components injection molding.

Optical parts injection molding is widely used in mass production of plastic parts, but the traditional optical product parts injection molding technology is difficult to achieve the accuracy of optical components. To achieve the required dimensional tolerances and surface quality, Optical Products Component Injection Molding the entire process chain must be optimized. After years of research, can now be precision optical components through the injection molding technology to create more functional, reasonable price of precision optical components to meet the needs of the market.

Research on the injection molding process of optical components can be found in precision optics parts injection molding compared with the traditional optical product parts injection molding compared to six significantly different.

First, the product structure design

In order to obtain the best surface quality and minimum dimensional tolerances, product structure design is very important. The product design also indicates the dimensional tolerances of the plastic parts. Optical Products Component Injection Molding From the experience that the common design principles are as follows: to avoid plastic parts of the local wall thickness, resulting in shrinkage; control the minimum wall thickness of the size (material decision); in the optical components of the surface can not have holes, The formation of welds; wall thickness changes can not be too large, choose a smooth transition; to maintain plastic wall thickness

Evenly.

As the stability of the plastic than the glass is poor, so the plastic lens refractive index accuracy than the glass lens low. In general, under standard environmental conditions, the refractive index of plastic lenses ranges from more than 1%, and changes in refractive index will cause changes in the focal length of the lens. Optical Products Component Injection Molding From the physical experiments we can see that the focal length of the common spherical lens is determined by the refractive index n, the lens thickness T and the ball radius R, and the three parameters have different effects on the focal length, which in turn has the greatest influence on the refractive index n. In order to reduce the refractive index changes in the design must be strictly marked lens shape and position tolerance and processing accuracy.

Second, the tool design

Tool design and product design is equally important, the cutting effect will be directly reflected in the plastic parts on the surface. When the accuracy of the plastic parts reaches the micron level (μm), the dimensional tolerances of the tool must be less than 1 μm. Although this is not a simple matter for tool design, there are still many tool units to choose from. It is worth noting that the size of the tool requires high strength materials, Optical Products Component Injection Molding and the material can adapt to a variety of heat treatment process, while the importance of the latter are often overlooked. Experiments show that if the microstructure of the hardened steel from the austenite to martensite transformation is not completely completed, the microstructure of the material will change, causing a change in the size of the macro, even in the absence of load, There will be 0.01 ~ 0.001mm deformation.

Third, the optical components of the injection molding equipment

Optics Parts Injection molding equipment is an important part of the entire process chain. Injection molding equipment can melt, plasticize the polymer, make it into the mold, continuous circulation. It needs to accurately control each process parameters, such as injection temperature, injection volume, injection rate, cavity pressure, etc., the accuracy of injection molding equipment determines the accuracy of plastic parts.

Precision optics parts injection molding equipment is a closed loop, its operation is completely controlled by those parameters. When the optical components are molded, each mechanical action must be accurate (eg, parallelism when the two molds are mounted), Optical Products Component Injection Molding and all parts on the equipment require a high degree of stability. As the molding unit of the drive unit by the power transmission, in terms of accuracy and reproducibility has obvious advantages for precision optical products, parts injection molding.

Fourth, the processing capacity of the mold shop

In addition to design elements, precision machining is also a very important part of the injection molding of optical components. Mold processing must be carefully machined and closely fitted with the assembly process. If there is no good control of this part of the size of the tolerance, the late optical components of the injection molding process will be difficult to repair the size of plastic parts tolerance, or to allow adjustment of optical components of the injection molding parameters narrow range. With the development of high-speed cutting, it can be predicted that precision high-speed multi-axis milling will slowly replace EDM (EDM).

In order to achieve the quality requirements of the mold inserts, single crystal diamond can be used as a knife knife knife blade for turning. The biggest drawback of diamond turning is that it can not cut ferrous metals directly, such as steel, because iron will make the diamond wear quite fast. At present, Optical Products Component Injection Molding some enterprises in the heat treatment process has done some research, is to improve the cutting performance of alloy tool steel to achieve the effect of single crystal diamond turning. From the initial results look very promising. Of course, we must also pay attention to turning or milling tool itself, because the carbide turning tool after high-speed turning, the blade will wear, you need to use precision grinding machine grinding knife blade tip. Optical Products Component Injection Molding We must attach great importance to the cutting plane and cutting edge of these tools, even on the cutting edge of the tiny flaws will be reflected in the product after molding out.

Fifth, the optical product parts injection molding process

Optical parts injection molding process can be divided into two types: the traditional optical components of the injection molding and injection molding compression molding. Traditional optical product parts injection molding, the plastic cooling process will produce internal stress, change the plastic parts performance, causing the lens polarized. In order to overcome this potential internal stress, one of the treatment methods is plastic parts annealing, but this method will make plastic parts deformation, not appropriate. It can now be molded using injection molding. Injection molding is often used to shape products with fine structure, such as plastic lenses with diffractive functions, which are significantly different from traditional injection molding of optical components. Summary of its molding process parameters are as follows:

Injection molding temperature: 200 ~ 320 ℃; mold temperature: 100 ~ 150 ℃; injection temperature: 200 ~ 320 ℃; mold temperature: 100 ~ 150 ℃; Molding cycle: 0.5min or more.

Because precision optics parts injection molding is a new type of injection molding method, so its molding parameters are not experienced can learn from. In order to obtain the appropriate molding parameters, the following methods can be used to try. First, the design and manufacture of a set of injection mold (without considering the shrinkage), the second step to select one of the optical components of the injection molding parameters, Optical Products Component Injection Molding will be divided into several differential, one by one for injection optimization. And then check the plastic parts after molding, according to plastic parts to modify the shape and size of injection mold. The process parameters obtained by this method often have high stability and accuracy. Of course, to implement this program must have sophisticated measurement equipment (coordinate measuring instrument), advanced mold shop (multi-axis milling center) and design part of the mathematical ability (simulation analysis).

Six, technical staff ability

In order to obtain strict dimensional tolerances for plastic parts, precision optical components must be considered from the very beginning. Consider the optical design, product structure design, molding process parameters and molding equipment and other factors, and these interactions of multiple factors as a whole unified consideration, can not ignore any one. So they need to hire some high-tech and experienced design engineers, Optical Products Component Injection Molding they can complete such as optical design, product structure design, tool design, finite element analysis and mold flow analysis and so on. On the other hand, although most of the operations of the optical product parts injection molding process are now controlled by computer to achieve fully automated production, the workshop still needs some highly educated high-tech talent. Because the precision optical components of the injection molding process control is the optical components of the field of injection molding the most cutting-edge technology. Its typical feature is the injection molding machine has an advanced control interface, need someone to monitor, and timely adjustment of key process parameters, Optical Products Component Injection Molding so the human factor is very important.

With precision optical components injection molding, polymer optical components to achieve high-volume and high-precision production. Of course, this is just the beginning, precision optical components injection molding in some areas still did not do perfect, such as: polymer materials research and development, optical components injection molding equipment design, mold state detection, plastic parts precision measurement, molding simulation analysis software Applications and other aspects can be in-depth study, which will provide people with better quality plastic optical lens.


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