Precision manufacturing of the hottest micro produ

The trend of precision manufacturing of micro products requires designers to integrate multiple functions into micro components. The advantage of multi-functional components is that complex installation steps can be avoided, and the fitting accuracy between movable components is higher. Therefore, multi-component injection molding will become more important with the rise of micro component manufacturing

injection unit for micro parts

due to different products, different technical conditions and design quality levels, the injection equipment used for the production of micro parts is also different. The most widely used small equipment is based on the screw piston principle, and the diameter of the screw used is more than 10mm. Its minimum emission is about one to two cubic centimeters. The only way to reduce the emission is to carefully optimize the process. Due to the high proportion of gate, the injection volume of micro parts is too large, which becomes a technical problem

when injecting micro injection parts with an injection volume of several cubic millimeters, it must be ensured that when the piston moves, only part of the material is injected through control. If a typical 0.1mm runner is used, the injection volume can be less than one cubic millimeter only when a piston with a diameter of only a few millimeters is used at most in HRC production. However, it is not practical to use such a small screw piston, so some micro injection units with pre plasticized screw and injection piston should be used

these problems show that in order to achieve the best injection volume, we must use the screw piston injection unit

this makes KL 歝 kner DESMA company in Germany determined to develop a micro injection molding machine that can meet the above requirements. The new product can accurately control the injection volume. It has a two-stage injection unit (Figure 1). 6mm piston is used for pre plasticization and 3mm piston is used for high-precision injection

this injection molding machine is formicaplast micro injection molding machine

the reduction of injection quantity and gate makes the mold and equipment gain the following main advantages:

■ the molding surface and mold parts can be reduced, allowing the mold to be designed into a standard mold

■ the driving part becomes smaller, more accurate and more powerful

■ the injection pressure exceeds 3000 bar and the injection rate is 500 mm/s

■ the equipment components are installed on a rigid flat base plate, with compact structure and convenient operation

two component injection molding with diversified structures

all equipment can be used for multi-component injection molding. Two component injection molding not only combines the single component injection process, but also integrates the multi-component injection equipment. Among the latter, the most widely used are piggyback, parallel, vertical and horizontal layouts. Moreover, the equipment with injection unit on the locking side of the actual mold and adjustable plug-in on the operating side is becoming more and more common. This means that almost all sides of the mold have been actually utilized

once the production of semi-finished products is completed, the arc surface of the mold must be changed. The semi-finished product can be moved into another the first mock examination cavity by installing a moving slider. Its transfer can be realized by rotating the horizontal or vertical axis in the mold, or demoulding after the first stage of injection, and then putting it into another mold cavity, either in the same mold or in other molds. These are also used in micro component injection molding

the two-component formicaplast micro injection molding machine is a multi-purpose injection molding machine, which can meet the molding of a variety of products. More importantly, it achieves a balance between the gate weight and the formed product. For this reason, the gate must be short. The injection head must be close to the mold cavity, so this size eliminates the possibility of using hot runner and long injection head. In addition, the buoyancy in the mold must be evenly distributed to keep the mold cavity balanced. For example, the injection unit is symmetrical in the axial direction

by himself, which limits the application of a variety of standard injection molding methods: for example, the vertical arrangement between injection units will lead to the unsatisfactory arrangement of long gates or products formed in the mold

through experiments and research, it is found that the structure of the injection unit parallel to the fixed plate mold and combined with a rotating motion or transfer method can well meet the requirements

two component transfer index micro injection molding

the solution for two component micro injection molding is best known as the transfer index method because it combines the common index method with rotating products and the transfer method parallel to the equipment (Figure 2). The equipment is placed very tightly so that the molds can be coupled with each other. After the mold is opened, the mold base extends from the mold platform and rotates 180 ° to enter the new injection position. The rotary arm attached to the mold can realize the precision of the mold. The settlement of the ACTC R & D center is another good practice of in-depth cooperation between enterprises and the government (Figure 3)

this method is similar to the index method, and has the following advantages in multi-component molding:

it can be injected on the rotating surface of the back of the mold; It can carry out diversified design and has a high degree of freedom; It can produce semi-finished products and finished products at the same time; Short production cycle; The semi-finished and finished mold cavities have good heat insulation performance

the solution described here includes the exponential method between two parallel equipment units, which can be realized through the small module of formicaplast. The whole structure and its parallel injection unit can be matched with the improved machine shell. If two standard molds are used to replace the coupled two component mold, the control part can also allow two injection machines to inject it separately

at fakuma exhibition, the function of the system was demonstrated by showing the optical path with a three-way splitter (Figure 4). At this time, the gates of the two components can still be seen on the product. The injection volume of each component is 9mg and 10mg respectively (the transparent part is polycarbonate PC and the shell is ABS). The overall weight of the two components is only 19mg, which has never been achieved before

conclusion

the new formicaplast two-component injection technology provides an integrated and flexible two-component micro injection equipment for micro molding product manufacturers for the first time. It can make the production of two components as accurate and simple as the production of one piece. Two injection units placed in parallel on the equipment platform can minimize the gate and achieve a balance between the gate weight and the product weight. Therefore, this new technology provides users with a wide range of process options. It is a complete module, which can realize the rapid production of micro optical components or hybrid components without further installation. (end)