CN1569441A - Method for manufacturing direct pressure injection molded optical molded article - Google Patents

Abstract

The present invention provides a method for manufacturing a direct injection molding optical molded product, which comprises the following steps: firstly, an upper mold and a lower mold are arranged in a vertical corresponding manner, and a feeding device capable of quantitative and rapid feeding is used to perform lateral displacement for quantitative and rapid feeding, and after the feeding device is withdrawn, the upper mold is pressed together with the lower mold to mold the optical molded product. The present invention can improve the production speed and product quality, and can reduce the manufacturing cost.

Description

Method for manufacturing direct pressure injection molded optical molded article

【Technical field】

The present invention relates to a method for manufacturing an optical molded product, in particular to a method for manufacturing a direct pressure injection molded optical molded product.

【Background technique】

With the rapid development of electronic technology, more and more electronic products are launched, especially mobile phones and computers, which bring convenience to people's work and life, and these electronic products all use liquid crystal displays , to provide the data displayed on the screen. In addition to the liquid crystal display substrate, the liquid crystal display also has optical molded products such as light guide plates, diffusion sheets, and light-concentrating sheets. The light guide point on the reflective surface of the light guide plate is reflected and emitted from the light-emitting surface, and then the light source is uniformed by the diffusion sheet and the light intensity is enhanced by the light-concentrating sheet to obtain sufficient and uniform light energy, and then projected onto the liquid crystal substrate to make the screen display On the liquid crystal display substrate, the optical molded products such as the light guide plate, diffusion sheet, and light-concentrating sheet are extremely important components of the liquid crystal display; and taking the manufacturing method of the light guide plate as an example, most of them are made of resin by injection molding. The conventional manufacturing method is shown in Figure 1, which is to make the vertical male mold 1 move laterally so that it is pressed together with the pressing block 11 in the center of the corresponding end face of the female mold and the mold cavity 21 of the female mold. In a sealed state, the resin in a high-temperature molten state is injected from the injection channel 22 of the female mold 2 to fill the mold cavity 21 of the female mold, and after the resin is cooled, the male mold 1 is laterally shifted and returned to its original position. Then remove the hardened resin from the mold cavity 21 to obtain the finished light guide plate. Although this lateral displacement injection molding method can achieve the purpose of manufacturing the light guide plate, the light guide plate is in the shape of a plate and its thickness is It is proportional to its area, so when the resin is injected from the injection channel 22, because the high-temperature resin is pushed to flow into the mold cavity 21 naturally, when the mold cavity 21 is large, the filling speed of the resin is naturally slow, so that the mold is full The time required for the cavity 21 is also relatively long, and the mold is made of metal material, and the temperature of the material itself is low, so that the resin in the high-temperature molten state is injected into the mold cavity 21 through the injection channel 22. If the temperature is lowered by contact, it is easy for the injected resin to harden before the mold cavity 21 is filled. In order to prevent the resin from cooling and hardening too early in the middle of the injection and forming a defective product, the resin is in a high-temperature molten state. In addition, the male mold 1 and the female mold 2 must also be heated to a high temperature state, so that the resin can be successfully filled into every part of the mold cavity 21, but because of this, when the injection is completed, the male mold must also be heated. The temperature of mold 1 and female mold 2 should be lowered to facilitate the cooling of the resin, so that the subsequent ejection action can be carried out. At the same time, when remolding is required, the male mold 1 and female mold 2 must be heated again. Time increases the time required for injection molding, and relatively increases the manufacturing cost. In addition, because the light guide point must be set on the reflective surface of the light guide plate, there are many ways to form the light guide point, but there are three commonly used methods; one is to use printing to print special ink on the Reflective surface molding, the second is to form on the reflective surface by knife carving, and the third is to engrave patterns on the pressing block 11 of the male mold 1 or the mold cavity 21 of the female mold during injection molding to form together. Of the above three methods, it is most convenient and cost-effective to form together during injection molding. However, because the pattern of the light guide point is very fine, when it is used in a light guide plate with a small area such as a mobile phone, it is necessary to form it together. There is not much trouble with the method, but if it is a light guide plate with a large area used for computers or TVs, the thickness may even reach more than 1cm during injection molding, resulting in too long a waiting time for cooling after injection. The industry will not heat the male mold 1 and the female mold 2 to a very high temperature, but take a resin that can be melted at high temperature, and the temperature can be cooled quickly after the injection is completed to reduce the resin cooling time, but this causes the resin in the molten state to gradually harden after the injection is completed. The pattern of the mold cavity 21 of the mold 2 cannot be completely transferred to the light guide plate after the resin has gradually hardened, but as shown in FIG. Only when the hardened resin is pressurized can the pattern be smoothly formed into a good light guide point, which involves the time point of high pressure application, the magnitude of the force, the time required for injection, and the time change of resin hardening The coordination of various relationships is not easy to grasp, so it is easy to cause the loss of precision of the pattern, resulting in defective products. In addition, the high pressure also increases the volume of the production machine and takes up a large space. The increase in power has also increased the manufacturing cost. At the same time, high temperature and high pressure are used to form the light guide plate, which is prone to stress during molding, resulting in an increase in the defective rate of the finished product. In addition, the same must be done for the diffuser and light concentrator. There are many or many continuous concave-convex shapes on the surface of the diffusion sheet and the light-concentrating sheet, which can make the light diffuse and light-condensing. Different shapes, but no matter what shape the body is, its precision requirement is as high as that of the light guide point, and it is impossible to achieve good results by conventional methods, so the conventional manufacturing method is not a one-size-fits-all Appropriate method of manufacture.

【Content of invention】

The object of the present invention is to provide a method for manufacturing optical molded products of direct pressure injection molding. By using the upper and lower vertical displacement of the mold, after the upper mold is raised, a feeding device is used to move the lower mold at a set speed. The mold performs the feeding action, and after the feeding device exits, the upper mold presses down on the lower mold to form the light guide plate, so as to improve the production speed and product quality, and reduce the manufacturing cost.

In order to achieve the above object, the present invention provides a method for manufacturing optical molded products of direct pressure injection molding, which is characterized in that it includes the following steps: firstly make an upper mold and a lower mold a vertical corresponding setting, and a The feeding device capable of quantitative and rapid feeding is laterally shifted for quantitative and rapid feeding. After the feeding device exits, the upper die is pressed together with the lower die to form optical molded products.

The manufacturing method of the direct pressure injection molding optical molded article is characterized in that: after the feeding device completes the quantitative feeding, the upper and lower molds can be moved and pressed together synchronously.

The above-mentioned manufacturing method of a direct pressure injection molding optical molded article is characterized in that: a feeding device can be used to feed materials to several groups of molds in turn.

【Description of drawings】

FIG. 1 is a schematic diagram of forming a conventional light guide plate.

FIG. 2 is a schematic diagram of conventional pressurization of a light guide plate.

3A, 3B, 3C, and 3D are schematic diagrams of each step of the method of the present invention.

Fig. 4 is a schematic diagram of another embodiment of the present invention.

【Detailed ways】

In order to understand the preparation method of the present invention and the effect that can be achieved more easily, the accompanying drawings are described as follows.

Please refer to Fig. 3A at first, the manufacturing method of the optical molded article of the present invention is to utilize a upper mold 3, a lower mold 4 and a feeding device 5 to achieve, the upper mold 3 and the lower mold 4 are vertical corresponding to the upper and lower set, and the feeding device 5 is configured to move laterally, and can feed at a high speed. Wherein, the bottom side of the upper mold 3 is provided with a protruding briquetting block 31, and the briquetting block 31 is concave with the upper end surface of the lower mold 4. The mold cavity 41 that enters is the corresponding size, and the pattern of the light guide point to be formed or the concave-convex shape of light diffusion and light concentrating are also engraved on the briquetting block 31 or the mold cavity 4, please refer to Fig. 3B, by feeding The device 5 laterally shifts to its feeding port 51 relative to the front end of the mold cavity 41, and then retreats at a set speed and simultaneously feeds the material to the mold cavity 41. The feeding device 5 feeds quickly, and can The quantitative feeding action is completed in a very short time, and the amount of feeding is set according to the size of the optical molded product to be formed, so that the resin in the molten state can be quickly filled in the mold cavity 41. At this time, the feeding The device 5 has returned to its original position, please refer to Fig. 3C, then, the upper mold 3 is pushed to move downward, so that the briquetting block 31 of the upper mold 3 is pressed in the mold cavity 41 of the lower mold 4 to form a plus Pressing action, finally, please refer to FIG. 3D, the upper mold 3 is driven up, and the hardened and formed optical molded product can be taken out from the mold cavity 41 of the lower mold 4, and the processing step is completed.

The effect of the present invention is, owing to be by feeding device 5 to mold cavity 41 and do a fast quantitative feeding, so the time of feeding can be reduced to the minimum limit, then upper and lower mold 3,4 only need be a micro The state of heating can prevent the hardening of the resin in the molten state. Therefore, after the upper and lower molds 3 and 4 are pressed together, it is not necessary to perform a longer cooling step on the upper and lower molds 3 and 4, and the , The lower molds 3 and 4 do not need to be heated to a high temperature, and the heating time can also be shortened, which can effectively reduce the molding time and reduce the manufacturing cost. In addition, because the feeding speed is fast, it can be finished after the feeding Afterwards, the resin falling in the mold cavity 41 is in a state that has not yet started to harden. Then, after the upper mold 3 and the lower mold 4 are pressed together, it is not necessary to perform the pressing action of squeezing again as in the conventional way to form the light guide point. , and can reduce the steps of construction, this is because under the condition that the resin is not hardened, after the briquetting block 31 of the upper mold 3 is pressed into the mold cavity 41 of the lower mold 4, the pressure formed by it on the resin is enough to make The pattern engraved on the bump 31 or the mold cavity 41 forms a light guide point or a shape that wants to diffuse and condense light, and because the resin is not hardened, it can allow the light guide point or to diffuse and condense light The shape forming has better fineness, which greatly reduces the defective rate of finished optical molding products such as light guide plates, diffusers, and concentrators, and avoids the high cost of defective products. In addition, it is also Because there is no need to perform another pressing action, the volume of the molding machine will not be enlarged, the occupied space can be reduced, the power consumption can be reduced, and the manufacturing cost can also be reduced.

Also, when the action of quantitative feeding is completed, in addition to the upper mold 3 descending, the lower mold 4 can also rise synchronously to reduce the pressing time of the upper and lower molds 3 and 4, and the upper and lower molds 3 can be used , 4. Simultaneously shifted pressing to increase the pressure on the resin to facilitate the formation of optical molded products, so that defective products can be reduced. In addition, as shown in Figure 4, a feeding device 5 can also be used at the same time. Groups of molds perform alternate feeding actions, which can not only reduce equipment costs, but also increase production speed without waiting for a single group of molds to cool down.

Claims (3)

1, a kind of manufacture method of direct press type ejection formation optical product, it is characterized in that: it may further comprise the steps: a shilling patrix and a counterdie are the setting of a vertical type correspondence, and by one can be quantitatively fast the charging gear of feed carry out transverse shift and make quantitatively feed fast, after charging gear withdraws from, again by the incompatible optical product that molds of the downward mold pressing of patrix.

2, the manufacture method of direct press type ejection formation optical product as claimed in claim 1 is characterized in that: after charging gear is finished dosing, and the pressing that is shifted synchronously of upper and lower mould.

3, the manufacture method of a kind of direct press type ejection formation optical product as claimed in claim 1 is characterized in that: come the array mould is made feed in turn by a charging gear.