Thick Wall Optical Lens Mold Video

Injection molding method of plastic thick-wall optical lens mold

YOUNGER MOULD FACTORY focuses on the manufacture of injection molds for automotive plastic thick-wall optical lenses,

Specializing in LED car lamp mold design, optical product mold design, automobile optical plastic thick-wall lens mold, light guide injection mold, automobile lamp plastic lens thick-wall mold and other injection mold manufacturing.

The injection molding method and technology of plastic thick-wall optical lens mold is to divide the thick-wall lens into an upper surface layer, a lower layer and a core part according to its thickness direction, and divide the core part into multiple layers surrounding from the outside to the inside, according to the core part From the inner to the outer layer to the upper surface layer and the lower layer, the injection molding is divided into multiple layers. Each layer of the core from the inside to the outside is equipped with an independent cooling station. The injection molding of the core It is achieved by first injecting the inner layer and then injecting the outer layer surrounding the inner layer. The inner layer and the outer layer are injected in the first injection station and the second injection station respectively, and the lower and upper surface layers are respectively in the third injection station and The fourth injection station is completed. Between the first injection station and the second injection station is a first cooling station, and between the second injection station and the third injection station is a second cooling station. The optical lens mold made by YOUNER MOULD FACTORY has a short injection cycle and good injection quality. It is especially suitable for the lens of 25 32mm thick car lamp lighting unit.

Injection technology of plastic thick-wall optical lens mold:

YOUNGER MOULD FACTORY focuses on the manufacture of automotive plastic thick-wall optical lens injection molds, manufacturing optically designed shock-resistant and heat-resistant plastic lens injection molds instead of glass injection lens molds. The thickness of the lens is about 21～45mm, and the injection molding materials are general. It is injection molded from PMMA, PC and other plastic materials.

Optical lenses have extremely high requirements for weight, appearance, and surface shape, and need to meet the requirements of light distribution. This kind of thick-walled transparent product injection molding is different from general injection molding, and its technical difficulty is very difficult.

There are currently two ways to inject optical lens injection molds:

Optical lens injection molding also has the disadvantages of the following technologies, and the reasons for these problems have been clear:

1. The thickness of the lens is large, the shrinkage is very serious after molding, and the optical surface is often deformed, and the dents, shrinkage pits, and surface shape positions cannot meet the product requirements; in order to reduce these defects, the holding pressure and cooling time can only be greatly increased to maximize It takes about 12 to 18 minutes to form a lens in a single-cavity mold, and only 4 pieces per hour are produced. This leads to a long molding cycle; however, the design and injection process of the injection molding thick-wall lens is very difficult, and the multi-cavity mold It is impossible to balance the mold flow of each cavity to ensure the consistency of the product. Generally, there are only one or two cavities in an injection mold. With such low productivity and extremely low yield, the cost of producing a qualified lens is very high, and it is not cost-effective for mass production.

2. Reduce the molding cycle, reduce product molding defects, and improve product yield. Multi-layer injection molding is used, that is, a thick lens is injected in multiple layers to reduce the cooling and holding time, thereby avoiding one injection The shortcomings of a long molding cycle, and avoid the defects of too large thickness that cause large shrinkage and large product deformation, which greatly improves the yield and productivity compared with one injection.

3. Adopt a layer-by-layer full-enclosure method, that is, in the order of I→II→III, first form the innermost core layer I, then surround the molding layer II, and finally surround the I and II layers with the III layer to form the final product. Because layer I is placed in the mold of layer II and layer II is placed in the mold of layer III, the positioning structure is limited and difficult to locate. The flow path of the high temperature and high pressure molten plastic from the injection nozzle of the injection molding machine is complicated. If the enclosed part is offset, or the positioning structure is broken, or even the enclosed part will be squeezed into the outer cavity of the mold, and the surface of the product has multiple streams of bonding lines, which cannot meet the product requirements.

4. Adopt a layer-by-layer stacking method, generally using the order of Ⅰ→Ⅱ→Ⅲ or Ⅱ→Ⅰ→Ⅲ. Although this method has the disadvantages of 2, the mold structure is complicated, and the mold cost is large, which is more serious. It is that the fusion effect of the interface between each layer is unstable during molding, and subtle delamination phenomena often appear between each layer, which causes the light to be unable to pass through.

5. Layered injection molding needs to be equipped with expensive special injection molding machines, various special equipment and strict production environment. The equipment investment cost is very high, and the cost is high. Even if there are few layers, the corresponding mold is relatively large and the mold structure is complicated. The tier scheme currently does not exceed three tiers at most. In the absence of new technologies, this method is still a last resort technology. The product molding defects are still large, the yield rate is very low, the cost is large, and the productivity is not high, which restricts the increase in production capacity and cannot meet the requirements. The mass production requirements of LED car lights severely restrict the application of LED headlights.