Why medical mould is difficult to do and price is high

Medical mould selection materials is very strict.

The selection of mold materials is very strict, because medical equipment molds are completed in the clean room. First, the mold materials need stainless steel materials, and they need to be matched with surface treatments, such as vacuum heat treatment, PVD coating, laser heat treatment and so on. The plastic materials of medical device products are usually medical grade PP, PVC, ABS, PSU, POM, PA, etc., there are high strength, corrosive, need abrasion resistance and high transparency, etc. The requirements for injection molds are relatively high. Commonly used mold steels are imported S136, 2316, S136H, NAK80, etc., to meet high corrosion resistance and high polishing. Many injection molds for medical consumables require high hardness and abrasion resistance for the materials of injection molds because of their multiple cavities and large production batches. The hardness of the commonly used medical equipment mold steel is about HRC48-56. It is suitable, which can ensure both the strength of the mold and the good polishing performance.

Medical mould design requirements of the mold forming structure.

The medical consumable products are mostly transparent parts. The product should choose hot runners to reduce the trace of fusion. When using cold runners, the size of the flexible PVC should be as short as possible. Device products are small in size and large in batches, so automatic discharge and shear gates should be used to ensure production efficiency and quality. There are many transparent tubular parts for disposable medical device products. When designing, pay attention to the gate feeding position and The fixed model of the moving model Z is fixed to avoid the improper selection of the gate position and the core fixing method, which will cause uneven material flow during injection, which will cause elastic deformation of the core, uneven or incomplete product filling, and uneven wall thickness. Expansion pipe shape products should pay attention to adopt appropriate exhaust method, the inlet splitter should be based on the product molding situation to open the overflow well to avoid product molding difficulties caused by closed air; mold cooling system should take multiple sets of separate cooling water channels, reasonable Control the temperature of the moving mold to control the deformation of the product. In addition, many medical device products involve the issue of bolus sealing. The core of the mold must be designed to be straight and cannot be designed with a draft angle, and it can ensure that the demolding is normal without straining. In this case, the designed cooling must be uniform and can provide The higher the mold temperature, the surface of the core needs to be treated, and special requirements are required in the demolding method to ensure the quality and accuracy of the product after injection.

The manufacturing precision of medical molds is high

Because the products are in contact with blood and liquid entering the human body, the injection molding products related to medical devices are definitely not allowed to have burrs, because many parts that cooperate with each other are directly matched by plastic parts. The effect of sealing and pressure resistance and the requirements of multi-cavity products wildly require high processing accuracy of the mold core, and the processing accuracy of some cores is less than 0.005mm. The surface of the mold core is required to ensure that the Ra value is above 0.20. These precisions have basically reached the high manufacturing accuracy of imported precision equipment. In the polishing process of the mold, protection and special treatment are needed.
Generally speaking, there is not much difference in structure between the medical device mold and the traditional mold, which is mainly reflected in the control of processing technology and control of processing accuracy. The environment in which medical device molds are used is relatively harsh.