Reasons for difficulties in manufacturing injection molds

The cavity and core are three-dimensional surfaces.

The external and internal shapes of plastic parts are directly shaped by cavities and cores, these complex three-dimensional surface processing is more difficult, especially the cavity of the blind hole molding surface processing, if the traditional processing method, not only requires a high level of worker skills, more auxiliary fixtures, more tools, and long processing cycle.
 

High precision and surface quality are required, and a long service life is required.

At present, the dimensional accuracy of general plastic parts requires IT6-7, surface roughness Ra0.2-0.1μm, and the corresponding injection mold parts require dimensional accuracy of IT5-6 and surface roughness Ra0.1μm or less.

The roughness of the laser disk recording surface should reach the level of mirror processing of 0.02-0.01μm This requires the surface roughness of the mold to reach 0.01μm or less. Long-life injection mold is necessary to improve efficiency and reduce costs, the current life of the injection mold generally requires more than 1 million times.

Precision injection mold should use a rigid mold frame, increase the thickness of the template, increase the support column or conical positioning elements to prevent the mold from deformation after pressure, sometimes the internal pressure can reach 100MPa.

The ejector is an important factor affecting the deformation and dimensional accuracy of the product, so the best ejector point should be selected to make the mold release evenly in all places. Most of the high-precision injection molds adopt inlay or full-assembly structures, which requires the processing accuracy and interchangeability of mold parts to be greatly improved.

The process is long and the manufacturing time is tight.

For injection molded parts, most of them are complete products with other parts, and in many cases are in other parts that have been completed, eagerly waiting for the injection molded parts supporting the market. Because of the high requirements for the shape or dimensional accuracy of the products, coupled with the different characteristics of resin materials, after the mold manufacturing is completed, it is also necessary to repeatedly test the mold and correction, so that the development and delivery time is very tight.
 

Off-site design and off-site manufacturing.

Mold manufacturing is not the final purpose, but the user proposed the final product design, mold manufacturers according to the user's requirements, design and manufacture of molds, and in most cases, the injection production of products in other manufacturers. This causes the product design, mold design and manufacturing, and product production off-site situation.
 

Professional division of labor, dynamic combination.

Mold production batch is small, generally belongs to the production of a single piece, but the mold needs a lot of standard parts, as large as the mold frame, small to the thimble, these can not and can not be completed by a manufacturer alone, and the manufacturing process is complex, ordinary equipment and CNC equipment use is extremely uneven.