Plastic fruit container mould
P20H, 2344, 718H die steel
Glue feeding method
Hot runner multi-point injection
Cylinder ejection, bullet ejection
Multi-point cross short circulation system
Mold cycle (from blanking to trial mold)
40-65 working days (except for special circumstances)
In recent years, the rapid economic development of various countries and regions, and the transportation demand of various industries have also increased year by year. The demand for turnover boxes, frames, and plastic pallets has increased. Our company designs and manufactures molds for customers' plastic fruit turnover boxes.
This kind of plastic products are transportation packaging products, which have requirements for the weight and strength of the products, and higher requirements for the mold. The company uses high-quality mold steel with precision processing technology in the mold, and the structure is matched with the cavity elastic Block structure and large slider cylinder demoulding structure. Compared with the traditional structural design, the produced products have thin walls and ensure their strength, which greatly improves the production efficiency and product qualification rate for customers.
718H die steel
718H mold steel generally refers to 718H. my country's GB standard steel number 3Cr2NiMo; German DIN standard material steel number 2738; Sweden ASSAB ASSAB standard steel number 718; American AISI/SAE standard steel number P20 optimization; Japan JS standard steel number SNCM optimization; International Standard Organization ISO standard steel number 35CrMo2.
718H is a vacuum-melted chromium-nickel-molybdenum alloy steel, which has been hardened and tempered before leaving the factory. It has the following advantages: no risk of quenching cracking and heat treatment deformation; no heat treatment costs; shortened mold production cycle; reduced mold requirements Cost (for example, there is no need to deform the mold); the mold is easy to modify; nitriding and surface hardening treatment can be applied to improve the surface hardness and wear resistance of the mold.
718H steel is a pre-hardened mirror-surface acid-proof plastic mold steel. The steel is pre-hardened, and the material is uniform, clean, and has excellent polishing performance and photoengraving properties. It also has high hardenability, good electrical processing performance and skin texture processing performance. Pre-hardened steel can also be used in the die cavity without quenching. The flange can be flame hardened to increase the hardness to 52HRC.
718H is plastic mold steel, pre-hardened to 33~38HRC.
In the protected state, it is heated to 700°C, after soaking, it is cooled to 600°C at a rate of 15°C/h in the furnace, and then air-cooled.
After rough processing, heat to 550°C, keep for 2 hours, slowly cool to 500°C, and then air cool.
Before quenching, it must be fully annealed to eliminate processing stress. Preheat at 500~600℃ for 2 hours and keep it at 850℃ quenching temperature for 30 minutes; heat and keep in protective atmosphere to avoid decarburization and oxidation. Then cool in oil, or cool in air at 300°C for 4 minutes. When cooled to 50~70℃, it should be tempered immediately.
It can increase the surface hardness of the mold and improve the wear resistance. The method is to use oxyacetylene flame (wind coal) to heat the surface of the mold, and then cool and harden, the hardness can reach 45~52HRC.
Treatment method: preheat 150~200 HRC to prevent cracking; then continuously heat the mold surface to 850~950℃ (the surface is light red), and then cool it in air; when it is cooled to 50~70℃, immediately at 180~200℃ Tempering to prevent cracks during grinding.
The carburizing treatment temperature is 850~940℃, and the time depends on the depth of product demand. If the carburizing temperature exceeds 880°C and the time exceeds 2 hours, it must be normalized to keep the structure grain fine. After carburizing, it is cooled to 830°C in the furnace, quenched in oil after soaking, and then tempered. The tempering temperature is as listed; thus, the surface hardness is improved and the wear resistance is increased. If only high hardness is required and no fine grain structure is required, it can be quenched at a carburizing temperature above 880°C.
Nitriding treatment can obtain a harder surface layer. At the same time, it has good wear resistance and corrosion resistance. The hardness after nitriding treatment in ammonia gas can reach 650HV.
Soft nitriding treatment at 570°C can obtain a surface hardness of 700HV. After 2 hours of treatment, the depth of the hardened layer is 0.01mm.
Hard chromium layer covering, tools covered with hard chromium layer must be tempered at 180°C for 4 hours to avoid hydrogen embrittlement.
The correct grinding technology can avoid cracks and increase the life of the mold. The material that has been tempered at low temperature is very sensitive to cracks during grinding. At this time, the grinding wheel must be trimmed. Only a soft and open-grained grinding wheel is suitable. At the same time, sufficient lubricant and proper peripheral speed are also important.
718H has good polishing properties. It is usually polished with alumina powder and diamond paste. The steps are as follows:
The five-axis machining center has the characteristics of high efficiency and high precision, and the workpiece can be processed in a pentahedron in one clamping. If equipped with a five-axis linkage high-end numerical control system, it can also perform high-precision processing of complex spatial curved surfaces, which is more suitable for processing modern molds such as auto parts and aircraft structural parts. There are two ways for the rotary axis of the vertical five-axis machining center. One is the table rotary axis. The table set on the bed can rotate around the X axis, which is defined as the A axis. The general working range of the A axis is +30 degrees to- 120 degrees. There is also a rotary table in the middle of the worktable, which revolves around the Z axis at the position shown in the figure, which is defined as the C axis, and the C axis rotates 360 degrees. In this way, through the combination of A-axis and C-axis, except for the bottom surface of the workpiece fixed on the worktable, the other five surfaces can be processed by the vertical spindle. The minimum graduation value of A-axis and C-axis is generally 0.001 degrees, so that the workpiece can be subdivided into any angle, and inclined surfaces, inclined holes, etc. can be processed. If the A-axis and C-axis are linked with the XYZ three linear axes, complex spatial surfaces can be processed. Of course, this requires the support of high-end CNC systems, servo systems and software. The advantage of this arrangement is that the structure of the spindle is relatively simple, the rigidity of the spindle is very good, and the manufacturing cost is relatively low. However, the general worktable cannot be designed to be too large, and the load-bearing capacity is also small, especially when the A-axis rotation is greater than or equal to 90 degrees, it will bring a large bearing moment to the worktable when the workpiece is cut. The other is to rely on the rotation of the vertical spindle head. The front end of the main shaft is a revolving head that can circle the Z axis 360 degrees to become the C axis. The revolving head also has an A axis that can rotate around the X axis, which can generally reach more than ±90 degrees to achieve the same function as above. The advantage of this arrangement is that the spindle processing is very flexible, the worktable can also be designed to be very large, and the huge fuselage and huge engine shell of the passenger aircraft can be processed on this type of machining center. This design also has a big advantage: when we use a spherical milling cutter to process curved surfaces, when the center line of the tool is perpendicular to the processing surface, since the linear velocity of the apex of the spherical milling cutter is zero, the surface quality of the workpiece cut by the apex will be poor. The spindle rotation design is adopted to make the spindle rotate an angle relative to the workpiece, so that the spherical milling cutter avoids the apex cutting, guarantees a certain linear speed, and improves the surface processing quality. This structure is very popular for high-precision surface machining of molds, which is difficult for rotary table machining centers. In order to achieve the high precision of rotation, the high-end rotary axis is also equipped with circular grating scale feedback, and the indexing accuracy is within a few seconds. Of course, the rotation structure of this type of spindle is more complicated and the manufacturing cost is also high.
Reply: The mold can provide LKM, DME, Futaba, Harsco and other standard mold bases to design and manufacture molds according to customer requirements, and can also customize special standard molds for customers from the production needs.
Reply: Once we get enough information from the customer, we will provide the exact quotation within 1-2 working days.
Reply: We need 2D product drawings and 3D files, or specific samples with detailed instructions and mold separation.
Reply: The total cycle from blanking to mold trial is 40-65 working days (except for special circumstances), and each link is kept on file so that customers can understand the progress of the mold at any time.