Based on high-end machining centers, Eclipse Mold has set a good example for effective zero-tolerance machining. Diemakers at Eclipse Mold have apparently felt that there are many advantages to the zero-plus cutting of the molds, which they can prove with facts. At present, the company has a mold processing workshop, which can produce approximately 140 molds per year. This business also includes a large number of mold repair services, accounting for about 40% of the total business volume. The remaining 60% of the company's revenue comes from three injection molding plants, all of which are located in the suburbs of Detroit. In fact, the company has a total of 42 injection molding machines with pressure ranging from 22 to 750 tons. Fig. 1 After finishing the car mold, there is no excess margin on the surface of one side of the core. In addition to polishing with a lighter medium, the mold actually does not require hand polishing. From the figure, one side of the cavity can be seen, in which the quality of the machined surface of the closed face can also be seen The Eclipse Mold mold factory is located in Clinton Township. The molds used in the above-mentioned injection molding machines are manufactured at its factory. The company adopts zero-tolerance processing to varying degrees on almost all of these molds. Mr. Steve Craprotta, the company’s vice president and general manager, said: “The tools used in the net cutting process have faster working speed, longer service life and lower maintenance costs. The parts they produce are of good quality and are very clean and clean. Every day we maintain our existence with such production results, so we know how valuable this method is to us." Only 15% of Eclipse's annual molds are used in their own factories. The rest of the molds are shipped to large Tier 1 automotive suppliers, whose customers include familiar American and Japanese car manufacturers. Mr. Craprotta said without exaggeration: “All our customers think that our mold shop is the best.†The reason he emphasized this is to further convince people that zero-tolerance machining is to establish its processing workshop. An indispensable part of this market's competitive position. In order to meet the needs of mold production, Eclipse Company specializes in providing secondary injection molds. Such molds usually have only one core or one cavity, they must be suitable for the installation of the other two mold halves, or they need to rotate 180° on one side to meet the needs of the second injection molding. Mr. Craprotta explained: “If these molds are machined in the usual way, then they will need to be hand-worked and hand-polished. It will take too long to meet the deadline or meet our own production plan.†The closed surface is machined to zero tolerance dimensions (in many cases, even to negative tolerances), which can reduce manual grinding time to several hours. He said that one side can be matched with the other side. When it is rotated or matched with the other half, the tightness of the fit is almost perfect. Most of the molds produced by Eclipse are very complex multi-cavity, high-precision molds. Although medium-size molds for presses of 300 to 700 tons are common, the largest molds can reach 40 in × 50 in (1 in = 25.4 mm). ), the minimum can reach 8 in × 8 in. 70% to 80% of the molds are related to mechanically-operated parts such as slides, push rods, collapsible cores, and similar parts. The use of zero-tolerance machining not only cuts a lot of point-by-point grinding time, but also improves the production level of the mechanical parts. For example, the push rod is mounted directly in the recess of the mold, with little or no adjustment. The shop's zero-tolerance machining relied on three state-of-the-art machining centers, including the V55 and V56 VMC vertical machining centers offered by Makino (Mason, Ohio) and a Johnford DMC-1500 Type machining center. Mr. Craprotta said: “The firmness and precision of Makino's machine tool is the fundamental guarantee for achieving zero tolerance machining capability.†The 30 in × 50 in large workbench of Johnford's machine tool can meet the needs of the workshop for processing large molds. According to Mr. Craprotta, the machine has achieved zero-tolerance cutting, which is comparable to a small VMC vertical machining center. Figure 2 Eclipse believes that the rigidity of its machining center is critical to zero-volume processing. The Makino V55 VMC vertical machining center shown in the figure above has a spindle speed of up to 20 000 r/min and is equipped with an HSK interface. As can be seen from the figure, the machine tool is undergoing semi-finishing Suitable for milling hard materials Eclipse Mold Mold Co. started cooperation with SST in 1992 when the shop just purchased the first high-speed milling machine from Makino to produce graphite electrodes. Mr. Craprotta recalled: “We have learned high-speed machining through the production experience of these machine tools.†When Makino started selling hard material milling machines for processing more than a small amount of mold parts, it caught the attention of Eclipse. In 2001, the company purchased the first machining center for milling hard materials. Compared with ordinary milling, hard material milling has a certain "risk", and in the initial processing, it will encounter certain difficulties, may cause tool fracture or ablation, and may also cause the retirement of expensive mold materials . It is hard to imagine a mechanical operator to carry out high-precision milling of hard materials every day. They almost want to give up this processing method. Mr. Craprotta stated: “Because we began to apply this process early on, we took a step earlier than other processing plants, so we have a certain amount of room for conversion and easy transition.†First, the workshop began to gradually decrease. The required machining allowance was reduced from 0.003 in to 0.002 in and 0.001 in. In this process, the machining shop gradually accumulated experience in machine tools, tools and tool paths. Facts have proved that it is also wise to invest directly in zero-tolerance processing for all assistive technology investments. For example, the shop began using the HSK interface and balanced tools. The company's CAM programming software has also been further upgraded. When operators saw that the process produced such good results, their attitudes began to change and they were willing to accept new training and new operating practices. Mr. Craprotta said that in the end they were not only eager to adopt a zero-tolerance cutting process, but also began to implement negative tolerance cutting on the closed surface of the mold. The adoption of this process took about a year or so to transition. As the programming of the mold surface becomes more and more precise by the programmer, it ensures the mechanical operator's full trust in the tool path. The shop applies the PowerMill software provided by Delcam (Windsor, Ontario) to generate a tool path for zero tolerance cutting. One of the most experienced programmers at the workshop, Mr. John Zube, said: “It is critical for programmers to establish a good relationship with the mechanical operator. The comments and suggestions from the workshop tell him how to work and how to work. it is good." Feedback from the press forming shop is also important. Reports from these business units are helpful to programmers and mechanical operators and help them to further improve their work. Figure 3 In this injection molding machine, the secondary injection mold can be rotated 180° on the platen to facilitate the secondary injection molding of soft plastic parts. Since the closed surfaces in both directions must be sealed, a precision machining process is used, eliminating the need for manual machining. This ensures that the point-by-point grinding time required to complete the mold is minimized. Machine rigidity, high precision, high machining efficiency The principle of Mr. Craprotta's purchase of milling hard material milling machines boils down to the following: Should try to purchase the most rigid precision machine tools. The rigidity of the machine is a very critical factor because it minimizes the vibration of the tool tip. He added that, of course, the design of other parts of the tool is also very important, the stability is better, and the radial runout error is lower. Makino's VMC vertical machining center has the following characteristics: The rigidity of the machine structure is good, including its spindle box and guide rails, linear roller bearings, excellent quality bases and columns, and ball screws supported on both ends. Makino's machine tool spindles have a maximum speed of 20 000 r/min. For small tooling applications, such high speeds are absolutely necessary to achieve proper chip loads when operating at high feed rates and low cutting depths. Mr. Craprotta thinks: “We can see such a phenomenon on these machines: In the high-speed operation, the heat of the machine spindle does not increase. These machines have been running more than 10 hours a day, and there has never been a problem of Z depth.†Mr. Craprotta added: "Machine machining must maintain accuracy, not only to maintain its center-wide accuracy, but also to maintain its full accuracy over its entire operating range." When sub-miniature tools do micro-motion, they also need to Use glass rulers with a few parts per million resolution. The final finishing cut uses tools as small as 0.010 in, but the typical tool is 0.030 in. When Eclipse cuts cores and cavity surfaces, its tolerance accuracy often reaches ±0.0004 in. The surface finish is in the range of 16 to 24 rms. Mr. Craprotta said that the main advantage of Johnford's machine tools is that they are more economical. He said: "This machine has outstanding value advantages in terms of price and function." This machine is equipped with a 90° gantry bridge and Y-axis offset guide, which can extend the deviation of the stroke when machining a large mold. Reduced to the minimum. The headstock rails in the Y-axis and Z-axis directions help to increase rigidity, while the X-axis uses linear guides to help the precise movement of heavier workpieces. However, Mr. Craprorotta said that the machine shop had obtained the best results from this machine because SST had adjusted the axes of the machine tool before the machine was shipped, so it was ideal for the milling of hard materials. Mr. Craprotta stated: “We have obtained a lot of benefits from this machine. The machine is particularly suitable for high-precision machining. That is to say, using this machine can meet the requirements of zero-tolerance machining.†More importantly, this machine The extended stroke of the machine tool allows the shop to produce multi-cavity molds for the injection molding of large parts such as automotive interior dashboards. Mr. Craprotta said: “For us, this has always been a promising area for development.†Finally, he further emphasized the importance of milling of hard materials, requiring at least one shift per day to be unattended. In general, during the first and second shifts of working hours every day, an operator of Eclipse Mold is on duty to monitor and control the production of seven CNC machine tools. However, depending on the change of production load, it is not always necessary. One operator is on duty. Figure 4 Mr. Steve Craprotta (right) and Mr. John Montalbano, mold production manager, are inspecting a part that is injection molded from this 4-cavity mold. Part surface and mechanical parts are cut to zero Further expand business As the zero-tolerance machining process helped Eclipse further increase productivity, Mr. Craprotta was convinced that his shop had to expand the scope of processing and assume all the business work it could undertake on a traditional customer basis. The goal of this workshop is to provide high-quality, high-precision mold processing services for customers in medical and aerospace industries. Mr. Craprotta is not as eager as his counterparts in the automotive industry to seek the outside machining of molds from overseas manufacturers, especially in the southeastern Michigan region. Other mold processing workshops are fully capable of undertaking this processing. business. He said: "Zero-tolerance processing has made tremendous contribution to our company's current status." Now, the processing plant has begun to shift its attention to lean production technology to further increase production efficiency. Potassium Ferrocyanide,Potassium Ferrocyanide Cas,Potassium Ferrocyanide Price,Potassium Ferrocyanide In Salt Sichuan Yibin United Import & Export Ltd. , https://www.ybund.com
