Thin-wall injection molding machines and molds for injection What are the requirements
on the production of small and light workpiece so that the demand has become a thin-walled injection molding machines are most needed to increase performance. "Thin" is usually less than 1mm from the wall thickness of the workpiece defined by the light electron. For large cars workpiece, the "thin" can be 2mm. In short, thin-walled products calling for a change processing technology: a higher pressure and speed, a shorter cooling time, to change the workpiece top-out and gate array. The following is a thin-walled injection molding of injection machine and die requirements.
Injection molding machine
a standard injection machine for the production of a variety of thin-walled products. At present the performance of the new injection machine far more than 10 years ago. Materials, gate technology and design advances, further broadening the standard injection machine thin-walled workpieces filling performance. However, wall thickness of the steady decline in need for a more special, high-speed and high-performance injection machine. For example, a thickness of less than 1mm of electronic workpieces, filling time of less than 0.5 seconds and the injection pressure in excess of 210MPa is normal. Used for thin-wall injection molding machine of the design of hydraulic accumulator can be frequently driven injection mold harmony. High-speed and high performance all-electric injection machines and electric / hydraulic injection machine is also available in. To be able to withstand the new high-pressure injection machine, clamping force must be a minimum of 5 to 7 tons / inch (projection area). In addition, when the wall thickness reduction of injection pressure is increased, large-scale templates help to reduce bending. Thin-walled injection machine products used in the thickness of the rod template ratio of 2:1 or lower. Production of thin-walled products, the injection speed and pressure as well as other processing parameters, an infinite loop controls can help under the control of high pressure and high-speed filling and packing.
As for the injection volume, large-diameter cylinder is often too large, the proposed injection volume of cylinder capacity of 40% to 70%, thin-walled products significantly shorten the overall molding cycle, it is possible to reduce the minimum injection volume barrel capacity 20 % ~ 30%. Injection when the user must be very careful because of the material, the small injection volume means that materials in the machine cylinder with a longer retention time, which will lead to performance degradation products
thin wall injection speed is a key factor in the success of one. Quick mold filling and high pressure can speed the melting of the thermoplastic material into the mold cavity, thereby preventing cold-gate. If a standard workpiece in two seconds to complete filling, then the mold thickness reduced by 25%, it is possible to mold filling time reduced by 50%, just 1 second.
One advantage of thin-walled injection molding is that when the thickness reduction, the need for cooling less material. With the reduction in thickness can be cut in half the molding cycle. Melt transfer device so that a reasonable set of hot runner and the runner does not impede the shortening of molding cycle. The use of hot runner and sprue bushings help to shorten the molding cycle to a minimum. In addition, consideration should be given to the mold timber. P20 steel is widely used in the mold of traditional products, but because of the pressure of a higher thin-walled injection molding, mold manufacturing to be very strong. H-13 and other hard steel as thin-walled mold an additional safety factor. However, the firm may be higher than the standard cost of mold die 30% ~ 40%. However, the increased costs will normally be offset by improved production performance.
this Information from Wishsino Plastic Injection Molding Company
