How will the clamping force and injection pressure of injection mould be set?
According to the product design of the mold to decide, you still find a master, so you can not ask what
The clamping force is usually formulated according to the projection area of the product, and there is an estimate of the clamping force in the die design to select the model of the injection machine. Injection pressure is generally obtained from the die flow analysis, but the flow analysis is not very accurate. In general, the injection pressure of PP products is 50-70, and the injection molding is a little higher (plastic with poor flowability, such as POM, PA, etc.). Injection pressure is based on actual production experience
Standard method:Calculation of clamping force of injection molding machineThere are two important factors to calculate the clamping force: 1. projection area and 2. cavity pressureThe 1. projection area (S) is the maximum area to be viewed along the opening and closing of the die.2. cavity pressure determination (P) the cavity pressure is affected by the following factors (1) the number and location of the gate (2) the size of the gate (3), the wall thickness of the product (4), the viscosity characteristics of the plastic (5), the speed of injection2.1 grouping of flow characteristics of thermoplasticsGroup 1 GPPS, HIPS, TPS, PE-LD, PE-LLD, PE-MD, PE-HD, PP-H,, PP-CO, PP-EPDMGroup PA6, PA66, PA11/12, PBT, PETP,Group CA, CAB, CAP, CP, EVA, PEEL, PUR/TPU,, PPVCGroup ABS, AAS/ASA, SAN, MBS, PPS, PPO-M, BDS,, POMFifth groups PMMA, PC/ABS, PC/PBTGroup PC, PES, PSU, PEI, PEEK, UPVC,2.2 viscosity grade above each group of plastics have a viscosity (flow capacity) level.The relative viscosity of each group is as follows: Group multiplication constant (K)Group 1 * 1Second groups * 1.3 to 1.35Third groups * 1.35 to 1.45Fourth groups * 1.45 to 1.55Fifth groups * 1.55 to 1.70Sixth groups * 1.70 to 1.902.3 the cavity pressure is determined by the wall thickness, the ratio of the process to the wall thickness, and the table P0 = P=P0. K (Bei Zeng constant)2.4 determination of clamping force (F) F=P ? S= P0 ? K ? S
The clamping force can be calculated, and the injection pressure should be determined according to the actual condition of the mold and the specifications of the injection molding machine.A simpler approach:When the material is injected into the mold cavity at high pressure, it will produce a support force, so the mold locking unit of the injection molding machine must provide sufficient clamping force to prevent the mold from being opened. The clamping force is calculated as follows: from the demand for the appearance of the finished product size projection area in the direction of the switch mode of finished products; projection area of the supporting die strength = finished in switching mode direction (cm2) pressure * * mold cavity number (kg/cm2); mold pressure with raw materials and different raw materials, general 350~400kg/cm2 machine; the clamping force is greater than the supporting die strength, and to be on the safe side, the machine clamping force usually must be greater than 1.17 times the strength of the supporting die.
