It is true that large machine has a large clamping force and small machine has a small clamping force. Main basis for classification of injection molding machines is clamping force.
#Force calculation tool software#
Calculated using CAE software (MOLDFLOW, etc.).
#Force calculation tool Pc#
Projection area value of PC lamp holder.P = 160*1.9 bar = 304 bar for safety reasons, we take 1.9 times. Compared with the first group, viscosity of PC is 1.7-1.9 times of that, different viscosities are reflected in cavity pressure, so cavity pressure of PC lamp holder should be 160 bar*K (the viscosity grade of PC). Determination of cavity pressure value of PCįlow properties of PC belong to viscosity class of sixth group.For other groups of plastics, we should multiply corresponding multiplication constant K. Data is applied to the first group of plastics. It can be seen from figure that cavity thickness of 1.9mm, cavity pressure of flow/wall thickness ratio of 105:1 is 160Bar. Relationship between cavity pressure and wall thickness, process/wall thickness ratio is provided. Application of cavity pressure/wall thickness curve.Process / wall thickness = longest melt process / thinnest part wall thickness = 200mm / 1.9mm = 105:1 Process / wall thickness ratio calculation.Place where flow resistance of melt is the largest occurs at position where wall thickness is thinnest (1.9 mm), so value of 1.9 mm should be used when calculating required injection pressure. K (multiplication constant)įor example, part: calculation of clamping force of polycarbonate (PC) lamp holderĪs shown in figure is a round PC plastic lamp holder with outer diameter of 220mm, wall thickness range of 1.9-2.1mm, and pin-type center gate design.Group 6 * 1.70～1.90 3.3 Cavity pressure is determined by ratio of wall thickness, flow to wall thickness Relative viscosity grades of each group of plastics are as follows: Group 6: PC PES PSU PEI PEEK UPVC 3.2 Viscosity gradeĮach of above groups of plastics has a viscosity (flow capacity) rating. Group 4: ABS AAS/ASA SAN MBS PPS PPO-M BDS POM Group 3: CA CAB CAP CP EVA PEEL PUR/TPU PPVC Group 1: GPPS HIPS TPS PE-LD PE-LLD PE-MD PE-HD PP-H PP-CO PP-EPDM (5) Injection speed 3.1 Grouping of thermoplastic flow characteristics (4) Viscosity characteristics of plastics used Projected area (S) is the largest area viewed along mold opening and closing.Ĭavity pressure is affected by following factors Two important factors in calculating clamping force:ġ. Empirical Formula 2Īs above, 350*410/1000=143.5T, choose 150T machine.Ībove two methods are coarse calculation methods, following are more accurate calculation methods. Clamping force (T) = clamping force constant Kp * product projected area S (CM * CM)įor example, a product has a projected area of 410 cm2 and material is PE, calculate clamping force.Ĭalculated by above formula: P = Kp * S = 0.32 * 410 = 131.2 (T), 150T machine tool should be selected.
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