Table of Contents
What is injection pressure in injection molding?
Injection pressure is that pressure under which the mold fills; sometimes this is called the first-stage pressure. The holding pressure is the pressure that is maintained on the melt after the mold is filled and until the gate freezes or the pressure is removed by cycle timer-control.
How do you calculate cavity pressure in injection molding?
different viscosities are reflected in cavity pressure, so cavity pressure of PC lamp holder should be 160 bar*K (the viscosity grade of PC). P = 160*1.9 bar = 304 bar for safety reasons, we take 1.9 times. F=P*S=304bar*380cm2=304kg/cm2*380 cm2=115520Kg or 115.5Ton, so 120T can be used.
How do you calculate injection capacity?
To calculate the injection stroke or shot size, we can put all values in the formula of shot volume, i.e., Shot Volume = π x r2 x Shot Size. Here, r=1.4 and shot volume is 26.71 cm^3.
How is clamping pressure calculated?
The required clamping force can be calculated from the cavity pressure inside the mold and the shot projected area, on which this pressure is acting. There are variables that affect the clamping force calculation, like the material type (low-flow versus high-flow plastic), and the depth of the part.
How do you increase injection pressure?
The increase of injection pressure is accomplished by increasing the injector opening pressure from 400 up to 1600 bar.
How do you calculate clamping pressure in injection Moulding?
Mold Clamping Force Formula (F: tf) The total projection area is the total of the projected areas of the cavities and runners in relation to the parting surface. Therefore, this value varies depending on the number of items molded and on the runner layout. 400 × (16.0 + 5.0) ÷ 1000 = 8.4 (tf).
What is cavity pressure?
What is cavity pressure? In injection molding, cavity pressure – the pressure in the interior of the injection mold, which is filled with liquified plastic – is a key indicator of the quality of the molded part that is produced.
How do you calculate clamping tonnage for injection molding?
T = A x cf. For example, the projected area of the molded part is 150 sq/in times a clamp factor of 3 (tonnage needed/square inch from material data sheet). 150 x 3 = 450 tons needed. If you are running in a 500-ton press, try starting at 450 tons.
How is clamping load calculated?
Clamp load (lb.) is calculated by arbitrarily assuming usable bolt strength is 75\% of bolt proof load (psi) times tensile stress area (sq. in.) of threaded section of each bolt size. Higher or lower values of clamp load can be used depending on the application require- ments and the judgement of the designer.
What is injection rate?
An injection rate can be defined as the volume of fluid or gas injected into a well during pumping in which the fluid or gas is artificially lifted using a downhole pump.