Table of Contents
What is holding time in injection molding?
Hold time comes during the second stage of a Decoupled-II process, which occurs after the first stage fills the cavity 95-98\% full. During the second stage, the hold pressure is used to completely fill the cavity and pack out any important complex detail or texture.
How do you set cooling time in injection molding?
Although material begins to cool as soon as it exits the heated injection nozzle and enters the mold cavity, cooling time should only be calculated as a separate phase, after packing and holding. At this point, the liquefied resin begins to re-solidify and hold the shape of the mold cavity.
What determines the cycle time in injection molding?
Cycle time is dependent on the design of the mold, cavity (part) configuration and material being molded. Total cycle time includes the time required to inject the plastic into the mold, cool the plastic, open the mold, eject the part(s) and re-close the mold.
How do you set injection molding parameters?
Injection of main process parameters are as follows:
- (1) cylinder temperature.
- (2) the melting temperature.
- (3) the mold temperature.
- (4) injection pressure.
- (5) injection speed.
- (6) time parameter (molding cycle)
What is the holding 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 find the hold time on an injection molder?
To find the true hold time, the molder must subtract the actual fill time from the set time on the injection timer. A series-logic controller ignores any remaining time on the injection timer after first stage is reached and provides a second-stage time exactly at whatever is set.
How to set the speed of injection molding machine?
Speed: set injection speed from slow ; set screw rotating speed from low; set mold open/close speed slowly at first; injection volume from small position. Time: set long pressure holding time of injection molding machine at first (ensure sprue closed); set long cooling time at first.
Why are injection molding pack and hold times so important?
These timing aspects — along with holding pressure in injection molding — can be considered the building blocks of the overall injection molding process, and they can make a big difference in your finished product, including its bottom line. Let’s first define injection molding pack and hold times, and then look at some ways to optimize them.
What is the pressure holding time and cooling time of injection mold?
For example, if estimated injection time is 0.85s, then pressure holding time is 8.5s, and extra cooling time is 8.5s. by this way, it can make sure the product and runner system solidification enough for ejecting. Generally, the mold open time can be set 2~5s, including mold open, ejecting, mold close.