Adjusting the Injection Molding Process

　　Confirm and prepare parameter settings before setting parameters

　　Confirm whether the material drying, mold temperature, and heating cylinder temperature are correctly set and reach a processable state;

　　Check the action and distance settings of opening and closing the mold and ejecting;

　　The injection pressure (P1) is set at 60% of the maximum value;

　　Maintain the pressure (PH) set at 30% of the maximum value;

　　Set the ejection velocity (V1) to 40% of the maximum value;

　　The screw speed (VS) is set at approximately 60RPM;

　　Set the back pressure (PB) at approximately 10kg/cm2;

　　Set the loosening to approximately 3mm;

　　The position for pressure maintaining switching is set at 30% of the screw diameter. for example φ 100mm screw, set 30mm;

　　Setting the measuring stroke to be slightly shorter than the calculated value;

　　The total shooting time is slightly shorter, and the cooling time is set to be slightly longer.

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　　Mini program

　　Manual operation parameter correction

　　Lock the mold (confirm the rise of high pressure) and advance the injection seat;

　　Manually shoot until the screw stops completely and pay attention to the stop position;

　　Screw rotation back feed;

　　After cooling, open the mold and take out the formed product;

　　Repeat steps (1) to (4) until the screw finally stops at a position between 10% and 20% of the screw diameter, and there are no short shots, burrs, whitening, or cracks in the formed product.

　　Correction of semi-automatic operation parameters

　　1. The correction of the metering stroke [metering end point] increases the injection pressure to 99%, and temporarily sets the pressure holding to 0. Adjust the metering end point S0 forward to the occurrence of short shot, and then backward to the occurrence of rough edge, with its middle point as the selected position.

　　2. Correction of discharge velocity restores PH to the original level, adjusts the discharge velocity up and down, and identifies individual velocities where short shots and burrs occur. The appropriate velocity is the midpoint. At this stage, you can also enter parameter settings that correspond to appearance issues at multiple speeds.

　　3. Adjust the holding pressure up and down to identify the individual pressures that cause surface dents and burrs, and select the middle point as the holding pressure.

　　4. The correction of the holding time [or injection time] gradually extends the holding time until the weight of the formed product is significantly stable, which is a wise choice.

　　5. Gradually adjust the cooling time and confirm that the following conditions can be met:

　　① The molded product will not whiten, crack or deform when pushed out, clamped out, trimmed, or packaged.

　　② The mold temperature can be balanced and stable. A simple algorithm for the cooling time of products with a meat thickness of 4mm or more:

　　Theoretical cooling time=S (1+2S)... mold temperature below 60 degrees Celsius.

　　Theoretical cooling time=1.3S (1+2S)... The mold is above 60 degrees [S represents the maximum thickness of the formed product].

　　6. Correction of plasticizing parameters

　　Confirm whether the back pressure needs to be adjusted;

　　Adjust the screw speed to make the metering time slightly shorter than the cooling time;

　　To confirm whether the measurement time is stable, try adjusting the gradient of the heating coil temperature.

　　Confirm whether there is any material dripping from the nozzle, whether there is pig tail or mold sticking in the main channel, and whether there are air marks in the finished product. Adjust the temperature or loosening distance of the nozzle appropriately.

　　7. Flexible use of pressure maintaining and multi stage firing rate

　　① Generally speaking, injection should follow the principle of high speed without affecting the appearance, but should be carried out at a lower speed before passing through the gate and pressure switching;

　　② The pressure should be gradually reduced to avoid high residual stress in the formed product, which can easily deform the formed product.