Plastic parts injection molding parameters requirements, worth collecting!

 

Plastic parts injection molding parameters

Injection molding, also known as injection molding, is a molding method of injection and molding. The advantages of injection molding method are fast production speed, high efficiency, automatic operation, variety of designs and colors, shape can be from simple to complex, size can be from large to small, and the product size is accurate, the product is easy to replace, can form complex shape parts, injection molding is suitable for mass production and complex shape products and other molding processing fields. In the process of injection molding, we must be clear about the parameter Settings and requirements. Please kindly sort out some injection molding parameter requirements:

 

First, before parameter setting, it is necessary to confirm and prepare to set the injection molding parameters

 

⑴ Confirm whether the material drying, mold temperature and heating cylinder temperature are set correctly and can be processed.

⑵ Check the action and distance setting of the opening and closing mold and the ejection.

⑶ The injection pressure (P1) was set at 60% of the maximum value.

⑷ Keep the pressure (PH) at 30% of the maximum value.

⑸ The ejection velocity (V1) is set at 40% of the maximum value.

⑹ The screw speed (VS) is set at about 60RPM.

⑺ Back pressure (PB) was set at about 10kg/cm2.

⑻ loosening is set at 3mm.

⑼ Voltage switch position is set at 30% of the diameter of the screw. For example, a screw of φ100mm is set to 30mm.

(10) The measuring stroke is set slightly shorter than the calculated value.

(11) The total time of injection is slightly shorter, and the cooling time is slightly longer.

 

Two, manual operation injection molding parameters correction

 

⑴ Lock mold (confirm the rise of high pressure), the injection seat forward.

⑵ Manually shoot until the screw stops, and pay attention to the stop position.

⑶ screw back feed.

⑷ After cooling, open the mold to take out the molding products.

⑸ Repeat the steps of ⑴~⑷, the screw stops at the position of 10% ~ 20% of the diameter of the screw, and the molding product has no short shot, burr and whitening, or cracking.

 

Three, semi-automatic operation parameters correction

 

⑴ The correction of measuring stroke [measuring end point, increase the injection pressure to 99%, and temporarily adjust the pressure holding to 0, adjust the measuring end point S0 forward to the occurrence of short shot, and then backward to the occurrence of burr, with the middle point as the selection position.

 

⑵ The PH is returned to the original level, and the injection speed is adjusted up and down to find out the individual speed of short shot and burr, and the middle point is the appropriate speed [this stage can also enter the parameter setting of multi-section speed corresponding to appearance problems].

 

⑶ The correction of the holding pressure adjust the holding pressure up and down, find out the individual pressure of the surface depression and burr, and choose the holding pressure at the middle point.

 

⑷ the pressure holding time [or injection time] correction gradually extend the holding time, until the shape of the weight is obviously stable for the appropriate choice.

 

⑸ Correction of cooling time gradually reduce the cooling time, and confirm that the following conditions can be met:

 

① Molded products are jacked out, clipped out, trimmed, packaging will not whiten, convex crack or deformation.

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

 

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

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

 

⑹ Modification of plasticizing parameters:

 

① Confirm whether the back pressure needs to be adjusted;

② Adjust the screw speed, so that the measuring time is slightly shorter than the cooling time;

③ To confirm whether the measurement time is stable, you can try to adjust the gradient of the heating ring temperature.

④ Confirm whether the nozzle has dripping material, whether the main channel has pig tail or sticky mold, whether the finished product has air marks and other phenomena, and adjust the temperature of the nozzle or the loosened distance appropriately.

 

The use of ⑺ pressure holding and multiple firing rate

 

① In general, without affecting the appearance, the injection should be carried out at a high speed, but it should be carried out at a lower speed before passing through the gate and pressure holding switch;

② The pressure retention should be gradually decreased to avoid too high residual stress in the molded product, so that the molded product is easy to deform.