How to deal with the silver streak in the plastic storage box mould

- Jun 27, 2018-

    When the plastic storage box mould is in injection production,silver steak appear duo of the water vapor,decomposition gas,solvent gas,and aire interference.The sliver streak includes surface bubbles and internal pores.How to deal it for this phenomenon in making plastic injection mould.

   Consider Injection machine aspects

1.       Barrel,screw is wear and tear,and there is a material flow dead corner ,lone term heat and decomposition.

2.       The heating system is out of control and the temperature is too high.Check whether there are any problem with the heating elements such as thermocouples and heating coils.Incorrect design of the screw leads to a solution or easy air.

Consider Plastic storage box mould aspects:

1.       The mould had bad venting system

2.       The runner ,gates ,and cavities in the mould have large frictional resistance,causing partial overheating and decomposition

3.       Gating and cavity is unbalanced distribution,unreasonable cooling system cause heat unbalanced or blocked air passages.

4.       The cooling passage leaks into the cavity.

Consider Plastics raw material aspects:

1.       The plastic has high humidity, and the proportion of recycled materials added is too high or contains hazardous waste materials

2.       The amount of lubricants, stabilizers, etc. added to plastics is excessive or mixed unevenly, or the plastics themselves contain volatile solvents. When the degree of heat is difficult to take into account, the mixed plastics will also decompose.

3.       Plastics are contaminated and mixed with other plastics.

Consider plastic industry mould Injection processing aspects:

1.       Set the temperature, pressure, speed, back pressure, melt motor speed is too high to cause decomposition, or pressure, speed is too low, the injection time, pressure is not sufficient, back pressure is too low, due to the failure to obtain high pressure and low density can not be melted The appearance of silver grains in the gas should be set with proper temperature, pressure, speed and time, and multiple injection speeds.

2.       Insufficient material quantity, too large feeding cushion, too low material temperature or too low mold temperature all affect the material flow and forming pressure, and promote the formation of bubbles.