Factors to influence product are mainly as follows: (1) machine problems; (2 )mould problems; (3) material problems; (4) human factor; (5) environment factor
(1) Machine problems
Time: Screw advance, material cooling, mould opening time, injection speed
Temperature: Heater, nozzle, raw material drying, heat from screw rotation
Pressure: Ejector, insufficient injection cavity, pressure holding
(2) Mould problems
Time control: Injection time, cooling time
Pressure control: Design of main sprue and other sprue, design of flow line length of melting material in die cavity, die exhaust
Temperature control: Design of flow line length of melting material in die cavity, whether the design of cooling tube in die is even and reasonable
(3) Material problems
Flow property: Melt viscosity in injection molding, viscosity change under different flow particles (i.e. shear force influenced by viscosity), resin formula
Thermal property : Thermal conductivity, the time required for the starting of the material from cooling to crystallization
Colloidal particles: Size and shape, lubrication property
(4) Human factor
Human factor refers to the professional skills of operators. It’s the dependent factor on product quality.
(5) Environment factor
The surrounding temperature and humidity to a great extent influences the injection process. The higher quality you need about the machine, the higher requirements are needed on the surroundings.
II. Ways to refine product defectiveness
1. Analysis of refine product defectiveness
An approximate injection cycle depends at first on operator’s experience. Check whether the products are good. If not, adjust the time, temperature, pressure one by one. If there’s no difference, it might be the problem of mould and material.
2. Five principles to abide by
(1) Set next plan; (2) Change one factor a time; (3) Adjust one factor a time; (4)Write down operation condition every time; (5) Save up the operation note for future reference More information please visit petblowingmachine