common questions in plastic injection 2

common questions in plastic injection 2

11. Reasons and solutions for white spots in transparent products.

The transparent products have white spots because of the cold glue in the products or the dust in the materials. Raise the temperature of the nozzle, add the cooling well, and keep the raw materials to prevent dust from entering.
12. What is the injection ability of injection molding machine.
Firing capacity PW = firing pressure (kg / cm2) × firing volume (cm3) / 1000
13. What is the injection horsepower of injection molding machine?
Injection horsepower PW (kw) = injection pressure (kg / cm2) × injection rate (cm3 / sec) × 9.8 × 100%
14. What is the injection rate of injection molding machine?
Injection rate V (CC / sec) = л / 4 × D2 × RD2: diameter of material pipe R: density of material
15. What is the injection force of the injection molding machine?
Rubber injection thrust f (KGF) = л / 4 (d12-d22) × P × 2D1: inner diameter of oil cylinder D2: outer diameter of piston rod P: system pressure
16. What is injection pressure of injection molding machine?
Injection pressure P (kg / cm2) = [л / 4 × (d12-d2 2) × P × 2] / (л / 4 × D2)
17. What is the plasticizing ability of the injection molding machine?
Plasticizing capacity w (g / sec) = 2.5 × (D / 2.54) 2 × (H / 2.54) × n × s × 1000 / 3600 / 2H = screw front tooth depth (CM) s = raw material density
18. What is system pressure? What's the difference with injection pressure?
System pressure (kg / cm2) = the highest working pressure set in the oil pressure circuit. Injection pressure refers to the actual pressure of the injection molding machine, and the two are not equal.
19. Requirements for hydraulic oil of injection molding machine:
(1) Proper viscosity and good viscosity performance
(2) Good lubricity and antirust
(3) Good chemical stability, not easy to gasify into gum
(4) good foams.
(5) Less corrosive to parts and sealing devices
(6) The ignition point (flash point) requires low freezing point.
20. How does the viscosity of hydraulic oil affect the injection molding machine?
When the working temperature of the system is high, the oil with higher viscosity should be used; otherwise, the oil with lower viscosity should be used. When the working pressure of the system is high, the oil with higher viscosity should be used, because at high pressure, sealing is difficult, and leakage is the main problem;
On the contrary, when the working pressure of the system is low, the oil with low viscosity should be used. When the operating speed of the working parts of the hydraulic system is high, the flow rate of the oil is also high, at this time, the pressure loss will also increase, and the leakage amount will be relatively reduced, so the oil with low viscosity should be used. On the contrary, when the operating speed of the working parts is low, the oil with high viscosity should be used.