Application method of lubricating oil for injection molding machine

Injection molding machine is a thermoplastic molding equipment that plasticizes solid plastic, then injects it into the closed mold cavity at a certain pressure and speed with the help of screw, and obtains products after curing and shaping.

Injection molding machine is generally composed of injection device, clamping device, frame, gearbox, hydraulic and electrical system. In the injection molding process, the injection molding machine not only has the rotation, linear and spiral movement of mechanical equipment, but also the kinetic energy transmission of hydraulic equipment, as well as the heat energy conversion of electric heating device, which puts forward more requirements for lubrication. Of course, for the lubrication of injection molding machine, we can follow the general rules of lubrication of mechanical equipment, hydraulic equipment and electric heating equipment respectively according to the movement mode, but some parts (such as injection parts and gearbox) need to be considered comprehensively and adopt the method of mixed lubrication.

Lubrication of a manual or semi-automatic plastic injection molding machine

1. Lubrication of gear box

Any failure of the gearbox will affect the quality and quantity of processing. The hardened spur gear and quenched and tempered shaft in the box shall ensure uniform and reliable lubricating oil film. Generally, the oil cup and splash lubrication method can meet the lubrication requirements.

2. Lubrication of injection parts

The function of the injection part is to heat the plastic evenly to the injection temperature through the electric heating ring, and the injection pressure is formed by the screw compression of the pressing rod. Oil cup, oil rope and other lubrication methods are generally used for the lubrication of the pressing rod.

3. Lubrication of mold locking part

The mold locking parts are composed of belt pulley, lead screw, nut, vice, etc. Adjust the position of the bump on one side of the vise to match with the travel switch on the base, and control the feed travel of the screw rod to make the vise open and close the mold. Because the friction joint of screw rod and nut is small, the oil film is easy to be squeezed and cracked, so the lubricating oil should have good oiliness. Generally, l-an46 oil or HL hydraulic oil is used for lubrication through oil cup and oil rope.

4. Lubrication of base

The sliding guide rail on the base is generally made of cast iron. Because the load and speed borne by the guide rail are not large, mineral lubricating oil can ensure a certain boundary oil film. Generally, after gently touching the guide rail surface with your hand, you can see oil stains on your hand, that is, it is considered that an oil film has been maintained on the guide rail surface.

II. Lubrication of automatic hydraulic injection molding machine

This injection molding machine is characterized by high degree of automation, stable performance, electrical and hydraulic interlocking protection devices, high precision and complex structure.

1. Lubrication of injection part

Because this part is the key part to complete the injection, the double oil cylinder pulls the pre plastic speed change gearbox, pushes the screw through the gearbox, and injects the uniformly plasticized plastic into the membrane cavity to implement injection molding. Due to frequent movement and electric heating device, the lubrication system must be strictly implemented. Main lubrication parts of this part:

(1) add l-an46 full loss system oil on the guide rail surface of injection base and rack, once per shift.

(2) add l-an46 full loss system oil on the guide rail surface at the bottom of the gearbox (roller), once per shift.

(3) grease the slewing center, about 0.3L.

(4) add about 10L of l-an46 full loss system oil into the transmission gearbox.

2. Lubrication of die moving parts

The die moving adopts hydraulic power and direct pressure liquid filling device, which has the advantages of simple structure, reliable action and few lubrication points. It is mainly to ensure the formation of lubricating oil film on the four guide pillars, which can be lubricated with l-an46 mechanical oil through oil cup and oil rope.

3. Motor lubrication

Most automatic hydraulic injection molding machines are driven by multiple motors. During daily lubrication, the motors shall be lubricated as required.