In addition to other injection molding plastics , electricity is the maximum cost of
the finished injection molding in China , it is necessary to save .
Saving nature : Injection confidential generated as clamping and injection etc, and also to generate heat
inside the plastic barrel heating / plastics . Kinetic and thermal energy savings ,reduce waste only from the
start, no other way. Let us first study the two laws of thermodynamics .
First law of thermodynamics : the first law of thermodynamics is the conservation of energy . Conversion of the energy , the energy is only changed from one type to make another type , but the conversion of energy before and after are equal , neither increased nor decreased.
Second law of thermodynamics : the second law of thermodynamics that the conversion process , the
thermal entropy (entropy) will only increase , not decrease . Thermal entropy concept is difficult to use a few
words clearly.For this discussion , the second law can be simplified as "useless" output energy is heat.
Induction motors : the traditional injection molding machine is asynchronous ( squirrel cage ) motors to drive the pump . Three-phase asynchronous electric motor stator driven in a rotating magnetic field . A four -pole stator and a 50Hz power supply , for example, magnetic field is rotated at a speed 1500rpm .
Start the china plastic injection molding machine, injection molding machine motor and no action after the state is called the standby state.
In the following cases, the china injection molding machine is in standby mode.
(1) When the cooling time is longer than the plasticizing time, the extra cooling time,China injection molding
machine is in standby mode. The thicker the product, the longer standby time.
(2) Remove the finished robot / outlet when.
3 semi-automatic operation, the operator opens the safe door remove the finished product / outlet or plug.
Induction motor driven variable displacement pump in standby mode, but no traffic is constant speed, but in a
11kW china injection molding machine measured motor current is 7A, 24A than 11kW motorrated current is a
large proportion (29% ).
Servo motor driven variable displacement pump in standby when not rotating. Is wasted servomotor (e) drive energy. To 11kW servo motor, for example, the current is less than 1A. A number of rotor copper diagonal
branch , they are short- circuited at the end . Squirrel hence the name. The rotating magnetic field , a current is induced copper branches .Interaction with the magnetic field generated under the current torque to turn the rotor . Rotor speed rotating magnetic field lower than 20 ~ 60rpm, it is known as asynchronous ( asynchronous ) motors.
Silicon iron sheets piled up branches supporting the rotor and the stator coil of copper .Induction motors
convert electrical energy into kinetic energy. During the conversion process , the resistance of the coil,
eddycurrent generated in the silicon and iron tablets bearing friction, the output of the " useful" kinetic energy
is only about 90percent of the input electrical power ( at full load ) , the other is converted to heat. Therefore,
the motor will bring their own fans, the heat energy away, so as to avoid excessive motor heating .
Transient overload induction motor can reach twice . Overload, the current increases , the heat is increased.
In the absence of overload protection under the coil will burn .
Pump: pump converts the kinetic energy of the rotating fluid energy ( pressure and flow ) . Will reduce friction
within the pump output pressure. Pump output flow will reduce internal leakage . Therefore, the output ( Useful ) solution can be lower than the input rotational kinetic energy , without the use of heat they went to pressure oil
to make it heat up, injection molding machine is why you want to install one of the reasons the pressure oil cooler .
Motor oil , fuel tanks : motor oil and hydraulic cylinders respectively reversed rotational kinetic energy and linear momentum , to drive such as a screw plasticizing and injection movements. Like for example, pumps ,
heat is generated during the conversion process , improve oil .
Tubing : pressure oil flow in the pipeline , the pipe joints turn , are divided against the tube wall and reduces
the friction pressure generated heat. Inexpensive injection molding machine with a small diameter are to reduce
costs , but it must then increase the oil flow within the tube , and the friction loss increases , the oil temperature
will rise higher, more energy will be wasted .