Injection molding machine is also well known as injection moulding machine or injection machine.It is the main equipment for thermoplastic or thermosetting plastic using kinds of molding die for making kinds of different shape product.It can divided into vertical,horizontal,all-electric.The injection molding machine heat the plastic material,then apply high pressure to the melt plastic and let it inject in and fill the mold cavity.
Structure and composition
Generally, the injection moulding machine consist of injection unit,clamping unit,hydraulic system,electrical control system,lubrication system,heating and cooling system,and safety monitoring system.
- Injection unit
injection unit is one of the most important parts of injection moulding machine.Usually, there are 3 types,plunger type,screw type and screw pre-plastic plunger tyep.The most common type is the screw type.
During one cycle of the injection molding machine, the injection unit will heat a certain amount of plastic material and plasticize,then inject the melt material inside the mold cavity with a certain pressure and speed through the screw.After injection,keep the melt material inside the mold cavity till shape fixed.
The injection unit mainly consist of screw,barrel,nozzle,heating band,injection cylinder,carriage moving cyclinder,charging motor,etc.
- Clamping Unit
The function of clamping unit is opening the mold,closing the mold and ejecting out the product.At the same time,after the mold being closed,providing sufficient clamping force to resist the cavity pressure generated by the melt material entering the mold cavity.
The clamping unit mainly consist of fixed mold platen,moving mold platen,rear mold platen,ejecting plate,ejecting cylinder, clamping cylinder,toggle links,etc.
- Hydraulic system
the function of hydraulic system is for providing the force of kinds of movment of the injection machine,and meat the requirement of the speed,pressure,temperature,etc. The motor and oil pump is the power source of the hydraulic system.By controlling the different valves to control the pressure and flow in order to do different movment.
- Electrical system
The electrical system working together with the hydraulic system in order to relize different molding technology of the injection machine,such as pressure,speed,temperature,time,etc.
The electric system mainly consit of motor,contactor,relay,PLC,heater,sensor,etc.
- Heating and cooling
Heating systme is mainly for heating the barrel and nozzle of the injection molding machine.Electrical heating bands are used for heating the barrel which are fixed outside of the barrel,then use the thermocouples to inspect the temperature by different sections.
Cooling systme is for cooling the temperature of the hydraulic oil. If the oil temperature is too high,it will lead kinds of problem of the machine and damage the injection machine.The other cooling position is the feeding position of the barrel,in order to avoid the material melt at the feeding inlet position and blocked.
- Lubrication system
Lubrication is mainly providing the lubrication oil for the moving platen,mold-adjust device,toggle links,injection unit which are usually moving. it can reduce the wearing and ensure the lifetime of the machine.Generally, the latest injection molding machine is euqipped with the automatic central lubrication system.
- Safety monitoring system
The safety device of the injection molding machine is mainly used to protect people and machines. Mainly composed of safety door, safety baffle, hydraulic valve, limit switch, photoelectric detection component, etc., to achieve electrical-mechanical-hydraulic interlock protection.
Working principle of injection machine
The basical working principle of the injection molding machine is plasticizing the plastic material,inject the melt plastic material into the mold cavity with pressure and speed,and achieve the final product after cooling and pressure holding.
Generally, one simple cycle include:Mold close – injection – charging – cooling and pressure holding – mold open – ejecting – mold close..
it can be divided in two parts. power system and heating system
By using the servo motor and servo driver to realize the precision control of the output of the power system. For example,daya HXM series servo motor injection molding machine can save 20%-80% energy compared to standard fixed pump injection machine.
By using the latest heating system- infrared heating band,it can also save energy compared to normal ceramic heating band.
Application of injection moulding machine
It is widely used in various fields such as national defense, electromechanical, automobile, transportation, building materials, packaging, agriculture, culture, education and health. The plastics industry is developing rapidly. The injection molding machine plays an important role in terms of quantity and variety. Its total production accounts for 20%-30% of the entire plastic molding equipment, thus becoming the fastest growing and most productive equipment in plastic machinery.