Relationship between mold and mold temperature controller
1 , thermal equilibrium control, plastic injection mold injection machine and die of heat conduction is the production of injection molded parts of the key. The mold and is made of plastic (thermoplastics) caused by radiative heat transfer of heat to the materialand die steels, by convective pass heat conductive. In addition, the heat is passed through thermal radiation into the atmosphere, and mold. Tools for thermal equilibrium can be described as: P=Pm-Ps. Heat temperature taken modulo p; the heat introduced by Pm plastic; Ps for die heat released into the atmosphere.
2, prerequisites for effective controlling mold temperature temperature control system by mould, die temperature, thermal conductivity is composed of three parts. In order to ensure that the heat added to the mold or the removal of, different parts of the system must meet the following conditions: the first is in the mold cooling channel surface area must be large enough and runner diameter to match the pump capacity (pump pressure). Cavity temperature and internal pressures have a big impact. Reasonable cooling channel reduces inner pressure, so as to improve the quality of injection molded parts. It can also reduce the cycle time, reduce product cost. Followed by the mold temperature must be able to make heatconductive fluid within the temperature constant at 1-3 ° c, depending on the quality requirements of injection molded parts. Third, heat-conducting must have good thermal conductivity, and most importantly, to be able to import or export a large amount of heat in a short time. From a thermodynamic point of view, water is betterthan oil.
Principle 3, mold temperature machine consists of tank, heating and cooling systems, power transmission systems, liquid level control system, temperature sensors, injection devices such as composition. Typically, power pumps hot fluid from transmission system has a built-in heater and cooler water tank reaches the mold and die back to the tank temperature sensor measures the thermal fluid temperature and transmit the data to the control part of the controller; controller thermal fluid temperature, thus indirectly regulate the mould temperature. If die temperature in production, the die temperature exceeds the set point of the controller, the controller opens the solenoid valve connected to inlet pipe, liquid temperature until heat flow, that is, the temperature to the set value of the stencil. If the temperature is below the set value, the controller will open the heater.
4, types of mold temperature controller is based on the use of heat conductive fluid(water or oil), divided. Die machine water temperature is usually the maximum outlet temperature 95 ℃. With oil-type mold temperature machine for working temperature ≥ 150 occasions. Typically, the mold temperature controller is suitable for use with the open water tank heating water temperature machine or machine oil temperature, maximum outlet temperature is 90 ° c to 150 c, the main feature of this mold temperature machine is of simple design, low price. In this machine is derived on the basis of a high temperature water temperature, which allows the temperature to 160 ° c or higher, because when the temperature is higher than 90 ℃, the thermal conductivity of the water much better than oil with temperature, so the machine has a prominent high-temperature working capability. In addition to time, there is a forcedflow of mold temperature machine, for security reasons, this module temperature working temperature 150 ℃, using heat-conducting oil. In order to prevent the moldtemperature machine oil in the heater from overheating, the machine uses a forcedflow pumping system and heaters are made up of a number of tubes stacked, tubeswith finned heating elements for the diversion.
5, uneven temperature points control the mold and is connected to the injection points in the cycle. After the injection mould cavity temperature rise to the top, then met hot melt cavity wall, when the temperature of parts removed to a minimum. Moldtemperature controller's job is to keep the temperature constant at θ 2min and θ 2max, that is preventing the temperature difference θ w or gap up and down the production process. Following several control methods suitable for controlling mold temperatures: fluid temperature control is the most common method, and control accuracy can meet most of the requirements. Using this method, and display temperature and mold temperature controller is not consistent; die considerable temperaturefluctuations, effect of thermal factors not directly measuring and compensating for these factors include changes in injection cycle, injection speed, melt temperature and room temperature. Second is direct mold temperature control. This method is internal temperature sensor in the mold, which in the case of mold temperature controlaccuracy requirements are relatively high. Mold temperature control the main features include: set temperature and mold temperature controller line effect on thermal factor can be directly measured and compensated. Generally, mold temperature stability better than by controlling fluid temperature. In addition, the mould temperature control in the control of the production process repeatability. Third, joint control. Joint control is a comprehensive method, it can control the fluid and mold temperature. In joint control, temperature sensor location is extremely important in a mold, place the temperature sensor, the location of the shape, structure and cooling passages must be considered. In addition, the temperature sensor should be placed in themolding place where quality plays a decisive role. Connects to one or multiple moldtemperature controller to controller of injection molding machine in many ways. From the operation, reliability and anti-interference considered best to use a digital interface, such as RS485. In the injection molding machine and control unit may transmit information through software. Mold temperature controller can control.
6, mold temperature controller configuration with the use of mold temperature controller should be configured according to the processing of materials, weight of the mould, and kg/h to determine the required Preheat time and productivity. Dang using thermal conductivity oil Shi, operation who must comply with such of security provides: don't put die temperature machine put in near heat stove of place; joint using has cone degrees of anti-leak and has resistance temperature resistance pressure of hose or hard tube; regularly check temperature control loop die temperature machine, joint and mold has no leaked, function whether normal; regularly replaced thermal conductivity oil; should selection artificial synthesis oil, hot stability good, knot Coke tendencies small. Mold temperature controller used, choose a suitable heat-conducting is essential. Water for heat-conducting economic, clean, easy to use, once the temperature control loop hose coupler leak, the flow out of the water can be discharged to the sewer. But water as heat-conducting water also have disadvantages:the boiling point of water is low; according to the composition of water, corrosion and scaling in may, causing increased pressure loss and die between the fluid and the heat exchange efficiency reduction. When you are using water as a heat-conducting, you should consider the following precautions: anticorrosive treatment temperature control loop; in front of the water filter regularly wash water temperature with rust removal pharmaceutical machines and molds. Disadvantages of use oil without water. The boiling point of oil is high, they can be used for temperatures above 300 ° c or higher, but the heat conducting oil of heat transfer coefficient of water 1/3, so no water temperature in the oil temperature in the molding machine is widely used.
Asia Billion Industry Co., Limited (ABIL) is a Hong Kong registered company with manufacturing plant in Shenzhen. We are a professional manufacturer of plastic injection tooling , injection molded component and precise machining. We are a ISO 9001-2008 certified and ISO/TS 16949 compliance high qualification company.
Quality assurance, cost-efficiency , short lead time and professional excellent service help us to found our reputation and high quality position in our industry.
We are aimed at to be the best plastic and mold project solution company in Asia Industry all the time with global sight and service.