Product Introduction

Mold temperature control machine, also known as mold temperature control machine, is widely used in various industries such as plastic molding, light guide plate die-casting, rubber tires, rollers, chemical reaction vessels, bonding, and mixing. In a broad sense, it is called a temperature control device, which includes two aspects of temperature control: heating and freezing

The use of mold temperature machines in the plastic industry is quite common, and their main function is to

1，Improve the molding efficiency of products；

2，Reduce the occurrence of defective products；

3，Improve product appearance and suppress product defects；

4，Accelerate production progress, reduce energy consumption, and save energy;

There is also a lot of room for the application of mold temperature machines in the die-casting industry, especially in the manufacturing of magnesium and aluminum alloys. Uneven or inappropriate mold temperatures can lead to unstable casting dimensions, deformation of the castings during the production process, and defects such as thermal pressure, mold sticking, surface depression, internal shrinkage, and hot bubbles. It also has an impact on the production cycle, such as unstable variables in filling time, cooling time, and spraying time. The lifespan of the mold can also be accelerated by the impact of supercooling and overheating, leading to thermal cracking of expensive steel and accelerating its aging. In modern factories, it is urgent to adopt a business strategy of saving manpower, improving quality, and reducing costs in response to market competition. The use of mold temperature machines can reduce mold preheating time, improve the surface quality of finished products, and fully automate production. Improving the lifespan of molds is a necessary means to increase productivity. The application of temperature control machines in other industries is a necessary condition for equipment composition, and their names are also different. In PVC sheet roller temperature control, it is called an oil heater, in extruder equipment, it is called a temperature control device, in rubber mixer equipment, it is called a temperature control system or temperature control machine. These devices are basically a process of rapid heating first, followed by insulation. After heating up in rubber equipment, a long-term cooling process is required.

Water transport type mold temperature machine

Characteristic

1、Maximum operating temperature of 40 ℃ -180 ℃, accurate to ± 1 ℃；

2、Micro computer touch control operation is simple；

3、Automatic exhaust upon startup；

4、Display of outlet and return water temperature；

5、Mold return water function (optional)；

6、Stainless steel pipeline, reducing pipe yin and rust scale；

7、Fault display, maintenance does not require professional personnel。

Function Description

The power of the ordinary water heating series is 6KW-30KW, and the temperature is between 30 ℃ and 120 ℃; The power of the ordinary oil heating series is 6KW-72KW, and the temperature is between 30 ℃ and 200 ℃; The high-temperature water heating series has a power of 6KW-120KW and a temperature range of 120 ℃ -180 ℃; The high-temperature oil heating series has a power of 18KW-120KW and a temperature range of 250 ℃ -350 ℃.

Oil operated mold temperature machine

Characteristic

1、Temperature controller (using touch mode internal storage, automatic calculation, precise and reliable control within ± 2 ℃, saving more than 35% electricity)；

2、Two sets of electric heating tubes, can be used separately or together；

3、Fast heating and cooling time, stable temperature；

4、Electric heating tubes and other materials are made of stainless steel；

5、Improvement of safety protection and fault indication system；

Application industry

Application areas: petroleum and chemical industry: polymerization, condensation, distillation, melting, dehydration, forced insulation. Oil and fat industry: Temperature control and heating of reaction vessels for fatty acid distillation, oil decomposition, concentration, esterification, vacuum odor, etc. Synthetic fiber industry: polymerization, melting, spinning, extension, drying. Textile printing and dyeing work: heat setting roller heating, drying room heating, heat capacity dyeing. Non woven industry: Non woven fabrics. Feed industry: drying. Plastic and rubber industry: hot pressing, rolling, extrusion, vulcanization molding. Paper industry: drying, corrugated paper processing. Wood industry: pressure forming of plywood and fiberboard, heating of laminated boards, heating of hot pressed boards, temperature control by hydraulic presses, wood drying. Building materials work: drying gypsum boards, heating asphalt, and curing concrete components. Mechanical industry: spray painting, printing and drying. Food industry: oven heating, sandwich pot heating. Air conditioning industry: Heating for industrial and civil buildings. Road construction industry: asphalt melting and insulation. Pharmaceutical industry: drying. Light industry: producing ink and laundry detergent. Chemical light industry: polymerization, condensation reaction, distillation, distillation, concentration, evaporation, melting Petrochemical industry: synthesis, reaction, distillation, distillation, heating, insulation, tank heating, heavy oil heating Oil and fat: oil decomposition, deodorization, fatty acid distillation, heating, hydrogenation reaction, esterification Plastic rubber: hot pressing, rolling, extrusion, vulcanization molding Leather industry: artificial leather processing Textile printing and dyeing: heat setting, drying, baking, evaporation, and melting of synthetic fibers: polymerization reaction, melt spinning, weaving machine processing, molding, thermosetting, extension, and drying. Painting: paint baking, drying, high-temperature melting, home appliance and vehicle painting, painting Automobile and aircraft: painting, drying, heating and forming, high-temperature bonding wood processing: hot pressing, drying, wood processing and wood products (wood making, furniture), artificial boards (medium density fiberboard, particle board, plywood, oriented particle board), artificial fiberboard, laminated board forming, wood drying, wood drying Plywood, particleboard, medium density board, suitable fuel (sanding powder, wood powder, bark, wood blocks) Forestry industry: hot pressing, drying, artificial board, medium density fiberboard, particle board, oriented particle board, wheat straw board, plywood/artificial board veneer, wood processing, timber making, solid wood flooring, wood drying, wood products, furniture, solid wood flooring Paper printing: corrugated board processing, paper processing, ink production processing, hot melting, drying Building materials: asphalt dissolution, concrete curing tank, waterproof materials and fuel consumption production Cement: fuel heating Carbon industry: asphalt heating, insulation, melting, melting, impregnation, mixing, forming Highway transportation: road construction machinery, asphalt heating, melting, and insulation. Municipal road construction: asphalt heating, melting, and insulation. Asphalt heating: asphalt heating and melting. Air conditioning: heating source, heating and ventilation, radiation heating. Pharmaceutical industry: pharmaceuticals, healthcare, atomic energy industry: nuclear fuel processing Metal processing: pickling, electroplating, painting, oil bath, heat treatment Electrical: resin impregnation, dissolution, insulation Electroplating industry: zinc plating, chromium plating, silver plating.

Calculation method for heating power selection

Computing method

1. Special circumstances require calculation: A. Calculate the heater power or refrigeration power KW=W × △ t × C × S/860 × T W=mold weight or cooling water KG △ t=temperature difference between the required temperature and the starting temperature. C=specific heat Oil (0.5), steel (0.11), water (1), plastic (0.45-0.55) T=time to heat up to the required temperature (hours) B. To determine the size of the pump, it is necessary to understand the customer's required pump flow rate and pressure (head) P (pressure Kg/cm2)=0.1 x H (head M) x α (specific gravity of heat transfer medium, water=1, oil=0.7-0.9) L (required flow rate of medium L/min)=Q (required heat of mold Kcal/H)/C (medium to hot water ratio=1) Oil=0.45) x △ t (temperature difference between circulating media in and out of the mold) x α x 60

2. Refrigerator capacity selection A, Q (freezing capacity Kcal/H)=Q1+Q2 Q1 (heat brought into the mold by raw materials Kcal/H)=W (weight of raw materials injected into the mold per hour KG) x C x (T1-T2) x S (safety factor 1.5-2) T1 The temperature of the raw materials in the material tube; The temperature at which the T2 finished product is taken out of the mold; Q2 heat generated by hot runner Kcal/H B, quick calculation method (not applicable with hot runner) 1RT=7-8 OZ 1OZ=28.3g (including safety factor) 1RT=3024Kcal/H=1200BTU/H=3.751KW 1KW=860 Kcal/H 1 Kcal=3.97BTU 3. Cooling water tower selection=A+B A, for injection molding machine Cooling water tower RT=Ejection machine horsepower (HP) x 0.75KW x 860Kcal x 0.4 ÷ 3024 B. Cooling water tower for chillers RT=Refrigerator cold ton (HP) x 1.25

Matters needing attention

When selecting a mold temperature controller, the following points are the main considerations；

1．The size and capacity of the pump。

2．The size of the internal throat。

3．Heating capacity。

4．Cooling capacity。

5．Control form。

From the known heat dissipation required per cycle, we can easily calculate the required volumetric flow rate of the coolant, and then determine the correct cooling capacity required. Most manufacturers of temperature controllers provide formulas for calculating the lowest pump flow rate. Table 4.1 is very useful when selecting pumps, as it accurately lists the heat dissipation capacity of different plastics. The following empirical rule determines the minimum flow rate that a pump needs to provide:

If the temperature difference on the surface of the mold cavity is 5 ℃, the temperature difference is 0.75gal/min/kW @ 5 ℃ or 3.4151/min/kW @ 5 ℃ If the temperature difference on the surface of the mold cavity is 1 ℃, the minimum required flow rate needs to be multiplied proportionally by five times, which is 3.75gal/min/kW or 17.031/min/kW. In order to ensure the stability of product quality, many injection molding companies should control the temperature difference on the surface of the mold cavity within 1-2 ℃. However, in reality Many injection molding manufacturers may not be aware of the importance of this temperature difference or believe that the optimal range for temperature difference is 5-8 ℃.

To calculate the required volumetric flow rate of coolant, the following procedure should be used:

1．First, calculate the heat to be discharged by planting a plastic/mold combination: if the aforementioned PC cup mold is taken as an example, the actual heat to be dissipated is: gross weight of the first mock examination (g)/cooling time (s)=208/12=17.333g/s The heat dissipation rate of PC is 368J/g or 368kJ/kg, so the amount of heat that needs to be dissipated per cycle is 368 × 17.33/1000=6.377 kW

2．Calculate the required volumetric flow rate for cooling again: according to the above empirical rule, if the temperature difference on the surface of the mold cavity is 5 ℃, the flow rate is 6.377 × 0.75=4.78 gal/min or 6.377 × 3.41=21.751/min If the temperature difference exhibited by the mold cavity is 1 ℃, then the flow rate is 4.78 × 5=23.9 gal/min or=21.75 × 5=108.731/min

3．In order to achieve good heat dissipation, the flow rate capacity of the pump should be at least 10% higher than the calculated result, so a pump of 27 gal/min or 120/min is required

4．The regulation of pump pressure; The operating pressure of a general mold temperature controller is 2-5 bar (29-72.5 psi). Due to insufficient pressure, it can affect the volumetric flow rate of the coolant (pressure loss caused by flow resistance). Therefore, the higher the pump pressure, the more stable the flow rate. For molds with very small cooling pipes (such as pipes with a diameter of 6mm/0) 236 inches, the pump pressure needs to be 10 bar (145 psi) to provide sufficient heat dissipation speed (i.e. coolant speed). Generally speaking, the higher the volume and velocity requirements of the coolant, and the smaller the diameter of the pipeline, the greater the required pump output pressure. So in general applications, the pressure of the mold temperature controller should exceed 3 bar (43.5 psi) B、 Heating capacity Figure 4.8 is a typical heating calculation table that provides the required heating amount for the weight of the mold

Freezing capacity

The design and components of the refrigeration circuit for the mold temperature controller are crucial for precise control of the mold temperature. When the temperature of the mold or heating liquid rises to the set value, the mold temperature controller must be able to quickly and effectively avoid further temperature rise by introducing another lower temperature liquid, which is controlled by an electromagnetic valve. So the elimination and stability of temperature overshoot depend on the size of the solenoid valve. The aperture of the cooling solenoid valve can be calculated using the following formula: freezing capacity (gal/min)=kW x 3.16/△ t, where △ t=the difference between the production temperature set by the mold temperature controller and the chilled water temperature: kW=the heat that the mold needs to remove The following table lists the volumetric flow rates that different solenoid valve apertures can provide: solenoid valve aperture volumetric flow rate in mm gal/min 1/min 0.25 6.35 0.7 3.18 0.375 9.53 1.2 5.45 0.500 12.70 3.3 14.98 0.750 19.65 5.4 24.52 1.000 25.40 10.0 45.40 1.250 31.75 13.0 59.02 1.500 38.10 20.0 After calculating the freezing capacity, the corresponding solenoid valve can be found from the above table. For example, the heat that needs to be discharged from the PC cup mold is 6.377 kW. The set temperature for production is 90 ℃, and the temperature of the chilled water is 18 ℃ △ T=90-18=72 ℃ So the freezing capacity is 6.377 × 316/72=0.28gal/min or 1.271/min. From the above table, it can be seen that electromagnetic valves with a pore size of 6.35mm/0.250in can provide sufficient volumetric flow rate and are suitable for use at mold temperature The control range is a precise requirement of ± 1 ℃. The pressure drop of the solenoid valve affects the flow rate. The flow rate values in the above table are based on a pressure drop of 1 bar (14.5psi). So the higher the pressure drop, the faster the flow rate of chilled water. The typical pressure drop of an electromagnetic valve is 2 bar (29 psi). C、 The main purpose of any mold temperature controller in a liquid mold temperature heating control system is to control the mold temperature within the range of ± 2 ° F. So the temperature control of the liquid running between the mold pipelines must be precise, otherwise the purpose of mold temperature control cannot be achieved. The control method of some temperature controllers only belongs to the on/off form, and their working principle is to compare the actual and set temperature. If the actual temperature is much lower than the set temperature, the electric heating will be fully turned on. When the actual temperature reaches the set value, the electric heating will be turned off due to the control of the on/off form There is a significant deviation in actual positive and negative temperature. This temperature change not only directly affects the temperature of the liquid, but also indirectly causes significant excessive lifting and lowering of the mold. It goes without saying that it must ultimately be reflected in the quality of the finished product. So we should use a PID (proportional, integral, differential) heating control system, which can ensure that the temperature control of the mold is maintained within the range of ± 1 ℃ (± 2 ° F).

Operation process

1、 Pre startup inspection

2、Whether the surrounding area is clean and free of debris, check whether the power supply, heater, controller, pressure gauge, pump, etc. are correct.

Check if the oil level in the expansion tank is above 1/2-3/5 of the liquid level, and if the liquid level sensor is normal.

3、Connect the power supply to the control cabinet, check if the voltage is normal, and check if the indicator lights and various display instruments are normal.

Start

1、Start the heat transfer oil circulation pump and circulate normally for about 0.5 hours after starting the pump to stabilize the pressure；

2、Press the heating start button and observe if the heating is normal；

Shutdown operation

1、Normal shutdown: ① Gradually reduce the temperature and stop heating; ② Stop the operation of the heat transfer oil circulation pump when the temperature of the heat transfer oil drops below 70 ℃; ③ Turn off the main power supply and keep a record of shift handover

2、If an emergency stop occurs due to an emergency situation, the heating tube should be quickly closed to allow for natural cooling of the heat transfer oil and prevent overheating

Precautions

1、During the inspection, attention should be paid to checking whether there is any leakage around the electric heating thermal oil furnace. There should be sufficient oil and electrical fire-fighting equipment nearby, and water should not be used as a fire extinguishing agent; Choose an appropriate mold temperature controller Randomly selecting mold temperature control products can result in a loss of 20% profit at any time, so when purchasing, we must carefully consider production needs and strictly review the capabilities of various mold temperature controllers before making a decision. Unfortunately, people often overlook the extremely important aspect of injection molding technology, often only waking up when there are issues with productivity and quality.

Maintenance of mold temperature machine

1. I have purchased a new mold heater. Please check if the cooling water is flowing before use to prevent damage to the mold heater due to insufficient cooling water. We need to keep the working environment of the mold temperature machine clean and avoid dust, which can greatly extend the service life of the electrical components of the mold temperature machine.

2. We need to take different maintenance measures for the new mold temperature machine based on the heat transfer medium used. For media containing water, we need to keep the water source clean to prevent scaling and prevent pipeline blockage. For media containing oil, we need to replace it regularly according to the usage temperature. For media above 200 ℃, we need to replace it once a month or two, while for media below 200 ℃, we can replace it about once a quarter, which effectively avoids the problem of temperature not increasing.

3. In terms of pipelines, we need to determine whether there is any blockage in the pipeline based on the relationship between the pump and pressure. If the pressure is too low, we can remove the heating pipe and clean it with tools, especially the filter cover at the system inlet, which is best cleaned once a month.

4. Regularly check the water pump and oil pump of the mold temperature machine for oil leakage. If necessary, the pump shaft seal can also be replaced regularly.

5. On electrical components, we can replace them in a timely manner based on their service life and conduct regular testing to ensure safety.

Cooling method

The cooling methods of the mold temperature machine are divided into direct cooling and indirect cooling. The indirect cooling method separates the cooling circuit from the main circuit, while the direct cooling method involves the cooling circuit directly participating in the main circuit. The water transport type mold temperature machine usually adopts direct cooling method. And for the oil operated mold temperature machine, due to the fact that water and oil cannot be mixed together during the heating process, indirect cooling is usually used, and the method is usually to use a plate heat exchanger for cooling. The high-temperature water transport type mold temperature machine is usually used at temperatures above 160 ℃, so the internal main pipeline circulates high-temperature steam. At this time, the internal pipeline pressure is relatively high. If direct cooling is used, the external water pressure needs to be greater than the internal main pipeline water pressure to enter the main pipeline for cooling. This method is prone to residual risks. Therefore, high-temperature water type mold heaters often use indirect cooling methods. The advantages and disadvantages of direct cooling: Direct cooling can only be used in situations with lower temperatures, but using direct cooling has a faster cooling speed. The advantages and disadvantages of indirect cooling: Indirect cooling is suitable for high-temperature temperature machines, but the heat exchange speed is slow, and heat will be lost in the heat exchange. Therefore, when the actual temperature of the medium deviates significantly from the set value, we adopt a direct cooling method with a higher cooling capacity. Direct cooling and indirect cooling Direct cooling and indirect cooling.

Application

1、The thermal balance control of injection molding machines and the heat conduction of molds are the key to producing injection molded parts. Inside the mold, the heat brought by plastics (such as thermoplastic) is transferred to the material and the steel of the mold through thermal radiation, and to the conductive fluid through convection. In addition, heat is transferred to the atmosphere and mold through thermal radiation. The heat absorbed by the conductive fluid is carried away by the mold temperature machine.

2、The purpose of controlling mold temperature and the impact of mold temperature on injection molded parts. In the injection molding process, the main purpose of controlling mold temperature is to heat the mold to the working temperature, and to maintain a constant mold temperature at the working temperature. If the above two points are successfully achieved, the cycle time can be optimized to ensure stable and high-quality injection molded parts. Mold temperature can affect surface quality, fluidity, shrinkage rate, injection molding cycle, and deformation in several aspects. Excessive or insufficient mold temperature can have different effects on different materials. For thermoplastic materials, a higher mold temperature usually improves surface quality and fluidity, but prolongs cooling time and injection molding cycle. A lower mold temperature will reduce the shrinkage inside the mold, but it will increase the shrinkage rate of the injection molded part after demolding. For thermosetting plastics, a higher mold temperature usually reduces the cycle time, and the time is determined by the time required for the part to cool. In addition, in the processing of plastics, higher mold temperatures can also reduce plasticization time and reduce the number of cycles.

3、The purpose of controlling mold temperature and the impact of mold temperature on injection molded parts. In the injection molding process, the main purpose of controlling mold temperature is to heat the mold to the working temperature, and to maintain a constant mold temperature at the working temperature. If the above two points are successfully achieved, the cycle time can be optimized to ensure stable and high-quality injection molded parts. Mold temperature can affect surface quality, fluidity, shrinkage rate, injection molding cycle, and deformation in several aspects. Excessive or insufficient mold temperature can have different effects on different materials. For thermoplastic materials, a higher mold temperature usually improves surface quality and fluidity, but prolongs cooling time and injection molding cycle. A lower mold temperature will reduce the shrinkage inside the mold, but it will increase the shrinkage rate of the injection molded part after demolding. For thermosetting plastics, a higher mold temperature usually reduces the cycle time, and the time is determined by the time required for the part to cool. In addition, in the processing of plastics, higher mold temperatures can also reduce plasticization time and reduce the number of cycles.

Operational Principle

The mold temperature machine is composed of water tank, heating and cooling system, power transmission system, liquid level control system, temperature sensor, injection port and other components. Normally, the pump in the power transmission system causes the hot fluid to reach the mold from the water tank equipped with a built-in heater and cooler, and then return to the water tank from the mold; The temperature sensor measures the temperature of the hot fluid and transmits the data to the controller of the control section; The controller adjusts the temperature of the hot fluid, thereby indirectly adjusting the temperature of the mold. If the temperature of the mold exceeds the set value of the controller during production, the controller will open the solenoid valve and connect the water inlet pipe until the temperature of the hot liquid, that is, the temperature of the mold, returns to the set value. If the mold temperature is below the set value, the controller will turn on the heater.