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Injection molding machine daily maintenance

A)

Check is divided into the following steps to take before use

First, check in the amount of oil in the tank determine within the oil standard. Then the heat chamber and the oil temperature check. Should be preheated oil indoor low temperature condition. Indoor temperature, heat treatment. The final inspection of pressure gauge, is serious, can return to zero and mileage.

B)

Second, the use of check is divided into the following steps

1. The startup overflow valve switch to the lowest pressure.

2. Check and adjust the regulation of overflow valve pressure, whether continuous uniform lift, all is well and then to set pressure.

3. The oil pump, oil casing, electromagnet inspection, oil temperature is 20 degrees to 50 degrees calculate normal, pump shell temperature is higher than room temperature 10 degrees to 30 degrees is normal.

4. The spill.

5. Noise vibration tests.

6. Check gauge.

7. The condition of the electrical components; safety device reliability tests.

8. Synfuels fiasco column cylinder components of fastening nut screw is loose.

C)

Three, use after the downtime after inspection

1. On the surface of the oil tank inspection

2. Check the hydraulic components

3. The valve handle position should return to "unloading" "stop" position such as "back".

4. Check whether the control switch and electrical components is loose, degree.

5. The machine column and filling lubricant oil bearing active connection movement parts.

6. Turn off the power supply, do a good job security

The operation of the injection molding machine

Boot before:

(1) to check whether there is water, oil into the electric control box, if be affected with damp be affected with damp, do not switch on. By maintenance personnel will be electrical parts should be dry again after boot.

(2) check whether the power supply voltage, the general should not be more than + / - 15%.

(3) check the urgent stop switch, before and after the safety door switch is normal. Verify motor and oil pump rotation direction.

(4) check the cooling pipe was clear, and the oil cooler and barrel end of the cooling jacket into the water.

5. Check the activity parts for lubricating oil (grease), add the lubricating oil and.

6. Open the electric control system, the heating tube paragraphs of the machine. When the temperature of the paragraphs is achieved, and then heat preservation for a period of time, so that the machine temperature to stabilize. Holding time according to the requirement of the different equipment and plastic raw materials.

All landowners in the hopper add enough plastic. According to different requirements of plastic injection molding, some raw materials best first after drying.

Today to cover the barrel on the insulation plate, both to save electricity, and can prolong the life of electric heating circle and current contactor.

n the process of operation:

1) don't for the sake of convenience, out door.

(2) pay attention to observe the pressure oil temperature, oil temperature is not beyond the prescribed scope. Ideal working temperature of hydraulic oil should be kept between 45 ~ 50 ℃, generally within the scope of 35 ~ 60 ℃ is more appropriate.

(3) pay attention to adjust the travel limit switch, avoid machine in action during the impact.

At the end of the operation:

1) before the downtime, should be clear plastic barrel inside, prevent or leftover material oxidation thermal decomposition for a long time.

(2) should open the mould, make the toggle lever mechanism for a long time in the blocking state.

(3) the workshop must be equipped with lifting equipment. Mould should be very careful about heavy components such as installation, in order to ensure production safety.

Injection technology

(1) cylinder temperature

Melting temperature is very important, the shot cylinder temperature is directional. Melt temperature can measure at the nozzle or the use of air injection method to measure. Shot of cylinder temperature setting depends on the melt temperature, screw speed, back pressure, feed rate and injection molding cycle. If there is no experience of processing a particular level of plastics, from the lowest setting. In order to facilitate control, shot material cylinder points area, but not all are set to the same temperature. If the operation time is long or operating at high temperature, the temperature of the first area should be set to a lower value, this will prevent premature plastic melt and shunt. Before the start of injection molding, to ensure that the hydraulic oil, hopper closure, molds and material cylinder are at the correct temperature. Cylinder temperature generally since after to escalate before, so that uniform plasticizing.

(2) the melting temperature

Melt temperature of the melt flow behavior plays a main role, plastic without specific melting point, the melting point is a segment of the temperature of the molten state, the plastic different molecular chain structure and composition, and therefore have different influence on its liquidity, molecular chain rigidity affected by temperature is obvious, such as PC, PPS, such as flexible chains such as PA, PP, PE and so on by changing the liquid temperature is not obvious, so should be based on different materials to reasonable injection temperature calibration.

(3) the mold temperature

Some plastic materials due to their high crystallization temperature, crystallization speed is slow, need higher mold temperatures, some due to control the size and deformation, or the need of mold release, to high temperature or low temperature, such as PC general requirements above 60 ℃, the PPS in order to achieve better appearance and improve liquidity, die temperature sometimes need to above 160 ℃, and mold temperature for improving product appearance, shape, size, the film has not underestimate role. On the conditions set of mold design and molding engineering, it is important not only to maintain suitable temperature, also can make the uniform distribution. Uneven distribution of die temperature, can lead to the uneven shrinkage and internal stress, so that the deformation and the warp caused by FRP products. The discretion of the die temperature will affect the speed of the plastic hardening inside cavity, too low will shrink pack more difficult and is not appropriate (or recrystallization) or hardening, makes more filling and moulded residual thermal stress; Is too high, burrs and need longer cooling time. Mold temperature on the inner plastic performance impact on the quality and performance, higher requirements for the surface of rubber parts, mold temperature, the demand is higher.

(4) injection pressure

Melt forward to overcome the resistance, a direct impact on product size, weight, and deformation, etc., different injection pressure needed for plastic products, such as PA, PP material, such as increasing pressure will significantly improve its liquidity, injection pressure determines the density of the product, namely the gloss appearance. It has no fixed value, and the more difficult the mold filling, the injection pressure is increased. Injection pressure setting is mainly control oil pressure to make it enough to drive the screw meet the injection speed setting of the requirements. Flow due to the nature of each type of plastic is different, also different, to the difficulty of the same material melt temperature, viscosity will also change, different products, mold design, mold temperature will change the resistance of the material flow, in a variety of different conditions to maintain the same injection speed, injection pressure would surely have to change, make it overcome the resistance of the melt flow caused by. Injection pressure and keep pressure, injection pressure is the main influence of filling stage, and keep the pressure effect is cooling stage. For illiquid plastics, injection pressure to take big value, for large thin-wall rubber mold resistance, injection also want to take the maximum hardness of the force.

(5) injection speed

The injection speed setting is to control the melt filling mould time and flow pattern, is the most important in the process of flow conditions. The adjustment of injection speed correctly or not has absolute control of product appearance quality. Injection speed setting is the basic principle of matching plastic flow inside the cavity, according to its flow formed by the cross section size to lift, and abide by the slow to fast, slow process and fast as far as possible (confirm appearance with and without defects). By adjusting the injection speed within unit time how much oil cylinder oil injection, in general, under the premise of without causing side effects) use rof molding as far as possible, to ensure the quality of plastics welding strength and apparent, and relatively low pressure and reduce internal stress of plastics, increase the strength. Adopt high low-speed feeding can make the flow smooth, small shear rate, plastics dimension stability, prevent shrinkage defect.

(6) time parameter (molding cycle)

Injection time and cooling time is the basic part of its length has a decisive influence on the quality of injection molded parts. Mold filling time is generally not more than 10 s. The holding time is longer, related to the plastic pieces of wall thickness (wall thickness) take a long time, to ensure minimum contraction. The cooling time depends on plastic crystalline factors such as material thickness, mold temperature, products, adjusted according to specific situation. Molding cycle is as follows.