The correct and reasonable use of extruder can give full play to the efficiency of the machine, maintain good working conditions, and extend the service life of the machine.

The use of screw extruder includes a series of links such as machine installation, adjustment, test machine, operation, maintenance and repair. Its use has the common characteristics of general machines, mainly in the drive motor and speed reduction device. However, the working system of the screw extruder is the extrusion system, but it has unique characteristics. Pay special attention to its characteristics when using the screw extruder.

The installation, adjustment, and test of the machine are generally clearly stipulated in the instruction manual of the extruder. Here is a brief description of the operation method of the extruder as follows:

Operators must be familiar with the structural characteristics of the extruder they operate, especially the structural characteristics of the screw, heating and cooling control instrument characteristics, head characteristics and assembly conditions in order to correctly grasp the extrusion process conditions , Operate the machine correctly.

The method of extruding different plastic products is different, but there are also similarities. The following briefly introduces the same operation steps and matters that should be paid attention to when extruding various products.

1. Preliminary preparations

(1) Plastics used for extrusion molding. The raw materials should meet the required drying requirements, and further drying should be done if necessary. The raw materials are sieved to remove agglomerates and mechanical impurities.

(2) Check whether the water, electricity, and gas systems in the equipment are normal, to ensure that the water and gas paths are unblocked and leak-free, whether the electrical system is normal, whether the heating system, temperature control, and various instruments work reliably; the auxiliary machine is empty Run the machine at low speed to observe whether the equipment is operating normally; start the vacuum pump of the sizing table to observe whether it works normally; add oil to the lubricated parts of various equipment. If any fault is found, remove it in time.

(3) Install the head and sizing sleeve. According to the variety and size of the product, select the specifications of the machine head. Install the machine head in the following order.

① The machine head should be assembled together and installed on the extruder as a whole.

② Before assembling the machine head, wipe off the grease applied during storage, carefully check the cavity surface for bruises, scratches, and rust spots, perform necessary polishing, and then apply a layer of silicone oil on the surface of the runner.

③ Assemble the plates of the machine head in order, apply high-temperature grease to the threads of the bolts, and then tighten the bolts and flanges.

④ Place the perforated plate between the flanges of the machine head to ensure that the perforated plate is pressed tightly without overflow.

⑤ The horizontal position of the die should be adjusted before the fastening bolts of the connecting flange of the machine head and the extruder are not tightened. The square machine head can be adjusted horizontally, and the round machine head should be used based on the bottom surface of the finalized model rubber. The bottom surface of the head and mouth mold is leveled.

⑥ Tighten the connecting flange bolts, tighten the machine head fastening bolts, install the heating ring and thermocouple, and pay attention to the heating ring to be close to the outer surface of the machine head.

⑦ Install the sizing sleeve and adjust it in place, check whether the center line of the main engine, the sizing sleeve and the tractor are aligned. After adjustment, tighten the fixing bolts. Connect the water pipes and vacuum tubes of the sizing sleeve.

⑧ Turn on the heating power supply, and evenly heat up the machine head and cylinder. At the same time, open the cooling water at the bottom of the hopper and the gear box and the water inlet valve of the exhaust vacuum pump. When heating, the temperature of each section is first adjusted to 140°C, and when the temperature rises to 140°C, the temperature is kept for 30-40min, and then the temperature is raised to the temperature during normal production. When the temperature rises to the temperature required for normal production, keep it for about 10 minutes to stabilize the temperature of each part of the machine before it can start production. The length of the heat preservation time varies according to different models of extruders and the varieties of plastic materials. Keep the temperature for a period of time to keep the temperature inside and outside the machine consistent, so as to prevent the meter indicating that the temperature has reached the required temperature, but the actual temperature is too low. At this time, if the material is put into the extruder, the actual temperature is too low and the melt viscosity of the material is too high, which will cause The axial force is overloaded and the machine is damaged.

⑨ Feed the raw materials used for starting up into the hopper for use.