Correct and rational use of the extrusion machine, can take advantage of machine performance, and maintain good working condition and prolong the life of the machine. The use of screw extruders, including machine installation, adjustment

Correct and rational use of the extruder, can take advantage of machine performance, and maintain good working condition and prolong the life of the machine.

The use of screw extruders, including machine installation, adjustment, commissioning, operation, maintenance and repair of a series of links, it is common to use a general machine, mainly in the variable speed drive motor and gear installations. But screw extruder system of work that is out of the system, but the unique characteristics of the use of screw extruder should pay special attention to its characteristics.

Machine installation, adjustment, test the general use of the extruder are clearly defined instructions, here extruder method of operation, maintenance and service are summarized as follows:

First, methods of operation extruder
The operator must be familiar with the operation of their own structural characteristics of the extruder, in particular, to correctly grasp the structural characteristics of the screw, the heating and cooling control instrument characteristics, the nose assembly of characteristics and circumstances, in order to correctly grasp the extrusion process conditions, properly operate the machine.
Extruded plastic products of different methods of operation are different, but also has its similarities. Briefly described below when the various products out of the same steps and operations should pay attention to.

1, the preparatory work before driving
(1) for the extrusion of plastic. Raw materials should be required to achieve the required drying, if necessary, require further drying. Sift to remove lumps and pellets of raw materials and mechanical impurities.

(2) Check the equipment in water, electricity, gas and the system is normal, to ensure that water, gas flow, no leakage, electrical system is normal, heating system, temperature control, all instruments are working and reliable; auxiliary low-speed test empty operation, observation equipment is working properly; start setting table vacuum pump is working properly observed; in various parts of lubrication equipment, lubricants. Found fault and remove.

(3) installed the first set and stereotypes. According to the product variety, size, select the right head size. In the following order to head installed.
① head should be assembled together, the overall installed in the extruder.

② head assembly, should wipe off the grease paint saved, double-check whether the cavity surface, bumps, scratches, rust, make the necessary polishing, and then flow coated with silicone oil.

③ in order to head the assembly of the boards together, the bolt thread at the coated with high temperature grease, then screw the bolt and flange.

④ the porous plate placed in between the head flange to ensure the compression plates without overflow.

⑤ without extruder screw head and the flange bolts fastening the die to adjust before the horizontal position, can adjust the level of meeting the level of the square head, round head shape model Zeyi with the head surface as the base rubber-soled leveling the bottom die.

⑥ tighten the flange bolts and tighten the fastening bolt head, installing heating coil and thermocouple, pay attention to the heating cycle closely aligns with the outer surface of the nose.

⑦ install and adjust the setting set in place, check the host, setting the center line of tractor units and whether the alignment. Adjustment, tighten the mounting bolts. Connection setting sets of pipes and tubes.

⑧ turn the heating power, on the nose, Jane uniform heating temperature. Hopper bottom and open at the same gearbox and exhaust vacuum pump cooling water inlet valve. Heating in the first, when transferred to the stage temperature 140 ℃, when the temperature rose to 140 ℃ when the heat 30-40min, and then when the temperature is raised to the temperature of normal production. When the temperature rose to normal production of the required temperature, then kept around 10min, so that all parts of the machine to stabilize the temperature in order to drive production. The length of time depending on the model insulation extruder and different varieties of plastic raw materials. Holding for some time, so that the temperature inside and outside the same machine, so instrumented temperature has reached the required temperature, while the actual temperature is low, then if the material into extruder, the actual temperature is too low, the material melt viscosity is too large, axial force will cause overload and damage the machine.

⑨ materials used to drive into the hopper, ready for use.

2. car
(1) after the temperature can drive, drive, flange should extruder head and then tighten a bolt, the bolt head to eliminate the difference of thermal expansion, tight head bolt tightening sequence is diagonal, force should be uniform. Tight head flange nuts, ask around the elastic line, or run material.

(2) drive, select "ready to drive" button and draw a line "drive" button, and then slowly rotating knob screw speed, screw speed slow start. And then gradually speed up, while a small amount of feed. Close attention to the host when feeding ammeter and a variety of instructions indicating changes in the header. Screw torque can not exceed the red label (usually 65% -75% torque table). Before being squeezed out of plastic profiles, no person shall stand in front of the die to prevent the bolts pulled off or because of raw material moisture and other reasons put foam caused injuries. Plastic from the extrusion die head, the things that need to be squeezed out slowly cooled and lead on the traction device and setting mode, and switch on the device. Control instruments and then the indicated value and the requirements of extrusion products. Parts will be adjusted accordingly to achieve the normal operation of the entire out of state. And, if necessary add a little material, measured using twin-screw extruder to feed feeder evenly constant.

(3) die out when the plastic material are uniform and good traction good people can be stereotyped sets. Need to empirically determine the degree of plasticization, the general appearance of the material according to judge out, that the surface gloss, no impurities, no foam, coke material and color, hand-out material will be squeezed down to a certain extent, does not appear burrs, cracks, have a certain flexibility, at this time that plastics material is good. If the adverse plasticizing screw speed can be adjusted, barrel and die temperature, until the requirements.

(4) in the extrusion process, technical requirements should be regularly inspected various process parameters are normal, and complete process sheets. Check the profiles according to the quality inspection standards of product quality, identify problems and take timely solutions.

3. parking
(1) stop feeding, will be squeezed out of plastic inside the light, exposing the screw, turn off the power cylinder and head, stop heating.

(2) Close the extruder and auxiliary power supply, so that the screw and the auxiliary stop.

(3) Open head flange, remove the nose. Porous plate and clean the parts of the nose. When cleaning the inner surface to prevent damage to the nose, the nose of residual material within the application of steel law to clean steel, and then use sandpaper to adhere to the nose than the plastic grinding and polishing, coated with oil or silicone oil rust.

(4) screw, barrel cleaning, remove the head, restart the host, add parking material (or broken material), clean the screw, barrel, then screw selection of low-speed (sr / min or so) to reduce wear. Material to be ground into powder completely out of parking, the available compressed air from the charging port, exhaust port pellets and powder residue repeated blows, until the machine barrel actually no residual material, the screw speed reduced to zero, stop out machine, shut off power and water main gas valve.

(5) should pay attention to safety out of the project are: electricity, heat, mechanical rotation and loading and unloading heavy parts. Extruder plant must have lifting equipment, loading and unloading head, screw and other bulky components to ensure safety in production.

II Maintenance of the extruder
Screw extrusion system uses two kinds of routine maintenance and periodic maintenance of way maintenance.
(1) routine maintenance is a regular routine, do not account for equipment operating hours, usually completed during the drive. Focus on clean machine oil to all moving parts, easy to loose the screw to tighten, timely inspection, adjustment motors, control instrumentation, and piping and other parts of the work.

(2) regular maintenance of normal continuous operation of the extruder machine is shut down for 2500-5000h for the machine requires the disintegration of inspection, measurement, identification of the main components of the wear and tear, replacement parts have reached the limits of the provisions of wear and tear, repair the damaged parts.

(3) does not allow empty running, so that the screw and simply rolled hair.

(4) extruder running event of unusual sound, should be immediately stopped for inspection or repair.

(5) prevent the metal or other debris into the hopper, so as not to damage the screw and barrel. To prevent iron debris into the barrel, the barrel in the feed material into the mouth of the magnetic components mounted suction or magnetic rack to prevent debris falling into the material prior to screening.

(6) Note that the production environment clean, Do not allow contamination of the material block spam filter board, affecting the product yield, quality, and increased head resistance.

(7) When the extruder may take longer to stop the use, should be in the screw, Jane, head, etc., coated with anti-rust grease. Small screw to be hoisted in the air or placed in special wooden box and use wood pad level, so as not to screw deformation or bumps.

(8) regular calibration of temperature control instrumentation, check the correctness of its regulation and control sensitivity.

(9) extruder gear box gear maintenance and the same general standard. Check the main gear and bearing wear and failure situation. Manual gear box should be specified using the machine oil, and apply the oil level by adding the oil, too little oil, lubrication is not anti-, lower part life; oil too much, heat a large, multi-energy, oil- metamorphism, as the lubrication failure, causing damage to parts of the consequences. Gearbox oil seals should be replaced as part of (circle), to ensure that the lubricant.

(10) attached to the cooling pipe extruder and easy guitar scale wall external corrosive rust. Maintenance checks should be done carefully, will plug the pipe scale too much, reach a cooling effect, corrosion serious leaks, so care must be taken in the cleaning and preservation measures to cool down.

(11) on the drive screw rotating brush DC motor to focus on examination of wear and exposure, the motor's insulation resistance value is more than the specified value should be measured regularly. In addition to check the cables and other parts for rust, and use of protective measures.

(12) The designated person responsible for equipment maintenance. And detailed records of each case included in maintenance and repair plant equipment management files.