Zhejiang Tianjie Industrial Corporation
Tel: +86 571 23656026
Fax: +86 571 23656068
Address: Linglong Economic Development Zone, Lin'an Hangzhou, China 311301
Common 11 types of defects in cable extrusion, 21 phenomena, 42 solutions
First, the phenomenon of sputum
(1) The ruthenium produced by the resin during the plasticization process has small crystal spots and small particles on the surface of the plastic layer, which are distributed around the surface of the plastic layer.
(2) The crucible generated by scorching has scorch on the surface of the plastic layer, which is particularly reflected on the surface of the glue joint.
(3) Impurities 疙瘩, there are impurities on the surface of the plastic, and there are impurities in the sliced crucible.
(4) Plastic enamel produced by poor plasticization. After slicing, it was found that the inside of the mash was cooked.
Second, the cause of embarrassment
(1) Since the temperature control is low, the plastic has not been plasticized and is extruded from the machine head.
(2) The quality of the plastic is poor, and there are resins that are difficult to plasticize. These are extruded without being completely plasticized.
(3) Some impurities are added to the hopper during feeding, causing impurities.
(4) The temperature control is super high, causing scorch, which causes burnt coke.
(5) There is no compression on the molded cover, and the aging deteriorates after the glue is applied, and the burnt sputum appears.
Third, the method of eliminating cockroaches
(1) The flaw caused by the plastic itself should be appropriately increased.
(2) Strictly check whether there is any foreign matter in the plastic feeding. Do not add other impurities into the hopper during feeding. If the impurities are found, clean the machine head immediately and run the glue in the screw.
(3) If the temperature is too high, the temperature should be appropriately lowered immediately. If the effect is not good, the head and the screw should be cleaned immediately to eliminate the burnt material.
(4) In the case of resin defects and poor plasticization, it is necessary to increase the temperature or reduce the speed of the screw and traction.
Defect 2: Positive and negative plastic layer
First, the phenomenon of excessive tolerance
(1) The speed of the screw and the traction is unstable, and the ammeter or the voltmeter swings left and right. Therefore, the outer diameter of the cable is affected, resulting in a deviation of the plastic layer.
(2) There is a problem with the quality of the semi-finished products, such as the wrapping of the steel strip or the plastic strip, resulting in unevenness of the convex or concave or defects such as wraps, ribs and pits in the plastic layer.
(3) The temperature control is super high, causing the extrusion amount to decrease, the outer diameter of the cable is suddenly thinned, and the plastic layer is thinned to form a negative difference.
Second, the cause of the out of tolerance
(1) The core or cable core is not round, and there is a serpentine shape, and the outer diameter changes too much.
(2) Semi-finished products have quality problems, such as: poor steel joints, loose steel strips, rolled steel strips, loose plastic sleeves, large joints, scattered flowers, etc.
(3) When the operation is performed, the core of the mold is too large, which causes the plastic layer to be eccentric.
(4) When the mold is adjusted, the mold adjustment screw is not tightened, and the reverse buckle phenomenon occurs to make the plastic layer eccentric.
(5) The screw or traction speed is unstable, resulting in an out of tolerance.
(6) The filling port or the filter is partially blocked, resulting in a decrease in the amount of glue and a negative difference.
Third, the method of eliminating the tolerance
(1) Always measure the outer diameter of the cable and check the thickness of the plastic layer. If the outer diameter changes or the plastic layer is uneven, it should be adjusted immediately.
(2) The matching mold should be suitable. After adjusting the mold, the mold adjustment screw should be tightened and the gland should be pressed tightly.
(3) Pay attention to the current and voltage meter of the screw and traction. If it is found to be unstable, it is necessary to find an electrician or a fitter for maintenance.
(4) Do not put strips or other debris into the hopper. If this condition is found, remove it immediately.
Defect 3: Charred
First, the phenomenon of scorching
(1) The temperature reflects super high, or the instrument that controls the temperature fails, causing the plastic to be ultra-high temperature and scorched.
(2) The nozzle of the machine head has a large smoke, a strong irritating odor, and a buzzing sound.
(3) Granular scorch on the surface of the plastic.
(4) There are continuous pores at the joints.
Second, the cause of the scorch
(1) The temperature control is super high, causing the plastic to burn.
(2) The screw is used for a long time without cleaning, and the scorch is accumulated and extruded with the plastic.
(3) The heating time is too long, and the plastic deposits are heated for a long time, which causes the plastic to deteriorate and burn.
(4) The parking time is too long, there is no cleaning head and screw, which causes the plastic to decompose and burn.
(5) Multiple mold changes or color changes, causing the plastic to decompose and burn.
(6) The head cover is not pressed, and the plastic is aged and decomposed inside.
(7) The instrument that controls the temperature fails, causing scorch after ultra-high temperature.
Third, the method of eliminating burnt
(1) Regularly check if the heating system is normal.
(2) Clean the screw or the machine head regularly and thoroughly clean it.
(3) According to the requirements of the process, the heating time should not be too long. If there is any problem with the heating system, it should be promptly found by relevant personnel.
(4) Change the mold or change the color in a timely and clean manner to prevent mottling or burnt scorching.
(5) After adjusting the mold, the mold cover should be pressed tightly to prevent the glue from entering.
(6) If the scorch is found, the machine head and the screw should be cleaned immediately.
Defect 4: Poor plasticization
First, the phenomenon of poor plasticization
(1) The surface of the plastic layer has a skin-like phenomenon.
(2) The temperature control is low, the meter pointer reflects the low temperature, and the actual measurement temperature is also low.
(3) The surface of the plastic is black, and there are tiny cracks or small particles that are not plasticized.
(4) The plastic glue is not well stitched, and there is a clear trace.
Second, the cause of poor plasticization
(1) The temperature control is too low or the control is not suitable.
(2) There are resin particles which are difficult to plasticize in plastics.
(3) The operation method is improper, the screw and traction speed are too fast, and the plastic does not completely reach plasticization.
(4) The plastic mixing is uneven during granulation or the quality of the plastic itself.
Third, the method of eliminating plasticization
(1) Control the temperature according to the process regulations, and find that the temperature is low and the temperature should be raised appropriately.
(2) It is necessary to appropriately reduce the speed of the screw and the traction, so that the plastic heating and plasticizing time is increased to improve the plasticizing effect of the plastic.
(3) Use screw cooling water to strengthen the plasticization and tightness of the plastic.
(4) When the mold is selected, the mold sleeve is appropriately smaller to strengthen the pressure of the glue outlet.
Defect 5: the outer diameter of the cable is uneven and the shape of the bamboo
First, the phenomenon of uneven thickness and bamboo shape
(1) Due to the unstable screw or traction, the outer diameter of the cable is not uniform.
(2) Since the traction is suddenly unstable, the plastic forming the cable is in the shape of a bamboo.
(3) The mold selection is small, and the outer diameter of the semi-finished product changes greatly, resulting in uneven thickness of the plastic layer of the cable.
Second, the reasons for uneven thickness and bamboo shape
(1) The speed of the retracting line or traction is uneven.
(2) The outer diameter of the semi-finished product changes greatly, and the mold selection is not suitable.
(3) The screw speed is unstable, the main motor speed is uneven, and the belt is too loose or slippery.
Third, the method of eliminating uneven thickness and bamboo shape
(1) Always check whether the speed of the screw, traction, and retracting line is uniform.
(2) The mold should be matched to prevent the glue from collapsing.
(3) Always check the operation of machinery and electrical appliances. If you find any problems, you should immediately find a fitter or an electrician to repair them. . .