A, scorch
1. Burning phenomenon
(1) the temperature reflects the high temperature, or the instrument failure to control the temperature, causing the plastic super high temperature to burn.
(2) the top of the nose is smoky, with a strong irritating odor and a crackling sound.
(3) granulated coke on plastic surface.
(4) there are continuous pores in the joint.
2. Causes of coke burning
(1) high temperature control causes plastic coke burning.
(2) the screw has been used for a long time and has not been cleaned, and the burnt property is deposited and extruded with the plastic.
(3) the heating time is too long and the plastic accumulator is heated for a long time, making the plastic aging and burning.
(4) the parking time is too long, and the machine head and screw are not cleaned.
(5) repeatedly changing or changing colors, causing the plastic to decompose coke.
(6) the head pressure is not pressed tightly; the plastic is decomposed in it.
(7) the control temperature of the instrument failure, resulting in the super high temperature coke.
3. Exclude the method of coke burning
(1) regularly check whether the heating system is normal.
(2) wash the screw or head regularly and thoroughly clean.
(3) according to the requirements of the process, the temperature should be warm and the temperature should not be too long. If there is any problem with the heating system, please find the relevant personnel to solve it in time.
(4) change the mold or change the color to be timely and clean, and prevent the color or coke burning.
(5) after adjusting the mould, press the die cover tightly to prevent the injection.
(6) the head and screw should be cleaned immediately.
2. Malplasticization
1. The phenomenon of malplasticization
(1) the plastic layer has a toad skin type surface.
(2) the temperature control is low, the instrument pointer reflects low temperature and the actual measurement temperature is low.
(3) plastic surface hair, with tiny cracks or no plasticized small particles.
(4) the plastic glue stitching is not good, there is an obvious trace.
2. Causes of malplasticization
(1) low temperature control or improper control.
(2) the plasticized resin particles in plastic.
(3) improper operation method, the screw and traction speed are too fast, and the plastic is not fully plasticized.
(4) the plastic mixing is not uniform or the plastic has a quality problem.
3. Eliminate the malplasticized method
(1) control the temperature according to the process rules, and find that the temperature should be adjusted appropriately when the temperature is low.
(2) it is necessary to reduce the speed of screw and traction properly to increase the time of plastic heating and plasticization to improve the plastic plasticizing effect.
(3) use the screw cooling water to strengthen the plasticization and the tightness of plastic.
(4) when the mold is selected, the mould sleeve is appropriately smaller, and the pressure of the adhesive mouth is strengthened.
Three, a knot in one's
1. The occurrence of pimples
(1) the lumps produced in the plasticization process of resin have small crystals and small particles on the surface of the plastic layer and are distributed around the surface of the plastic layer.
(2) the lumps of the burnt product on the surface of the plastic layer are reflected in the surface of the joint.
(3) impurity bumps, impurities on the plastic surface, and impurities in the lumps of the slices.
(4) plastic pimples produced by malplasticization. After slicing, the lumps are found to be ripe glue.
2. Causes of pimples
(1) because of the low temperature control, the plastic has not been plasticized, so it is extruded from the nose.
(2) the plastic quality is poor, and the resin is difficult to plasticize. These are extruded without total plasticization.(3) some impurities are added to the hopper, causing impurities.
(4) the temperature control is super high, which causes the coke burning, which can cause the burn.
(5) no pressing on the die cover, aging and deterioration after entering the glue, and the coke burn.
3. Remove the pimples
(1) the pimples caused by the plastic itself should raise the temperature appropriately.
(2) strictly check whether the plastic is sundry when adding materials. When adding materials, do not add other items to the hopper, and find that the impurities need to clear the head immediately, and clean the glue in the screw.
(3) it is found that the temperature should be reduced immediately and properly. If the effect is not good, clean the head and screw immediately and eliminate the coke.
(4) the lumps of the resin and malleable malleability should be adjusted to the high temperature or the speed of the screw and the traction.
Four, the plastic layer is positive and negative
1. The phenomenon of superdifference
(1) the screw and the traction speed are not stable, the current meter or the voltmeter wiggle, thus affecting the outer diameter of the cable and the deviation of the plastic layer.
(2) the semi-finished product quality is defective, such as the steel belt or plastic belt wrapped around the packing, resulting in the uneven appearance of the convex concave or the defects such as bags, edges and pits in the plastic layer.
(3) the temperature control is extremely high, resulting in a decrease in the extrusion quantity, and the outer diameter of the cable suddenly becomes thinner, and the plastic layer becomes thinner and the negative difference is formed.
2. The reason for the super difference
(1) the wire core or cable is not round, and the snake shape is too large.
(2) the semi-finished products have quality problems, such as: the steel belt joint is not good, the steel belt is loose, the steel belt is rolled, the plastic belt is loose, the joint is too large, and the loose flower etc.
(3) when operation, the mold core selection is too large, resulting in the plastic lamination of the plastic layer.
(4) when adjusting the mould, the adjustment screw is not tightened and the plastic layer is deflated.
(5) the screw or traction speed is unstable, resulting in the super difference.
(6) the loading port or the filter part is blocked, resulting in the decrease of the amount of glue and the negative difference.
3. Eliminate the super-poor method
(1) the outer diameter of the cable and the thickness of the plastic layer should be measured frequently, and the outer diameter or the plastic layer shall not be uniform.
(2) the mould should be suitable, and after adjusting the mould, tighten the die screw and tighten the cover.(3) notice the screw and traction current and voltmeter, and find that it is unstable, and timely find the electrician and the fitter for maintenance.
(4) do not add any material or other sundries to the hopper. If this is found, remove it immediately.
5. The thickness of cable outer diameter and the shape of bamboo
1. The phenomenon of coarse and fine irregularity and bamboos
(1) due to the instability of the screw or traction, the outer diameter of the cable is uneven.
(2) because of the sudden instability of the traction, the forming of the plastic of the cable is made of bamboo.
(3) the mould selection is smaller, the outer diameter of the semi-finished product is larger, and the thickness of the plastic layer of the cable is not equal.
2. The reasons for the uneven thickness and the shape of bamboo
(1) the uneven speed of the discharge line or traction.
(2) the outer diameter of the semi-finished product is relatively large, and the mold selection is unsuitable.
(3) the screw speed is unstable, the main motor speed is not uniform, the belt is too loose or skid.
3. The method of excluding coarse and fine and bamboo is excluded
(1) check the speed of screw, traction and collection line.
(2) mould selection should be suitable to prevent the phenomenon of pouring.
(3) constantly check the operation of machinery and electrical appliances, and find out the problems to immediately find locksmith and electrician repair.
Six, glue joint is not good
1. The phenomenon of joint gluing is not good
(1) on the outside of the surface of the plastic layer, the plastic merger is not good. There is a trace of upland, and there are serious cracks in it.
(2) the plastic lamination of plastic layer is not good, there are lumps and small particles, when severe, the hand will tear open.
(3) the control temperature is low, especially the control temperature of the machine head.
2. Reasons for poor joint sealing
(1) low temperature control and poor plasticization.
(2) long-term use of the machine head, causing serious wear and tear.
(3) the machine head temperature control fails, resulting in the low temperature, which makes the plastic laminating not good.
3. Eliminate the bad joint method
(1) properly increase the control temperature, especially the control temperature of the nose.
(2) thermal insulation is used on the outside of the machine head.
(3) add two layers of filter screen to increase the pressure and improve the plasticization of plastic.
(4) properly reduce the speed of the screw and the traction of the screw, so as to prolong the plastic plasticizing time and achieve the purpose of plastic joint.
(5) increase the bearing diameter of the mold and increase the extrusion pressure and temperature.
Other defects
1. Air holes, bubbles or air holes
(a) causes
(1) the local control temperature is very high.
(2) plastic moisture or moisture.
(3) the excess gas in the plastic after parking is not ruled out.
(4) the natural environment is humid.
(2) elimination of methods
(1) temperature control should be appropriate and the temperature should be adjusted immediately to prevent the local temperature from being super high.
(2) in addition, the plastic quality should be strictly inspected, especially during the wet and rainy season, when the moisture is found, the water should be stopped immediately, and then the tide will be clean.
(3) add the preheating device at the feeding place to expel moisture and moisture in the plastic.
(4) check whether the plastic layer has pores, air holes and bubbles.
2. Disjointed or broken glue
(1) causes of the cause
(1) the conductor has water or oil
(2) the core of the thread is too heavy with local contact with the mould core, causing the temperature to be reduced and the plastic partially cooling, resulting in disjointed or broken glue due to the stretching of the plastic.
(3) the semi-finished products are inferior in quality, such as steel strips and plastic straps, which are not strong or too large.
(2) elimination of methods
(1) the selection of mould should be larger, especially the selection of the moulds of the sheath, to enlarge 6 to 8mm.
(2) properly reduce the length and thickness of the core mouth.
(3) reduce the speed of screw and traction.
(4) adjust the temperature of the machine head properly.