1. the positive and negative out-of-tolerance of the plastic layer

1, the phenomenon of out-of-tolerance

(1) the speed of the screw and traction is unstable, and the ammeter or voltmeter swings left and right, thus affecting the outer diameter of the cable and causing the deviation of the plastic layer.

(2) Semi-finished products have quality problems, such as loose wrapping of steel belt or plastic belt, uneven unevenness or defects such as wrapping, edge and pit in plastic layer.

(3) The temperature control is too high, which causes the extrusion amount to decrease, the outer diameter of the cable suddenly becomes thinner, and the plastic layer becomes thinner, forming a negative difference.

2, causes of out-of-tolerance

(1) The core or cable center is not round, and there is also a serpentine shape, while the outer diameter changes too much.

(2) Semi-finished products have quality problems, such as: bad steel belt joints, steel belt loose sleeves, steel belt curling, plastic belt loose sleeves, too large joints, scattered flowers, etc.

(3) During operation, the mold core selection is too large, causing the plastic layer to be eccentric.

(4) When adjusting the mold, the mold adjusting screw is not tightened, causing the plastic layer to be eccentric.

(5) The screw or traction speed is unstable, causing out-of-tolerance.

(6) The feeding port or filter screen is partially blocked, resulting in a decrease in the amount of glue and a negative difference.

3. Method to eliminate out-of-tolerance

(1) Measure the outer diameter of the cable and check the thickness of the plastic layer frequently. If the outer diameter changes or the plastic layer is uneven, it should be adjusted immediately.

(2) The optional mold should be appropriate. After adjusting the mold, tighten the mold adjustment screw and press the gland tightly.

(3) Pay attention to the current and voltmeter of the screw and traction. If it is found to be unstable, find an electrician and fitter for maintenance in time.

(4) Do not add strips or other debris into the hopper. If this situation is found, it should be removed immediately.

2. uneven thickness of cable outer diameter and bamboo shape

1, uneven thickness and bamboo shape

(1) uneven thickness of cable outer diameter due to unstable screw or traction.

(2) Due to the sudden unstable traction, the plastic forming the cable is in the shape of a bamboo joint.

(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.

2. Causes of uneven thickness and slub shape

(1) Uneven speed of winding and setting out or traction.

(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 slipping.

3, method of eliminating uneven thickness and bamboo shape

(1) often check whether the speed of screw, traction and rewinding line is uniform.

(2) mold selection should be appropriate to prevent the phenomenon of pouring glue.

(3) Frequently check the operation of machinery and electrical appliances, and immediately find a fitter or electrician to repair the problem.

3. glue joint is not good

1, glue joint is not good

(1) On the outside of the surface of the plastic layer, the plastic is not well combined, with a trace of disintegration and cracks in severe cases.

(2) The plastic layer is not plasticized well, and there are pimples and tiny particles, which can be torn apart by hand in severe cases.

(3) The temperature controlled is low, especially the control temperature of the head is low.

2. Reasons for poor glue sewing

(1) Low control temperature and poor plasticization.

(2) Long-term use of the machine head causes serious wear and tear.

(3) The temperature control of the machine head fails, causing low temperature and making the plastic lamination glue not good.

3, the method of eliminating the bad glue seam

(1) appropriately increase the control temperature, especially the control temperature of the machine head.

(2) The outer side of the machine head shall be insulated by thermal insulation device.

(3) Add two layers of filter to increase the pressure and improve the degree of plasticization of the plastic.

(4) Appropriately reduce the speed of the screw to extend the plastic plasticizing time and achieve the purpose of plastic stitching.

(5) Extend the wire diameter of the mold and increase the extrusion pressure and temperature.

4. other defects

1, air holes, air bubbles or air holes

(I) causes

(1) Local control temperature is too high.

(2) The plastic is wet or has moisture.

(3) The excess gas in the plastic is not removed after parking.

(4) The natural environment is humid.

(II) exclusion method

(1) The temperature control should be appropriate, and the temperature should be adjusted immediately if the temperature is too high to prevent local temperature from being too high.

(2) When feeding, strictly check the quality of the plastic, especially in the rainy season, if it is found that there is moisture, stop using it immediately, and then run the damp material clean.

(3) Add a preheating device at the feeding point to drive off moisture and moisture in the plastic.

(4) Frequently take samples to check whether there are pores, air holes and bubbles in the plastic layer.

2, disjoint or broken glue

(I) causes

(1) conductive wire core has water or oil

(2) wire core is too heavy to contact with mold core locally, resulting in temperature drop, local cooling of plastic, disjoint or broken glue due to plastic stretching.

(3) Semi-finished products are of poor quality, such as steel belts and plastic belts with loose sleeves, and the joints are not firm or too large.

(II) Exclusion Method

(1) Mold selection should be larger, especially for sheath mold selection, which should be enlarged by 6 to 8mm.

(2) Appropriately reduce the length and thickness of the core nozzle.

(3) Reduce the speed of the screw and traction.

(4) Appropriately increase the control temperature of the machine head.

3, Pits and Eyes

Causes of (I)

(1) Press the conductive core tightly and the strand is not tight and there are gaps.

(2) The wire core has water, oil and dirt.

(3) The semi-finished product has defects, such as stranded wire expenditure, crushing, crossing, bending, overlapping of steel belt and plastic belt, loose sleeve, oversized joint, etc.

(4) Low temperature control.

(II) Exclusion Method

(1) The tight compression of the stranded conductor shall conform to the process regulations.

(2) Semi-finished products do not meet the quality requirements and should be processed before production.

(3) Remove dirt, and preheat the cable core or wire core.

4, plastic layer wrapping, edges and corners, ears, wrinkles and bumps

(I) causes

(1) quality problems caused by plastic wrapping and steel wrapping.

(2) The mold selection is too large, caused by vacuuming.

(3) Plastic pouring occurs after the mold core is damaged.

(4) The core is too heavy and the plastic layer does not cool well.

(II) Exclusion Method

(1) Check the quality of semi-finished products, and non-conforming products will not be produced.

(2) Check the mold before assembly, and use it after problems are found.

(3) Mold selection should be appropriate. Appropriately reduce the speed of traction, is the plastic layer completely cooled.

5, plastic surface traces

(I) causes

(1) mold sleeve bearing diameter surface is not smooth or notched.

(2) The temperature control is too high, the barium stearate of the plastic itself decomposes, and accumulates at the mold sleeve opening causing traces.

(II) Elimination Method

(1) When selecting the mold, check whether the surface of the mold sleeve bearing wire diameter is smooth, and deal with any defects.

(2) Reduce the temperature of the heating zone of the head appropriately, and remove barium stearate immediately after it is produced.