Normal tube appearance (smooth and well-proportioned)

1. The appearance is smooth, flat and well-proportioned.

2. The appearance is consistent in color and luster.

The product surface is rough

(1) Adjust the process temperature, usually caused by low temperature,

(2) Increase the cooling water temperature, or increase the production speed

(3) Check whether the water channel is blocked or the water pressure is uneven (uneven all around), resulting in rough water spots or high water pressure, and cooling quickly.

(4) Check whether the heating rings such as barrel and head are damaged, and the outer surface is rough due to insufficient processing temperature

(5) Adjust the inlet flow rate of the sizing sleeve to be the same as ( 3 )

(6) Consult the raw material supplier for the parameters of this batch of raw materials (melt size, processing temperature, etc.). ) )

(7) Check the core temperature of the mold. If it is higher than the temperature of the mold section, increase or decrease the core temperature (for rough inner walls)

(8) Clean the mold (coke is easily generated at 0.5-1CM in the core mold of the die, resulting in uneven surface)

(9) Adjust the distance between the sizing sleeve and the mold (the closer the distance, the smoother the distance; press and polish with the sizing sleeve)

(10) The adjustment of the formulation is usually caused by the poor ratio of low melt index and high melt index materials.

2. A brief description of the treatment of groove marks on the outer surface of the pe pipe production line

(1) Adjust the outlet pressure of the shaping sleeve, and require the outlet water to be balanced. Excessive amounts of water can easily create ditches.

(2) Adjust the angle of the nozzle in the vacuum forming box to ensure uniform cooling of the tube

(3) Check whether there are sundries and burrs in the hardware such as molds, sizing sleeves, and cutting machines.

(4) When the raw material is replaced, a striped groove mark will also be formed, which will take some time to improve. When changing the type of raw material (eg MPP for PE), the barrel needs to be cleaned first with about 200 kg of low melt index pure material.

Clean the other materials in the bucket, then use the recipe for production.

5.No vacuum:

(1) Check whether the water inlet of the vacuum pump is free of water or blocked. If clogged, unclog with a needle or remove the water fitting for cleaning.

(2) Check whether the vacuum pump works normally and reversely.

(3) Check whether the vacuum pipeline is leaking

(4) Check whether the small hole in the middle of the core forming screw is blocked. If it gets clogged, unclog it with a wire (causing the tube to suck flat and no vacuum)

(5) Check the vacuum box cover and sealing ring for air leakage.

6. The outer circle (outer diameter) of the pipe is out of tolerance:

(1) Adjusting the degree of vacuum can change the size of the outer circle

(2) Adjusting the speed of the pipe can change the size of the outer circle

(3) Modify the inner hole size of the sizing sleeve (such as SDR 17 - SDR 11 )

The editor of the pe pipe production line reminds you: Generally speaking, the vacuum control of the pipeline between 0.3 and 0.4 has little effect on the product quality. The slower the speed of the thick-walled tube (usually more than 30 mm extrusion ≥ 700 kg), the smaller the outer diameter, the faster the speed, the larger the outer diameter, the higher the water temperature, the larger the outer diameter, the lower the temperature, and the smaller the outer diameter .

7. Large out-of-roundness (ellipse) of the pipe:

(1) Adjust the angle of the nozzles in the vacuum setting machine and the spray box to make the pipes cool and uniform

(2) Check the vacuum setting machine, the water level in the spray box and the pressure of the water pressure gauge, so that the spray volume is large and powerful, and the best spray path is foggy.

(3) Check the water temperature of the spray tank, if it is > 35°C, a chilled water system needs to be configured to reduce the water temperature.

(4) Adjust the tube clamping device to correct the ovality of the tube

(5) Check whether the position of the support wheel is on the same level and whether it meets the product specification requirements, or convert the support wheel of the vacuum box into a semi-circular support plate.

(6) Adjustment process

(7) Check and correct the roundness of the inner hole of the sizing sleeve

(8) Extend the length of the vacuum box

(9) Check the waterway and clean the filter

8. Uneven pipe wall thickness:

(1) Adjust the wall thickness on the mold, adjust the size of the gap around the mold, the small diameter always surrounds, and the large diameter always surrounds the upper and lower small diameters

(2) Adjust the angle between the nozzle of the vacuum forming machine and the spray box to make the pipeline cool evenly

(3) Adjust the water outlet of the sizing sleeve (groove water hole) to make the water outlet evenly

(4) Remove the mold, check whether the screws in the mold are loose, and then tighten again.

(5) The wall thickness drawing ratio can be adjusted for large diameters to reduce the influence of the melting hammer on the pipe wall thickness

(6) Adjust the temperature around the mold, change the flow rate of the melt, and thus change the wall thickness (usually used for production lines above dn630-en25, and the mold heating ring is required to be at least divided into upper and lower parts)

(7) Adjust the concentricity between the sizing sleeve and the die core

(8) Vacuum leakage. The surface of the vacuum leak must be thin. Check for the cause of the vacuum leak.

(9) Check whether the temperature of the downstairs entrance is stable (usually stable at 65℃--preferred), whether it does not feel hot, and whether there is enough water in and out (the pipes are uneven before and after)