(1) Rough outer surface of plastic pipes
Adjust the process temperature: reduce the cooling water temperature, and the suitable cooling water temperature for P pipe is 20-25 ℃; Check the waterway for blockages or insufficient water pressure; Check whether the heating coils such as the barrel and head of the machine are damaged; Adjust the inlet flow rate of the sizing sleeve; Consult the raw material supplier for the parameters of this batch of raw materials; Check the temperature of the mold core. If it is higher than the temperature of the mouth mold section, lower the temperature of the core; Clean the mold.
(2) Groove marks appear on the outer surface of plastic pipes
Adjust the water pressure of the sizing sleeve to ensure a balanced water output; Adjust the nozzle angle inside the vacuum shaping box to ensure even cooling of the pipes; Check for debris, burrs, and other hardware such as mouth molds, sizing sleeves, and cutting machines.
(3) Groove marks appear on the inner surface
Check if there is water entering the inner tube. If there is water entering, pinch the tube blank that just exits the mold tightly to seal its inner cavity; Reduce the internal temperature of the mold; Clean and polish the mold.
(4) There is a shaking ring inside the pipeline
Adjust the water outlet of the sizing sleeve to make it evenly distributed; Adjust the vacuum level of the second chamber to make the vacuum level of the rear chamber slightly higher than that of the front chamber; Check if the vacuum sealing gasket is too tight; Check if there is any shaking phenomenon in the tractor; Check whether the discharge of the host is uniform.
(5) No vacuum
Check if the inlet of the vacuum pump is blocked. If it is blocked, use a needle to clear it; Check if the vacuum pump is working properly; Check if there is any air leakage in the vacuum pipeline; Check if the small hole in the middle of the compression screw is blocked. If it is blocked, use a thin wire to clear it.
(6) The outer diameter of the pipe exceeds the tolerance
Adjusting the vacuum degree can change the outer diameter size; Adjusting the traction speed can change the outer circle size; Correct the inner hole size of the sizing sleeve.
(7) Pipe roundness exceeds the tolerance
Adjust the angle of the nozzles in the vacuum forming machine and spray box to ensure even cooling of the pipes; Check the water level and pressure gauge inside the vacuum forming machine and spray box to ensure a large and powerful spray volume; Check the water temperature of the vacuum forming machine and spray box. If it exceeds 35 ℃, a chilled water system or an additional spray cooling box should be installed; Check the waterway and clean the filter; Adjust the process; Check and correct the roundness of the inner hole of the sizing sleeve; Adjust the pipe guide clamping device to correct the ellipticity of the pipe.
(8) Uneven wall thickness of pipes
Adjust the wall thickness on the mold; Adjust the angle of the nozzles in the vacuum forming machine and spray box to ensure even cooling of the pipes; Adjust the water outlet of the sizing sleeve to make it evenly distributed; Open the mold, check if the screws inside the mold are loose, and tighten them again.
(9) The plasticizing temperature is too high
Adjust the process; Adjust the heating temperature of the mold core and ventilate and cool the interior of the mold.
(10) Inaccurate cutting length measurement
Check if the measuring wheel is tightly pressed; Check if the measuring wheel swings and tighten the fixing bolts of the measuring wheel frame; Check if the travel switch of the cutting machine is damaged; Check if the rotary encoder is damaged; Is there any loose soldering in the wiring of the rotary encoder (whether the aviation plug socket is in good contact); Each individual machine casing (PE terminal) should be grounded to a reliable main grounding point, and the grounding point should have a grounding post that meets electrical grounding requirements. It is not allowed for each individual machine casing (PE terminal) to be connected in series and grounded, otherwise interference pulses will be introduced, causing inaccurate cutting length.
(11) Issue with co extruded identification strips
Co extrusion marking strip diffusion: generally caused by improper selection of co extrusion material by the user, special materials such as PE should be used, and the extrusion section temperature can be reduced if necessary.
The co extrusion identification strip cannot be extruded: If there is still no co extrusion identification strip after 2 hours of operation, it is generally caused by the screw of the co extrusion machine retreating; Remove the screw and tighten it again.
The co extrusion marking strip is too thin or too wide: generally caused by the mismatch between the extrusion amount of the co extrusion machine and the pipe traction speed. The frequency of the co extrusion machine frequency converter should be adjusted, or the traction speed should be changed to match the two speeds; The second reason is that the cooling water jacket in the feeding section of the co extrusion machine is not connected to the cooling water.
Sometimes the identification strip of the co extrusion machine is missing it is generally due to uneven co extrusion of the material at the discharge port of the co extrusion machine. The water flow of the cooling water jacket at the discharge port should be checked and the appropriate co extrusion material particle size should be selected (generally requiring particles<Φ 3 × 3mm).