Sudden rise of extruder head pressure

In the extrusion '2079851475616104457 production process, the product exhibits the quality defect of "Sudden rise of extruder head pressure".The specific manifestation is The head pressure rises abnormally and sharply.This defect is more common when processing materials such as HDPE, PP, PVC and PC, and its occurrence is usually related to unreasonable settings of melt temperature, extrusion speed, blowing pressure and mold temperature.When the Sudden rise of extruder head pressure situation is severe, it will cause a series of chain quality defects in the product's appearance, dimensional accuracy, mechanical properties and other aspects, which not only reduces the product's functionality and safety in use, but also directly increases the scrap rate and production cost.Therefore, this problem requires systematic diagnosis and optimization from multiple dimensions such as material selection, the status of the extruder, head, die, mold clamping mechanism and blowing system, and melt temperature, extrusion speed, blowing pressure and mold temperature.

1. Screen breakage blocking the die.The mechanical properties of the material and the structural strength of the product directly determine the safety and reliability of the product in use.The root causes of insufficient strength may come from factors such as intrinsic material properties, processing-induced degradation, poor welding and stress concentration caused by uneven wall thickness.Improving strength requires coordinated improvements in material selection, process optimization and structural design. 2. Temperature sensor failure causing actual temperature to be too low.Temperature is the core factor affecting melt fluidity and viscosity.Excessively high temperature settings will cause decreased melt viscosity, insufficient melt strength and even thermal degradation; excessively low temperature results in poor melt fluidity and insufficient plasticization, making smooth filling or forming impossible.A reasonable temperature window should be optimally determined within the recommended range according to the melting characteristics and thermal stability of the material. In addition, the insufficient overall coordination of parison wall thickness control and parison temperature uniformity is also a factor that cannot be ignored; there are complex interactions and coupling relationships among the process parameters, and the deviation of any parameter may aggravate the degree of Sudden rise of extruder head pressure through chain effects. In terms of equipment maintenance, the regular overhaul and accuracy confirmation of the extruder, head, die, mold clamping mechanism and blowing system are not in place, causing the actual operating parameters of the equipment to deviate from process requirements, which will also become a potential inducement of the Sudden rise of extruder head pressure problem.

1. Install a pressure alarm device.Installation of equipment or accessories should strictly follow the installation manual; key mating surfaces must be cleaned and checked for damage before installation.Fastening bolts should be tightened evenly according to the specified torque values and diagonal sequence; after installation, use precision measuring tools to verify whether the installation accuracy meets technical requirements. 2. Stop the machine to check the screen and temperature control system.Inspection work should establish a standardized checklist, specifying inspection items, technical standards, inspection frequency and responsible persons.Key equipment components should be regularly disassembled to check the condition of hidden parts, and judgment should not be based solely on operating appearance.Inspection results should be recorded in detail and a trend analysis mechanism established to predict potential failures. It is recommended to formulate a preventive checklist for the Sudden rise of extruder head pressure problem, incorporate parison wall thickness control and parison temperature uniformity into the daily inspection scope, and conduct online monitoring of key parameters through the SPC statistical process control method to achieve early warning and rapid response to problems. In terms of material management, incoming inspection of raw materials and in-process testing of work-in-progress should be strengthened, and key performance indicators of HDPE, PP, PVC and PC should be strictly controlled to ensure the stability of forming quality from the source.

In summary, the causes of the "Sudden rise of extruder head pressure" problem can be attributed to the combined action of multiple factors such as Screen breakage blocking the die, Temperature sensor failure causing actual temperature to be too low.To solve this problem, it is necessary to start from aspects such as Install a pressure alarm device, Stop the machine to check the screen and temperature control system and take systematic governance measures.In actual production, it is recommended to establish a prevention and rapid response mechanism for this problem, achieving stable production and continuous improvement through parison wall thickness control and parison temperature uniformity.