Ningbo Fangli Technology Co., Ltd. is a mechanical equipment manufacturer with nearly 30 years’ experiences of plastic pipe extrusion equipment, new environmental protection and new materials equipment. Since its establishment Fangli has been developed based on user’s demands. Through continuous improvement, independent R&D on the core technology and digestion & absorption of advanced technology and other means, we have developed PVC pipe extrusion line, PP-R pipe extrusion line, PE water supply / gas pipe extrusion line, which was recommended by the Chinese Ministry of Construction to replace imported products. We have gained the title of “First-class Brand in Zhejiang Province”.
The use methods of different plastic extruders are generally different, but the normal shutdown operation is much the same. As an enterprise with more than 30 years of extruders and related equipment, Ningbo Fangli Technology Co., Ltd. has simply sorted out a document about the normal shutdown sequence of conventional twin-screw plastic extruders. The details are as follows:
I. First, we need to stop feeding the plastic extruder. The conventional twin-screw plastic extruder has a feeder or a feeding system. If the multi-channel feeding system is used, the auxiliary feeders need to be stopped at this time.
II. If the extruder has a vacuum pumping system, we need to close the valve of the vacuum pipeline and then open the upper cover plate of the vacuum chamber.
III. The screw of the extruder cannot stop rotating directly. Instead, the screw speed should be gradually reduced and the residual materials in the barrel should be drained as much as possible. If the extruder uses heat sensitive materials that are easily decomposed by heat as raw materials, polyolefin materials shall be used to replace the residual materials in the main machine before shutdown, and the twin-screw main machine can be stopped after the materials are basically discharged. If the extruder production line is a two-stage unit, it is necessary to stop the first stage extruder first, and then stop the second stage extruder equipment.
IV. Stop the main motor cooling fan, oil pump, vacuum pump and water pump in turn. Disconnect the power switch of each section of heater on the electric instrument control cabinet.
V. Stop auxiliary equipment such as pelletizer.
VI. Close the valves of all external water pipes, including the cooling water of the barrel of the feeding section, the cooling water of the oil lubrication system, the cooling water of the vacuum pump and the water tank (the throttle valves of the water cooling pipes of the main barrel do not move).
We hope that the above information can provide you with some help. If you need more information, Ningbo Fangli Technology Co., Ltd. welcomes you to contact for a detailed inquiry, we will provide you with professional technical guidance or equipment procurement suggestions.