about machines

Step of start up double screw extrusion machine①After checking everything is normal, start the main motor, and adjust the main engine speed knob (note that the speed control knob should be set to zero before driving), gradually increase the main screw speed, idling speed is not higher than 40rpm without feeding. No less than 1Min, check whether the no-load current of the host is stable.②If there is no abnormality in the rotation of the main machine, you can follow the steps below. Start the auxiliary machine → start the main machine → start the feeder.③Add a small amount of material first, and start feeding at the lowest possible speed. After the material is discharged from the standby head, slowly increase the screw speed of the feeder and the screw speed of the host. When the speed is increased, the host speed should be increased first. Feed and match the speed of the feeder to the main engine. After each main engine is raised, you should observe a few minutes. After there is no abnormality, increase the speed until it reaches the working state required by the process.④ After the host runs smoothly, you can start the water pump of the soft water system, and then slightly open the shut-off valve of the barrel section to be cooled. After a few minutes, observe the temperature change in this section.⑤ After the host machine enters a stable running state, restart the vacuum pump (open the vacuum pump water inlet valve before starting to adjust and control the appropriate working water volume, subject to a small amount of water spraying from the vacuum pump exhaust port). Observe the plasticity and fullness of the material in the spiral groove from the exhaust port. If normal, you can open the vacuum line valve to control the vacuum within the required range. If there is a "blow-up" phenomenon at the exhaust port, it can be eliminated by adjusting the rotation speed of the screw of the host and the feeder, or changing the combined configuration of the screw.⑥ After the plastic is extruded, it is necessary to slowly introduce the extruded material to the cooling setting and traction equipment, and then adjust each link appropriately according to the instruction value of the control instrument and the requirements for the extruded product until the extrusion operation is normal. Status.⑦ Cutting and sampling, check whether the appearance meets the requirements, whether the size meets the standards, quickly detect the performance, and then adjust the extrusion process according to the quality requirements, so that the products meet the standard requirements.

PE-100Nominal O.D.SDR26PN6SDR26PN6SDR17PN10SDR17PN10SDR11PN16SDR11PN16mmwall thickness,mmweight,kg/mwall thickness,mmweight,kg/mwall thickness,mmweight,kg/m20----1.90.11225--1.80.132.30.1732--1.90.182.90.27401.80.222.40.293.70.43502.00.313.00.454.60.66632.50.493.80.725.81.06752.90.674.51.026.81.47903.50.975.41.468.22.131104.21.436.62.1710.03.181254.81.847.42.7611.44.201606.23.049.54.5214.66.722007.74.6911.97.0518.210.462258.65.8913.48.9320.513.242509.67.3014.81122.716.2928010.79.1116.613.725.420.431512.111.618.717.428.6PE-80Nominal O.D.SDR26PN6SDR26PN6SDR13.6PN10SDR13.6PN10SDR9PN16SDR9PN16mmwall thickness,mmweight,kg/mwall thickness,mmweight,kg/mwall thickness,mmweight,kg/m20--1.80.1072.30.13325--1.90.1442.80.232--2.40.2323.60.327401.90.2393.00.3564.50.509502.40.3743.70.5495.60.788633.00.584.70.8737.11.26753.60.8285.61.248.41.76904.31.186.71.7710.12.541105.31.778.12.6212.33.781256.02.279.23.3714.04.871607.73.7211.85.517.97.962009.65.7814.78.5622.412.422510.87.316.610.925.215.825011.98.9318.413.427.919.428013.411.320.616.831.324.33151514.223.221.235.230.8PE-63Nominal O.D.SDR17.6PN6SDR17.6PN6SDR11PN10SDR11PN10SDR7.4PN16SDR7.4PN16mmwall thickness,mmweight,kg/mwall thickness,mmweight,kg/mwall thickness,mmweight,kg/m20--1.90.1122.80.15425--2.30.1713.50.24321.80.1792.90.2724.40.386402.30.2853.70.435.50.6502.90.444.60.6666.90.936633.60.6885.81.058.61.47754.30.9766.81.4710.32.09905.11.398.22.1212.331106.32.0810.03.1415.14.491257.12.6611.44.0817.15.771609.14.3514.66.6721.99.4420011.46.7918.210.427.414.822512.88.5520.513.130.818.625014.210.622.716.234.22328015.913.225.420.338.328.931517.916.728.625.643.136.5

When you choose exhausting type screw...1）L/D Ratio: between 24-33,bigger length than single-step screw.The section before exhausting part will be 52%-58% of total length of screw, that ensure plasticizing before materials running into exhausting section.Generally speaking,when L/D is 30,length of exhausting section is about 4D(D=diameter of screw). The second compressing section should be less than 2D, but the second metering section is longer and better,15-25% OF total length,which is good for stable extrusion. 2）Pump ration: Ratio(X) of depth of screw slot on second metering section(h2) and first metering section(h1), X=h2/h1Usually, X is between1.6-1.7, that reduces the possibility of materials overflow out of screw.If extruder is for mixing color, X could be big. If for extrusion pipe profile,small.

After comparative test of impact resistance on UHMWPE escaping pipeline and steel pipe, the UHMWPE pipeline is proved to be with more reliability when applied to emergency rescue in construction of highway tunnel. Below is test result: Steel pipe UHMWPE pipeline Pressure/Mpa Size Weight/meter Size Weight/meter Φ89*4 6.4 Φ76*8 1.7 3 Φ108×4 10.26 Φ96×8 2.16 3 Φ121×4 11.54 Φ110×8 2.5 3 Φ146×5 17.39 Φ133×8 3.07 3 Φ168×4.5 18.1 Φ150×8 3.49 3 Φ180*5 25.75 Φ159*8 3.71 3 Φ219×6 31.5 Φ205×8 4.8 4 Φ273*6 39.51 Φ250*10 7.37 4 Φ240×6 34.6 Φ219×10 6.4 4 Φ290×6 42.02 Φ273*10 8.07 4 Φ325×6 47.2 Φ300×10 8.9 4 Φ342*6 49.71 Φ325*10 9.67 4 Φ377×8 72.8 Φ350×10 10.4 4 Φ395*8 76.35 Φ377*10 11.27 4 Φ426×8 82.5 Φ400×10 12 4 Φ450*8 87.2 Φ426*12 15.25 4 Φ530×10 128.23 Φ500×10 15.04 4 Φ560*12 182.88 Φ600*12 21.66 4 Φ660*12 191.76 Φ630×15 28.32 4

After comparative test of impact resistance on UHMWPE escaping pipeline and steel pipe, the UHMWPE pipeline is proved to be with more reliability when applied to emergency rescue in construction of highway tunnel. Below is test result: Steel pipe UHMWPE pipeline Pressure/Mpa Size Weight/meter Size Weight/meter Φ89*4 6.4 Φ76*8 1.7 3 Φ108×4 10.26 Φ96×8 2.16 3 Φ121×4 11.54 Φ110×8 2.5 3 Φ146×5 17.39 Φ133×8 3.07 3 Φ168×4.5 18.1 Φ150×8 3.49 3 Φ180*5 25.75 Φ159*8 3.71 3 Φ219×6 31.5 Φ205×8 4.8 4 Φ273*6 39.51 Φ250*10 7.37 4 Φ240×6 34.6 Φ219×10 6.4 4 Φ290×6 42.02 Φ273*10 8.07 4 Φ325×6 47.2 Φ300×10 8.9 4 Φ342*6 49.71 Φ325*10 9.67 4 Φ377×8 72.8 Φ350×10 10.4 4 Φ395*8 76.35 Φ377*10 11.27 4 Φ426×8 82.5 Φ400×10 12 4 Φ450*8 87.2 Φ426*12 15.25 4 Φ530×10 128.23 Φ500×10 15.04 4 Φ560*12 182.88 Φ600*12 21.66 4 Φ660*12 191.76 Φ630×15 28.32 4

Ultra big molecular weight polythylene(UHMWPE) tunnel escape pipeline,is linetype thermoplastic engineering plastic with more than 2.5 million molecular weight,which is polymerizated by ethylene, butadiene monomer and catalyzer. In 1957 years,Allied Chemical from USA is the first industrial manufacturer of such pipe.After then, Hoechst and Her-Cules from Germany, Ben-Mitsui Petrochemistry from Japan also start industrial production. China succeed in develop and produce UHMWPE in 1964 years.●Light weight, 1/3 weight of steel tube, easy to install and carry.●The pipeline with good toughness,high impact strength(5 times of polycarbonate pipeline),there is instant deformation on the pipeline when attacked by strong external force,absorb large of impact energy,then resile very quickly, that could ensure the safety condition for tunnel lifesaving.●High ring stiffness,good pressure resistance(Max.4Mpa),difficult to deform. With better performance of pressure bearing and anti destroy when tunnel collapse.

Pipe Water pressure test must be with connected PE Pipe before landfills, to check the pipe pressure whether reach the standard of working pressure and pipe pressure, also to check the strength of connecting part between pipe and fitting. The leakage or squib on joint will affect the whole pipe network’s running if water pressure test. Below is six criterion for HDPE Pipe pressure test: 1. At least 12 hours steeping in water for PE Pipe before pressure test.2.The still water pressure should not be less 1.5 times than pipe working pressure, and more than 0.80MPa. It is not allowed to use air pressure test instead of water pressure.3.During pressure test,the pipe length should be less than 1000meters when with joint. If no joint, her length should be less than 500 meters.4.The braced sheeting on joint should be checked carefully before pressure test, avoid loose and fall off.5.The pressure forcing machine should be with measure equipment. If with spring pressure measurement, her accuracy should be more than 1.5 grade, range should be 1.3-1.5 times of the testing pressure, diameter of dial plate should be more than 150mm.6.The valve on testing pipe should be open. Such like the valve on water-harmmer arrestor and fire hydrant.

If misoperation happened in production of HDPE Pipe, such like workers’immature technology, raw materials, and malfunction in the machine , which could caused many kinds of problem that could affect the quality of pipe. Today we are trying to talk about the SPOT on HDPE Pipe:1.Blocking of the cooling water channel in the calibration die, that could give regular distribution of spot on pipe. We could try to clean the water channel,to ensure the regular cooling water film, and to avoid the spot.2.Too much heating time for raw materials in machine nose or barrel,some dirty in the nose and barrel, too higher heating temperature,or damage in the screw, all of which could burn-in the raw materials,then spot occured。After the 1.5hrs of the machine stopped working,stop the recycled HDPE raw materials into machine. More importantly,reduce the heating temperature immediately to 150-200℃ if the machine will stop for more than 4 hrs.3.Un-regular cooling water quantity in the calibration die also could give spot on the pipe, especially for the Φ315 pipe or more,because it will need more cooling water to ensure the water film,but the more gravity of water will be a resistance. So please try to give more water to the upside of calibration die, or increase the water flow at weakness water channel.4.The un-plastify impurity in raw material also could give spot in the pipe. You could watch the impurity if spot is big. Try to increase the temperature, adopt screen filter, or change materials.5.The humidity in the raw materials will produce bubble in the surface of pipe,then the spot will be there after calibration. Also you will find a small tail in the negative extrusion direction,and you need to dry the raw materials.6.Too much water flow could give spot in the pipe surface. Especially for the hole-type calibration die,where there is no partition for the water channel, the bottom water pressure is bigger, but surface of pipe is soft, it is easy to get spot in the bottom. 

Our SJ-150/33 SJ-120/33 Extrusion Line could produce 1680mm diameter HDPE Pipe,which is applicable for Anticorrosive insulation.