CN108774349A - A kind of UHMWPE melting extrusions level composite material and preparation method thereof, moulding process and application - Google Patents

Abstract

The invention relates to a UHMWPE melt extrusion grade composite material and its preparation method, molding process and application. The composite material comprises 100 parts of ultra-high molecular weight polyethylene, 2-40 parts of composite flow modifier, 0.5- 5 parts of lubricant, 0.1-10 parts of melt lubricant are mixed at high speed (700-1400 rpm), and then the mixture is extruded through a single-screw extruder, and the extrusion temperature is controlled at 150-280 ° C, and then the pipe Compress and form in the mold, and finally cool and shape the pipe in a vacuum setting water tank. Compared with the prior art, the molding speed of the melt-extruded ultra-high molecular weight polyethylene pipe prepared by the extrusion of the present invention is 5-50m/h, which is 10 times higher than that of the ultra-high molecular weight polyethylene pipe prepared by the hard-top extrusion method at present. ‑15 times, greatly improving production efficiency, and the pipe also has excellent wear resistance and impact resistance.

Description

A UHMWPE melt extrusion grade composite material and its preparation method, molding process and application

technical field

The invention belongs to the technical field of polymer processing and molding, and in particular relates to a UHMWPE melt extrusion grade composite material and its preparation method, molding process and application.

Background technique

Ultra-high molecular weight polyethylene (UHMWPE) is polyethylene (PE) with a viscosity average molecular weight greater than 1.5 million. It is a new type of thermoplastic engineering plastic. Its extremely high molecular weight and highly entangled segment structure endow it with excellent mechanical properties, Impact, wear resistance, self-lubrication, chemical corrosion resistance and other properties, and UHMWPE has excellent low temperature resistance, it still has high impact strength at -40°C, and can even be used at -269°C. The excellent performance of UHMWPE makes it widely used in the fields of machinery, textile, papermaking, mining, chemical industry and sports equipment, among which large packaging containers and pipes are the most widely used. In addition, based on the excellent physiological inertia of UHMWPE, it has been used in the field of medicine and health as heart valves, orthopedic parts, artificial joints, etc.

The plastic pipe made of UHMWPE as the basic raw material has the characteristics of wear resistance, impact resistance, corrosion resistance, self-lubrication, and no scaling. It is an ideal pipe suitable for conveying solid-liquid mixture, solid powder, liquid, gas and other media. It is widely used in solid grain transportation, tailings transportation in mines, river sediment dredging projects, etc. Although UHMWPE is a thermoplastic, because of its extremely high relative molecular weight, the molecular chain segments are very long and intertwined with each other, and its characteristics during melting are completely different from those of general thermoplastics, which brings difficulties to the molding process. Very difficult.

UHMWPE has extremely excellent properties, but the viscosity of UHMWPE in the molten state is as high as 10 ⁸ Pa s, and its fluidity is extremely poor. UHMWPE is extremely difficult to form and process, so it is difficult to process it with general mechanical processing methods. Even UHMWPE after flow modification , is also prone to melt fracture. In recent years, the processing technology of UHMWPE has developed rapidly. Through the transformation of common processing equipment, UHMWPE has been developed from the initial pressing-sintering molding to extrusion molding and other special methods. At present, the processing and molding of UHMWPE pipe products in China is mainly through the UHMWPE special single-screw extruder, and the fluidized modified UHMWPE is formed by the "hard top method" extrusion process cooled in the mold. Because of this process, the pipe is cooled to below the crystallization temperature of the material in the mold, and then extruded after being shaped. This process is much more advanced than compression molding and foreign plunger extrusion.

At present, the UHMWPE "hard top method" extrusion molding realized by fluidization modification has an output of about 10kg/h, which is still 10-20 times lower than the processing efficiency of ordinary plastics such as PE, PVC, nylon, etc.; high-viscosity UHMWPE extrusion The production efficiency is poor, which restricts the production efficiency of UHMWPE, and is far from meeting the current demand for industrial pipes. Because the "hard top method" single-screw extrusion molding is to cool the pipe parison in the mold to the crystallization temperature of the material and then extrude it, the extrusion speed is fast, and the pipe parison has no time to cool and solidify, resulting in deformation of the pipe after molding.

Due to the extremely high molecular weight of UHMWPE, when processing the same product, the pressure in the machine head is 20 to 30 times higher than that of ordinary plastics, and the pressure of the machine head affects the shear rate during melt molding. The critical melting shear rate of UHMWPE is very low (<10 ^-2 /s), and melt fracture is prone to occur. In addition, UHMWPE has excellent self-lubricating properties, even in the molten state. Therefore, it is easy to slip in the feeding section during the feeding process, and the screw cannot advance to convey the raw material. This is another problem encountered in the processing of UHMWPE by the screw method, so the melt extrusion molding of UHMWPE is very difficult technically.

Contents of the invention

The purpose of the present invention is to provide a UHMWPE melt-extruded grade composite material and its preparation method, molding process and application in order to solve the above problems, modify the fluidity of UHMWPE to improve the mechanical properties, and break through the bottleneck of the existing processing and molding technology. Improve product production efficiency.

The object of the present invention is achieved through the following technical solutions:

A kind of UHMWPE melting extruded grade compound material, comprises following components and content by weight:

Wherein, the composite flow modifier is composed of low molecular weight polyolefins with different molecular weight gradients.

Further, the molecular weight of the composite flow modifier is 50,000 to 500,000, and the melt flow rate is 0.1 to 20 g/10 min under a load of 2.16 kg.

Further, the composite flow modifier is composed of linear low-density polyethylene, low-density polyethylene, high-density polyethylene, ultra-low-density polyethylene and polyolefin elastomer with a molecular weight distribution of 4-6. The weight ratio, low molecular weight part (50,000-150,000): high molecular weight part (150,000-500,000) is 1/9～3/7.

Further, the ultra-high molecular weight polyethylene is a copolymer of ethylene and α-olefin with a viscosity average molecular weight of 1 million to 9 million, and the molecular weight distribution is >3.0.

Further, the mole fraction of the α-olefin is 15%-0.1%, preferably 10%-0.5%, more preferably 5%-1%, and the α-olefin is selected from propylene, 1-butene, 1 -One or more of pentene, 1-hexene, 1-heptene, 1-octene, cyclohexene or butadiene.

Further, the lubricant is selected from one or more of polyethylene wax, barium stearate, calcium stearate, zinc stearate, oleic acid amide, stearic acid, microcrystalline paraffin or fatty acid.

Further, the melt smoothing agent is selected from one or more of hyperbranched polyester, hyperbranched polyether, hyperbranched polyetherketone or hyperbranched polystyrene.

A preparation method of UHMWPE melt extrusion grade composite material, comprising the following steps:

(1) Mix 0.2-1 part of grafting monomer with acetone by weight to prepare a mixed solution, then use spray dispersion to blend and compound the above solution with 10 parts of ultra-high molecular weight polyethylene, complete the grafting treatment, and obtain A material;

(2) Mix the high molecular weight part of the composite flow modifier with the lubricant at high speed (700-1400 rpm), and mix the low molecular weight part of the composite flow modifier with the melt lubricant at high speed (700-1400 rpm). / minute) mixing, and then the two are mixed to obtain material B;

(3) Add 90 parts of ultra-high molecular weight polyethylene, material A and material B into the cold mixer and stir to cool down to obtain the product. Cooling water needs to be passed into the jacket of the cold mixer, and the mixing time is 1-60 minutes , The discharge temperature is below 40°C.

Further, the grafting monomer in step (1) is selected from one or more of maleic anhydride, acrylic acid or acrylamide.

A molding process of UHMWPE melt-extrusion grade composite material, which specifically includes the following steps: after high-speed mixing of UHMWPE melt-extrusion grade composite material, put it into the feeding bin of a single-screw extruder, convey and extrude through a screw, extrude The temperature of the melt outlet die is controlled at 150-280°C, and then compressed and formed in the pipe mold, the mold compression ratio is greater than 3, and finally the pipe is cooled and shaped in the vacuum setting water tank, and the vacuum degree of the vacuum water tank is kept at 0.4-0.8MPa , The cooling water temperature is divided into multiple sections, the initial section is near the sizing sleeve, and the temperatures are 90°C, 80°C, 60°C, and 20°C.

The composite material is used to prepare super-large-diameter pipes. The outer diameter of the pipe is 10-1000 mm, the wall thickness is 2-50 mm, the extrusion speed is 5-50 m/h, and the extrusion melt temperature is 150-280 ° C. , the viscosity average molecular weight is 1.5-6 million, and it is also suitable for high-efficiency extrusion molding of plates and profiled materials.

The composite flow modifier used in the present invention modifies ultra-high molecular weight polyethylene, the molecular weight of the composite flow modifier used is 50,000-500,000, the melt flow rate is 0.1-20g/10min under a load of 2.16kg, and the molecular weight distribution Composed of 4-6 linear low-density polyethylene, low-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, polyolefin elastomer, etc., it has a similar structure to ultra-high molecular weight polyethylene, good uniformity, and is not easy Produces phase separation and has high strength. Polyolefin elastomer has the characteristics of high strength, heat aging resistance, and is not easy to warp during extrusion processing. The compound flow modifier added has a short-chain branched structure and will penetrate into the ultra-high molecular weight polyethylene resin. Realize the division of secondary particles of ultra-high molecular weight polyethylene resin, the secondary particles are deformed and separated under shearing, the distance between molecular chains is increased, the entanglement point is reduced, the melt viscosity is reduced, and the processing performance is excellent.

In the present invention, the different molecular weight gradient distribution of the composite flow modifier is mixed with the lubricant and the melt lubricant respectively, and the high molecular weight part is mixed with the lubricant, which effectively promotes the distribution of the lubricant in the outer layer of the melt during the extrusion process, and its lubricating effect Helps reduce melt pressure during screw advancement. The low molecular weight part is mixed with the melt lubricant. Due to the low viscosity and high fluidity of the melt lubricant, it helps to reduce the shearing effect of the melt and prevent melt fracture and phase separation.

The lubricant used in the present invention makes the blend of ultra-high molecular weight polyethylene and compound flow modifier form a differential phase during the extrusion process, precipitates on the inner and outer surfaces of the pipe, and forms a certain friction and lubrication layer with the screw and the barrel. This enables the blend to be extruded efficiently.

The melt smoothing agent adopted in the present invention has low viscosity, high fluidity, and few molecular entanglement points, and the blend with ultra-high molecular weight polyethylene and composite flow modifier is effectively precipitated in the melt type during extrusion. The surface of the embryo improves the processing performance of the melt and effectively increases the strength of the melt. During the high-speed extrusion process, the formed pipe does not deform and has excellent mechanical properties.

Compared with the existing UHMWPE "hard top method" extrusion molding, the modified UHMWPE composite material can be melt-extruded to form pipes, so that the pipe parisons are extruded in a melt state, cooled and shaped in a vacuum water tank, and the pipes Rapid cooling and crystallization improves the straightness and roundness of the pipe, and has excellent mechanical properties. At the same time, the product also has excellent wear resistance and impact resistance. The invention breaks through the bottleneck of the existing UHMWPE processing and molding technology, greatly improves the production efficiency of UHMWPE products, and promotes the development of UHMWPE products.

Detailed ways

The present invention will be described in detail below in conjunction with specific examples, but it is by no means a limitation of the present invention.

Example 1

(1) A mixture of 0.2 parts of maleic anhydride and acetone was dispersed by spraying on 10 parts of ultra-high molecular weight polyethylene with a molecular weight of 2.5 million to complete the grafting reaction to obtain composite material A.

(2) Mix 15 parts of the high molecular weight part of the compound flow modifier (150,000-500,000) with 0.5 parts of zinc stearate and 1 part of oleic acid amide at high speed (rotating speed 700-1400 rpm) for 5min-8min, low molecular weight Part (50,000-150,000) mixed with 5 parts of hyperbranched polyester at high speed (700-1400 rpm) for 5min-8min, and finally the low molecular weight part and high molecular weight part were mixed at high speed (700-1400 rpm) for 3min -5min, to obtain the premix B material of the special material for melt extrusion of ultra-high molecular weight polyethylene pipes.

(3) Add 90 parts of ultra-high molecular weight polyethylene with a molecular weight of 3.5 million, composite material A, and premix B into a cold mixer, stir and cool quickly, and the mixing time is 1 minute to obtain a molten ultra-high molecular weight polyethylene pipe. Extrusion special materials.

Put the prepared special material into a single-screw extruder for extrusion, the extrusion speed is 5 m/h, the outer diameter of the pipe is 1000 mm, the wall thickness of the pipe is 40 mm, and the extrusion melt temperature of the pipe is 250 ℃.

The performance indicators of the pipes are shown in Table 1.

Example 2

(1) Spray and disperse 1 part of acrylic acid and acetone mixture on 10 parts of ultra-high molecular weight polyethylene with a molecular weight of 1.5 million by weight to complete the grafting reaction to obtain composite material A.

(2) Mix 25 parts of the high molecular weight part of the compound flow modifier (150,000-500,000) with 2 parts of zinc stearate and 1 part of calcium stearate at high speed (700-1400 rpm) for 3min-5min, low The molecular weight part (50,000-150,000) is mixed with 0.1 part of hyperbranched polystyrene at high speed (700-1400 rpm) for 3min-5min, and finally the low molecular weight part and the high molecular weight part are mixed at high speed (700-1400 rpm) Mix for 5 minutes to 8 minutes to obtain the premixed material B which is a special material for melt extrusion of ultra-high molecular weight polyethylene pipes.

(3) Add 90 parts of ultra-high molecular weight polyethylene with a molecular weight of 4.5 million, composite material A, and premix B into a cold mixer, stir and cool rapidly, and the mixing time is 60 minutes to obtain a molten ultra-high molecular weight polyethylene pipe. Extrusion special materials.

Put the prepared special material into a single-screw extruder for extrusion, the extrusion speed is 8.0 m/h, the outer diameter of the pipe is 30 mm, the wall thickness of the pipe is 2 mm, and the extrusion melt temperature of the pipe is 220 ℃. The performance indicators of the pipes are shown in Table 1.

Example 3

(1) Spray and disperse 0.5 parts of acrylic acid and acetone mixture on 10 parts of ultra-high molecular weight polyethylene with a molecular weight of 2 million to complete the grafting reaction to obtain composite material A by weight.

(2) Mix 30 parts of the high molecular weight part of the composite flow modifier (150,000-500,000) with 2 parts of stearic acid and 3 parts of microcrystalline paraffin wax at high speed (700-1400 rpm) for 4min-6min, and the low molecular weight part (50,000-150,000) mixed with 2 parts of hyperbranched polyether ketone at high speed (700-1400 rpm) for 3min-5min, and finally the low molecular weight part and the high molecular weight part were mixed at high speed (700-1400 rpm) for 5min -6min, obtain the premix B material of the special material for melt extrusion of ultra-high molecular weight polyethylene pipes.

(3) Add 90 parts of ultra-high molecular weight polyethylene with a molecular weight of 2.5 million, composite material A, and premix B into a cold mixer, stir and cool rapidly, and the mixing time is 10 minutes to obtain a molten ultra-high molecular weight polyethylene pipe. Extrusion special materials.

Put the prepared special material into a single-screw extruder for extrusion, the extrusion speed is 50 m/h, the outer diameter of the pipe is 20 mm, the wall thickness of the pipe is 2 mm, and the extrusion melt temperature of the pipe is 250 ℃. The performance indicators of the pipes are shown in Table 1.

Example 4

(1) Spray and disperse 1 part of acrylamide and acetone mixture on 10 parts of ultra-high molecular weight polyethylene with a molecular weight of 4.5 million in parts by weight to complete the grafting reaction to obtain composite material A.

(2) Mix 15 parts of the high molecular weight part of the composite flow modifier (150,000-500,000) with 4 parts of calcium stearate at high speed (700-1400 rpm) for 2min-3min, and the low molecular weight part (5-15 10,000) mixed with 10 parts of hyperbranched polyether ketone at high speed (700-1400 rpm) for 2min-5min, and finally the low molecular weight part and the high molecular weight part were mixed at high speed (700-1400 rpm) for 4min-5min to obtain Premix B material of special material for melt extrusion of ultra-high molecular weight polyethylene pipes.

(3) Add 90 parts of ultra-high molecular weight polyethylene with a molecular weight of 6 million, composite material A, and premix B into a cold mixer, stir and cool rapidly, and the mixing time is 15 minutes to obtain a molten ultra-high molecular weight polyethylene pipe. Extrusion special materials.

Put the prepared special material into a single-screw extruder for extrusion, the extrusion speed is 5 m/h, the outer diameter of the pipe is 500 mm, the wall thickness of the pipe is 20 mm, and the extrusion melt temperature of the pipe is 240 ℃.

The performance indicators of the pipes are shown in Table 1.

Example 5

(1) The mixed solution of 1 part of maleic anhydride and acetone was dispersed by spraying on 10 parts of ultra-high molecular weight polyethylene with a molecular weight of 2.5 million to complete the grafting reaction to obtain composite material A.

(2) Mix 5 parts of the high molecular weight part of the compound flow modifier (150,000-500,000) with 4 parts of zinc stearate at high speed (700-1400 rpm) for 4min-5min, and the low molecular weight part (5-15 10,000) mixed with 5 parts of hyperbranched polyether at high speed (rotating speed 700-1400 rpm) for 3min-5min, and finally the low molecular weight part and high molecular weight part were mixed at high speed (rotating speed 700-1400 rpm) for 4min-8min to obtain hyperbranched polyether Premix B material for high molecular weight polyethylene pipe melt extrusion special material.

(3) Add 90 parts of ultra-high molecular weight polyethylene with a molecular weight of 3.5 million, composite material A, and premix B into a cold mixer, stir and cool rapidly, and the mixing time is 5 minutes to obtain a molten ultra-high molecular weight polyethylene pipe. Extrusion special materials.

Put the prepared special material into a single-screw extruder to extrude, the extrusion speed is 15 m/h, the outer diameter of the pipe is 65 mm, the wall thickness of the pipe is 4 mm, and the extrusion melt temperature of the pipe is 230 ℃. The performance indicators of the pipes are shown in Table 1.

Example 6

(1) A mixture of 0.8 parts of maleic anhydride and acetone was dispersed by spraying on 10 parts of ultra-high molecular weight polyethylene with a molecular weight of 1.5 million to complete the grafting reaction to obtain composite material A.

(2) Mix 20 parts of the high molecular weight part of the compound flow modifier (150,000-500,000) with 4 parts of oleic acid amide at high speed (700-1400 rpm) for 4min-6min, and the low molecular weight part (50-150,000 ) mixed with 6 parts of hyperbranched polyester at high speed (700-1400 rpm) for 2min-5min, and finally the low molecular weight part and the high molecular weight part were mixed at high speed (700-1400 rpm) for 6min-8min to obtain ultra-high Premix B material of special material for melt extrusion of molecular weight polyethylene pipe.

(3) Add 90 parts of ultra-high molecular weight polyethylene with a molecular weight of 4.5 million, composite material A, and premix B into a cold mixer, stir and cool rapidly, and the mixing time is 45 minutes to obtain a molten ultra-high molecular weight polyethylene pipe. Extrusion special materials.

Put the prepared special material into a single-screw extruder to extrude, the extrusion speed is 15 m/h, the outer diameter of the pipe is 133 mm, the wall thickness of the pipe is 9 mm, and the extrusion melt temperature of the pipe is 280 ℃.

The performance indicators of the pipes are shown in Table 1.

Example 7

(1) A mixture of 0.6 parts of maleic anhydride and acetone was dispersed by spraying on 10 parts of ultra-high molecular weight polyethylene with a molecular weight of 2.5 million to complete the grafting reaction to obtain composite material A.

(2) Mix 30 parts of the high molecular weight part of the composite flow modifier (150,000-500,000) with 4 parts of polyethylene wax at high speed (700-1400 rpm) for 2min-3min, and the low molecular weight part (50,000-150,000 ) mixed with 6 parts of hyperbranched polyether at high speed (700-1400 rpm) for 2min-5min, and finally the low molecular weight part and the high molecular weight part were mixed at high speed (700-1400 rpm) for 4min-5min to obtain ultra-high Premix B material of special material for melt extrusion of molecular weight polyethylene pipe.

(3) Add 90 parts of ultra-high molecular weight polyethylene with a molecular weight of 3.5 million, composite material A, and premix B into a cold mixer, stir and cool rapidly, and the mixing time is 15 minutes to obtain a molten ultra-high molecular weight polyethylene pipe. Extrusion special materials.

Put the prepared special material into a single-screw extruder for extrusion, the extrusion speed is 25 m/h, the outer diameter of the pipe is 35 mm, the wall thickness of the pipe is 5 mm, and the extrusion melt temperature of the pipe is 260 ℃. The performance indicators of the pipes are shown in Table 1.

Example 8

(1) A mixture of 0.7 parts of maleic anhydride and acetone was dispersed by spraying on 10 parts of ultra-high molecular weight polyethylene with a molecular weight of 2.5 million to complete the grafting reaction to obtain composite material A.

(2) Mix 10 parts of the high molecular weight part of the composite flow modifier (150,000-500,000) with 5 parts of polyethylene wax at high speed (700-1400 rpm) for 5min-8min, and the low molecular weight part (50,000-150,000 ) mixed with 5 parts of hyperbranched polyether at high speed (700-1400 rpm) for 2min-4min, and finally the low molecular weight part and the high molecular weight part were mixed at high speed (700-1400 rpm) for 5min-6min to obtain ultra-high Premix B material of special material for melt extrusion of molecular weight polyethylene pipe.

(3) Add 90 parts of ultra-high molecular weight polyethylene with a molecular weight of 2.5 million, composite material A, and premix B into a cold mixer, stir and cool rapidly, and the mixing time is 10 minutes to obtain a molten ultra-high molecular weight polyethylene pipe. Extrusion special materials.

Put the prepared special material into a single-screw extruder for extrusion, the extrusion speed is 36 m/h, the outer diameter of the pipe is 89 mm, the wall thickness of the pipe is 7 mm, and the extrusion melt temperature of the pipe is 190 ℃. The performance indicators of the pipes are shown in Table 1.

Example 9

(1) A mixture of 0.8 parts of maleic anhydride and acetone was dispersed by spraying on 10 parts of ultra-high molecular weight polyethylene with a molecular weight of 1.5 million to complete the grafting reaction to obtain composite material A.

(2) Combine 5 parts of the high molecular weight part of the composite flow modifier (150,000-500,000) with 1 part of zinc stearate, 1 part of calcium stearate, and 2 parts of oleic acid amide at high speed (rotating speed 700-1400 rpm) Mix for 4min-5min, mix the low molecular weight part (50,000-150,000) with 5 parts of hyperbranched polyether at high speed (rotating speed 700-1400 rpm) for 5min-6min, and finally the low molecular weight part and high molecular weight part again at high speed (rotating speed 700- 1400 rpm) and mixed for 3min-5min to obtain the premix B material of the special material for melt extrusion of ultra-high molecular weight polyethylene pipes.

(3) Add 90 parts of ultra-high molecular weight polyethylene with a molecular weight of 2.8 million, composite material A, and premix B into a cold mixer, stir and cool rapidly, and the mixing time is 10 minutes to obtain a molten ultra-high molecular weight polyethylene pipe. Extrusion special materials.

Put the prepared special material into a single-screw extruder for extrusion, the extrusion speed is 25 m/h, the outer diameter of the pipe is 75 mm, the wall thickness of the pipe is 3.5 mm, and the extrusion melt temperature of the pipe is 150 ℃. The performance indicators of the pipes are shown in Table 1.

Example 10

(1) The mixed solution of 1 part of maleic anhydride and acetone was dispersed by spraying on 10 parts of ultra-high molecular weight polyethylene with a molecular weight of 2.5 million to complete the grafting reaction to obtain composite material A.

(2) Mix 40 parts of the high molecular weight part of the composite flow modifier (150,000-500,000) with 4 parts of stearic acid and 1 part of calcium stearate at high speed (700-1400 rpm) for 3 minutes to 4 minutes, and the low molecular weight Part (50,000-150,000) mixed with 10 parts of hyperbranched polyether at high speed (700-1400 rpm) for 5min-8min, and finally the low molecular weight part and high molecular weight part were mixed at high speed (700-1400 rpm) for 4min -5min, to obtain the premix B material of the special material for melt extrusion of ultra-high molecular weight polyethylene pipes.

(3) Add 90 parts of ultra-high molecular weight polyethylene with a molecular weight of 3.5 million, composite material A, and premix B into a cold mixer, stir and cool rapidly, and the mixing time is 12 minutes to obtain a molten ultra-high molecular weight polyethylene pipe. Extrusion special materials.

Put the prepared special material into a single-screw extruder for extrusion, the extrusion speed is 28 m/h, the outer diameter of the pipe is 30 mm, the wall thickness of the pipe is 2.5 mm, and the extrusion melt temperature of the pipe is 240 ℃.

The performance indicators of the pipes are shown in Table 1.

Table 1 Example pipe mechanical properties

The invention realizes the melt extrusion of UHMWPE pipes, and the output reaches 110kg/h, which is 10-15 times higher than the production efficiency of the existing UHMWPE pipes, and the UHMWPE melt extrusion with higher straightness and roundness and better mechanical properties Special materials for pipes are of great significance, breaking through the bottleneck of existing UHMWPE processing and forming technology, greatly improving the production efficiency of UHMWPE products, and promoting the development of UHMWPE products.

Claims (10)

1. a kind of UHMWPE melting extrusions level composite material, which is characterized in that including following components and parts by weight content：

Wherein, the compound flow ability modifying agent is made of the low-molecular-weight polyolefin of different molecular weight gradient.

2. a kind of UHMWPE melting extrusions level composite material according to claim 1, which is characterized in that the compound flowing The molecular weight of modifying agent is in 5-50 ten thousand, and melt flow rate (MFR) is 0.1~20g/10min under 2.16kg loads, by molecular weight point Cloth is in the linear low density polyethylene of 4-6, low density polyethylene (LDPE), high density polyethylene (HDPE), ultra-low density polyethylene and polyolefin bullet Property body composition, according to the weight part ratio of different molecular weight, low molecular weight part (5-15 ten thousand)：High molecular weight moieties (15-50 ten thousand) It is 1/9~3/7.

3. a kind of UHMWPE melting extrusions level composite material according to claim 1, which is characterized in that the supra polymer Weight northylen is the ethylene and alpha olefin copolymer that viscosity average molecular weigh is 1,000,000-900 ten thousand, molecular weight distribution>3.0.

4. a kind of UHMWPE melting extrusions level composite material according to claim 3, which is characterized in that the alpha-olefin Molar fraction is 15%-0.1%, and the alpha-olefin is selected from propylene, 1- butylene, 1- amylenes, 1- hexenes, 1- heptene, 1- octenes, ring One or more of hexene or butadiene.

5. a kind of UHMWPE melting extrusions level composite material according to claim 1, which is characterized in that the lubricant choosing One from polyethylene wax, barium stearate, calcium stearate, zinc stearate, oleamide, stearic acid, microcrystalline wax or aliphatic acid Kind is several.

6. a kind of UHMWPE melting extrusions level composite material according to claim 1, which is characterized in that the melt is smooth Agent is selected from one or more of hyper-branched polyester, hyperbranched polyether, hyperbranched polyether ketone or superbranched polystyrene.

7. a kind of a kind of preparation method of UHMWPE melting extrusions level composite material as described in claim 1, which is characterized in that Include the following steps：

(1) 0.2-1 parts of grafted monomers and acetone are prepared by mixing into mixed solution by weight, it then will be upper with spraying dispersion The super-high molecular weight polythene blending that solution is stated with 10 parts is compound, completes grafting processing, obtains A material；

(2) by the high molecular weight moieties of compound flow ability modifying agent and lubricant mixed at high speed, by low point of compound flow ability modifying agent Son amount part and melt smoothing preparation mixed at high speed, then the two is mixed, obtain B material；

(3) 90 parts of ultra-high molecular weight polyethylene, A material, B material are added in cold mixing device stir it is cooling to get to product.

8. a kind of preparation method of UHMWPE melting extrusions level composite material according to claim 7, which is characterized in that step Suddenly (1) described grafted monomers are selected from one or more of maleic anhydride, acrylic acid or acrylamide.

9. a kind of a kind of moulding process of UHMWPE melting extrusions level composite material as described in claim 1, which is characterized in that Specifically include following steps：By UHMWPE melting extrusion level composite materials after mixed at high speed, it is put into single screw extrusion machine Feeding bin is squeezed out by screw rod transmission, and melt extrusion die temperature is controlled at 150-280 DEG C, then compressed in pipe mold, Molding, dies compress ratio are more than 3, finally the cooling and shaping tubing in Vacuum shaping water tank, and the vacuum degree of vacuum water tank is kept In 0.4-0.8MPa, cooler-water temperature is divided into multistage, is the initial segment close to calibration sleeve, temperature is respectively 90 DEG C, 80 DEG C, 60 DEG C, 20℃。

10. a kind of a kind of application of UHMWPE melting extrusions level composite material as described in claim 1, which is characterized in that should For composite material by extrusion molding for manufacturing super large caliber tubing, the outer diameter of tubing is 10-1000 millimeters, and wall thickness is 2-50 millis Rice, extruded velocity are 5-50 ms/h, can be used for extrusion molding plank or profile shapes.