CN206242464U - A kind of processing unit (plant) for improving ultra-high molecular weight polyethylene plasticizing and transportation performance - Google Patents

Abstract

The application relates to a processing device for improving the plasticizing and conveying properties of ultra-high molecular weight polyethylene, mainly including a mixing device and an extruder, the mixing device mixes treated graphite material with HDPE, and the extruder includes a feeding barrel , barrel, screw, insulation layer, first stage of electromagnetic heating device, second stage of electromagnetic heating device, third stage of electromagnetic heating device, extruder die head, particle cooling and molding system and transmission system. The screw is located inside the barrel and outside the barrel There is an insulation layer, and the outer part of the insulation layer is arranged from the feeding port of the barrel to the die head of the extruder, and the first section of the electromagnetic heating device, the second section of the electromagnetic heating device, and the third section of the electromagnetic heating device are arranged, and the feeding barrel is installed at the feeding port of the barrel. Electromagnetic heating can improve temperature control accuracy, and is also an efficient and energy-saving heating method, reducing energy consumption and cost.

Description

A processing device for improving plasticizing and conveying properties of ultra-high molecular weight polyethylene

technical field

The invention relates to a device for improving the plasticizing and conveying performance of ultra-high molecular weight polyethylene (UHMWPE), which belongs to the field of UHMWPE processing and molding.

Background technique

UHMWPE is a polyethylene with a viscosity average molecular weight of 1.5 million to 10 million. Its molecular chains are very long, arranged in the same direction, and intertwined with each other. By strengthening the interactions between molecules, longer molecular chains can more efficiently transfer loads to the main chain. Such a special structure makes UHMWPE have excellent wear resistance, environmental stress cracking resistance and aging resistance, as well as high impact strength, good self-lubricating performance, non-adhesion, and low surface free energy. In foreign countries, UHMWPE is called "amazing plastic", and it is widely used in chemical industry, textile, medicine, construction, metallurgy, mining, water conservancy, coal, electric power and other fields.

UHMWPE has large molecular weight, high melt viscosity, low critical shear rate, small friction coefficient, narrow molding temperature range, and easy oxidative degradation, so it is not easy to be molded and processed, which limits its application to a certain extent. Particularly important.

At present, the common methods of UHMWPE molding processing mainly include compression molding, extrusion molding, injection molding and special molding methods developed in recent years, each of which has its own advantages and disadvantages. Among them, the compression molding equipment is simple, low in cost, and relatively economical, but it is unevenly heated during processing, and has low production efficiency, high labor intensity, and unstable quality. For extrusion molding and injection molding, efficiency and product quality have been improved to varying degrees. Qin Jianhua et al. invented a UHMWPE pipe single-screw extrusion barrel molding equipment (public number CN101117017A), which improves production efficiency, but its stability The performance needs to be improved. Liu Yufeng and others used the high-pressure and high-speed injection machine of Battenfeld, Germany, to study the injection molding process of UHMWPE. By reducing the diameter of the nozzle and matching it with a suitable speed to produce products with relatively good performance, the shortcoming of the equipment is the power Small and easily degraded under high shear. The extrusion molding method is generally a melting method of screw stirring and external resistance heating ring heating. How to achieve uniform and efficient plasticization, and overcome its self-lubricating characteristics to achieve stable delivery has become a problem that needs to be solved.

The invention will solve the problem of high viscosity of UHMWPE and difficulty in uniform plasticization, and at the same time overcome the problem of insufficient conveying friction, and propose a solution combining device and method, which is used in occasions where UHMWPE is required to be plasticized and conveyed in different processing fields.

Contents of the invention

The invention proposes a processing device for improving plasticizing and conveying performance of UHMWPE. Prepare high-density polyethylene (HDPE) masterbatches with surface-treated graphite materials, and add UHMWPE blends to plasticizing extrusion equipment. An electromagnetic heating device is installed outside the equipment. The barrel and graphite materials are in an electromagnetic field. Under the action of eddy current, it generates heat and acts as a heat transfer medium to uniformly transfer heat to UHMWPE. At the same time, the addition of graphite material weakens the self-lubricating performance of UHMWPE, improves the friction between the material and the barrel, and improves the screw conveying capacity. This method can be extended to various process equipment that requires efficient plasticization and transportation of UHMWPE.

In order to achieve the above object, the present invention adopts the following technical scheme: the operation steps are as follows: the first step, the graphite material is treated with nitric acid, then cleaned with alcohol and dried, then blended and stirred with the coupling agent and put into a high-speed disperser to make It is mixed evenly, and the addition ratio of graphite material is 50% to 98%; the second step is to add the blend obtained in step 1 to HDPE in a certain ratio (for example, the ratio of 1:1 to 1:3) to the twin-screw Blending and extruding in the extruder to obtain graphite material/HDPE masterbatch after granulation; the third step is to uniformly stir and mix the above masterbatch and UHMWPE in a certain proportion (the optional proportion is 1% to 20%) and put The extruder barrel adopts an electromagnetic heating system. Under the action of electromagnetic heating, the graphite material in the barrel, screw and material generates heat at the same time. UHMWPE obtains the heat of the graphite material evenly dispersed in it, and the screw shear Heat generation and the heat transferred by the barrel and screw, the graphite material uniformly dispersed in the matrix UHMWPE makes up for the shortcomings of insufficient mass and heat transfer, and also plays the role of increasing frictional resistance, that is, the driving force for the forward transport of the melt block get bigger.

The mass fraction of graphite material/HDPE in UHMWPE does not exceed 30%. The higher the graphite material content, the greater the heat generated and the easier the matrix moves under the same electromagnetic external action conditions. In particular, graphene or graphitized carbon fiber Adding helps to improve the overall mechanical properties and electrical conductivity of processed products, and achieve multiple effects.

High-frequency electromagnetic heating is used to heat and melt the powder, replacing the traditional resistance heating coil heating. The electromagnetic heating frequency is optimized to match the resonance frequency of the graphite material, which helps to improve the heating efficiency of the graphite material and helps to improve Bonding strength of graphite material and matrix material.

The graphite material can also be other conductive materials such as aluminum powder. The function is that under the action of an alternating magnetic field, an eddy current can be generated to generate heat, and it can be uniformly dispersed in UHMWPE to achieve efficient and uniform heating.

The invention proposes a processing device for improving UHMWPE plasticization and conveying performance, which mainly includes a mixing device and an extruder, and the mixing device mixes treated graphite material with HDPE, and the extruder includes a feeding barrel, a machine barrel, Screw, insulation layer, first stage of electromagnetic heating device, second stage of electromagnetic heating device, third stage of electromagnetic heating device, extruder die head, pellet cooling and molding system and transmission system, the screw is located inside the barrel, and there is an insulating layer outside the barrel, The outer part of the insulation layer is arranged from the feeding port of the barrel to the die head of the extruder, and the first stage of the electromagnetic heating device, the second stage of the electromagnetic heating device, and the third stage of the electromagnetic heating device are arranged. The feeding barrel is installed at the feeding port of the barrel, and the transmission system controls the rotation of the screw. , the treated graphite material and HDPE are uniformly plasticized through the extruder die, and then granulated through the particle cooling and molding system to obtain the masterbatch. The masterbatch and UHMWPE are mixed in proportion according to the performance requirements, and then processed into the required profile through the extruder. The extruder for profile processing includes feeding barrel, barrel, screw, insulation layer, first stage of electromagnetic heating device, second stage of electromagnetic heating device, third stage of electromagnetic heating device, extruder die head, profile shaping cooling system and control system , due to the mixing of masterbatches, the friction coefficient between the mixed material of UHMWPE and masterbatches and the inner diameter of the barrel in the feeding section increases, and the extrusion performance is improved. According to the processing temperature requirements of UHMWPE, the electromagnetic heating device is designed and adjusted. Adjust the temperature of the second stage and the third stage of the electromagnetic heating device. After the mixture is fully and uniformly melted, it is extruded from the extrusion die, and the required product is obtained through the profile shaping cooling system.

The invention discloses a processing device for improving UHMWPE plasticization and conveying performance. The high-frequency electromagnetic heating method is also suitable for heating other polymers, such as injection molding, rotational molding, and die-casting. Electromagnetic heating can improve temperature control accuracy, and is also an efficient and energy-saving heating method, reducing energy consumption and cost.

The present invention is a processing device for improving UHMWPE plasticization and conveying performance, wherein the graphite material used can be graphite powder, graphite sheet, graphene or graphitized carbon fiber, wherein the average diameter of the graphite powder is between 500nm-1mm, and the graphitized The average length of carbon fiber is between 0.01mm-3mm, and the scale distribution does not exceed 50%. The control of the material scale helps to improve the friction coefficient of the matrix material melt. The larger the scale, the greater the friction coefficient, and the electromagnetic effect generates heat. The effect is more obvious.

The invention is a processing device for improving the plasticizing and conveying performance of UHMWPE, wherein the coupling agent used is preferably a silane coupling agent.

As can be seen from the above technical solutions, the present invention has the following advantages compared with the prior art:

1.Using graphite material/HDPE as modified masterbatch, adding UHMWPE extrusion process, it has good compatibility under electromagnetic action, and one masterbatch is a good heating medium as a heat source, providing uniformly dispersed heat for UHMWPE , Melt the UHMWPE adjacent to the masterbatch.

2. The addition of graphite materials or other metal particles increases the friction coefficient between the base material and the barrel, which promotes the improvement of the conveying capacity under screw extrusion.

3. The addition of graphite materials can improve the conductive properties of the base material, and can be used in occasions that require electrostatic shielding.

4. When graphene and graphitized carbon fiber are used as the graphite material, the mechanical properties of the matrix material after molding will be improved.

Description of drawings

Fig. 1 is a processing flowchart of a processing device for improving UHMWPE plasticizing and conveying performance according to the present invention.

Fig. 2 is a schematic diagram of extrusion processing equipment of a device for improving UHMWPE plasticizing and conveying performance according to the present invention.

In the figure: 1-feeding barrel; 2-barrel; 3-insulation layer; 4-one section of electromagnetic heating device; 5-second section of electromagnetic heating device; 6-three sections of electromagnetic heating device; 7-extruder die head; 8-screw; 9-motor seat; 10-coupling; 11-sleeve; 12-thrust bearing; 13-shaft sleeve.

detailed description

The present invention is a processing device for improving the plasticizing and conveying performance of UHMWPE, as shown in Fig. 1, which is a mixing preparation process.

The first step is to treat the graphite material with nitric acid, then wash it with alcohol and dry it, then blend it with the coupling agent and add it to the high-speed disperser to make it evenly mixed, and the addition ratio of the graphite material is 50%; the second step , the blend obtained in step 1 is added to the twin-screw extruder with HDPE in a ratio of 1:1 for blending and extrusion, and graphite material/HDPE masterbatch is obtained after granulation; in the third step, the above masterbatch and UHMWPE Blended powder was obtained after uniform stirring and mixing at a ratio of 8%. The device of the present invention mainly includes a mixing device and an extruder, and the mixing device mixes the processed graphite material with HDPE. The extruder comprises a feed barrel 1, a barrel 2, a screw 8, an insulation layer 3, a first section of an electromagnetic heating device 4, a second section 5 of an electromagnetic heating device, a third section 6 of an electromagnetic heating device, an extruder die head 7, Particle cooling and molding system and transmission system, part of the composition is shown in Figure 2, the screw 8 is located inside the barrel 2, there is an insulation layer 3 outside the barrel 2, and the outside of the insulation layer 3 is from the feeding port of the barrel 2 to the extruder die The head 7 is arranged with one section 4 of the electromagnetic heating device, the second section 5 of the electromagnetic heating device, and the third section 6 of the electromagnetic heating device. The feeding barrel 1 is installed at the feeding port of the machine barrel, and the transmission system controls the rotation of the screw rod 8. The screw rod 8 shown in Fig. 2 There are also couplings 10, sleeves 11, thrust bearings 12, shaft sleeves 13 and motor bases 9. The treated graphite material and HDPE are evenly plasticized through the extruder die 7 and then passed through the particle cooling and molding system. Perform granulation to obtain master batches. The masterbatch and UHMWPE are mixed in proportion according to the performance requirements, and then processed into the required profile through the extruder. The extruder for profile processing includes feed barrel, barrel, screw, insulation layer, electromagnetic heating device first stage, electromagnetic heating device second stage, electromagnetic heating device third stage, extruder die head, profile shaping cooling system and control system, Due to the mixing of masterbatch, the friction coefficient between the mixed material of UHMWPE and masterbatch and the inner diameter of the barrel in the feeding section increases, and the extrusion performance is improved. According to the processing temperature requirements of UHMWPE, the first stage of the electromagnetic heating device and the second stage of the electromagnetic heating device are designed and adjusted. section and adjust the temperature of the third section of the electromagnetic heating device, the mixture is fully and evenly melted and extruded from the extrusion die, and the required product is obtained through the profile shaping cooling system.

The outer surface of the masterbatch can be made into a ribbed structure, or the masterbatch is rolled by a rough roller before being mixed into UHMWPE, so that the outer surface of the masterbatch is rough, when the masterbatch is mixed with UHMWPE and plasticized in the extruder , the friction between the mixed material and the barrel is greater, which can further increase the extrusion volume.

The invention discloses a processing device for improving the plasticizing and conveying performance of UHMWPE, and the extruder is a twin-screw extruder.

Claims (6)

1. a kind of improvement ultra-high molecular weight polyethylene plastifies the processing unit (plant) with transportation performance, it is characterised in that：It is main to include mixing Attach together and put and extruder, mixing arrangement mixes treated graphite material with HDPE, described extruder includes feeding cylinder, machine Cylinder, screw rod, heat-insulation layer, one section of electromagnetic heater, two sections of electromagnetic heater, three sections of electromagnetic heater, extruder die head, Particle is cooled down and formation system and transmission system, and screw rod is located inside machine barrel, has heat-insulation layer outside machine barrel, from machine barrel outside heat-insulation layer Charge door to extruder die head arrangement one section of electromagnetic heater, two sections of electromagnetic heater, three sections of electromagnetic heater, machine barrel Feeding cylinder is installed, transmission system controls the rotation of screw rod, treated graphite material and the uniform warp of HDPE plasticizings at charge door Granulate obtaining master batch by particle cooling and formation system again after extruder die head；Master batch will according to performance with UHMWPE After asking mixing in proportion required section bar is machined to through extrusion；Shape extrusion includes feeding cylinder, machine barrel, spiral shell with extruder Bar, heat-insulation layer, one section of electromagnetic heater, two sections of electromagnetic heater, three sections of electromagnetic heater, extruder die head, section bar Sizing cooling system and control system, due to the mixing material and feeding section machine barrel that have being mixed into for master batch, UHMWPE and master batch The coefficient of friction increase of internal diameter, extrusion performance is improved, according to the processing temperature requirement design regulation electromagnetic heater of UHMWPE One section, regulation two sections of electromagnetic heater and regulation three sections of electromagnetic heater temperature, after the full and uniform melting of mixture from Extrusion neck ring mold is extruded, and required product is obtained through sections shaping cooling system.

2. a kind of improvement ultra-high molecular weight polyethylene according to claim 1 plastifies the processing unit (plant) with transportation performance, its It is characterised by：The graphite material of use is graphite powder, graphite flake, Graphene or graphitized carbon fibre.

3. a kind of improvement ultra-high molecular weight polyethylene according to claim 2 plastifies the processing unit (plant) with transportation performance, its It is characterised by：The average diameter of graphite powder between 500nm-1mm, the average length of graphitized carbon fibre 0.01mm-3mm it Between.

4. a kind of improvement ultra-high molecular weight polyethylene according to claim 1 plastifies the processing unit (plant) with transportation performance, its It is characterised by：The preferred silane coupler of coupling agent.

5. a kind of improvement ultra-high molecular weight polyethylene according to claim 1 plastifies the processing unit (plant) with transportation performance, its It is characterised by：Graphite material is aluminium powder.

6. a kind of improvement ultra-high molecular weight polyethylene according to claim 1 plastifies the processing unit (plant) with transportation performance, its It is characterised by：The outer surface of master batch is fabricated to the structure with rib, or master batch was carried out before UHMWPE is mixed into by matte roll Rolling so that the outer surface of master batch is coarse.