PP回收（PP recycling）.doc

PP回收（PP recycling）recyclingOne PP woven bag recyclingL materialWaste PP woven bags: collected from waste products by 800 yuan/fPurchase;SgS: yueyang chemical plant production;SIS: yueyang chemical plant production;EVA: low vinyl acetate, 100 "(2) meltingIndex MI: 1.37 g / 10 n (100 * C, 5kg);POE: M I: 0.876 g/lOnfm (230 "12,2. (6kg) American production;Carbon black: chongqing yongchuan chemical plant production.2. The equipmentThin film granulator: diameter of 65t120mm; Length to diameterRatio = 13:1; The number of threads is 13; Slot width 65ram; Spiral depth 20ram; Screw width 10rrma; Screw speed 1 5-150rmp; Motor power 18.5 kW; Cutting motor power 0.75 kW.125g injection molding machine: used for injection molding tensile strength test spline, impact strength test bar, hardness test sample and appearance sample.3. InstrumentationTest machine factory of melt flow rate meter; Plastic rockwell hardness tester factory; XNR 1 400, changchun 2 XHR 1 150, Shanghai materials 1ZOD cantilever impact tester: UJ 1 4, chengde test machine factory; Hydraulic universal testing machine: WE + 50B, changchun test machine factory.Process of 4.(1) materialTo dry in the sun, remove the cotton thread from the seaming, shake off the sand and the residues of the packaging (such as cement, fertilizer, etc.).(2) extrude granulationUsing thin film granulator granulator, the temperature control of the granulator is as follows:The first paragraph (feed end) : 150 ; The second paragraph: 155 ;The third paragraph: 160 ; The fourth section: l70 .The woven bag is sent in one by the loading port, and under the dual effect of the heat of the cylinder and the shear force of the screw, the woven bag becomes the melting state of PP at the end of the cylinder.The melting bodies are extruded from a number of small holes (aperture 2mm) in the mold head of the granulation machine. At the outlet of the hole is a smooth circular plane, which is perpendicular to the extruding direction of the extruder. There are two - to - 180 cutting knife, the edge of the blade is close to the plane, and it is rotated clockwise in the direction of the cutting motor. The cutting motor speed can be adjusted by adjusting the speed of the cutter motor and adjusting the length of the cut. There are round walls (or thick wall battalions) of 50ram on the four sides of the die plane, and many of them are evenly distributed around the circular wall. Through these small holes, the viscous PP melt is cooled by spraying water cold water on the circular die surface, and the cutter face is used to cut the grain. The particles under the cutting continue to cool under the water spray and keep the particles from sticking to each other. The cooling water that is sprayed into the surface of the die, and the particles that are cut off are separated from the water by the filter, and the PP recycling granules with a small amount of water are sent to the cyclone separator by the 5m long air duct. In the wind tunnel and cyclone separator, water is taken away. The dry PP recovery granules are released from the bottom of the cyclone separator and packed in a woven bag. If the dewatering of PP is not ideal, it can be dry again.(3) toughening modificationIn the above PP charge, A suitable PP is toughened and A little carbon black, the mixture is mixed and then put into the injection molding machine hopper, and the sample injection molding is made. The proportion of ingredients and toughening effect are listed in table 1. The carbon black is used for coloring and the PP recycling is dyed black.The process temperature control of the injection molding machine is as follows:The first paragraph (feed end) : l7O ; The second paragraph: 200 ; The third section; 200 "C;Nozzle temperature: appropriate; Mold temperature: 40 or less.Second, the conclusionWe measured the Beijing yanshan chemical corporation production of ethylene propylene random impact strength of PP 1330 / m2, 10.81 d homopolymerization polypropylene impact strength of the 1300 5 81 "d/m2. It shows that through the toughening modification, in addition to the EAA, waste PP woven bag impact strength of recycled aggregate are able to achieve, even more than the level of the fresh homopolymerization polypropylene, and add the SIS andThe PO E is more than the fresh and random polynene 1330 level. On the waste PP woven bag adding appropriate varieties, the right amount of recycled aggregate flexibilizer, can make the waste PP woven bag increase the performance of the recycled aggregate to fresh propylene homopolymerization tired 1300 performance levels. You can even reach the performance level of fresh tired of PP 1330. Running, convenient operation, smooth control. The process of production materials and the comprehensive utilization of acidic water, not only to achieve "zero discharge" of the wastewater, and achieved economic lessons, the unity of the social benefit and environmental benefit.In the waste PP woven bag recycling granules, suitable varieties and a suitable amount of toughening agent can improve the performance of waste PP woven bag recycling granules to the performance level of the fresh polypropylene 1300To reach the performance level of fresh co-polypropylene 1330.The recycling of PP car bumpers1.1 polypropylene copolymer/elastomer mixturePp blending modification is made of compatibilizers, strengthening agent, filling agent, coupling agent, crosslinking agent, the melt index of regulator and anti-aging agent and other materials and polypropylene blend, modified polypropylene, greatly improve its performance. The application of polysynthetic rubber and PP to improve the low temperature toughness of PP is the traditional process of producing PP bumpers. Most bumpers are used to toughen EPDM.1.2 block copolymer PP/polyolefin thermoplastic elastomer (TPE) blendsSome brands of polyolefine thermoplastic elastomers, like EPR, can give PP a good low temperature toughness, and it is also good for blending. Another reason to adopt TPE is that TPE particles do not need to be likeSuch EPR for broken pieces again after mixing with PP resin blend (sometimes without vulcanization processing), and TPE granules and PP particles can be in the process of using proportional mixing, directly add to the injection molding machine for processing, which can reduce the cost.1.3 PP/EPDM reactor mixturesWith the continuous improvement of the catalyst, two series gas-phase polymerization technology can be used to produce high quality anti-impact PP with high rubber content. By raising the ethylene content and control the different methods of vinyl monomer into PP macromolecular chain, can not only get toughness good products, also can be in a certain range adjust polymer, comonomer content relative relation between the rigidity and toughness of the same material, to obtain the required performance of new materials. This material is a mixture of PP and ethylene-propylene rubber, which is known as the PP/EPDM type "reactive blend". At present domestic car bumpers mostly choose polypropylene copolymer/elastomer.Although EPDM has a good toughening effect on PP, EPDM prices are high, and it is difficult to break the glue, and the liquidity is not ideal. In recent years, the introduction of the polyethylene elastomer (POE), a polyethylene polyethylene polyethylene, has made it an advantage in the traditional elastomer for the toughening modification of PP.The recycling of car bumpersFigure l waste car bumper recovery process2.1 sorting and recycling technologyDue to the difference in the performance of fin of different materials, it is difficult to add in the mixed recovery. After the classification screening, the egg was applied to different types and use requirements. Currently abroad has developed a computer automatic sorting system, mainly according to the plastic pervious to light quality, density, or the difference of solubility, realize continuous and automatic sorting process, my best friend still is given priority to with manual sorting method.2.1.1 optical separation methodBueher company of Switzerland USES halogen lamp as a strong light source, after 4 kinds of filters and auxiliary computer can isolate PE, PP, PS, PVC and PET waste plastics, the separation capacity is l t/h.2.1.2 density separationThe density of PE and PP is less than 1.0 g/m; The density of PVC and PET is greater than 1.3 g/cm; The density of PS is at 1.0 1.1 g/cm. Therefore, the flotation can be carried out according to the different density of plastic. This separation rate of the Japanese plastics processing promotion association can be achievedOver 99.9 percent.Solvent separation methodIn the United States, the selective separation and recovery technology of solvents developed by professional personnel does not require manual sorting to separate the mixed waste plastics. The method is to add the chopped waste plastics into some kind of solvent. At different temperatures, the solvent can selectively dissolve different polymers and separate them.2.2 recovery and utilization of old PP car bumpers2.2.1 simple utilizationThis method is mainly used to manufacture products that are not high in appearance and performance, such as earthwork materials and the carrier of filler. If the recycling PP is used for the production of the ground work grille, the green net, building materials, waterproof material, etc. Some car companies recycle PP bumpers to produce dust - proof dashboard and air filter housing.2.2.2 compound regenerationFrom an economic and technical point of view, one of the competing technologies of plastic recycling is to upgrade the grade of mixed plastics to meet the market demand. Because of the difference between the polymer in the bumpers, the key is how to increase the dispersion mixture in the mixing process. The combination of compatible agent, toughening agent and reinforcing material can effectively improve the mixing effect and obtain the composite material with excellent mechanical properties. Prosche company has made a new bumper of raw materials with waste bumper recycling and 7% of glass fiber reinforced and elastomer modified PBT. The company has improved the stability and thermal stability of the components due to the use of fiberglass, but the low temperature impact and optical performance have declined. It is important to emphasize that the use of these two methods to recycle the old PP bumpers must be used to remove the coating.In the forming process of PP material mixed with film, the film is used to prevent the fluidity of the melt resin, and it is easy to be used for machining anomalies such as gap and fusion. According to the coating mechanism, the technology can be divided into three categories: mechanical, physical and chemical. It is.1. The method of mechanical stripping film is through friction, impact, grading and filtration and removal of film. The advantages are that the environment is safe. The disadvantage is that the processing time is not easy to master, the removal effect is not ideal. For example, high pressure water spraying method and sand blasting method can be used to remove the bending parts. The type, wet grading method and filtration method cannot avoid the mixing of residual spray paint.2. The technology of physical-stripping film technology was applied to the coating film/substrate coating/PP substrate by means of halogen solvent and various organic solvents. But the technology has environmental safety problems. Secondly, the film removal effect and treatment ability are low, the PP material is easy to deteriorate, and the practicability is poor.3. Chemical removal coating technology is mainly used to boil the strong acid and alkali. But it is dangerous, and the film removal effect and processing ability are low, and need neutralization and other post-processing procedures.2.3 heat solution to recycle old PP car bumpers2.3.1 make chemical raw materialsThe thermal decomposition of mixed waste plastics can make liquid hydrocarbons, and the super high temperature gasification can be made of water gas, which can be used as chemical raw materials. Germanys Hoechst, Rule, BASF, Japans kansai electric power and mitsubishi heavy industries have all developed the ultra-high temperature gasification of waste plastics in recent yearsSyngas is used to make chemical raw materials such as methanol and has been industrialized.2.3.2 the production of fuel oil and fuel gasPlastic burns can release a lot of heat. The combustion experiments show that waste plastics have the basic properties of fuel, which are equivalent to coal and oil and contain no sulfur. In addition, the burning rate is fast because of the lack of ash. Therefore, waste plastics are used in blast furnaces to be used in blast furnaces instead of coal.Oil and coke; The use of cement rotary kiln for coal and garbage solid fuel (RDF) has received good results and promising prospects.Recycling of PP processing1. High performance nucleating agent to solve mixed PP recovery problemBecause different batches of polypropylene (PP) recycled materials contain different coloring. Agents and nucleating agents make it increasingly difficult to recycle PP. The difference of colorant and nucleating agent can affect the recovery rate of the recovery PP, and its processed products are prone to warping. The latest "super nucleating agent" HyperformIIPN a 68 l can make any PP with high crystallization peak temperature (t3, HPN a 681 recovery after PP. Obviously improve the recycled PP crystallization peak temperature, and therefore speed up the processing of recycled PP, and can keep continuous stable processing. In addition, Hyperform HPN a 68 l join also helps keep the recycled PP isotropic contraction, thus reduce the recycled PP molding products warp.2. The new foaming agent will improve the environmental performance of foam materialHoneywell announced recently. The company is developing a new type of low. Global warming potential foaming agent for energy saving polyurethane foam insulation. This new foaming agent in the development phase is an unflammable liquid,Can help customers reduce the overall impact of the bubble on the environment. Honeywell hopes the foaming agent not only has the same performance as other fluorocarbons, but its global warming potential is less than 15. In addition, the foaming agent can only exist in the atmosphere for days. Based on these characteristics, the foaming agent has a relatively low impact on the greenhouse gas emission from the environment and can provide high insulation, dimensional stability and compressive strength. This non-flamma