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采用双螺杆挤出机对CO_2与环氧丙烷共聚物(聚碳酸亚丙酯多元醇)、异氰酸酯和扩链剂1,4-丁二醇进行反应挤出,从而提高共聚物的相对分子质量。通过单螺杆挤出机,用偶联剂对共聚物进行处理使其力学性能达到吹塑要求。结果表明,异氰酸酯指数为1.3,扩链剂羟基用量与体系总羟基量的摩尔比为0.6,双螺杆挤出机挤出温度为120℃,螺杆转速为30 r/min,偶联剂质量分数为0.2%,反应挤出的共聚物可以进行稳定的吹塑实验。 相似文献
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在双螺杆挤出机中进行了聚乙烯-醋酸乙烯酯共聚物与马来酸酐的接杆反应,通过红外分析证实了接枝产物的存在,研究了醋酸乙烯酯质量分数、引发剂种类及接枝单体和引发剂用量地接枝反应的影响。结果表明,相对于100份乙烯醋酸乙烯酯,接枝单体和引发剂用量分别为2和0.3份较为适宜。 相似文献
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巴顿菲尔辛辛那提新的平行双螺杆挤出机twinEX展示最佳性能凭借其最新开发的平行双螺杆挤出机系列twinEX,巴顿菲尔辛辛那提的建筑事业部在型材挤出的产量和能效方面树立了行业的新标准。 相似文献
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锥形双螺杆挤出机的自动控制大致可分为机筒外加热温度控制、机简冷却与螺杆温度控制、自动切割和翻架装置控制三部分。本文以北京福田公司生产的60/130锥形双螺杆挤出机为例,对其控制原理及生产型材产品时的故障处理方法进行了详细的介绍。 相似文献
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凭借其最新开发的平行双螺杆挤出机系列twinEX,巴顿菲尔辛辛那提的建筑事业部在型材挤出的产量和能效方面树立了行业的新标准。新的twinEX在产量上比其原有的机型提高了约10%。twinEX挤出机是巴顿菲尔辛辛那提成功的双螺杆挤出机中的又一新生代。30年前在 相似文献
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It is usually reported that wood particles in wood/polymer composite foams can act as nucleating sites. Since high wood contents are used, it is difficult to determine exactly the effect of wood particles. In this study, LDPE was chemically foamed in a twin‐screw extruder, and small amounts of wood (0–5 phr) were added to determine their effect. Particle size was investigated by using three mesh sizes: 45–61, 104–125, and 180–210 μm. As expected, wood particles acted as nucleating agents that substantially reduced cell size and increased cell density. J. VINYL. ADDIT. TECHNOL., 12:19–24, 2006. © 2006 Society of Plastics Engineers 相似文献
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In this study, PVC/(wood flour) (WF) composites were prepared by using a counterrotating twin‐screw extruder, and the effects on the mechanical properties of concentration and particle size of the WF, type and amount of coupling agent, K value of PVC, feed rate of extruder, and die temperature were investigated. Optimization of various formulation parameters based on the Taguchi method demonstrated that the wood content and wood particle size were the most important parameters. Flexural modulus increased upon increasing WF loading up to 50 wt%. Also, flexural strength and modulus increased with particle size because of the higher aspect ratio and better quality of mixing. Use of coupling agents had a minor effect that was attributed to the moderately high polarity of PVC causing relatively good compatibility between WF particles and the PVC matrix. The optimum level of WF calculated by considering the contribution factor was 50 wt%. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers 相似文献
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Naret Intawong Chatchawan Kantala Watit Lotaisong Narongrit Sombatsompop 《应用聚合物科学杂志》2011,120(2):1006-1016
A die‐rotating system was proposed in this work for moderations of extrusion forces and entrance pressure drop for molten polypropylene (PP) and wood/polypropylene (WPP) composites in a capillary rheometer and a single screw extruder. The effects of processing conditions and wood loading in PP were of our interests. The extrusion force and entrance pressure drop with and without the die rotating system were monitored in real‐time. This was the first time that the die‐rotating system was used for processing of highly viscous wood/polymer composite materials. It was found that the flow properties of the molten PP and WPP composites obeyed pseudoplastic non‐Newtonian behavior. The behavior was more obvious at wood contents of above 6 wt % and in the capillary rheometer. The rotation of the die could moderate the extrusion load by 60% and entrance pressure drop by 20% in the capillary rheometer, and the entrance pressure drop by 30% in the single screw extruder, especially at the conditions where the viscosities of the WPP and the extrusion rate were high. Greater fluctuations in entrance pressure drop caused by die rotation were observed in the single screw extruder. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120:1006–1016, 2011 相似文献
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Poly(vinyl chloride)/wood fiber (flour) composites are currently experiencing a dramatic increase in use. Most of them are used to produce window/door profiles, decking, railing, and siding by using conical counterrotating intermeshing twin‐screw extruders. Heat stabilizers, processing aids, impact modifiers, lubricants, and pigments are still important for PVC/wood composite formulations. Poly[methylene(polyphenyl isocyanate)] (PMPPIC), γ‐aminopropyltriethoxysilane, maleated polypropylene (MAPP), and copper metallic complex have proved to be effective coupling agents for this composite system. Mechanical properties of PVC/wood composites can be enhanced by combining wood with mica or glass fibers to form hybrid reinforcements. Ultraviolet light resistance and weathering dimensional stabilities of PVC/wood composites are superior to those of natural wood. Density reduction can be achieved through the microcellular foaming technique by using chemical blowing agents, such as azodicarbonamide and sodium bicarbonate, or physical blowing agents, such as carbon dioxide. J. Vinyl Addit. Technol. 10:59–69, 2004. © 2004 Society of Plastics Engineers. 相似文献
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木纹结皮发泡PVC异型材的挤出 总被引:2,自引:0,他引:2
用普通单螺杆挤出机和自制结皮发泡模具,应用不同树脂进行配方工艺试验,结果表明:利用不同材料的流动性差异,并结合模具进行设计,可以挤出木纹效果良好的PVC结皮发泡异型材。 相似文献
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研究了硬质KPVC低发泡窗饰片材的工艺配方及生产中易出现的问题。指出:(1)选择配方时,应选择来源可靠、质量稳定的原材料;根据不同的要求,可选用铅系或有机锡稳定体系,配以适量的润滑剂、发泡剂、加工助剂及改性剂。(2)挤出造粒时,应严格控制机头和均化段温度。(3)挤出成型时,机头和均化段温度是关键,采用较低的机身温度和较高的螺杆转速有利于提高产品质量。 相似文献
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将木粉和PVC共混,同时加入相容剂POE—MAH,三者经挤出机挤出形成化学反应相容。生成PVC塑化木粉。研究了该塑化木粉的吸水性。研究表明:体系中PVC比例增加、木粉比例减小时。临界含水量变小,即吸水性变小。 相似文献
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In this research, the improvement of the impact strength of wood flour–recycled polypropylene (PP) composites through impact modification was studied. For this purpose, a virgin polypropylene (VPP) was thermomechanically degraded by five extrusions under controlled conditions in a twin‐screw extruder at a rotor speed of 100 rpm and a temperature of 190°C. PP (VPP and recycled PP at the second and fifth stages) and wood flour were compounded at 50 wt % wood flour loading in a counterrotating twin‐screw extruder in the presence different contents of ethylene vinyl acetate (EVA) to produce the wood flour–PP composites. From the results, the composites containing recycled PP exhibited significantly lower impact strengths. The addition of EVA up to 9 wt % increased the impact strengths of the composites made with PP recycled two and five times by about 63 and 41%, respectively. The composites containing VPP exhibited higher impact strengths than those containing recycled PP and EVA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
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介绍一种利用不同聚合度的PVC树脂在相同温度下塑化程度的不同,从而导致流动性差异而产生木纹效果的方法,研究了原料配方、挤出工艺条件、口模结构和挤出生产线类型对木纹效果的影响。结果表明,采用平均聚合度与基料树脂聚合度相近的着色剂载体、选择与几种树脂平均分子量的塑化温度相当的挤出温度、采用压缩比和长径比较大(L/D25)、塑化能力强但不带混炼头的单螺杆挤出机,能产生较好的木纹效果;不同的口模结构对基料和着色料的阻流不同,使木纹形状有所不同。经多次试验证明,本文所述产生木纹的方法切实可行,与二次印刷等后加工相比,具有更好的经济性。 相似文献