24-SJ90-25擠出機(jī)設(shè)計(jì)【5張圖紙】
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The Solid State Shear Extrusion processoptimization for cross-linked polymers固態(tài)剪切擠出交聯(lián)聚合物的工藝優(yōu)化The Solid State Shear Extrusion processoptimization for cross-linked polymersMahnaz Eskandari, Hamid Arastoopour and Jay D. SchieberSeptember 30, 2005Reducing the size of the solid material specially polymeric material is an important process in industry. Using small particle size provides a homo-geneous feed, near fluid-like handling characteristic, a desired temperature distribution among material during processing or molding, enhanced effective surface area and good mixing.In order to obtain polymer powders basically there are three technologies: Suspension or emulsion polymerization, Precipitation of powder from dilute polymer solutions, Mechanical grinding of solid polymers. The first and the second technologies are used to obtain virgin powder polymers, although removing emulsifier and organic solvents from pro- duced polymers are costly and usually cannot entirely be removed (such as emulsifier). Mechanical grinding can be used for both virgin and waste poly-mers although the produced particles may not have exactly the same quality. Beside the flexibility of the mechanical grinding for pulverization of different polymeric material, the other advantage of the mechanical grinding is its high capacity and large scale operation capability. The fundamental idea in the mechanical size reduction technique is to subject the solid ma-terial to sufficient stresses such that material breaks into small pieces. In general, mechanical pulverization falls into these categories: crushing, im-pacting, cutting, and pulverizing at high compression and shear force.Based on our experimental data obtained by using screws with different CR, we may conclude that the degree of compression of the granulates in Zones 2 and 3 could be the most critical parameter of our process. There are two major effects of compression: one is the storage of large strain energy in the rubber granulates, and the other is the prohibition of slip at the rubbermetal interfaces and, in turn, the allowance of shear straining of the granulates as a result of the relative rotation of the screw with respect to the barrel wall. The combined high compressive shear results in more strain energy storage in the granulate. At a critical energy level, the granulate cannot be held together by any cohesive forces, and new surfaces form through the crack propagation and dissipation of the stored energy. Our previous study on the breakage of single rubber discs under high compression and tangential shear in a Bridgman Anvil apparatus supported such effects of the compression on the pulverization phenomenon.The idea of using high compression and shear force at the same time has been proposed by Bridgman, who established an apparatus with two disks that could apply hydrostatic pressure on metal sample between them and pulverize material. Enikolopian extended the idea of the high pressure and shear force to pulverize polymers by using extrusion process8. This process is a non-cryogenic pulverization process and it works in room temperature. Further a Bridgman anvil was used in Center of Excel-lence in Polymer Science and Engineering (CEPSE) at Illinois Institute of Technology (IIT) 6 to study the pulverization mechanism of the polymers. The search for finding the mechanism of the pulverization in the extrusionprocess for both linear and cross-linked polymers in CEPSE has been pursued till present. In this work, we applied Solid State Shear Extrusion (SSSE) process as a mechanical size reduction technique to waste low-cross-link-density natural rubber. The objective was to optimize the SSSE process and to determine the mechanism of the pulverization during the SSSE process, particularly for low-cross-link-density natural rubber. The Particle Size Distribution (PSD) of the produced particles, which was obtained from the process, was analyzed. The first goal of this analysis was to optimize the process condition to obtain a desirable output PSD (desired average particle size, or a narrow PSD); and the second goal was to find a relation between the process conditions and the output PSD. We showed that the produced particles in this pulverization process was reproducible and the variation coefficient of such powders was less than 3 percent. In order to satisfy the second goal, the produced PSD and torque were measured at different combinations of the temperature in heating zone along the screw length and rotating speed. Our results showed a non-monotonic behavior of both PSD and required torque with rotation speed (rpm) at different operating temperatures. Based on these results andthe previous works on the SSSE process using polyethylene and polystyrene,it can be concluded that the pulverization mechanism depends on the mole-cular structure of the material, the distribution of the dispersed phase in matrix (in case of the filled polymer or blend polymers) and the nature of the interactions between the dispersed phase and the matrix. Since rubber was the matrix material that was subjected to the SSSE process, we focused on the structure of rubber, and its filler, Carbon Black (CB). We used tworubber samples with the same recipe but one with CB and the other one without CB. The difference between the average particle size of the sample with CB and without CB (around 30 percent) is an evidence for the effectof the second component on the produced particle size by the SSSE process. There are evidences that adding second polymer to the first polymer in the SSSE process changes the produced particle size same as adding filler. The magnitude of the change in the produced particle average size depends on the mechanical properties of the filler, the interaction between filler and polymer and the size distribution of the filler in polymer matrix. Pulverization also causes change in cross-link density of the polymer. Based on theses results it can be concluded that the smallest length scale, which undergoes through the breakage in the SSSE process is smaller than the size of the average distributed filler in the polymer matrix and it may be in molecular length scale, but because of high shear and compression forces and poor temperature control, the broken polymer chains react with each other rather than creating new surface and further they agglomerate. In order to examine this hypothesis, we have designed a new extended extruder, which provides high temperature control and shear force. The produced particleaverage size of our new extended extruder design supports our hypothesis. In principal, the SSSE process is a multi-length-scale process and capable of producing very fine particles. In order to achieve this capability, it is required to improve the process and one of the ways is modelling this process. A material model as a function of the temperature and deformation rate may be used to practice the process condition (the screw geometry, temperature change due to heating the barrel, bond breakage, and energy dissipation 5,8, 1, rotation rate, and particulate flow) and further to improve the process. Developing a material model based on the molecular approach can provide sufficient information for such a multi-length-scale model. Our parallel work has been establishing a Gaussian slip-link model for cross-linked polymers to satisfy this requirement. The pulverization of rubber granulates under high compressive shear was achieved using a single screw extruder without using a cryogenic fluid for cooling in the SSSE process. A higher degree of compression of the granulate and significant cooling of the pulverization zone were the most significant factors in the successful pulverization of the granulates. Agglomeration of the produced particles, especially the fine particles, was found to be competing with the pulverization process. The extent of agglomeration was observed to increase with a higher fraction of the fine particles, a greater degree of compaction, and a higher temperature of the pulverization zone.The rubber granulates that experience high compressive shear strain can develop tensile stresses and store significant strain energy leading to the formation of new surfaces through the crack opening mechanism (Mode I).The granulates can fragment repeatedly until their size becomes so small that a high compressive strain and consequent high stresses can no longer be applied. Therefore, we conclude that there is a minimum size of the particles produced by the SSSE process, which is determined by the processing conditions and the design of the extruder.References1 National materials advisory board publication, nmab-364, washington,d.c., national academy press. 1981.2 Particle size analysis-evaluating laser differential diffraction systems inthe light of iso 13320-1 - part 1. 2000.3 K.K. Khait A.H. Lebovitz and J.M. Torkelson. Sub-micron dispersed-phase particle size in polymer blends: overcoming the taylor limit viasolid-state shear pulverization. Polymer, 44(1):199206, November 2003.4 P.W. Bridgman. Effects of high shearing stress combined with highhydrostatic pressure. Physical review, 48:825847, November 1935.5 K. Khait D. Ahn and M.A. Petrich. Microstructure changes in ho-mopolymers and polymer blends induced by elastic strain pulverization.Journal of Applied Polymer Science”, 55:14311440, 1995.6 H. Arastoopour D. Schocke and B. Bernstein. Pulverization of rubberunder high compression and shear. Powder Technology, 102:207214,1999.7 H. Arastoopour E. Bilgili and B. Bernstein. Pulverization of rubbergranulates using the solid-state shear extrusion (ssse) process: Part i.process concepts and characteristics. Powder Technology, 115(3):265276, April 2001.8 N.S. Enikolopian. Some aspects of chemistry and physics of plastic flow.Pure and Applied chemistry, 57(11):17071711, 1985.9 K. Khait and S.H. Carr. Solid-State Shear Pulverization, A New Poly-mer Processing and Powder Technology. SPE, 2001.10 K. Khait N. Furgiuele, A.H. Lebovitz and J.M. Torkelson. Efficientmixing of polymer blends of extreme viscosity ratio: elimination of phaseinversion via solid state shear pulverization. Polymer Engineering andScience, 40(6):14471457, June 2000.11 F. Teymour N. Shahidi and H. Arastoopour. Amphiphilic particulatephase semi-interpenetrating polymer networks based on recycled rubbermatrix. Polymer, 45(15):51835190, Jul 2004.12 S.A. Wolfson and V.G. Nikolskii. Powder extrusion: fundamentals anddifferent applications. Polymer Engineering and Science, 37(8):12941300, August 1997.4固態(tài)剪切擠出交聯(lián)聚合物的工藝優(yōu)化Mahnaz Eskandari,哈米德Arastoopour和Jay D. Schie二零零五年九月三十日降低固體物料的大小是一個(gè)特別高分子材料的重要過(guò)程工業(yè)。利用小粒徑提供一個(gè)均勻擠出,接近流體態(tài)的特點(diǎn), 在所需材料的加工過(guò)程中或成型工藝,提高有效表面積和良好的混合為了獲得聚合物粉末基本上有三種技術(shù):懸浮液或乳液聚合;從聚合物溶液稀釋沉淀粉末,機(jī)械磨固態(tài)聚合物,第一個(gè)和第二個(gè)技術(shù)是用于獲得原始粉末聚合物, 盡管從親和聚合物中消除乳化劑和有機(jī)溶劑是昂貴的,通常所無(wú)法完全被清除(例如乳化劑)。機(jī)械研磨是可用于新料和廢物產(chǎn)生粒子聚合物的研磨,雖然可能沒(méi)有完全相同的質(zhì)量。另外靈活的機(jī)械磨可粉化不同的高分子材料, 他的另一優(yōu)點(diǎn)是它的機(jī)械研磨,高容量的、大規(guī)模的操作能力。機(jī)械尺寸還原工藝的基本理念是給固體材料足夠的壓力把這種材料斷裂成小塊。一般來(lái)說(shuō),機(jī)械粉碎陷入這些類別:破碎,擠壓,切割,和高壓縮和剪切力的粉碎。我們用不同CR螺桿所做實(shí)驗(yàn)得到的數(shù)據(jù),我們可以讀出結(jié)論:區(qū)域2和3的擠出機(jī)的壓縮程度是固相剪切粉碎過(guò)程最重要的影響因素。壓縮有兩個(gè)重要的影響:第一:大量的剪切能的貯存;第二:阻止膠料在橡膠金屬接觸面的滑動(dòng)。循環(huán)的,螺桿的旋轉(zhuǎn)和機(jī)筒相互作用產(chǎn)生了對(duì)膠料的剪切應(yīng)力。綜合作用產(chǎn)生的高壓縮剪切使更多的應(yīng)變能貯存于膠料中。當(dāng)它達(dá)到臨界狀態(tài),膠料不能承受時(shí)。通過(guò)能量的是放和裂紋的延伸而產(chǎn)生新的表面。用布里奇曼壓砧對(duì)我們以前關(guān)于單個(gè)橡膠磁盤進(jìn)行的高壓縮、線性剪切破碎的研究證實(shí)了粉碎現(xiàn)象中的這種作用。這種利用高壓縮和剪切力在同一時(shí)間被布里奇曼提出,他用兩個(gè)磁盤建立了一種儀器,可以應(yīng)用金屬樣品之間的靜水壓力粉碎物料。Enikolopian拓展了利用高壓力和剪切力對(duì)聚合物擠出過(guò)程中利用粉碎的方法。這個(gè)過(guò)程是在室溫下工作,一個(gè)非低溫粉化的過(guò)程。在伊利諾理工學(xué)院(公歷),比 Bridgman更早把鐵砧用在中心卓越的高分子科學(xué)與工程中研究聚合物粉碎機(jī)理。搜索尋找粉碎機(jī)理的基礎(chǔ)上,在注射成型工藝為線性和交聯(lián)聚合物在CEPSE被追趕直到現(xiàn)在。這種設(shè)備,采用固態(tài)剪切擠壓過(guò)程,機(jī)械尺寸還原工藝?yán)速M(fèi)交聯(lián)密度低的自然橡膠。目的是優(yōu)化固態(tài)剪切擠壓的過(guò)程,并在固態(tài)剪切擠壓過(guò)程確定粉碎作用,尤其是對(duì)交聯(lián)密度低的天然膠。通過(guò)對(duì)固態(tài)剪切擠壓過(guò)程獲取粒徑分布所產(chǎn)生粒子的進(jìn)行了分析。這個(gè)分析的首要目標(biāo)是優(yōu)化工藝條件來(lái)獲得一個(gè)理想的輸出功率譜(所需的平均粒徑,或一條狹窄的粒徑分布), 第二個(gè)目標(biāo)是尋找一種工藝條件和粒徑分布輸出之間的關(guān)系。 我們發(fā)現(xiàn),在這個(gè)粉碎產(chǎn)生的粒子過(guò)程是重復(fù)性好,這種粉末的變異系數(shù)為不到3。為了滿足第二個(gè)目標(biāo),所生產(chǎn)的粒徑分布和扭矩分別測(cè)定在不同組合中的溫度加熱區(qū)沿螺旋長(zhǎng)度和旋轉(zhuǎn)速度。我們的研究結(jié)果表明兩者的粒徑分布,所需的轉(zhuǎn)矩轉(zhuǎn)速(RPM)在不同的操作溫度。根據(jù)這些結(jié)果和在以往的作品固態(tài)剪切擠壓過(guò)程中使用聚乙烯和聚苯乙烯,可以得出結(jié)論,粉碎機(jī)制上取決于材料的分子結(jié)構(gòu),在矩陣分布的分散相(在填充聚合物或聚合物混合的情況下)和的分散相與基體之間的相互作用的性質(zhì)。由于橡膠是基質(zhì)材料,在SSSE過(guò)程中,我們集中在橡膠結(jié)構(gòu),其填料,炭黑(CB)我們使用相同的配方,但一個(gè)有炭黑,另外一個(gè)沒(méi)有炭黑兩個(gè)橡膠樣品。同CB樣本的平均粒徑和無(wú)CB(約30)之間的區(qū)別,是為第二個(gè)組件上產(chǎn)生的粒子尺寸效應(yīng)的固態(tài)剪切擠壓過(guò)程的證據(jù)。證據(jù)是,添加第二個(gè)聚合物在固態(tài)剪切擠壓過(guò)程的變化,增加填料的聚合物,是為第二個(gè)組件上產(chǎn)生的粒子尺寸效應(yīng)的固態(tài)剪切擠壓過(guò)程中產(chǎn)生的證據(jù)粒徑相同。而在生產(chǎn)顆粒平均尺寸的變化幅度取決于填料的力學(xué)性能,填料和聚合物之間的相互作用并在聚合物基體的填料粒度分布。粉碎還導(dǎo)致交聯(lián)的聚合物密度的變化。根據(jù)論文的結(jié)果可以得出結(jié)論說(shuō),最小的尺度,它通過(guò)在固態(tài)剪切擠壓過(guò)程中破損經(jīng)過(guò)比平均分布在聚合物基體的大小和填充物小,也可能是在分子尺度,但由于高剪切和壓縮力差溫度控制,破碎聚合物鏈相互反應(yīng),而不是創(chuàng)造新的表面和他們進(jìn)一步凝聚。為了檢驗(yàn)這一假設(shè),我們?cè)O(shè)計(jì)了新的擴(kuò)展擠出機(jī),可提供高的溫度控制和剪切力。我們所生產(chǎn)的顆粒擠出機(jī)設(shè)計(jì)新的擴(kuò)展支持我們的假設(shè)平均規(guī)模。原則上,固態(tài)剪切擠壓過(guò)程是一個(gè)多長(zhǎng)的規(guī)模和能力的過(guò)程生產(chǎn)極細(xì)的粒子。為了實(shí)現(xiàn)這種能力,這是需要改進(jìn)的過(guò)程和途徑之一是模擬這個(gè)過(guò)程。一個(gè)作為溫度和變形速率功能材料模型可能用來(lái)練習(xí)過(guò)程中條件(螺桿的幾何形狀,溫度由于改變加熱桶,鍵斷裂,能源消耗5,8,1,旋轉(zhuǎn)速度和顆粒流),并進(jìn)一步提高的過(guò)程。開(kāi)發(fā)材料模型為基礎(chǔ)的分子方法可以提供足夠的信息對(duì)于這樣的多長(zhǎng)度比例模型。我們的并行工作已建立交聯(lián)聚合物,以滿足這一要求高斯滑鏈路模型。在在固態(tài)剪切擠壓過(guò)程中橡膠在高壓剪切下進(jìn)行粉碎可以通過(guò)單螺桿擠出機(jī)在無(wú)冷卻液冷卻的情況下實(shí)現(xiàn)。對(duì)橡膠顆粒的較高壓縮和對(duì)剪切區(qū)域的重點(diǎn)冷卻是橡膠粉碎能夠成功的最重要的因素。所生產(chǎn)橡膠顆粒的凝塊,特別是精細(xì)橡膠顆粒,與橡膠的粉碎過(guò)程是同步存在的。粉碎區(qū)域的較高溫度、較高程度的壓縮,精細(xì)顆粒的較高摩擦力都會(huì)使凝結(jié)現(xiàn)象明顯。橡膠顆粒在高剪切應(yīng)力作用下會(huì)產(chǎn)生拉應(yīng)力并貯存應(yīng)變能,并通過(guò)“雪崩”使機(jī)理釋放能量產(chǎn)生新的表面。橡膠顆??梢员谎h(huán)的破碎直到小到高的壓縮應(yīng)力和隨之發(fā)生的高應(yīng)變不能夠?qū)崿F(xiàn)。因此,我們得出結(jié)論:通過(guò)SSSE粉碎橡膠得到的顆粒有一個(gè)最小尺寸,這個(gè)尺寸由加工條件和擠出機(jī)的設(shè)計(jì)來(lái)決定。參考文獻(xiàn)1 National materials advisory board publication, nmab-364, washington,d.c., national academy press. 1981.2 Particle size analysis-evaluating laser differential diffraction systems in the light of iso 13320-1 - part 1. 2000.3 K.K. Khait A.H. Lebovitz and J.M. Torkelson. Sub-micron dispersed-phase particle size in polymer blends: overcoming the taylor limit viasolid-state shear pulverization. Polymer, 44(1):199206, November 2003.4 P.W. Bridgman. Effects of high shearing stress combined with highhydrostatic pressure. Physical review, 48:825847, November 1935.5 K. Khait D. Ahn and M.A. Petrich. Microstructure changes in ho-mopolymers and polymer blends induced by elastic strain pulverization.Journal of Applied Polymer Science”, 55:14311440, 1995.6 H. Arastoopour D. Schocke and B. Bernstein. Pulverization of rubberunder high compression and shear. Powder Technology, 102:207214,1999.7 H. Arastoopour E. Bilgili and B. Bernstein. Pulverization of rubbergranulates using the solid-state shear extrusion (ssse) process: Part i.process concepts and characteristics. Powder Technology, 115(3):265276, April 2001.8 N.S. Enikolopian. Some aspects of chemistry and physics of plastic flow.Pure and Applied chemistry, 57(11):17071711, 1985.9 K. Khait and S.H. Carr. Solid-State Shear Pulverization, A New Poly-mer Processing and Powder Technology. SPE, 2001.10 K. Khait N. Furgiuele, A.H. Lebovitz and J.M. Torkelson. Efficientmixing of polymer blends of extreme viscosity ratio: elimination of phaseinversion via solid state shear pulverization. Polymer Engineering andScience, 40(6):14471457, June 2000.11 F. Teymour N. Shahidi and H. Arastoopour. Amphiphilic particulatephase semi-interpenetrating polymer networks based on recycled rubbermatrix. Polymer, 45(15):51835190, Jul 2004.12 S.A. Wolfson and V.G. Nikolskii. Powder extrusion: fundamentals anddifferent applications. Polymer Engineering and Science, 37(8):12941300, August 1997.擠出機(jī)設(shè)計(jì)文獻(xiàn)綜述 采用螺桿擠出聚合物迄今已有120多年的歷史。這種方法在聚合物加工工業(yè)中已經(jīng)占有十分重要的地位。據(jù)統(tǒng)計(jì),全世界60以上的產(chǎn)品是采用螺桿擠出法來(lái)加工的。擠出成型制品的產(chǎn)量雄居于其它聚合物成型制品之上。隨著聚合物加工工業(yè)的飛速發(fā)展,螺桿擠出裝備的技術(shù)發(fā)展和進(jìn)步也受到人們更多的關(guān)注。與其它成型方法比較,聚合物的螺桿擠出成型法具有一些突出的特點(diǎn),如:生產(chǎn)過(guò)程連續(xù);生產(chǎn)率較高;適用范圍廣,其不僅能用于加工幾乎所有的熱塑性塑料制品,而且也能用于擠出一些熱固性材料。此外,螺桿擠出設(shè)備通常結(jié)構(gòu)較為簡(jiǎn)單、操作容易,而且投資少,收效快。因此,螺桿擠出成型法已成為目前最廣泛采用的一種聚合物成型加工方法,螺桿擠出裝備也理所當(dāng)然成為聚合物成型加工機(jī)械中的最重要的機(jī)種之一。目前,用螺桿擠出法生產(chǎn)的制品有:管材、板材、片材、棒材、薄膜、單絲、電纜、中空制品、異型材、各種復(fù)合制品等。此外,螺桿擠出還大量用于進(jìn)行聚合物的造粒、脫水、共混、增強(qiáng)、反應(yīng)擠出、合金化、喂料及色母料等作業(yè)。螺桿擠出機(jī)的分類,目前最通常是按螺桿數(shù)目分為:?jiǎn)温輻U擠出機(jī),雙螺桿擠出機(jī)和多螺桿擠出機(jī)。其中前兩類目前應(yīng)用最廣泛。此外,還可按用途分為:造粒擠出機(jī)、排氣脫揮 式擠出機(jī)、喂料擠出機(jī)、傳遞混煉擠出機(jī),按結(jié)構(gòu)特點(diǎn)分為:磨盤式擠出機(jī)、可視化科研擠 出機(jī)、電磁動(dòng)態(tài)塑化擠出機(jī)、自熱式高速擠出機(jī)、立式擠出機(jī)、階式多級(jí)擠出機(jī)等,以上機(jī)型還可有通用機(jī)和專用機(jī)之分。常規(guī)型單螺桿擠出機(jī),易操作、造價(jià)低,因此在聚合物加工工業(yè)得到廣泛的應(yīng)用。但它存在混合、分散和均化效果差,物料溫差大和難以吃粉料等不足之外。因此,通常只適用于一般性造粒和塑料制品的加工。目前,歐美等國(guó)單螺桿擠出機(jī)應(yīng)用的比例是:平膜及片材10;異型材20;發(fā)泡材30%40;吹膜100%;電纜100%;單絲100%;配混(包括雙級(jí)式)10。隨著機(jī)械制造技術(shù)的進(jìn)步,常規(guī)型單螺桿擠出機(jī)螺桿,制品的質(zhì)量有所提高。但由于常規(guī)型單螺桿擠出機(jī)存在上述許多的不足,如今正逐漸被新型單螺桿擠出機(jī)所取代。新型單螺桿擠出機(jī)的出現(xiàn),極大地改善了常規(guī)單螺桿擠出機(jī)的不足,使單螺桿擠出機(jī)的產(chǎn)量和質(zhì)量有了較大的提高。目前,各國(guó)新型螺桿的相關(guān)專利眾多,得以實(shí)用的主要有以下類型 :(1) 分離型螺桿 分離型螺桿是在普通螺絲桿的加料段末端設(shè)置一外徑小于主螺紋的副螺紋,并在固體物料熔融結(jié)束處與主螺紋相交,從而有效地避免常規(guī)單螺桿在熔融段后期出現(xiàn)的固相破碎,使熔融速率得到提高。分離型螺桿的熔體溫度、壓力和流率波動(dòng)小,擠出量大。不僅適用于通用的聚稀烴塑料、尼龍、聚碳酸酯和聚砜等工程塑料,而且可用于聚氯乙烯和聚甲醛等熱敏性的塑料加工。分離型螺桿的BM型、Barr型熔體槽型、XLK雙層型、PM 型和ICT型等,目前工業(yè)應(yīng)用最多的是BM型。(2) 屏障型螺桿 屏障型螺桿是在均化段設(shè)置屏障,以阻止未熔融固相進(jìn)入均化段,并促進(jìn)物料熔融。屏障元件有直槽式、斜槽式、三角槽式、深槽漸變型、斜槽雙屏障式或多屏障式等多種結(jié)構(gòu)。該螺桿屬高剪切元件,通常僅適用于聚烯烴物料。但只要屏障頭設(shè)計(jì)合理,也可用于擠出熱敏性的塑料。(3) 分流型螺桿 分流型螺桿是在常規(guī)螺桿螺槽內(nèi)設(shè)置分流元件(如銷釘、犁釘、凸臺(tái)、分流溝槽、分流孔等),其作用是打亂固液兩相流動(dòng)、增加固體和熔體間的剪切,促進(jìn) 熔融和混合。主要結(jié)構(gòu)型式為銷釘型和DIS型。這種螺桿可適用于硬聚氯乙烯制品、發(fā)泡擠出、交聯(lián)擠出、聚乙烯和尼龍等混配作業(yè)。(4) 變流道型螺桿 該螺桿的結(jié)構(gòu)特征是螺桿流道截面形狀或截面面積大小是變化的。其代表是波形螺桿和HM型(其具有多邊形的螺桿段)。由于物料在這種螺桿內(nèi)要承受不斷的壓縮、捏合和混煉作用,故可強(qiáng)化熔融和混合。變流道型螺桿雖然制造麻煩,但塑化、混合質(zhì)量好,尤適于加工難以熔融的塑料。但這種螺桿不適用于熱敏塑料。(5) 減壓螺桿減壓螺桿是在螺槽熔融段內(nèi)設(shè)置23個(gè)螺距槽深較淺的區(qū)域,目的是避免熔體因過(guò)大的剪切熱而導(dǎo)致塑料過(guò)熱分解。由于熔體可在較小的剪切作用下進(jìn)行熱量的擴(kuò)散和均化,故可適用于熱敏性塑料和需脫揮的物料擠出。此外,還有溝槽型螺桿、排氣螺桿、剪切錐螺桿、強(qiáng)冷輸送螺桿、空心螺桿和分段組合螺桿等新型螺桿。除了上述擠出機(jī)外,還有特殊型單螺桿擠出機(jī):(1) 剖分式單螺桿擠出機(jī)該機(jī)型的特點(diǎn)是機(jī)筒可沿軸線剖分,使得清理螺桿和機(jī)筒極為方便和省時(shí),特別是當(dāng)突遇停電或機(jī)器故障時(shí),便于機(jī)內(nèi)塑料的清除。尤其適用于熱固性塑料(如粉末涂料。酚醛塑料等)的擠出。(2) 排氣式單螺桿擠出機(jī)這種機(jī)型具有排氣脫揮的能力,其特點(diǎn)是機(jī)筒中部位置開(kāi)有排氣口和抽真空系統(tǒng)。排氣式擠出機(jī)能排除固體粒料間帶入機(jī)內(nèi)的空氣、粒料吸附的水分、殘留單體、低沸點(diǎn)增塑劑和低分子揮發(fā)物等。它適用于聚合物擠出造料時(shí)對(duì)需要排除熔體中的揮發(fā)物以及吸濕性大的塑料的加工,如對(duì)硬聚氯乙烯、聚碳酸酯、尼龍和聚甲醛等的擠出。 (3) 全程透明視窗單螺桿擠出機(jī) 這種機(jī)型主要用于科學(xué)研究和螺桿結(jié)構(gòu)優(yōu)化試驗(yàn)之用,其特點(diǎn)是機(jī)筒兩邊交錯(cuò)設(shè)置透明玻璃視窗,可以在正常擠出條件下,觀察拍攝物料在機(jī)筒內(nèi)的形態(tài)變化過(guò)程。(4) 電磁動(dòng)態(tài)塑化單螺桿擠出機(jī) 該設(shè)備的特點(diǎn)是將擠出系統(tǒng)(螺桿和機(jī)筒)置于電機(jī)轉(zhuǎn)子內(nèi)腔中。略去了常規(guī)擠出機(jī)由電機(jī)驅(qū)動(dòng)、皮帶輪、齒輪傳動(dòng)、螺桿和機(jī)筒塑化的模式 ,采用能量直接轉(zhuǎn)換方式塑化物料,實(shí)現(xiàn)了機(jī)電磁一體化,其能量消耗、機(jī)器重量及制造成本均大幅下降。一,擠出機(jī)的組成,塑料擠出機(jī)的主機(jī)是擠塑機(jī),它由擠壓系統(tǒng)、傳動(dòng)系統(tǒng)和加熱冷卻系統(tǒng)組成。1、 擠壓系統(tǒng) 擠壓系統(tǒng)包括螺桿、機(jī)筒、料斗、機(jī)頭、和模具,塑料通過(guò)擠壓系統(tǒng)而塑化成均勻的熔體,并在這一過(guò)程中所建立壓力下,被螺桿連續(xù)的擠出機(jī)頭。(1) 螺桿:是擠塑機(jī)的最主要部件,它直接關(guān)系到擠塑機(jī)的應(yīng)用范圍和生產(chǎn)率,由高強(qiáng)度耐腐蝕的合金鋼制成。(2) 機(jī)筒:是一金屬圓筒,一般用耐熱、耐壓強(qiáng)度較高、堅(jiān)固耐磨、耐腐蝕的合金鋼或內(nèi)襯合金鋼的復(fù)合鋼管制成。機(jī)筒與螺桿配合,實(shí)現(xiàn)對(duì)塑料的粉碎、軟化、熔融、塑化、排氣和壓實(shí),并向成型系統(tǒng)連續(xù)均勻輸送膠料。一般機(jī)筒的長(zhǎng)度為其直徑的1530倍,以使塑料得到充分加熱和充分塑化為原則。(3) 料斗:料斗底部裝有截?cái)嘌b置,以便調(diào)整和切斷料流,料斗的側(cè)面裝有視孔和標(biāo)定計(jì)量裝置。(4) 機(jī)頭和模具:機(jī)頭由合金鋼內(nèi)套和碳素鋼外套構(gòu)成,機(jī)頭內(nèi)裝有成型模具,機(jī)頭的作用是將旋轉(zhuǎn)運(yùn)動(dòng)的塑料熔體轉(zhuǎn)變?yōu)槠叫兄本€運(yùn)動(dòng),均勻平穩(wěn)的導(dǎo)入模套中,并賦予塑料以必要的成型壓力。塑料在機(jī)筒內(nèi)塑化壓實(shí),經(jīng)多孔濾板沿一定的流道通過(guò)機(jī)頭脖頸流入機(jī)頭成型模具,模芯模套適當(dāng)配合,形成截面不斷減小的環(huán)形空隙,使塑料熔體在芯線的周圍形成連續(xù)密實(shí)的管狀包覆層。為保證機(jī)頭內(nèi)塑料流道合理,消除積存塑料的死角,往往安置有分流套筒,為消除塑料擠出時(shí)壓力波動(dòng),也有設(shè)置均壓環(huán)的。機(jī)頭上還裝有模具校正和調(diào)整的裝置,便于調(diào)整和校正模芯和模套的同心度。擠塑機(jī)按照機(jī)頭料流方向和螺桿中心線的夾角,將機(jī)頭分成斜角機(jī)頭(夾角120o)和直角機(jī)頭。機(jī)頭的外殼是用螺栓固定在機(jī)身上,機(jī)頭內(nèi)的模具有模芯坐,并用螺帽固定在機(jī)頭進(jìn)線端口,模芯座的前面裝有模芯,模芯及模芯座的中心有孔,用于通過(guò)芯線,在機(jī)頭前部裝有均壓環(huán),用于均衡壓力,擠包成型部分由模套座和模套組成,模套的位置可由螺栓通過(guò)支撐來(lái)調(diào)節(jié),以調(diào)整模套對(duì)模芯的相對(duì)位置,便于調(diào)節(jié)擠包層厚度的均勻性,機(jī)頭外部裝有加熱裝置和測(cè)溫裝置。2、 傳動(dòng)系統(tǒng) 傳動(dòng)系統(tǒng)的作用是驅(qū)動(dòng)螺桿,供給螺桿在擠出過(guò)程中所需要的力矩和轉(zhuǎn)速,通常由電動(dòng)機(jī)、減速器和軸承等組成。3、 加熱冷卻裝置 加熱與冷卻是塑料擠出過(guò)程能夠進(jìn)行的必要條件。(1) 現(xiàn)在擠塑機(jī)通常用的是電加熱,分為電阻加熱和感應(yīng)加熱,加熱片裝于機(jī)身、機(jī)脖、機(jī)頭各部分。加熱裝置由外部加熱筒內(nèi)的塑料,使之升溫,以達(dá)到工藝操作所需要的溫度。(2) 冷卻裝置是為了保證塑料處于工藝要求的溫度范圍而設(shè)置的。具體說(shuō)是為了排除螺桿旋轉(zhuǎn)的剪切摩擦產(chǎn)生的多余熱量,以避免溫度過(guò)高使塑料分解、焦燒或定型困難。機(jī)筒冷卻分為水冷與風(fēng)冷兩種,一般中小型擠塑機(jī)采用 風(fēng)冷比較合適,大型則多采用水冷或兩種形式結(jié)合冷卻;螺桿冷卻主要采用中心水冷,目的是增加物料固體輸送率,穩(wěn)定出膠量,同時(shí)提高產(chǎn)品質(zhì)量;但在料斗處的冷卻,一是為了加強(qiáng)對(duì)固體物料的輸送作用,防止因升溫使塑料粒發(fā)粘堵塞料口,二是保證傳動(dòng)部分正常工作。二,擠出機(jī)的分類, 隨著塑料擠出成型法的廣泛應(yīng)用和發(fā)展,塑料擠出機(jī)的類型日益增多。根據(jù)螺桿的數(shù)量分:五螺桿擠出機(jī)(其中又分柱塞式擠出機(jī)和彈熔體擠出機(jī))、單螺桿擠出機(jī)、雙螺桿擠出機(jī)等。 根據(jù)螺桿的轉(zhuǎn)速分:普通擠出機(jī)、高速擠出機(jī)、和超高速擠出機(jī)。根據(jù)裝配結(jié)構(gòu)分,整體式擠出機(jī)和分開(kāi)式擠出機(jī)。整體式擠出機(jī)結(jié)構(gòu)緊湊,需要機(jī)械加工的零件件數(shù)少,同事占地面積較小等,因而是目前最通用的形式。分開(kāi)式擠出機(jī)可以采用標(biāo)準(zhǔn)減速器,裝配精度要求較低,易于裝拆魚維修,同事擠壓部分的熱 不易傳到減速器而改善了它的工作條件。其缺點(diǎn)是結(jié)構(gòu)不如整體式緊湊、零件數(shù)目較多、加工制作量較大、螺桿軸承需要單挑的調(diào)滑系統(tǒng)等,因而此類擠出機(jī)應(yīng)用較少。根據(jù)安裝位置分:螺桿在空間呈水平裝置的臥式擠出機(jī)和螺桿直立于地面安裝的立式擠出機(jī)。前者重心較低而穩(wěn)定,且機(jī)器的中心高度可視操作方便而定,同事能方便地配置各種輔機(jī),操作維修都較方便,因此此式最為常用。其缺點(diǎn)是占地面積較大,吹制中空制品和吹塑薄膜時(shí)往往需要用直角機(jī)頭。立式擠出機(jī)的優(yōu)點(diǎn)恰好與臥式擠出機(jī)相反,它重心高而穩(wěn)定性較差,配置輔機(jī)教困難,操作維修也不方便,此外還受廠房高度的限制,因此應(yīng)用甚少。但因其占地面積較小,且當(dāng)上吹中空制品和吹塑薄膜時(shí)可避免采用直角型機(jī)頭,因此在吹塑薄膜時(shí)中小型擠出機(jī)扔有采用。此外,還有排氣式擠出機(jī)、混煉式擠出機(jī)、兩段式擠出機(jī)和超高分子量聚合物擠出機(jī)等。目前應(yīng)用最多的是臥式單螺桿整體裝配式擠出機(jī)。三,擠出機(jī)機(jī)械原理:在原料粉末里添加水或適當(dāng)?shù)囊后w,并進(jìn)行不斷的攪拌。將攪拌好的材料,用高擠出壓力從多孔機(jī)頭或金屬網(wǎng)擠出。 通常是把材料放入圓筒形容器以后,用螺桿擠出材料。在使用變頻技術(shù)以后,可對(duì)壓力進(jìn)行控制,從而可以選擇最合適的線性速度。 單螺桿擠出機(jī)原理 單螺桿一般在有效長(zhǎng)度上分為三段,按螺桿直徑大小 螺距 螺深確定三段有效長(zhǎng)度,一般按各占三分之一劃分。 料口最后一道螺紋開(kāi)始叫輸送段:物料在此處要求不能塑化,但要預(yù)熱、受壓擠實(shí),過(guò)去老擠出理論認(rèn)為此處物料是松散體,后來(lái)通過(guò)證明此處物料實(shí)際是固體塞,就是說(shuō)這里物料受擠壓后是一固體象塞子一樣,因此只要完成輸送任務(wù)就是它的功能了。 第二段叫壓縮段,此時(shí)螺槽體積由大逐漸變小,并且溫度要達(dá)到物料塑化程度,此處產(chǎn)生壓縮由輸送段三,在這里壓縮到一,這叫螺桿的壓縮比3:1,有的機(jī)器也有變化,完成塑化的物料進(jìn)入到第三段。 第三段是計(jì)量段,此處物料保持塑化溫度,只是象計(jì)量泵那樣準(zhǔn)確、定量輸送熔體物料,以供給機(jī)頭,此時(shí)溫度不能低于塑化溫度,一般略高點(diǎn)。四 雙螺桿擠出機(jī)和單螺桿擠出機(jī)的優(yōu)勢(shì)區(qū)別 塑料擠出機(jī)按其螺桿數(shù)量可以分為單螺桿擠出機(jī)、雙螺桿擠出機(jī)和多螺桿擠出機(jī)。目前以單螺桿擠出機(jī)應(yīng)用最為廣泛,適宜于一般材料的擠出加工。雙螺桿擠出機(jī)由于具有由摩擦產(chǎn)生的熱量較少、物料所受到的剪切比較均勻、螺桿的輸送能力較大、擠出量比較穩(wěn)定、物料在機(jī)筒內(nèi)停留長(zhǎng),混合均勻 。SJZ系列錐形雙螺桿擠出機(jī)具有強(qiáng)制擠出、高質(zhì)量、適應(yīng)性廣、壽命長(zhǎng)、剪切速率小、物料不易分解、混煉塑化性能好、粉料直接成型等特點(diǎn),溫度自控,真空排氣等裝置。適用于管、板、異形材等制品的生產(chǎn)。單螺桿擠出機(jī)無(wú)論作為塑化造粒機(jī)械還是成型加工機(jī)械都占有重要地位,近幾年業(yè),單螺桿擠出機(jī)有了很大的發(fā)展。目前德國(guó)生產(chǎn)的大型造粒用單螺桿擠出機(jī),螺桿直徑達(dá)700mm,產(chǎn)量為36t/h。單螺桿擠出機(jī)發(fā)展的主要標(biāo)志在于其關(guān)鍵零件螺桿的發(fā)展。近幾年以來(lái),人們對(duì)螺桿進(jìn)行了大量的理論和實(shí)驗(yàn)研究,至今已有近百種螺桿,常見(jiàn)的有分離型、剪切型、屏障型、分流型與波狀型等。從單螺桿發(fā)展來(lái)看,盡管近年來(lái)單螺桿擠出機(jī)已較為完善,但隨著高分子材料和塑料制品不斷的發(fā)展,還會(huì)涌現(xiàn)出更有特點(diǎn)的新型螺桿和特殊單螺桿擠出機(jī)。從總體而言,單螺桿擠出機(jī)向著高速、高效、專用化方向發(fā)展。雙螺桿擠出機(jī)喂料特性好,適用于粉料加工,且比單螺桿擠出機(jī)有更好的混煉、排氣、反應(yīng)和自潔功能,特點(diǎn)是加工熱穩(wěn)定性差的塑料和共混料時(shí)更顯示出其優(yōu)越性。近些年來(lái)國(guó)外雙螺桿擠出機(jī)已經(jīng)有很大的發(fā)展,各種形式的雙螺桿擠出機(jī)已系列化和商品化,生產(chǎn)的廠商也較多,大致分類如下:(1)按兩根軸線相對(duì)位置,有平行和錐形之分; (2)按兩根螺桿嚙合程序,有嚙合型和非嚙合型之分; (3)按兩根螺桿的旋轉(zhuǎn)方向,有同向和異向之分,在異向中又有向內(nèi)、向外之分; (4)按螺桿旋轉(zhuǎn)速度,有高速和低速之分; (5)按螺桿與機(jī)筒的結(jié)構(gòu),有整體和組合之分。五,中國(guó)擠出機(jī)技術(shù)創(chuàng)新近年來(lái),中國(guó)常規(guī)擠出機(jī)及生產(chǎn)線,以優(yōu)異的性價(jià)比逐漸走俏國(guó)際巿場(chǎng)。同時(shí),中國(guó)在先進(jìn)擠出技術(shù)領(lǐng)域不斷創(chuàng)新,開(kāi)拓出了多種新型擠出產(chǎn)品。精密擠出技術(shù)適應(yīng)高精加工需要精密擠出成型可以免去后續(xù)加工手段,更好地滿足制品應(yīng)用的需求,同時(shí)達(dá)到降低材料成本、提高制品質(zhì)量的目的。如今,滿足塑料制品精密直接擠出的需要,多種成熟的技術(shù)已經(jīng)推向巿場(chǎng),聚合物熔體齒輪泵就是其中一種重要手段。這一技術(shù)已經(jīng)廣泛應(yīng)用于化纖、薄膜、型材、管材、板材、線纜、復(fù)合擠出、造粒等生產(chǎn)線。北京化工大學(xué)橡塑機(jī)械研究所經(jīng)過(guò)多年對(duì)熔體齒輪泵的系統(tǒng)研究,已成功完成塑料熔體齒輪泵的系列開(kāi)發(fā)和研制,現(xiàn)已能夠設(shè)計(jì)制造塑料熔體齒輪泵產(chǎn)品如28/28(中心距/齒寬)、56/56、70/70、90/90等,最大出入口壓力差可達(dá)30MPa,能夠滿足不同產(chǎn)量的要求,并已在實(shí)際中得到應(yīng)用,取得良好的效果。北京化工大學(xué)橡塑機(jī)械研究所通過(guò)對(duì)一體型齒輪泵擠出機(jī)進(jìn)行深入研究,設(shè)計(jì)開(kāi)發(fā)了115一體型齒輪泵擠出機(jī)。齒輪泵對(duì)橡膠行業(yè)精密成型同樣大有裨益。為了滿足國(guó)內(nèi)對(duì)橡膠熔體齒輪泵的需求,北京化工大學(xué)還與北京航空制造工程研究所、杭州朝陽(yáng)橡膠有限公司合作,共同研制開(kāi)發(fā)XCP150/100、XCP120/90兩種型號(hào)橡膠熔體齒輪泵擠出機(jī)組。這一機(jī)組具有理想的工作特性,保證擠出量與齒輪泵的轉(zhuǎn)速成線性關(guān)系,可以實(shí)現(xiàn)對(duì)產(chǎn)量精確控制,提高產(chǎn)品的尺寸精度。多層共擠技術(shù)成熟發(fā)展多層復(fù)合技術(shù)利用具有中高阻隔性能的材料與其他包裝材料復(fù)合,綜合阻隔材料的高阻隔性與其他材料的廉價(jià)或特殊的力學(xué)、熱學(xué)等其他性能,實(shí)現(xiàn)特定的功能需要。共擠出復(fù)合薄膜的結(jié)構(gòu)設(shè)計(jì)逐步要求能系統(tǒng)地達(dá)到集功能、技術(shù)、成本、環(huán)保、安全、二次加工于一體的理想境界,從而實(shí)現(xiàn)復(fù)合層數(shù)最大化的可能性成為供應(yīng)商追求的技術(shù)之一。廣東金明塑膠設(shè)備有限公司七層復(fù)合薄膜共擠吹塑技術(shù)可謂中國(guó)在這一領(lǐng)域發(fā)展的典型。該七層復(fù)合薄膜共擠吹塑機(jī)組采用的關(guān)鍵技術(shù)包括:兩短一長(zhǎng)及螺距變化的螺桿塑化擠出系統(tǒng),工程分析軟件對(duì)振動(dòng)誘導(dǎo)塑化裝置的優(yōu)化設(shè)計(jì),平面閥加成型模頭和斜式閥加成型模頭,內(nèi)冷技術(shù)及雙風(fēng)口負(fù)壓冷卻技術(shù),多組分失重式計(jì)量喂料,在線薄膜厚度精確控制系統(tǒng),計(jì)算機(jī)集中自動(dòng)控制系統(tǒng)和總線控制(CANOPEN)技術(shù)等。在層數(shù)增多的同時(shí),適應(yīng)特殊功能的薄膜生產(chǎn)技術(shù)也是巿場(chǎng)發(fā)展的熱點(diǎn)之一。近日,廣東仕誠(chéng)公司設(shè)計(jì)制造了一條幅寬為3150mm的PP環(huán)保木紋膜流延生產(chǎn)線。該生產(chǎn)線產(chǎn)能超過(guò)800kg/h。螺桿設(shè)計(jì)為高速的剪切、混煉,高效率塑化螺桿,客戶可以直接使用高填充碳酸鈣粉以及無(wú)機(jī)顏料色粉,從而節(jié)約昂貴的原材料成本。整線除了可以生產(chǎn)PP環(huán)保木紋膜生產(chǎn)外,還可以靈活地轉(zhuǎn)換生產(chǎn)其它產(chǎn)品,拓寬客戶產(chǎn)品種類。在仕誠(chéng)公司試生產(chǎn)過(guò)程中,不但生產(chǎn)出了美觀的PP木紋膜,還生產(chǎn)了CPP薄膜、PP文具薄膜及PP文具片材。六,塑料擠出機(jī)五大發(fā)展趨勢(shì) 高速、高產(chǎn)化擠出機(jī)高速、高產(chǎn),可使投資者以較低的投入獲得較大的產(chǎn)出和高額的回報(bào)。但是,擠出機(jī)螺桿轉(zhuǎn)速高速化也帶來(lái)了一系列需要克服的難點(diǎn):如物料在螺桿內(nèi)停留時(shí)間減少會(huì)導(dǎo)致物料混煉塑化不均,物料經(jīng)受過(guò)度剪切可能造成物料急驟升溫和熱分解,擠出穩(wěn)定性控制困難會(huì)造成擠出物幾何尺寸波動(dòng),相關(guān)的輔助裝置和控制系統(tǒng)的精度必須提高,螺桿與機(jī)筒的磨損加劇需要采用高耐磨及超高耐磨材質(zhì),減速器與軸承在高速運(yùn)轉(zhuǎn)的情況下如何提高其壽命等問(wèn)題都需要解決。 高效、多功能化塑料擠出機(jī)的高效主要體現(xiàn)在高產(chǎn)出、低能耗、低制造成本方面。在功能方面,螺桿擠出機(jī)已不僅僅用于高分子材料的擠出成型和混煉加工,它的用途已拓寬到食品、飼料、電極、炸藥、建材、包裝、紙漿、陶瓷等領(lǐng)域。此外,將混煉造粒與擠出成型工序合二為一的“一步法擠出工藝”也值得重視。 大型化和精密化實(shí)現(xiàn)擠出成型設(shè)備的大型化可以降低生產(chǎn)成本,這在大型雙螺桿造粒機(jī)組、吹膜機(jī)組、管材擠出機(jī)組等方面優(yōu)勢(shì)更為明顯。國(guó)家重點(diǎn)建設(shè)服務(wù)所需的重大技術(shù)裝備,大型乙烯工程配套的三大關(guān)鍵設(shè)備之一的大型擠壓造粒機(jī)組長(zhǎng)期依靠進(jìn)口,因此必須加快國(guó)產(chǎn)化進(jìn)程,滿足石化工業(yè)發(fā)展需要。而精密化可以提高產(chǎn)品的含金量,如多層共擠復(fù)合薄膜等均需要精密擠出,而作為實(shí)現(xiàn)精密擠出的重要手段?熔體齒輪泵必須加大力度進(jìn)行開(kāi)發(fā)研究。 模塊化和專業(yè)化模塊化生產(chǎn)可以適應(yīng)不同用戶的特殊要求,縮短新產(chǎn)品的研發(fā)周期,爭(zhēng)取更大的市場(chǎng)份額;而專業(yè)化生產(chǎn)可以將擠出成型裝備的各個(gè)系統(tǒng)模塊部件安排定點(diǎn)生產(chǎn)甚至進(jìn)行全球采購(gòu),這對(duì)保證整期質(zhì)量、降低成本、加速資金周轉(zhuǎn)都非常有利。 智能化和網(wǎng)絡(luò)化發(fā)達(dá)國(guó)家的擠出機(jī)已普遍采用現(xiàn)代電子和計(jì)算機(jī)控制技術(shù),對(duì)整個(gè)擠出過(guò)程的工藝參數(shù)如熔體壓力及溫度、各段機(jī)身溫度、主螺桿和喂料螺桿轉(zhuǎn)速、喂料量,各種原料的配比、電機(jī)的電流電壓等參數(shù)進(jìn)行在線檢測(cè),并采用微機(jī)閉環(huán)控制。有的公司已采用網(wǎng)上遠(yuǎn)程監(jiān)測(cè)、診斷和控制,對(duì)擠出成型生產(chǎn)線進(jìn)行網(wǎng)絡(luò)控制。這對(duì)保證工藝條件的穩(wěn)定、提高產(chǎn)品的精度都極為有利。 七,結(jié)語(yǔ)我國(guó)橡膠機(jī)械制造業(yè)的發(fā)展雖然存在著科技發(fā)展相對(duì)滯后、市場(chǎng)化程度不高、機(jī)械加工手段不夠先進(jìn)、接觸國(guó)際市場(chǎng)較晚以及國(guó)產(chǎn)液壓元件和系統(tǒng)的穩(wěn)定性差等諸多制約因素, 但是, 我們應(yīng)該有信心克服這些制約因素, 依靠我國(guó)自主研發(fā)力量推動(dòng)國(guó)產(chǎn)開(kāi)煉機(jī)的快速發(fā)展, 逐步完善產(chǎn)品性能, 達(dá)到國(guó)際先進(jìn)水平, 增強(qiáng)國(guó)產(chǎn)開(kāi)煉機(jī)的國(guó)際市場(chǎng)競(jìng)爭(zhēng)力。參考文獻(xiàn):1、橡膠工業(yè)手冊(cè)第九分冊(cè)上、下冊(cè)2、橡膠塑料機(jī)械產(chǎn)品樣本,大連塑材機(jī)械研究所編,機(jī)械工業(yè)出版社,第二版3、液壓元件產(chǎn)品樣本, 杜國(guó)森,機(jī)械工業(yè)出版社 第一版4、塑料機(jī)械液壓傳動(dòng),北京化工大學(xué),華南理工大學(xué),中國(guó)輕工業(yè)出版社,第一版5、行走機(jī)械液壓驅(qū)動(dòng)技術(shù)發(fā)展大觀,王意, 液壓氣動(dòng)與密封,2000 (2)
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