圆锥破碎机铸型尼龙轴套的生产与应用

一、铸型尼龙生产工艺 铸型尼龙,又称单体浇铸尼龙(MC尼龙),是目前机械工业中比较广泛应用的工程塑料之一。它是用己内酰胺单体,通过简便的熔融浇注聚合工艺,可直接在模具内聚合成型,制成各种毛坯件,经加工后达到工程用料的要求。 铸型尼龙制品的分子量很高,结晶度     

重轨轨底横向划伤的原因分析及防止对策

采用已内酰胺工程塑料（ＭＣ铸型尼龙）作为重轨生产过程中的输送移滑轨，较好地解决了轨底横向划伤问题，满足了用户对重轨表面质量的要求。     

河北省故城县同业高耐磨材料厂

河北省故城县同业高耐磨材料厂是生产高耐磨自润滑含油铸型尼龙衬板，轴承的专业厂家。具有全国最大的真空反应和控温设备及独特的动态离心浇注设备。     

40米~2筒型外滤机的三项革新

(一)用 MC 铸型尼龙6做过滤机的分配盘、错气盘 我矿与沈阳矿山机械厂合作,采用 MC 铸型尼龙6代替普通铸铁和黄铜材质的分配盘、错气盘,在40米~2的圆筒型外滤机上作工业试验,从1975年8月6日开始,到1976年7月中旬止,使用一年     

铸型尼龙件在圆锥破碎机上的试验与应用

近年来,在尼龙6塑料的制造方面,研究出了一种新的合成工艺技术,可以用浇铸的方法在尼龙聚合体的熔点以下制造出大型尼龙制件。它是用尼龙6的原料已内酰胺单体,加上催化剂直接注入预热的模具中,使其聚合反应凝结成为固体的毛坯件。用这种方法制成的尼龙,称为铸型尼龙,又叫单体浇铸Mc尼龙。这个方法的特点是:工艺过     

圆锥破碎机应用铸型尼龙大型衬套鉴定和经验交流会

在毛主席革命路线指引下,近年来用尼龙制品代替铜合金的应用得到迅速发展。为了总结交流经验,促进尼龙在矿山机械中更广泛的应用,辽宁省冶金局和机械局子四月二日至六日在杨家杖子矿务局召开了“圆锥破碎机应用铸型尼龙大型衬套鉴定和经验交流会”。出席会议的有来自各省、市的二     

稀土在MC尼龙上的应用

MC尼龙俗称铸型尼龙,是聚酰胺塑料的一种,是主要的工程塑料之一。MC尼龙由于具有较好的机械性能和耐磨、耐油、耐化学品腐蚀、高绝缘等特性,广泛应用于冶金、电子、机械、交通、化工、建筑等领域,可代替铜、铝、钢铁等金属制作齿轮、滑轮、滑块、导辊、密封圈、垫等。但MC尼龙吸水率较大,在水及受热条件下尺寸稳定性较差,力学性能和金属相比差距较大,故而限制了MC尼龙的应用范围。经试验在MC尼龙聚合过程中,加入适量的环烷酸稀土化合物,聚合产物和不加稀土的MC尼龙相比,其主要物理及力学性能都有不同程度的提高和改善。从而扩大了尼龙塑料     

改性MC尼龙轴瓦在2300三辊劳特式中板轧钢机上的应用

本文简要介绍了改性MC尼龙轴瓦在2300三辊劳特式轧机上试验及应用情况。     

河北省故城县同业高耐磨材料厂

河北省故城县同业高耐磨材料厂是生产高耐磨自润滑含油铸型尼龙材板、轴承的专业厂家。具有全国最大的真空反应和控温设备及独特的动态离心浇注设备。产品广泛用于冶金、矿山、机械、轻工、化工、电力行业等领域。本厂专业制造各种规格烧结圆筒混合机衬板、     

7′超重型圆锥MC尼龙衬套试用情况分析

分析了 7′超重圆锥破碎机直衬套 ,由MC尼龙取代铜做成衬套 ,在试用过程中出现的现象 ,并对如何确定产品的尺寸进行了说明 ,认为改性MC尼龙衬套可以成为铜衬套的替代品     

MC尼龙的性能和应用

本文简介了MC尼龙的优良性能及易成型加工的特性,并以一些典型的MC尼龙应用事例来说明,MC尼龙在各个领域中的实用性和经济性.     

Study on Preparation and Properties of La2O3/MC Nylon Nanocomposites

MC nylon,monomer casting nylon,is a newtypeof engineering plastics,whichis synthesized by anion-ic polymerization with caprolactam as the major rawmaterial,under normal pressure,pouring directlyto amould preheatedto a certaintemperature.It has manyadvantages,such as low polymerized temperature,si mple technology,high crystallinity,low-cost,highequipment efficiency as well as good mechanical prop-erties,shock decrease but wear proof,corrosion-resis-ting,self-ubricant,chemicals-resisting,wide us…     

Effect of heparin on mesangial cell growth and gene expression of matrix proteins

BACKGROUND: Mesangial cell (MC) proliferation and matrix expansion are characteristics of many glomerulopathies. Heparin has been shown to inhibit MC proliferation in vitro and mitigate cell proliferation, matrix expansion, proteinuria, renal insufficiency, and hypertension in experimental glomerulonephritis and subtotal renal ablation. We examined the effect of standard heparin on MC proliferation and matrix protein expression in vitro which necessarily excludes the confounding influences of haemodynamic, inflammatory, haemostatic, and various other processes that are present in vivo. METHODS: Gene expression and release of fibronectin (FN), collagen IV and laminin by cultured rat MC were tested in the presence and absence of heparin. In addition the effect of transforming growth factor-beta1 (TGF-beta1) on the gene expression of those matrix proteins was assessed. RESULTS: Within a 3-1000 microg/ml concentration range, heparin inhibited gene expression and release of FN by 10% fetal calf serum (FCS)-stimulated MC in a concentration-dependent manner. At concentrations of 300 and 1000 microg/ml, heparin inhibited fibronectin mRNA levels in TGF-beta1 (6 ng/ml) stimulated cells. However, heparin had no effect on gene expression or release of collagen IV or laminin under these conditions. Heparin markedly inhibited 10% FCS-stimulated MC proliferation in a concentration-dependent manner. CONCLUSIONS: Heparin inhibited MC growth and fibronectin production. These effects may, in part, account for the reported beneficial effects of heparin on the course of renal disease in experimental animals.     

Regulation of survival and death of mesangial cells by extracellular matrix

BACKGROUND: Cell-matrix interactions exert major effects on such phenotypic features as cell growth and differentiation. Apoptosis is an active form of cell death that is crucial for maintaining the appropriate number of cells as well as the organization of tissue. Recently, it has been suggested that apoptosis of the mesangial cells (MC) is important in glomerular remodeling after injury. The MC are surrounded by an extracellular matrix (ECM) in vivo. Since in disease conditions the mesangial matrix is altered quantitatively and qualitatively, it is of interest to determine whether cell-matrix interactions may influence apoptosis of the MC. METHODS: We first investigated the differences in the susceptibility to apoptotic stimuli of the MC cultured on various ECM components (type I collagen, fibronectin, basement membrane matrix). We then determined whether the inhibition of MC-matrix interactions would affect apoptosis. Finally, interactions between MC and matrix were disrupted by the inhibition of beta1-integrin expression with antisense oligonucleotides (ODN). RESULTS: When MC were cultured on type I collagen or fibronectin and deprived of serum for eight hours, the extracted DNA from the MC demonstrated an internucleosomal ladder pattern on gel electrophoresis that constituted the biochemical characteristic of apoptosis. However, no ladder pattern was apparent when MC were cultured on basement membrane matrix. The attachment of cells was completely inhibited when the MC were cultured on agarose-coated dishes for 24 hours. Gel electrophoresis of DNA extracted from these cells showed a ladder pattern. However, the MC attached to the substratum did not show any apoptosis. MC showed an increase in apoptotic cell death after treatment with antisense ODN against beta1-integrin molecule. CONCLUSIONS: These results indicate that normal ECM may prevent the MC from undergoing apoptosis and serve as a survival factor for MC. Signals from ECM that prevent apoptosis may be mediated by beta1-integrin molecules.     

Determination of potential migrants present in Nylon 'microwave and roasting bags' and migration into olive oil

Two groups of potential migrants were found in Nylon "microwave and roasting bags' (MRBs): volatile compounds were released at cooking temperatures and non-volatile compounds were extracted with methanol and/or water. A dynamic headspace system at 200 degrees C followed by gas chromatography (GC) coupled to mass spectrometry (MS) was used for determination of volatile compounds. Cyclopentanone (31.7 mg/bag), 2-cyclopentyl cyclopentanone (17.4 mg/bag), hexadecane (2.6 micrograms/bag), heptadecane (3.2 micrograms/bag), octadecane (3.0 micrograms/bag) and epsilon-caprolactam (5.0-35.5 mg/ bag) were the main volatile compounds present in the MRBs. High performance liquid chromatography (HPLC) and mass spectrometry were combined for identification and quantification of non-volatile compounds extracted with methanol (46.0 mg/bag). Nylon 6,6 cyclic monomer and cyclic oligomers up to the tetramer and Nylon 6 monomer and cyclic oligomers up to the octamer were identified and quantified, confirming that the plastic was made of Nylon 6,6 and Nylon 6 polymers. The same non-volatile compounds (except Nylon 6 heptamer and octamer) were found to migrate into olive oil at 175 degrees C for 1 h. A total of 0.916 mg/dm2 (19.2 mg/bag) of non-volatile compounds migrated into olive oil (41.8% of those quantified in the plastic material).     

Application of the Master Curve Approach for the Irradiation Embrittlement Evaluation of Pressure Vessel Steels

The Master Curve (MC) approach and the associated reference temperature, T₀, as defined in the test standard ASTM E1921, is rapidly moving from the research laboratory to application in integrity assessment of components and structures. T₀ is the index temperature for the universal MC, which considers the toughness behaviour of a specific material. “The Structural Integrity Assessment Procedures for European Industry” (SINTAP) contain a MC extension for analysing the fracture behaviour of inhomogeneous ferritic steels. This paper presents the application of the MC approach to the T₀ determination of different types of Russian WWER‐type reactor pressure vessel (RPV) steels. In addition the SINTAP‐MC approach was applied to determine an alternative reference temperature, T_R. The influence of different microstructures and compositions within one type of RPV steel and the effect of irradiation with fast neutrons on T₀ are experimentally evaluated. In general the MC based T₀ is about 72 K below the Charpy V‐notch transition temperature related to an impact energy of 48 J. The paper demonstrates the application of MC based T₀ and T_R as an alternative reference temperature for neutron embrittled RPV steels used in the RPV integrity assessment.     

Analysis of genes implicated in osteogenic signaling by osteogenic protein-1 (OP-1) using differential display method

Bone morphogenetic proteins (BMPs), members of a transforming growth factor-beta (TGF-beta) superfamily, are growth and differentiation factors which induce ectopic bone formation in vivo. Although many studies on osteoinductive properties of BMPs have been conducted, little is known about the downstream components in the signal transduction machinery, beyond the mechanism of BMP receptor activation. In this study, the osteogenic effects by osteogenic protein-1 (OP-1, BMP-7) on osteoblastic cell line MC3T3-E1 and murine stromal cell line ST2 were investigated, especially focusing on differentially expressed genes induced by OP-1 using the differential display method. The major findings were as follows: 1) Alkaline phosphatase specific activities of both MC3T3-E1 and ST2 increased in a dose-dependent manner by OP-1 stimulation. 2) Northern analysis showed a significant increase of osteocalcin mRNA after 7 days of OP-1 treatment. 3) 77 genes, which were differentially expressed in MC 3 T 3-E1 and ST 2 cells, were detected on differential display fingerprints after 16-hour treatment of OP-1. 4) Some of these clones showed high levels of identical to known genes. 5) One clone called ST3v, down-regulated in ST2 cells by OP-1 stimulation, was confirmed with quantitative RT-PCR.     

Significance of ventricular myocytes and nonmyocytes interaction during cardiocyte hypertrophy: evidence for endothelin-1 as a paracrine hypertrophic factor from cardiac nonmyocytes

BACKGROUND: In cardiac hypertrophy, both excessive enlargement of cardiac myocytes and progressive interstitial fibrosis are well known to occur simultaneously. In the present study, to investigate the interaction between ventricular myocytes (MCs) and cardiac nonmyocytes (NMCs), mostly fibroblasts, during cardiocytes hypertrophy, we examined the change in cell size and gene expression of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in cultured MCs as markers for hypertrophy in the neonatal rat ventricular cardiac cell culture system. METHODS AND RESULTS: The size of cultured MCs significantly increased in the MC-NMC coculture. Concomitantly, secretions of ANP and BNP into culture media were significantly increased in the MC-NMC coculture compared with in the MC culture (with the possible contamination of NMC <1% of MC). Moreover, in the MC culture, enlargement of MC and an increase in ANP and BNP secretions were induced by treatment with conditioned media of the NMC culture. A considerable amount of endothelin (ET)-1 production was detected in the NMC-conditioned media. BQ-123, an ET-A receptor antagonist, and bosentan, a nonselective ET receptor antagonist, significantly blocked the hypertrophic response of MCs induced by treatment with NMC-conditioned media. Angiotensin II (Ang II) (10(-10) to 10(-6) mol/L) and transforming growth factor-beta1 (TGF-beta1) (10(-13) to 10(-9) mol/L), both of which are known to be cardiac hypertrophic factors, did not induce hypertrophy in MC culture, but both Ang II and TGF-beta1 increased the size of MCs and augmented ANP and BNP productions in the MC-NMC coculture. This hypertrophic activity of Ang II and TGF-beta1 was associated with the potentiation of ET-1 production in the MC-NMC coculture, and the effect of Ang II or TGF-beta1 on the secretions of ANP and BNP in the coculture was significantly suppressed by pretreatment with BQ-123. CONCLUSIONS: These results demonstrate that NMCs regulate MC hypertrophy at least partially via ET-1 secretion and that the interaction between MCs and NMCs plays a critical role during the process of Ang II- or TGF-beta1-induced cardiocyte hypertrophy.