国外轮胎胎圈的发展变化

通过分析国外轮胎剖析结果,研究国外轮胎胎圈的发展趋势。胎圈钢丝方面:轿车子午线轮胎直径有所增大,质量不断提高,镀层仍以青铜为主;载重子午线轮胎变化不大。钢丝圈方面:轿车子午线轮胎小规格为矩形,大规格为六边形,新开发的有圆形;载重子午线轮胎为六边形,新开发的有矩形和圆形。采用薄胶片替代钢丝圈包布可提高钢丝圈结构和形状的稳定性。     

φ1.2mm NT胎圈钢丝在轿车子午线轮胎中的应用

研究φ1.2 mm NT胎圈钢丝替代φ0.96 mm NT胎圈钢丝在轿车子午线轮胎中的应用.结果表明,采用φ1.2 mm NT胎圈钢丝替代φ0.96 mm NT胎圈钢丝用于轿车子午线轮胎钢丝圈,并对钢丝圈排列形式进行调整,轮胎成品性能提高,特别是动平衡性能提高显著.     

国(境)外轮胎剖析所揭示的骨架材料发展变化

介绍国(境)外轮胎剖析所揭示的骨架材料发展变化情况。纤维骨架材料:新品种纤维帘布不断出现,原有帘布的性能和规格产生变化,加粗帘线和加密帘布涌现;载重斜交轮胎胎体骨架材料仍然首选锦纶6和锦纶66帘线;高速、高性能轿车轮胎冠带层主要采用930dtex/2和1400dtex/1(2)低捻度锦纶66帘线;聚酯适用于Z级以下速度级别的轿车子午线轮胎和轻型载重子午线轮胎;人造丝改进后成为高性能和跑气保用轮胎的首选骨架材料;芳纶开始用于三角胶和钢丝圈包布以及胎体冠带层中。钢丝骨架材料:钢丝帘线强度提高,国外轮胎公司主要采用高强度或超高强度钢丝帘线,破断强度基本保持在2 700~3 200 MPa,原有结构钢丝帘线仍在使用,新结构钢丝帘线不断出现;轿车轮胎多采用直径为1.25 mm左右的胎圈钢丝,破断强度为2 000 MPa左右,轻型载重和全钢载重子午线轮胎胎圈钢丝直径一直保持在1.3~1.6 mm。     

φ1.2 mm NT胎圈钢丝在轿车子午线轮胎中的应用

研究Ф1.2mm NT胎圈钢丝替代Ф0.96mm NT胎圈钢丝在轿车子午线轮胎中的应用。结果表明,采用Ф1.2mm NT胎圈钢丝替代Ф0.96mm NT胎圈钢丝用于轿车子午线轮胎钢丝圈,并对钢丝圈排列形式进行调整,轮胎成品性能提高,特别是动平衡性能提高显著。     

Φ1.83 mm HT胎圈钢丝在载重子午线轮胎中的应用

试验研究Φ1.83 mm HT胎圈钢丝在全钢载重子午线轮胎中的应用.结果表明,以Φ1.83 mm HT胎圈钢丝替代Φ1.65 mm NT胎圈钢丝用于全钢载重子午线轮胎钢丝圈,可在保证成品轮胎性能的基础上,提高生产效率,降低生产成本.     

Φ1.3 mm高强度胎圈钢丝在半钢子午线轮胎中的应用

研究以Φ1.3 mm高强度胎圈钢丝替代Φ1.2 mm高强度胎圈钢丝在半钢子午线轮胎中的应用。结果表明:以Φ1.3 mm高强度胎圈钢丝替代Φ1.2 mm高强度胎圈钢丝,生产过程无异常,能够满足工艺要求;钢丝圈安全倍数为6.3,成品轮胎性能良好;钢丝圈缠绕效率提高了15%,钢丝圈质量减小,每年可降低生产成本35万元。     

矩形钢丝钢丝圈在载重斜交轮胎中的应用

介绍矩形钢丝钢丝圈的结构特点、生产工艺及其在载重斜交轮胎中的应用.矩形钢丝钢丝圈的结构特点是钢丝表面不包胶,钢丝多股、多层紧密排列,沿圆周等分并用薄钢带箍紧;使用矩形钢丝钢丝圈能有效保证硫化后胎圈部位的材料分布符合设计要求,可简化生产工艺,减小钢丝圈质量.胎圈采用矩形钢丝钢丝圈的10.00-20 18PR轮胎耐久性能提高.     

六角形钢丝圈缠卷机组

一、前言六角形钢丝圈是由单根包胶钢丝连续缠卷成六角形断面的钢丝圈。按其结构而言,可以分为平底六角形钢丝圈和斜底扁六角形钢丝圈(图1)。平底六角形钢丝圈适用于有内胎的子午线轮胎,斜底扁六角形钢丝圈用于无内胎的子午线轮胎。六角形钢丝圈的钢丝排列紧密整齐,一个钢丝圈只有二个钢丝端头,因而具有较高的承载能力。在钢丝用量相同的条件下,六角形钢丝圈的承载能力比矩形钢丝圈提高25％。[1]子午线轮胎的钢丝圈所受的应力比斜交轮胎高30～40％,六角形钢丝圈完全可以适应子午线轮胎的要求,[2]而对于钢丝子午线轮胎(单层胎体)来说,尤为适用。斜底扁六角形钢丝圈用于无内胎的子午线轮胎,不仅有利于保证轮胎成型和硫化的质量,而且能保证轮胎的胎圈部     

全钢载重子午线轮胎装配线裂口和胎圈脱空原因分析及解决措施

分析全钢载重子午线轮胎装配线裂口和胎圈脱空的原因,并采取相应解决措施.通过胎侧胶与耐磨胶搭接面厚度增大0.5～1.0 mm,胎圈包布外端点胶片粘贴方式由包边改为搭接,上下三角胶端点高度提高5～8 mm,胎体帘布和钢丝圈包布外端点高度提高2～3 mm,胎体帘布外端点处三角胶厚度增大1 mm,缩小钢丝圈直径;降低胶片挤出温度,在钢丝压延辊增设划气泡装置,成型时采用激光灯标定位等措施,基本解决了轮胎装配线裂口和胎圈脱空问题.     

国内外全钢载重子午线轮胎使用钢丝的差异

根据国内外全钢载重子午线轮胎剖析结果讨论国内外全钢载重子午线轮胎使用钢丝的差异。对于无内胎全钢载重子午线轮胎,国外厂家大都采用密集型钢丝帘线作为胎体帘线,钢丝帘线直径都比较小,且比较柔软,但钢丝帘线密度较大;国内外厂家都采用了4层带束层结构,带束层钢丝帘线直径普遍较大。对于有内胎全钢载重子午线轮胎,国内厂家轮胎胎体使用最多的是3＋9＋15钢丝帘线,带束层多采用3层带束层结构,以3＋9＋15钢丝帘线为主,配合一些高抗冲击、高伸长钢丝帘线;国外厂家仍以采用4层带束层结构为主。国内外全钢载重子午线轮胎胎圈钢丝直径都比较大,且多采用六角形钢丝圈,其中无内胎轮胎采用斜六角形钢丝圈的较多,有内胎轮胎采用正六角或扁六角形钢丝圈的居多。     

Magnetic bead cellulose

Mangetic bead cellulose was prepared from viscose and ferrite powder by employing the suspension procedure using the thermal sol-gel transition. The particles thus obtained can be stirred if acted upon by an external rotary magnetic field of a common permanent magnet. Isolation of the particles from reaction suspensions should proceed in a thin layer using a strong magnetic field. Magnetic bead cellulose prepared from supermagnetic powder of the SmCoFe alloy shows a better behaviour in the magnetic field than ferrite materials.     

胎圈结构对钢丝圈应力分布的影响

从理论上分析三角形径向扩张模式和L形扭转扩张模式胎圈结构对钢丝圈应力的影响,并用有限元方法进行计算验证.结果表明,与L形胎圈结构相比,三角形胎圈结构钢丝圈应力分布较均匀,有利于提高钢丝圈强力和轮胎的安全性能,延长轮胎使用寿命.     

六角型六工位钢丝圈生产线

对新研发的六角型六工位钢丝圈生产线作了简介,对生产线的多部件分别作了工作原理和工作步骤的分析和介绍,包括导开机、挤出机、钢丝牵引储存装置、缠绕机等共10个部件。     

钢丝圈生产线的改造

介绍钢丝圈生产线的改造情况：取消立式导开架，改装卧式导开架；取消浸酸槽、洗酸加温槽及擦干装置，改装电热除锈机；改进挂胶挤出机机头和卷成机机头结构；冷却槽、牵引机合并，改成牵引冷却机，取消吹干装置。生产线改造后，钢丝圈质量大大提高，钢丝浪费减少。     

优化全钢型腔胶囊夹盘设计降低轮胎子口胎趾圆角缺陷

针对目前轮胎产品子口胎趾圆角缺陷比例较高进行分析,制定相应的改进方案(主要是优化型腔胶囊夹盘设计)。通过对改进后实际使用效果进行跟踪对比,达到了预期设计改进目的,并吸收改进该规格设计实际运行效果扩大到其它圆角缺陷比例靠前规格,均达到了改进目的。极大的降低了产品圆角缺陷比例,提高了产品交付能力,降低了产品内部失败成本,为提高产品质量作出了巨大的作用。     

Polymer bead preparation from bulk polymers

A method of preparing polymer beads from chloroform solutions of bulk polymer was developed. The technique involved solvent removal while the polymer solution was stirred in an aqueous dispersing medium. Bead size could be varied by adjusting the concentration of the suspending medium and the method was found to be applicable to chloroformsoluble, water-insoluble polymers. Copolymers, low-tack rubbers, and polyblends were also converted to bead form and, in the latter case, phase separation occurred. Furthermore, it was possible to encapsulate finely divided inorganic fillers within the polymer beads. © 1992 John Wiley & Sons, Inc.     

Viscosity of bead suspensions in polymeric solutions

Viscosity measurements made by a cone-plate viscometer on polyisobutylene in decalin solutions at different concentrations and their corresponding glass bead suspensions with filler loadings up to 40% by volume are reported. The range of shear rate $ \dot \gamma $ investigated is between 0.1 and 1000 sec^?1. The solutions show shear-thinning behavior, and the relative viscosity η_r of the slurries generally decreases with increasing shear rate. The results indicate two different types of mechanism, respectively at high and low shear rates. At low $ \dot \gamma $, the relative viscosity can be correlated extending relations already well known for suspensions in Newtonian liquids which are based on the mechanism of aggregate disruption. The behavior at high $ \dot \gamma $ values is believed to be due to the influence of the filler on the flow properties of macromolecules, in particular on relaxation time. Through a shifting procedure, an increase in relaxation time which depends on filler content and not on polymer concentration is shown.     

Enhancing pseudoislet biofunctionality using gelatin bead technology

Abstract

Central necrosis hampers the formation of highly biofunctional Pseudoislets (PIs), which consist of aggregates of insulin-secreting pancreatic β-cells. Necrosis arises because of a shortage of nutrient and oxygen diffusion to the core of the PIs during culture, especially when PIs exceed >200?µm. This study aimed to generate ‘vents’ by incorporating gelatin beads (GBs) into the center of PIs and to examine if this promotes nutrient and oxygen diffusion by blocking the center for cell residence. In addition, we examined the impact of delivering GBs loaded with anti-necrosis or anti-apoptosis drugs to the center of PIs. The BRIN-BD11 rat pancreatic β-cell line was used to generate PIs by suspension culture. PIs were generated at a seeding density of 32,000 cells/PI and cultured for up to 7?days. GBs of 40?µm diameter were produced from Gelatin A and crosslinked with 5% glutaraldehyde for 6?h. The neat GBs or GBs loaded with 100?ng/mL IL-10, or 5?µg/mL anti-IL-1β were incorporated into PIs. The cell viability of the PIs was assessed using cell counting kit-8 (CCK8) and lactate dehydrogenase (LDH) assays. Glucose-stimulated insulin release (GSIS) from PIs was evaluated after stimulation with 16.7?mM glucose for 20?min. Incorporating IL-10, or anti-IL-1β -loaded GBs to PIs synergistically enhanced cell proliferation and reduced cell death. Importantly, PIs cultured for 1 week following incorporation of cytokine-loaded GBs displayed enhanced biofunctionality in terms of higher GSIS.     

一种新型电镀串珠制造工艺

提出了一种采用新型电镀方法制造各类型电镀串珠的全新工艺,着重介绍了串珠试制过程中的脉冲电镀工艺、磨具设计,实验结果表明,电镀串珠镀层质量提高,生产时间缩短,胎体高度的偏差也有较大提高.     

全钢载重子午线轮胎胎圈质量问题分析

分析造成全钢载重子午线轮胎胎圈质量问题的因素.分析表明,尽量使用标准轮辋、适当提高轮胎中心断面水平轴位置、六角形钢丝圈生产保留预硫化工艺、模具加热采用带蒸汽室的定型硫化机或及时调整硫化工艺使轮胎硫化程度均一性提高等均有利于提高胎圈质量.