短纤维-橡胶复合材料的混炼工艺

研究了转子转速和短纤维用量对短纤维-橡胶复合材料混炼过程及硫化胶质量的影响。结果表明,随着转子转速和短纤维用量的增加,混炼过程中消耗的最大功率、单位能耗等增加,当转子转速为70r/min,聚酯短纤维用量为3份时,硫化胶的拉伸强度、撕裂强度等物理机械性能出现最佳值。     

湿法混炼芳纶短纤维/丁腈橡胶复合材料的性能研究

用湿法混炼方法制备了芳纶短纤维/丁腈橡胶(NBR)复合材料,研究增稠剂和芳纶短纤维用量对复合材料性能的影响。结果表明:添加聚丙烯酸钠(PNaAA)和聚氧化乙烯(PEO)两种增稠剂有利于提高芳纶短纤维的分散性,添加质量分数为0.007 5 PNaAA的复合材料拉伸性能最好;随着芳纶短纤维用量的增大,复合材料的拉伸性能先提高后降低;芳纶短纤维用量为2份时,复合材料的拉伸性能总体最好,芳纶短纤维补强效果最佳。     

纤维素短纤维复合胶料的性能研究

本文研究了纤维素短纤维的用量、取向对复合胶料物理机械性能、耐磨性、压缩生热性的影响以及纤维素短纤维对胶料混炼特性的影响。结果表明，随短纤维用量增大，混炼过程中最大功率和排胶温度提高，胶料的门尼粘度增大，流动性差，混炼特性变差；加入短纤维对提高胶料的综合物性有利；短纤维在胶料中沿不同方向取向后，胶料的物理机械性能出现了明显的各向异性现象。沿压延方向取向，胶料的耐磨性随短纤维用量增大而下降；而沿半径方向取向，胶料的耐磨性变化不大。短纤维用量和取向方向对胶料生热性影响不大。     

聚酯短纤维用量对SFRC性能的影响

研究聚酯短纤维用量对短纤维/橡胶复合材料(SFRC)混炼特性及物理性能的影响.试验结果表明,随着聚酯短纤维用量的增大,混炼过程中最大功率和排胶温度提高,胶料的门尼粘度增大,流动性变差;随聚酯短纤维用量增大,SFRC的邵尔A型硬度、拉伸强度和撕裂强度先增大后减小,300%定伸应力明显提高,拉断伸长率下降;聚酯短纤维用量为5份时SFRC综合物理性能较好.     

聚酯短纤维用量对其增强胎面胶性能影响的实验研究

研究了预处理聚酯短纤维用量、取向对其增强胎面胶混炼特性及物理机械性能的影响.结果表明,随着短纤维用量的增加,混炼过程中的最大功率、单位能耗和排胶温度均提高,炭黑分散度降低,胶料的门尼粘度增大,流动性变差;加入适量的短纤维有利于提高胶料的物理机械性能;短纤维在胶料中沿不同方向取向后,胶料的物理机械性能出现了明显的各向异性现象.     

含短纤维胎面胶的混炼工艺

介绍了含短纤维胎面胶的混炼工艺,分析了在混炼过程中短纤维在橡胶中的混合分散模型.指出当短纤维-橡胶复合材料处于最佳黏度状态时,混炼效果最佳.     

芳纶短纤维增强天然橡胶复合材料性能研究

分析芳纶短纤维添加量对天然橡胶/纤维复合材料的性能影响。结果表明,在相同混炼工艺条件下,随着芳纶短纤维添加量的增多,橡胶/纤维复合材料的性能先提高再下降;添加2份芳纶短纤维时,其力学性能最好,磨耗性能也达到最佳;添加芳纶短纤维会降低胶料的导热性;添加芳纶短纤维提高了使用橡胶/纤维复合材料胎面的抗湿滑性能和滚动阻力。     

含短纤维胎面胶混炼过程的探讨

在胎面胶中加入短纤维可使轮胎滚动阻力和抗湿滑性明显降低,特别是胎面抗撕裂性、抗崩花掉块性提高,轮胎质量轻化,行使噪声降低,但短纤维在胶料混炼过程中难以分散,从而影响混炼胶的质量.介绍了为提高含短纤维胎面胶的混炼质量,加速短纤维在轮胎中的推广应用而采取的原材料、混炼设备和混炼工艺.     

对含短纤维胎面胶混炼过程的探讨

胎面胶中加入短纤维可使轮胎的滚动阻力和抗湿滑性明显降低,特别是使胎面抗撕裂性、抗崩花掉块性提高,可使轮胎质量轻化、行使噪音降低,但是短纤维在胶料混炼过程中难以分散,从而影响混炼胶的质量。该文介绍了为提高含短纤维胎面胶的混炼质量、加速短纤维在轮胎中的推广应用而采取的原材料、混炼设备和混炼工艺。     

聚酯短纤维在胶料中的定向处理及应用

对聚酯短纤维在胶料中的定向混炼压延方法——单向差速压搓工艺进行了探讨和应用；对聚酯短纤维在不同制品中用量的选取提供了选择范围。     

采用新型变间隙转子混炼短纤维/橡胶复合材料

分析短纤维/橡胶复合材料的混炼机理,针对短纤维胶料混炼特点设计新型变间隙六棱同步转子。转子棱峰与密炼室内壁间隙影响短纤维在胶料中的混合和分散以及混炼胶中短纤维的长度。新型六棱同步转子采用变间隙设计,大间隙有助于短纤维的混合,小间隙有助于短纤维的分散。采用新型六棱同步转子可改善短纤维/橡胶复合材料的混炼质量和性能,并能够提高生产效率。     

Electrical conductivity of poly(vinyl chloride) plastisol–short carbon fiber composite

In this work, short carbon fibers were blended with poly(vinyl chloride) (PVC) plastisol forming a conductive network of the fibers in the composite. The effects of concentration and initial length of the carbon fibers on the conductivity of the network were studied. For an initial fiber length of 3 mm (L/D = 428), the volume resistivity of the network decreased rapidly from 4.3 × 10⁵ to 5.1 × 10⁰ Ω-m for a change in the fiber concentration of 0.5 to 1.0 phr. The samples prepared by the plastisol method also showed excellent antistatic properties at very low fiber concentration (e.g. 1.0 phr), better than the samples that were prepared by mill mixing. Observation of the morphology showed that the short carbon fibers maintained their initial length in the PVC plastisol-carbon fiber composite, without obvious breakage. This is why a conductive network in the plastisol-carbon fiber composite can be formed at very low fiber concentrations.     

Mechanical properties of short sisal fiber‐reinforced polypropylene composites: Comparison of experimental data with theoretical predictions

Sisal fibers were used for the reinforcement of a polypropylene (pp) matrix. Composites consisting of polypropylene reinforced with short sisal fibers were prepared by melt‐mixing and solution‐mixing methods. A large amount of fiber breakage was observed during melt mixing. The fiber breakage analysis during composite preparation by melt mixing was carried out using optical microscopy. A polynomial equation was used to model the fiber‐length distribution during melt mixing. The experimental mechanical properties of sisal/PP composites were compared with existing theoretical models such as the modified rule of mixtures, parallel and series models, the Hirsch model, and the Bowyer–Baders model. The dependence of the tensile strength on the angle of measurement with respect to fiber orientation also was modeled. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 602–611, 2003     

Mechanical dispersion of crosslinked polymers reinforced with randomly distributed short fiber

The dynamic viscoelastic properties of composites reinforced with randomly distributed short glass and carbon fibers were studied in relation to the dependence on the fiber length, the mixing ratio of glass fibers of different length, and the kind of polymer matrix. Although the composite reinforced with glass fiber of 0.05 mm in length shows only one dispersion (α) corresponding to the primary transition of polymer matrix, those reinforced with 3- and 10-mm glass fibers, and those reinforced with the mixture of 10- and 0.05-mm glass fibers are characterized by two additional dispersions (α′ and α″) which appear on the lower frequency side or higher temperature side of the α-dispersion. The composite reinforced with 3-mm carbon fiber does not show the additional dispersions. The α′- and α″-dispersions appear irrespective of the kind of matrix polymer.     

Melt rheological behavior of starch‐based matrix composites reinforced with short sisal fibers

A systematic analysis of the melt rheological behavior of a commercial starch‐based (MaterBi®) matrix composite reinforced with short sisal fibers is presented. The effects of shear rate, temperature, fiber content and treatment were analyzed by parallel‐plate rheometry, and classical non‐Newtonian models were applied to analyze the pseudoplasticity behavior of the molten composite systems. It is reported that shear rate is the most influential processing condition, while, from the point of view of the material structure, the intercalation effectiveness of the matrix in the fibers is directly linked to the rheological behavior. In fact, processing techniques with high stresses and more efficient mechanical mixing promote the opening of fiber bundles, increasing the aspect ratio of the fibers and the average viscosity of the molten composite. A similar effect on the increase of the aspect ratio and composite viscosity is observed when treated fibers are used. Polym. Eng. Sci. 44:1907–1914, 2004. © 2004 Society of Plastics Engineers.     

Whiskers and short fiber technology

This paper presents the technology of whiskers and short fibers for use in polymer substances. It starts with a definition and examples of what a whisker is and how it differs from other short fibers such as micro fibers, mineral fibers, chopped fibers, and milled fibers. Then this paper discusses the problems in working with whiskers and short fibers and gives solutions to these problems. Next, various ways of improving the efficiency of short fiber reinforcements is given. This is done by reviewing details of the theory of short fiber reinforcements and how the use of packing theory helps in making a better short fiber composite. Finally, suggestions are given for designing an idealized molding compound using whiskers and short fibers in harmony with good packing theories.     

Structurally different short aramid fiber–reinforced thermoplastic polyurethane

The reinforcing effect of two structurally different Aramid short fibers, Technora and Twaron on the mechanical, dynamic mechanical, and thermal properties of an ester‐based thermoplastic polyurethane (TPU) was investigated. A fixed fiber length of 6 mm is used by varying the fiber loading ranging from 3 to 10 phr. The Young's modulus and the low strain modulus of Technora–TPU composite was found three times higher than that of Twaron–TPU composite at all ranges of fiber loading. Optical microscopic analysis revealed that a severe processing‐induced fiber breakage of Twaron is the primary reason behind the inferior properties shown by these fiber‐reinforced TPU composite. A brittle kind of failure has been observed during tensile testing in both the composite at a fiber loading of 10 phr. To solve this problem, an economic pretreatment with maleic anhydride‐grafted polybutadine (PB‐g‐MA) has been applied on the Aramid fiber surface before mixing it with the TPU matrix. A good quality of fiber dispersion with significant improvement in mechanical properties could be achieved with the addition of only 5 phr of PB‐g‐MA. Morphological analyses on the tensile‐fractured and cryogenically fractured surfaces of these composites offer strong evidences for the dispersing and coupling action of PB‐g‐MA with these Aramid fibers and the TPU matrix. POLYM. COMPOS., 35:1767–1778, 2014. © 2013 Society of Plastics Engineers     

短纤维-橡胶复合材料的开发及应用

短纤维-橡胶复合材料(简称SFRC)的应用研究始于20世纪70年代。目前,短纤维的应用范围已经覆盖了几乎所有的橡胶制品,包括轮胎、胶管、胶带、胶鞋、密封件以及坦克履带挂胶等。最近几年,短纤维在轮胎中的应用研究尤为活跃,已经应用到各种不同类型的轮胎,笔者主要论述短纤维补强橡胶的性能及其在轮胎中的应用。     

Temperature dependence of impact fracture energies of short glass fiber–epoxy and unsaturated polyester composites

The temperature dependence of the impact fracture energies of composites reinforced with random-planar orientation of short fibers was studied theoretically and experimentally. The theoretical values of the impact fracture energy of these composites is described by the sum of the fracture energy of the matrix and the fibers and the energy necessary to pull out the fibers on the crack surface, taking into consideration the temperature dependence of the critical fiber length and the breaking probability of fibers. The impact fracture energies were studied experimentally for epoxy and unsaturated polyester resins reinforced with random-planar orientation of short glass fibers. The theoretical values of the impact fracture energy were in good agreement with the experimental values. It was found that in any composite, the impact fracture energy of the fibers in a composite mainly contributes to the impact fracture energy of the composite at room temperature. At higher temperatures, fiber pull-out energy is more significant.