Dynamic reaction inside co‐rotating twin screw extruder. I. Truck tire model material/polypropylene blends

Lee, Sung Hyo,Balasubramanian, Maridass,Kim, Jin Kuk Wiley Subscription Services, Inc., A Wiley Company 2007 Journal of applied polymer science Vol.106 No.5

<P><B>Abstract</B></P><P>Waste ground rubber tire (WGRT) is a complex composite containing various elastomers, carbon black, zinc oxide, stearic acid, processing oils, and other curatives. Most of the waste ground rubber tire is composed of mainly natural rubber (NR) and styrene butadiene rubber (SBR) in varying proportions. Blending it with other thermoplastic materials is difficult due to the inherent thermodynamic incompatibility. But, the compatibility can be increased by making the reactive sites in WGRT with suitable chemicals under optimum condition of shearing inside a twin screw extruder and it is said to undergo a dynamic reaction inside the extruder. To understand the mechanism of dynamic reaction process of a rubber/polyolefin blend, the blending of a truck tire model material rubber with polyolefin was first tried before it was applied to waste WGRT material. It was observed that the blends of a truck tire model rubber material and PP thermoplastic are physical mixture of two incompatible polymers in which a continuous plastic phase is largely responsible for the tensile properties. The rubber particles are the dispersed phase. The large particle size and the poor adhesion of these rubber particles are believed to be liable for the poor tensile properties. In case of blends of truck tire model material with isotactic polypropylene the tensile properties are found to be lower than that of its PP‐<I>g</I>‐MA counterpart which can be attributed to the reaction of the MA with the carbon black particles. A schematic representation of the possible interactions has been proposed. The effect of addition of compatibilizers such as SEBS and SEBS‐<I>g</I>‐MA has also been studied. The tensile and TGA studies indicate that the polarity of SEBS and SEBS‐<I>g</I>‐MA induces an increase in the performance characteristics for both types of polyolefins but the intensity of this increase is higher in the PP‐<I>g</I>‐MA based blends. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 106: 3193–3208, 2007</P>

고무 성형 공정에서 금형 형상에 따른 고무 흐름의 컴퓨터 모사

이단비 ( Dan Bi Lee ),이민아 ( Min A Lee ),최성현 ( Sung Hyun Choi ),류민영 ( Min Young Lyu ) 한국고무학회 2014 엘라스토머 및 콤포지트 Vol.49 No.3

자동차 타이어의 트레드는 노면과 직접적으로 접촉하며 제동력, 구동력, 소음 등 중요한 역할을 한다. 트레드는 많은 그루브로 이루어져 있는데 고무의 형상을 형성하는 가류 공정에서 불량이 발생하게 되면 트레드의 기능이 저하되어 자동차 성능의 문제로 이어지게 된다. 본 논문은 CAE 해석을 통하여 가류 공정 중 구체적인 고무의 흐름을 분석하였다. 트레드 형상에 따라 고무 흐름의 편차가 발생하기 때문에 형상에 따른 트레드의 고무가 금형에 접촉되는 순서와 속도 그리고 고무의 흐름을 관찰하였다. 트레드의 형상에 따라서 고무가 금형에 안착되는 양상이 다르게 나타났으며 고무의 흐름에 큰 변화를 주는 것을 확인할 수 있었다. The tire tread is contacted with road surface directly. It gives significant effect on the breaking conditions, traction, noise and so on. The tread having grooves with complex geometry is molded by shaping process. The flow behavior of tread rubber in a mold affects the quality of the tread and it leads to the running performance of automobile. In this study, the flow behavior of rubber in shaping process has been investigated by computer simulation. The objective of flow simulation is the design of tread shape based on the contact of rubber on the mold surface and flow behavior of rubber. Different sequences of contact of rubber on the mold surface and flow behavior of rubber are observed according to the shape of tread on the mold surface. It was verified that the shape of tread gives significant effect on the flow behavior of rubber. Different flow behaviors of rubber and sequential contact of rubber to the mold surface were observed according to the shape of tread on the mold surface. Therefore, we have identified that the shape of tread give a change in the flow behavior of rubber.

A Study of Silica Reinforced Rubber Composites with Eco-Friendly Processing Aids for Pneumatic Tires

이동주,송성호 한국고분자학회 2019 Macromolecular Research Vol.27 No.9

The conventional carbon black filler, used in tread formulations, is being replaced with silica with the development of “green tires” in the tire industry. For this, the addition of a processing aid containing zinc ion was required as a dispersing agent and lubricant. However, zink being a heavy metal, zinc-free processing aids (ZFAs) are needed to satisfy global environmental issues. Therefore, this study presented a series of catalytically synthesized ZFAs and studied the effects of replacing zinc-containing processing aids (ZCAs) in a silica tread compounds. Interestingly, the rubber composite replacing ZCAs with ZFAs in 2 phr (parts per hundred rubber) improved both its tensile strength and elongation by as much as 31% and 20%, respectively. In addition, the rubber compounds with ZFAs exhibited a two-fold enhancement in fatigue properties over those with ZCAs. Furthermore, pneumatic tires were fabricated from the rubber compounds containing ZFAs and compared against tires with ZCAs. The tires containing ZFAs rubber composite showed enhanced dry and wet braking and rolling resistance due to enhanced dispersion of silica in the rubber matrix. These results show that rubber composites prepared with ZFAs may be promising in tire engineering applications.

Geotechnical properties of tire-sand mixtures as backfill material for buried pipe installations

Terzi, Niyazi U.,Erenson, C.,Selcuk, Murat E. Techno-Press 2015 Geomechanics & engineering Vol.9 No.4

Millions of scrap tires are discarded annually in Turkey. The bulk of which are currently landfilled or stockpiled. These tires consume valuable landfill space or if improperly disposed, create a fire hazard and provide a prolific breeding ground for rats and mosquitoes. Used tires pose both a serious public and environmental health problem which means that economically feasible alternatives for scrap tire disposal must be found. Some of the current uses of scrap tires are tire-derived fuel, creating barrier reefs and as an asphalt additive in the form of crumb rubber. However, there is a much need for the development of additional uses for scrap tires. One development the creation of shreds from scrap tires that are coarse grained, free draining and have a low compacted density thus offering significant advantages for use as lightweight subgrade fill and backfill material. This paper reports a comprehensive laboratory study that was performed to evaluate the use of a shredded tire-sand mixture as a backfill material in trench conditions. A steel frame test tank with glass walls was created to replicate a classical trench section in field conditions. The results of the test demonstrated that shredded tires mixed with sand have a definite potential to be effectively used as backfill material for buried pipe installations.

Experimental Investigation on Mechanical characteristics and Environmental Effects on Rubber Concrete

Morteza Khorrami,AbolhassanVafai,Ahmad A. khalilitabas,Chandrakant S. Desai,M.H. Majedi Ardakani 한국콘크리트학회 2010 International Journal of Concrete Structures and M Vol.4 No.1

The feasibility of the use of scrap tire rubber in concrete was investigated. The tests conducted in two groups: replacing of coarse aggregates with crumb rubber and cement particles with rubber powder. To distinguish the properties of new concrete,the following mechanical and durability tests were designed: compressive, tensile and flexural strength, permeability and water absorption. Rubber addition could affect the concrete properties depend on the type and percentage of the rubber added. Although the rubber addition modifies the mechanical characteristics of concrete in a way, but higher rubber content could not be useful. Concrete durability showed more dependency to the type of rubber instead of percentage of rubber. Moreover, to optimize the mechanical and durability of rubberized concrete, the useful percentage of rubber has been recommended.

Experimental Lnvestigation on Mechanical Characteristics and Environmental Effects on Rubber Concrete

Morteza Khorrami,AbolhassanVafai,Ahmad A. Khalilitabas,Chandrakant S. Desai,M. H. Majedi Ardakani 한국콘크리트학회 2010 International Journal of Concrete Structures and M Vol.4 No.1

The feasibility of the use of scrap tire rubber in concrete was investigated. The tests conducted in two groups: replacing of coarse aggregates with crumb rubber and cement particles with rubber powder. To distinguish the properties of new concrete, the following mechanical and durability tests were designed: compressive, tensile and flexural strength, permeability and water absorption. Rubber addition could affect the concrete properties depend on the type and percentage of the rubber added. Although the rubber addition modifies the mechanical characteristics of concrete in a way, but higher rubber content could not be useful. Concrete durability showed more dependency to the type of rubber instead of percentage of rubber. Moreover, to optimize the mechanical and durability of rubberized concrete, the useful percentage of rubber has been recommended.

Experimental Lnvestigation on Mechanical Characteristics and Environmental Effects on Rubber Concrete

Khorrami, Morteza,Vafai, Abolhassan,Khalilitabas, Ahmad A.,Desai, Chandrakant S.,Ardakani, M. H. Majedi Korea Concrete Institute 2010 International Journal of Concrete Structures and M Vol.4 No.1

The feasibility of the use of scrap tire rubber in concrete was investigated. The tests conducted in two groups: replacing of coarse aggregates with crumb rubber and cement particles with rubber powder. To distinguish the properties of new concrete, the following mechanical and durability tests were designed: compressive, tensile and flexural strength, permeability and water absorption. Rubber addition could affect the concrete properties depend on the type and percentage of the rubber added. Although the rubber addition modifies the mechanical characteristics of concrete in a way, but higher rubber content could not be useful. Concrete durability showed more dependency to the type of rubber instead of percentage of rubber. Moreover, to optimize the mechanical and durability of rubberized concrete, the useful percentage of rubber has been recommended.

Effect of Wollastonite Microfibers and Waste Tire Rubber on Mechanical Properties of Concrete

Sina Lotfollahi,Alireza Jaidari,Parham Bakhtiari,Mojtaba Hosseini,Mohammad Ghorbani Heidari 한국콘크리트학회 2023 International Journal of Concrete Structures and M Vol.17 No.5

The main objective of the present research is to investigate the effect of adding wollastonite microfibers and waste tire rubber on the mechanical properties of concrete. For this purpose, two different series of mixtures were considered. Different percentages (5, 10, 15, and 20 percent) of wollastonite microfibers were added to the ordinary concrete and tested in the first series. Then, in the second series, wollastonite microfibers were added to the specimens in the amount of 20% by the weight of cement, and waste tire rubber was replaced with fine aggregate in different percentages (3, 5, 7, and 10 percent by the weight of fine aggregate), and the specimens were tested again. All the specimens were cured at the two ages of 7 and 28 days, and they were tested for the slump, compressive strength, tensile strength, and flexural strength. The results showed that the addition of 20% wollastonite microfibers to the specimens increased the compressive, flexural, and tensile strengths of the concrete at 28 days of age by 16, 87, and 78%, respectively, compared to the control specimen. The outcomes also demonstrated that replacing fine aggregate with tire rubber in samples containing 20% wollastonite microfibers reduces the strength of the samples. The highest reduction is related to the sample containing 20% of waste tire rubber, which has a reduced compressive strength of about 20% compared to the control sample. Furthermore, the results of this research showed that adding wollastonite microfibers to concrete reduces the concrete slump, while the density of the samples increases with the addition of wollastonite. Moreover, the presence of wollastonite microfibers reduces the porosity of concrete, but there is an increase in the number of pores in concrete samples containing waste tire rubber.

고무차륜형 경전철 고가구조물의 충격계수 계측시험연구

신정열(Jeong-Ryol Shin),이안호(An-Ho Lee),박재임(Jae-im Park),신인조(In-jo Shin) 한국철도학회 2013 한국철도학회 학술발표대회논문집 Vol.2013 No.11

국내 철도설계기준에는 고속철도, 일반철도, 전동차등 철제차륜형 열차에 대한 설계기준만 마련되어 있을 뿐, 고무차륜형 열차에 대한 설계기준은 별도 마련되어 있지 않다. 이러한 관계로, 고무차륜형 경전철 고가구조물은 설계당시 일반 전동차용 철도교 설계기준과 국외 경전철 차량제작사에서 제시한 설계기준을 참조하여 설계되었고, 이로 인해 경전철 고가구조물임에도 일반 철도교 수준으로 육중하게 비경제적으로 건설되었다. 특히, 국내 운영 중인 고무차륜형 경전철 고가구조물은 설계 당시 도로교 설계기준에서 제시된 충격계수 기준을 그대로 적용하여 설계되었다. 이에, 본 연구에서는 경전철 고가구조물의 합리적인 설계기준 마련을 위한 일환으로, 고무차륜형 경전철의 열차 정·동적 주행시 고가 상부구조물의 응력 및 처짐 측정 등 충격계수 계측시험을 수행하였고, 현재 철도설계 기준에서 제시하고 있는 충격계수와 계측시험결과를 비교·분석하였다. Unlike the steel-wheeled rail transit of conventional railway including high-speed railway, the design guideline of elevated structures for rubber-tired rail transit has not been established in Korea. For this reason, the elevated structures of rubber-tired light rail transit have been designed and constructed based on the design code of conventional heavy railway bridges or on the one suggested by foreign rolling-stock manufacturer. This is why the elevated structures of rubber-tired rail transit in Korea are much massive, or over-designed and non-economically constructed. In Korea, design engineers have no way but to refer to the standard of roadway for considering the dynamic effect of rubber-tired light rail transit. Therefore, in this paper, as the basic study on the design guideline of elevated structures for rubber-tired light rail transit, authors carried out the field test to analyze the dynamic factor of elevated structures, which induced by the driving train at the speed of 5km/hr, 10km/hr to 70km/hr. Authors also briefly demonstrate the test and analyzing results of dynamic factor acting on the superstructures of elevated light-rail structures.

타이어에서 채취한 고무배합물의 기계적 물성 측정

김용우,김종국 한국공작기계학회 2002 한국공작기계학회 춘계학술대회논문집 Vol.2002 No.-

Pneumatic tires usually contain a variety of rubber compositions, each designed to contribute some particular factor to overall performance. Rubber compounds designed for a specific function will usually be similar but not identical in composition and properties. Since 1970's finite element analysis of tire has been performed extensively, which requires some energy density functions of rubber components of a tire. The conventional Mooney-Rivlin material model is one of the description that is commonly used in the analysis of tire. In this paper, we report the two material constants of Mooney-Rivlin material model for some rubber compounds of a real pneumatic tire, which are obtained through uniaxial tension test.