Yarn on yarn abrasion performance of high modulus polyethylene fiber improved by graphene/polyurethane composites coating

As a high-performance fiber, high modulus polyethylene fiber (HMPE) has been widely used in the rope industry. However, due to its low melting point and poor thermal conductivity, it tends to break under the conditions of repeated yarn on yarn abrasion during tension-tension fatigue or tension-bending fatigue. This paper puts forward a method to improve the yarn on yarn abrasion performance of HMPE using a functional graphene/polyurethane composites coating (FG/PU) and discussed the influence of yarn tension, abrasion frequency on the yarn on yarn performance. Based on the yarn morphology and abrasion temperature observation, the failure mechanism was discussed. The experimental results show that the FG/PU coating obtained can improve the yarn on yarn abrasion performance obviously, especially in the case of high-frequency and large tension condition.

Tribological and Mechanical Properties of UHMWPE Polymer Composite filled with TiO2 and Al2O3 Particles used as TKR Implant

This study focused on the development of a polyethylene biomaterial for replacement of the joints like knee joints, etc. Through forming aluminum oxide and titanium oxide particles into ultra-high molecular polyethylene, commonly known as high modulus polyethylene, this substance has strengthened its mechanical and wear properties. The composite is made using the injection molding machine by reinforcement materials like bio-inert aluminum oxide (Al2O3 ) and titanium di oxide (TiO2 ) with UHMWPE. Mechanical properties like Tensile, Bending, impact strength and hardness and wear rate of the synthesized polymer composite is tested according to ASTM standards.C3 composite shows enhancement in mechanical and tribological properties, only decrease in the impact strength is seen comparing to other two compositions. So C3 composite can be used as implant

Thermal properties of polypropylene and high modulus polyethylene fibers reinforced concretes

Concrete is one of the materials most used by the construction industry. Reinforcing this material with fibers is a technique used to improve its mechanical properties. Steel and polymer fibers are the main types used in this application and there are few studies about the influence of polymer fibers on the thermal properties of concrete. In order to analyze this influence, the present work carried out thermal conductivity, thermal expansion, and compressive strength after exposure to a temperature of 200 °C on specimens made of concrete with addition of polypropylene (PP) fibers and concrete with addition of high modulus polyethylene (HMPE). It was also conducted thermogravimetric analysis (TGA) on PP and HMPE fibers. The results show that the addition of polymer fibers alters the thermal properties of the concrete, reducing its thermal expansion, for example.

Review Production Technology of Ultra High Modulus Polyethylene

The review of existing technologies of production and processing of ultra-high molecular weight polyethylene, as well as areas of its application, is presented. Ultra high modulus polyethylene has high performance characteristics – wear resistance, low friction coefficient, high corrosion and chemical resistance and high fracture toughness. These unique properties of ultra high modulus polyethylene distinguish it from other varieties of polyethylene.

Lifetime prediction of high-modulus polyethylene yarns subjected to creep using the Larson–Miller methodology

The aim of the present work is to apply the Larson–Miller technique for the study of the mechanical behavior under creep of high-modulus polyethylene (HMPE) fibers focused on use as in offshore mooring ropes. Creep is known to be a long-term phenomenon, so in most cases, reproducing such experiments in real time is not feasible, and as the life span of anchoring systems must be in the order of decades, accelerated tests are required to verify the long-term mechanical behavior of the material. The methodology using the Larson–Miller parameter is a well-documented and powerful technique for materials’ lifetime prediction, although seldom applied to polymeric materials. It involves in performing accelerated (high temperature and/or loads) creep tests to determine the parameters that are later used to estimate the rupture time of the material under constant load. It is concluded that the Larson–Miller technique is efficient for calculating the lifetime of HMPE subjected to creep.

Dynamic Modeling of Ship-to-Ship and Ship-to-Pier Mooring Performance

Traditional methods for the design of ship-to-pier moorings in normal and storm conditions and for ship-to-ship moorings under normal conditions are currently based on static calculations. These calculations have served well for many years, first with natural fiber ropes and later with nylon and other low- to medium-modulus synthetics. Key to the success of this simplistic approach is lines that can elongate enough under tension to share the loads between multiple lines. When wire rope mooring lines are introduced, an increased weight catenary and the use of constant tension winches allowed enough compliance for the moorings to load share successfully.Now, we have very lightweight, high-modulus synthetic lines like High Modulus Polyethylene (HMPE), Aramid, and Liquid Crystal Polymer (LCP), where there is almost no stretch and very little weight to form a weight catenary. When used with constant tension winches that allow the mooring load to be shared across multiple lines, these can work well. However, when they are used from bollard to chock to bit with no compliance, they are unable to share the load between multiple lines, and high tension failures occur where a weaker but more compliant mooring line would be fine.This article describes advanced dynamic modeling of ships loaded by wind, waves, and currents in these conditions and the tension sharing between mooring lines of different materials and constructions. The need to share the mooring load between multiple lines is the crux of the issue.