Papers by Keyword: Thermoplastic Resin

Abstract: Adaptive feed-rate controlled (AFC) drilling has been proposed as a high-quality and highly efficient drilling method for thermoplastic resins. The feed rate of the drill tool is controlled by the load in the thrust direction during AFC drilling. In the early stages of AFC drilling, the drill feed rate is extremely low, followed by a sudden increase in the drill feed rate. Experimental investigations revealed that the temperature near the drilling point had a dominant effect on the position at which the drill feed rate transitioned from low to high. The feed-rate transition temperature was approximately 150 °C for PA6. Therefore, the feed-rate transition position accelerated as the spindle speed increased, which significantly affected the cutting temperature. After the feed rate transitioned to a higher speed, drilling progressed at a constant rate. Additionally, the temperature of the drilled hole was generally constant regardless of the hole depth. One of the applications in which AFC drilling is expected to be superior is the drilling of different stacked materials. The effectiveness of AFC drilling was examined and compared with general constant-feed drilling for a stacked material of PA6 and carbon-fiber-reinforced thermoplastics. When the drilling efficiency was aligned, the maximum thrust force during AFC drilling was suppressed to less than 50% of that during general constant-feed drilling. Furthermore, the finished inner surface of the drilled hole was better after AFC drilling.

Abstract: Polymer-based fiber composites have a number of unique physical and mechanical properties and are widely used in the design of structural elements in rocket and space engineering. However, along with the high characteristics of strength and rigidity, there is a noticeable anisotropy of properties which contributes to occurrence and development of damage leading to degradation of the load bearing capacity of structures and their premature destruction. Along with development of micromechanical and phenomenological models, an important place has the procedure for identifying the basic characteristics of composite materials. Such characteristics, in particular, include those of layer elasticity which are usually used when designing structures. However, even such characteristics depend on the loading conditions and for their identification, computational methods based on statistical analysis should be used. This paper attempts to identify the elastic characteristics based on test results of unidirectional carbon plastic with AS4 carbon fibers and polyetheretherketone thermoplastic matrix. For identification, the least squares method was used for samples tested at off-axis angles of 0, 10, 30, 45, 60 and 90 ° and different values of strain rates.

Abstract: The results of in-plane shear tests performed on 5-hardness satin woven carbon/PPS thermoplastic prepregs are described. The experimental analyses are based on bias-extension tests performed in an environmental chamber. The results are given for different temperatures on both side of the melting point. This range of temperature is those of the part during a thermoforming process. In another hand it is shown that second-gradient energy terms allow for an effective prediction of the onset of internal shear boundary layers which are transition zones between two different shear deformation modes. The existence of these boundary layers cannot be described by a simple first-gradient model.

Abstract: The bending deformation of thermoplastic prepregs is one of the key deformation modes in the thermoforming due to its crucial role in the wrinkling occurrence. The influence of temperature is of main importance because the viscous effect of resin is temperature dependent and prepregs thermoforming is usually performed closed to resin’s melting point. The currently available bending test devices are not adapted for thermoplastic prepregs since these devices can only be operated at room temperature. To solve this problem, a new cantilever test with an optical measuring performed in an environmental chamber is proposed. The bending properties of PPS-carbon satin prepregs are measured at a series of high temperatures. It’s shown that the bending stiffness of the fore-mentioned pepregs is strongly affected by the temperature and shows a non-linear bending behaviour. The measured bending properties are used to simulate a thermoforming process. The influence of bending properties on the simulation results, especially to the wrinkling is presented as well.

Abstract: Recently, as the development of thermoplastic resin with excellent property and forming process of thermoplastic resin composite material, research of thermoplastic resin becomes a hot issue in related areas. Comparing with common composite material, thermoplastic resin composite material has many advantages, such as, excellent impacting resistance and many processes. So, more and more researchers focus in thermoplastic resin composite material. In this article, applications of carbon fiber strengthen thermoplastic resin composite materials are comprehensive.

Abstract: The FRP materials can be divided into FRTP( fiber reinforced thermoplastic plastic) and FRSP( fiber reinforced thermoset plastic) according to the resin materials. As a new kind of composite, FRTP attracts people. s attention for the characteristics of light weight, durability, no environmental pollution and reshaping. According to the characteristics of FRTP, we compare the impregnation and moldinging process of FRTP materials and the physical properties of FRTP and FRSP. We study the FRTP laminates products for civil engineering and its mechanical properties and the application situation at home and abroad. Some problem to be solved are also presented.

Abstract: The present investigation is concerned with the development of fibre reinforced thermoplastic composite rods using braiding process. An innovative technique has been developed to produce composite rods with outer braided layer of polyester fibres and axially reinforced with high performance glass fibres. Polypropylene filaments which were introduced in to the core along with the glass fibres during the braiding process formed the thermoplastic matrix upon melting. A special mould has been designed for uniform application of heat and pressure during the consolidation of the composite rods as well as for the alignment of core fibres. The cross-section of composite rods was characterized with help of optical microscopy in order to see the distribution of core fibres and matrix. The effect of amount of glass fibres on the mechanical properties (tensile and flexural) of composite rods has been investigated and discussed.

Abstract: A completely new diamond wheel, named the 3R wheel, has been developed. The 3R wheel has three unprecedented functions, reconfiguration, restoration and recyclability, and is molded from a mixture of special thermoplastic resin filler and diamond powder. The concept of the 3R wheel is to control the quantity and the position of abrasive material by actively using heat. In this study, tungsten carbide (WC) was ground using a thermoplastic resin bonded diamond wheels (radius 1.4 mm) with three different concentrations of 1500 grain size abrasive. As a result, a grinding ratio of over 200 and 18 nmRa roughness was achieved without dressing. In addition, a large quantity of abrasives was confirmed on the wheel surface by observation.