• Title, Summary, Keyword: Cure Cycle

Search Result 42, Processing Time 0.046 seconds

Cure Cycle for Thick Glass/Polyester Composites (두꺼운 유리섬유/폴리에스터 복합재료를 위한 경화 사이클)

  • 김형근;오제훈;이대길
    • Composites Research
    • /
    • v.14 no.2
    • /
    • pp.33-42
    • /
    • 2001
  • The cure kinetic equation fur 52-glass/polyester prepreg composites was established through DSC (differential scanning calorimetry). Using the established kinetic equation, the temperature distribution of the thick composite was calculated considering the change of heat transfer resistance due to resin impregnation of bleeder plies used. In order to reduce the overheat during cure of thick glass fiber composites, the cure cycle was modified by introducing the cooling and reheating steps. Then the thick glass composites were cured both by the conventional cycle without any cooling or reheating step and the modified cure cycle. The mechanical properties of the thick composites cured by the both cycles were tested by the short beam shear test and the Barcol hardness test, and then their results were compared.

  • PDF

Thermal Deformation of Carbon Fiber Reinforced Composite by Cure Shrinkage (탄소섬유강화 복합재료 성형시 화학수축에 의한 변형연구)

  • Choi, Eun-Seong;Kim, Wie-Dae
    • Composites Research
    • /
    • v.31 no.6
    • /
    • pp.404-411
    • /
    • 2018
  • As the autoclave process progresses in a given cure cycle, residual stress in the composite product is induced by cure shrinkage of the resin. As a result, It generates the thermal deformation such as spring-in and warpage, and the inaccuracy of the final product increases. It is important to predict thermal deformation in aerospace parts which require precise fabrication. The research has been done on predicting and grasping curing process of composite material. In this study, the cure mechanism of composite materials according to the process is predicted through finite element analysis, and the effect of cure shrinkage on thermal deformation generated by the process is analyzed.

Expert Cure System for the Carbon Fiber Epoxy Composite Materials (탄소섬유 에폭시 복합재료 제조의 전문가시스템 연구)

  • 최진호;이대길
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.18 no.7
    • /
    • pp.1773-1782
    • /
    • 1994
  • In this paper, the expert cure system for carbon fiber epoxy composite materials, which controls the temperature and pressure of the autoclave according to the several rules, was developed to manufacture better composite products in shorter curing time. The rules were based on the on-line measured quantities such as the dielectric properties and temperature of the composites and the pressure of the autoclave. The curing time and the mechanical properties of the composite materials manufactured with the expert cure system were compared to those of the specimens manufactured with the conventional cure cycle.

Investigation of cure cycle for co-cured metal/composite hybrid structures without fabricating thermal residual stress (동시경화 하이브리드 금속/복합재료 구조물의 제조 잔류 열응력 제거를 위한 경화사이클에 관한 연구)

  • Kim Hak Sung;Park Sang Wook;Lee Dai Gil
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • /
    • pp.83-87
    • /
    • 2004
  • In this work, the cure cycle of co-cured metal/composite structure was investigated to decrease fabricating thermal residual stresses between the metal and the composite material. DSC (Differential scanning calorimetry) experiment and static lap shear test of co-cured aluminum/composite double lap joint as well as the curvature experiment of co-cured steel/composite strip were performed to investigate the effect of curing cycle on the thermal residual stress of co-cured hybrid structures. From the experiments, it was found that post curing method after abrupt cooling of co-cured aluminum/composite hybrid structure at certain point of degree of cure during curing process could eliminate fabricating the thermal residual stresses.

  • PDF

Cure simulation and Consolidation for a Thick Glass/Epoxy Laminate (유리섬유/에폭시 후판 복합재료의 경화공정 및 압밀해석)

  • O, Je-Hun;Lee, Dae-Gil
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.24 no.11
    • /
    • pp.2853-2865
    • /
    • 2000
  • During the curing process of thick glass/epoxy laminates, a substantial amount of temperature lag and overshoot at the center of the laminates is usually experienced due to the large thickness and low thermal conductivity of the glass/epoxy composites. Also, it takes a longer time for full and uniform consolidation. In this work, temperature, degree of cure and consolidation of a 20 mm thick unidirectional glass/epoxy laminate were investigated using an experiment and a 3-dimentional numerical analysis. From the experimental and numerical results, it was found that the experimentally obtained temperature profile agreed well with the numerical one, and the cure cycle recommended by the prepreg manufacturer should be modified to prevent a temperature overshoot and to obtain full consolidation.

Cure Monitoring of Thick HSPE/Vinylester Composites with Dielectrometry (유전율 분석법에 의한 두꺼운 HSPE/Vinylester 복합재료의 경화 거동 관찰)

  • 이승구;김동철;주창환
    • Textile Science and Engineering
    • /
    • v.38 no.5
    • /
    • pp.214-221
    • /
    • 2001
  • HSPE/vinylester 50-ply laminates, thicker than 1 inch, were fabricated by compression molding. To investigate the consolidation procedure of thick HSPE/vinylester composites, a dielectrometric(DEM) cure monitoring with dielectric sensors the thermocouples was utilized. Behaviors of the ion viscosity(a reciprocal of ion conductivity) as a dielectric parameter was monitored and evaluated with the resin viscosity. minimum viscosity temperature and cure temperature were analyzed from the dynamic cure experiments. To obtain the proper compaction of composites, step cure process including an intermediate dwell step at 8$0^{\circ}C$ was set-up to coincide the viscosity window between inner and outer layers of the composite. From the result of DEM analysis, the optimum cure cycle for a thick HSPE/vinylester composite in compression molding was established. In addition, the effects of molding pressure on the properties of composites were evaluated.

  • PDF

Cure and Heat Transfer Analysis in LED Silicone Lens using a Dynamic Cure Kinetics Method (승온 반응속도식을 이용한 LED용 실리콘 렌즈의 경화 및 열전달해석)

  • Song, M.J.;Kim, K.H.;Hong, S.K.;Park, J.Y.;Lee, J.W.;Yoon, G. S.
    • Transactions of Materials Processing
    • /
    • v.24 no.2
    • /
    • pp.101-106
    • /
    • 2015
  • Recently, silicone is being used for LED chip lens due to its good thermal stability and optical transmittance. In order to predict residual stresses, which cause optical birefringence and mechanical warpage of silicone, a finite element analysis was conducted for the curing of silicone during molding. For the analysis of the curing process, a dynamic cure kinetics model was derived based on the results of a differential scanning calorimetry (DSC) testing and applied to the material properties for finite element analysis. Finite element simulation results showed that a step cure cycle reduced abrupt reaction heat and showed a decrease in the residual stresses.

Cure simulation for a thick glass/epoxy laminate (유리섬유 강화 후판 복합재료의 경화공정 해석)

  • 오제훈;이대길
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • /
    • pp.53-58
    • /
    • 2000
  • During the curing process of thick glass/epoxy laminates, a substantial amount of temperature lag and overshoot at the center of the laminates is usually experienced due to the large thickness and low thermal conductivity of the glass/epoxy composites. Also, it requires a longer time for full and uniform consolidation. In this work, temperature, degree of cure and consolidation of a 20mm thick unidirectional glass/epoxy laminate were investigated using an experiment and a 3-dimentional numerical analysis considering the exothermic reaction. From the experimental and numerical results, it was found that the experimentally obtained temperature profile agreed well with the numerical one and the cure cycle recommended by the prepreg manufacturer should be modified to prevent a temperature overshoot and to obtain full consolidation.

  • PDF

Dielectric Properties of Glass Fiber Reinforced Epoxy Composites by Cure under Pressure (가압 겔화법에 의한 에폭시 복합 재료의 유전적 특성)

  • 곽영순;신중홍;박정후
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.38 no.4
    • /
    • pp.292-297
    • /
    • 1989
  • To achieve fiber/resin reinforced composites with high quality (void-free, uniform compaction), a basic understanding of the principal factors related to a thermal cycle to cure the matrix and a pressure to compact the system is necessary. In this paper, some dielectric and mechanical properties of glass cloth reinforced epoxy composites are measured as a function of fabrication conditions, where the time that the pressure is applied to the sample during the cure process is controlled. Both the tensile strength and frequency characteristics of the sample are improved significantly when the pressure is applied at the start point of gelling.

  • PDF

Adenovirus vs AAV Vectors for Gene Delivery: Their Advantages and Disadvantages

  • Im Dong-Soo
    • Proceedings of the Microbiological Society of Korea Conference
    • /
    • /
    • pp.109-115
    • /
    • 2002
  • Gene therapy is to treat and cure diseases by an introduction of therapeutic genes in defective cells or tissues of human body. Gene delivery system, gene expression system, and therapeutic gene are three core elements for gene therapy. The efficient delivery of therapeutic genes and appropriate gene expression are the crucial issues for therapeutic outcome of gene delivery. Because it can be used in common for the treatment and cure of various diseases, gene delivery system is the most important core element for a successful gene therapy. Viruses are naturally evolved to transfer their genomes into host cells efficiently. This ability has made vectorologists exploit viruses as attractive vehicles for the delivery of therapeutic genes. Viral vectors based on adenovirus (Ad) and adeno-associated virus (AAV) have been often used for gene delivery in laboratory. Ad and AAV vectors derived from human DNA viruses differ greatly in their life cycle, expression level and duration of transgenes, immunogenicity, and vector preparation. Both vectors can be used as effective tools for gene therapy and more recently in functional genomics. Here, the characteristics of Ad and AAV vectors are discussed.

  • PDF