Xem 1-12 trên 12 kết quả Photopolymer
  • Photopolyme là một loại nhựa mà khi tiếp xúc với ánh sáng (thường thuộc vùng tử ngoại) thì đặc tính của nó sẽ thay đổi. Photopolyme thường mềm và rất nhạy sáng. Tổng hợp photopolyme Photopolyme là những hợp chất polyamit mà trong thành phần có nhóm (-CO-NH-).Photopolyme được ứng dụng rất phổ biến trong các ngành công nghệ cao như: Tạo ảnh quang, bản mạch in, quang khắc, thiết bị hiển thị, bộ nhớ quang, phép chụp ảnh laze, muối bicromat gelatin, tạo màng quang…...

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  • A photopolymer is a polymer that changes its properties when exposed to light, often in the ultraviolet frequency of the electromagnetic spectrum.Be bonds that link one polymer chain to another. Can be formed by chemical reactions that are initiated by radiation. Change physical properties of photopolymers.

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  • Cuốn sách "Polyme chức năng và vật liệu lai cấu trúc nano" được chia thành hai phần. Phần 1 giới thiệu đến bạn đọc nội dung tương ứng phần I trong sách về polyme chức năng (functional polymers). Phần này bao gồm 6 chương, với các nội dung chính như: Photo polyme, photopolyme hệ tạo ảnh khuyếch đại hóa học, polyme dẫn điện thuần, polyme hydrogel thông minh ((intelligent hydrogels polymers), polyme cấu trúc nano, polyme nanocomposit.

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  • This book comprises the contributions of several authors in the area of polymer physics by application of conducting polymers; hydrogel films on optical fiber core; thin film polymers; PDLC films application; photopolymers for holographic media; microwave absorption and EMI shielding behavior of nanocomposites based on intrinsically conducting polymers and graphene and carbon nanotubes; in the area of polymer synthesis of conducting polymers; oxidative polymerization of aniline; electro reductive polymerization; polysilanes with ordered sequences; radiation cross-linking poly(urethan...

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  • Biomedical Engineering is an exciting and emerging interdisciplinary field that combines engineering with life sciences. The relevance of this area can be perceived in our everyday lives every time we go to hospital, receive medical treatment or even when we buy health products such as an automatic blood pressure monitor device. Over the past years we have experienced a great technological development in health care and this is due to the joint work of engineers, mathematicians, physicians, computer scientists and many other professionals....

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  • In all different areas in biomedical engineering, the ultimate objectives in research and education are to improve the quality life, reduce the impact of disease on the everyday life of individuals, and provide an appropriate infrastructure to promote and enhance the interaction of biomedical engineering researchers. This book is prepared in two volumes to introduce recent advances in different areas of biomedical engineering such as biomaterials, cellular engineering, biomedical devices, nanotechnology, and biomechanics.

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  • Computerized Optical Processes For almost 30 years, the silver halide emulsion has been first choice as the recording medium for holography, speckle interferometry, speckle photography, moir´ and optical e filtering. Materials such as photoresist, photopolymers and thermoplastic film have also been in use. There are two main reasons for this success. In processes where diffraction is involved (as in holographic reconstruction), a transparency is needed. The other advantage of film is its superior resolution.

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  • The stereolithographic (SL) process is performed on the equipment shown in Figure 1. The movable platform on which the 3D model is formed is initially immersed in a vat of liquid photopolymer resin to a level just below its surface so that a thin layer of the resin covers it. The SL equipment is located in a sealed chamber to prevent the escape of fumes from the resin vat. The resin changes from a liquid to a solid when exposed to the ultra- violet (UV) light from a low-power, highly focused laser.

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  • The photomask is then moved to the exposure station, where it is aligned over a work platform and under a collimated UV lamp. Model building begins when the work platform is moved to the right to a resin application station where a thin layer of photopolymer resin is applied to the top surface of the work platform and wiped to the desired thickness. The platform is then moved left to the exposure station, where the UV lamp is then turned on and a shutter is opened for a few seconds to expose the resin layer to the mask pattern. Because the UV light is so intense, the layer...

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  • Most of the RP technologies are additive; that is, the model is made automatically by building up contoured laminations sequentially from materials such as photopolymers, extruded or beaded plastic, and even paper until they reach the desired height. These processes can be used to form internal cavities, overhangs, and complex convoluted geometries as well as simple planar or curved shapes.

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  • In the additive RP processes, photopolymer systems are based on suc- cessively depositing thin layers of a liquid resin, which are then solidi- fied by exposure to a specific wavelengths of light. Thermoplastic sys- tems are based on procedures for successively melting and fusing solid filaments or beads of wax or plastic in layers, which harden in the air to form the finished object. Some systems form layers by applying adhe- sives or binders to materials such as paper, plastic powder, or coated ceramic beads to bond them.

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  • Because the photopolymer used in the SL process tends to curl or sag as it cures, models with overhangs or unsupported horizontal sections must be reinforced with supporting structures: walls, gussets, or columns. Without support, parts of the model can sag or break off before the polymer has fully set. Provision for forming these supports is included in the digitized fabrication data. Each scan of the laser forms support layers where necessary while forming the layers of the model.

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