Xiu Ting Zheng

Investigation on Transmittance and Uniformity of Light Diffuser Plate of Scattering Optical Transmission Polymer

In this paper, the relations between scattering intensity and the radius of scattering particles, the refractive and the wavelength have been studied based on the MATLAB software, and the relations between the concentration of the particles, the radius and the refractive and the optical properties of diffuser have also been simulated by the Light Tools software based on the Monte-Carlo Method. The results show that with the increasing of radius and the wavelength, the distribution of scattering light energy gets concentrated. With the increasing of the particles, the transmittance decreases, and the uniformity increases first and decreases later. With the increasing of radius, the transmittance decreases. With the increasing of the index of refractive, the transmittance increases first and decreases later.

Effect of Aspect Ratio of Micro Sphere Lens Arrays on the Optical Property of Diffuser

The effect of the aspect ratio of micro sphere lens arrays on the optical properties of diffuser including transmittance and haze have been simulated by the LightTools software, and the results show that with the increasing of the aspect ratio, the haze rises first and drops later while the transmittance decreases all the time. Later, the mold with uniform micro sphere lens arrays arranged in regular triangle has been fabricated successfully by the ball embossing method. Then, the micro sphere lens arrays diffuser with aspect ratio of 0.19, 0.23, 0.26 and 0.29 have been made using the hot embossing method in polypropylene (PP) substrate. Last, haze and transmittance of the micro sphere lens arrays PP diffuser made are verified both by experiment and simulation and the results of experiment and simulation are consistent well.

The Research of the Extrusion Hot Embossing Process

In this paper,we analysed the problems that existed in the extrusion hot embossing process.To slove these problems,we designed a new extrusion hot embossing process and verified the effectiveness and feasibility of this process through experiments.The thickness and temperature of the extruded polymer film were affected by various factors.It is very difficult to ensure the uniformity of thickness and temperature before the polymer film enters into the hot embossing machine.Therefore,we add a planish unit and a temperature control unit to ensure the uniformity of thickness and temperature of the polymer film.At the same time,we produce the polymer film with microstructure on its surface by this two differern process sepatately and make some tests.The results show that:the new process greatly improved the uniformity of the thickness and temperature compared with the original embossing process.In this new process the uniformity of the thickness and temperature was better ensured.

Molecular Simulation of Polycarbonate and Thermomechanical Analysis

The influence of molecular structure of polycarbonate on performance was systematically investigated by both experiment and molecular simulation. Different types of polycarbonate molecular chain models were built and analyzed by molecular simulation method. By combining experimental and simulation results, it is concluded that the polycarbonate-OQ2720 has better thermal stability, mechanical properties and optical performance, which is a better choice for aviation materials and manufacturing process.

Design and Simulation Analysis of a New Type of Micro Metal-Plastic Heat Radiator

With the development of micro-nanomachining technology (MNMT), micro heat radiator is getting attention. In this paper, the heat dissipation mechanism of light emitting diode (LED) ball lamp is introduced. And the LED heat radiator is simplified. On the basis of that, a new type of micro metal-plastic heat radiator of LED is put forward. And the LED heat radiator is simplified. A series of numerical simulations are carried out to compare the heat dissipation performance of micro heat radiator respectively made by metal, plastic, metal-plastic composite by the FloEFD software. Micro metal-plastic heat radiator structures, including fin spacing, fin thickness, fin height and substrate thickness, are carry out to be simulated.

Influence of Light Scattering Particles on Optical Properties of Polymer Diffusion Plate

In order to analyze the influence of scattering particles on the optical properties of light scatter of polymer diffusion plate, we establish the microspheres of scattering particles in mathematical physics model. According to Mie scattering theory, we study the relationship between the scattering intensity distribution and the particle radius, the refractive index and the wavelength of the incident light. The results show that the particle radius is larger and incident wavelength is smaller, scattering intensity distribution is concentrated; the particle refractive index and scattering intensity distribution are not a simple corresponding relationship. At the same time according to the Monte Carlo method, the simulation is also used to analysis the effect that scattering particle concentration, the scattering particle radius and refractive index influence the diffusion plate light transmission rate and uniformity. The result shows that as the particle concentration is greater and transmittance is smaller, uniformity increases first and then decreases. As the particle radius is small, light transmission rate is higher and the particle refractive index is larger, light transmittance increases first and then decreases. But the relationship of the uniformity, the particle radius and the particle refractive index are all not simple corresponding law.

Design of the Diffuse Reflector Cup with Microstructure and the Research on the Optical Performance

The reflective properties and illumination uniformity of the polymer can be improved effectively with microstructure on the surface and scattering particles with high refractive index inside. The paper is based on the early research of the author. The reflector cup is processed by injection molding using the polymer of high reflective properties, which can achieve high efficiency of the light energy utilization and the uniform emergent ray.

Preparation and Testing of the Microstructure Diffuse Reflection Plate Based on the Continuous Extrusion

The article introduces a kind of preparation process of the micro structure diffuse reflection plate based on continuous extrusion and proposes a new preparation process of diffuse reflection plate. The process mainly includes two single screw extruders which work by means of co-extrusion composite. Then polymer sheet is got through the roller via the thermal printing. At last the micro structure is pressed on the polymer sheet. The preparation of diffuse reflection plate is successful. We can measure the surface microstructure of diffuse reflection plate by using ContourGT-X3 that is made from Germany. The content of the measuring includes the 3 d shape, depth, diameter and uniformity of the micro structure. The article analyzes that the die temperature, rolling depression and roll speed have the influence on the diffuse reflection plate replication rate. The experimental result shows that the die temperature has little impact on the replication rate; Along with the increase of roller press, diffuse reflection plate replication rate increases; Along with the increase of the roller speed, diffuse reflection plate replication rate reduces.

Analysis of the Influence of Bar-Defects to Warping of PMMA Products

Moldflow software is used to analyze the warping of the PMMA sheet in this article. It is shown that density of bar-defects, cross-section shape of bar-defects and sectional dimension of bar defects influence the warping in different level. The relationship of bar-defects and warping is amply analyzed. As a result, it is found that cross-section shape of bar-defects and sectional dimension of bar defects have more influence to warping, especially in the vertical direction of the surface. At last, some feasible method is put forward to decrease the warping.

Study on the Reflecting Properties of HFHIPS

With HFHIPS as the substrate, through the double-screw extrusion processing technology of blending modification, add the titanium dioxide (TiO2) and brightener (ZB) into the HFHIPS. Change the content of TiO2 and ZB of the substrate respectively, study the influence of content on the HFHIPS Reflective materials with microstructure on surface, Including reflectivity, whiteness, impact strength and tensile strength. The results show that, when add the TiO2 and ZB into the HFHIPS, reflectivity and whiteness were improved obviously. Reflectivity can reach 95.3%, at the same time, the intensity will not have a significant reduction; But when the content reaches a certain value, TiO2 and ZB will cover each other, this will reduce the reflectivity and whiteness.