KR102119789B1 - manufacturing methods diffuser plate for display by cars - Google Patents

Abstract

The present invention relates to a method for manufacturing a diffuser plate for a display of a vehicle, to provide a diffuser plate for display satisfying high shock-resistance, high flexibility, and high transmissivity for a next-generation vehicle. More specifically, the method comprises: a raw material supply step (S100) of separately supplying a pure start material of a product to be manufactured and an impurity for controlling chemical properties of the corresponding material by a set ratio; a raw material mixing step (S200) of supplying an organic material for adjusting attraction force between molecular connection chains of the start material while inputting the pure start material and the impurity in a prepared space to stir the mixed material; an extrusion step (S300) of applying pressure to the stirred material to output a limited amount of the stirred material to the outside while guiding entrance/exit toward a set space to induce modification of physical properties; a cooling step (S400) of cooling the output material in a direction corresponding to the flow direction of the corresponding material to minimize modification in mechanical properties of the output material; a processing step (S500) of processing the shape of the cooled material in a shape corresponding to the manufactured product and removing materials remaining on a surface; and a packing step (S600) of wrapping the corresponding product with a sheet having buffering force to prevent damage to the surface of the manufactured product.

Description

Manufacturing method diffuser plate for display by cars}

The present invention relates to a method for manufacturing a diffusion plate for a vehicle display. Specifically, a method for manufacturing a diffusion plate for a vehicle display capable of providing a next-generation vehicle display diffusion plate that satisfies high impact, high flow, and transmittance but actively prevents deformation of properties during cooling. It is about.

The diffuser plate is a translucent part that diffuses light to make the color and brightness appear uniformly across the screen. Polycarbonate assembled in a backlight unit that guides light to a liquid crystal in a liquid crystal display (LCD) ( Polycabonate).

That is, the diffuser plate converts a point light source or a linear light source into a two-dimensional surface light source by scattering and diffusing light emitted from the light source, and enhances the uniformity of brightness while hiding the shape of the light source. It is to support the material.

Such a diffuser plate is widely used in various displays, and in the case of a vehicle display in which the diffuser plate is used, there is a problem in that the visibility of the display screen is poor in bright daylight. This is a problem caused by failure to set an appropriate temperature in the extrusion step or unstable cooling.

Accordingly, in order to improve display visibility, light (luminance) efficiency and contrast ratio are improved, and for this purpose, the structure of the vehicle display is changing from edge type to direct type. Examples of technology are Patent Documents 1 to 2.

Patent Document 1 is a light-diffusion plate for a liquid crystal display in which a micro domain having a different refractive index is formed by stereo lithography in a light-diffusion plate for a liquid crystal display,

Patent document 2 is a diffusion plate for a liquid crystal display backlight manufactured by coextrusion or multi-layer extrusion of at least two or more diffusion layers containing or without diffusion particles and containing a binder resin, which is located at the lower end of the diffusion plate where light from the lamp enters. It is a diffusion plate for a liquid crystal display backlight, characterized in that it satisfies a structure in which the light diffusion rate of each diffusion layer is gradually increased to the upper end of the diffusion plate.

The material of the conventional diffusion plate is applying PMMA (Poly Methyl Methacrylate), PS (Poly Styrene), but in the case of PMMA, the impact is poor and PS has the disadvantage of poor heat resistance, and thus there is an unsuitable problem as the material of the next-generation vehicle diffusion plate.

In addition, in the case of PC (Poly Carbonate), it is a material with excellent impact strength and heat resistance, but it can compensate for these shortcomings, but materials that satisfy high impact with high flow are not currently developed. Has the disadvantage of falling.

In other words, domestically, various companies including LG Chemical and Lotte Chemical produce PCs, but they do not meet the requirements for performance and quality to be applied to diffusion plates. High-impact (NI 20kgcm/cm or higher), high flow (MFI 65 or higher), high heat resistance (HDT 120°C or higher), and TT (transmittance 50% or higher) to apply the next-generation vehicle display diffusion plate material with currently developed PC materials in Korea. ).

Patent Publication No. 10-2004-0032514 Patent Publication No. 10-2005-0016008

The present invention was created to more actively solve the above problems, and the present invention was developed to solve the problems of the prior art as described above. It is an object of the present invention to provide a method for manufacturing a diffusion plate for a vehicle display that satisfies the properties of high heat resistance and transmittance, and to provide a method for manufacturing a diffusion plate for a vehicle display that maximizes cooling efficiency and secures stability during cooling.

In particular, an object of the present invention is to provide a method for manufacturing a diffusion plate for a vehicle display with high impact, high flow, high heat resistance, and light diffusion using a PC compounding technology.

In order to achieve the above problem, the configuration of the method for manufacturing a diffusion plate for a vehicle display proposed in the present invention is as follows.

The present invention is a raw material supply step (S100) to separate the pure starting material of the product and impurities to control the chemical properties of the material at a separate set ratio; A raw material mixing step (S200) in which pure starting materials and impurities are introduced into a pre-prepared space to supply and stir the organic materials that regulate the attraction force between the molecular chains of the starting materials; Extruding step (S300) to induce physical property deformation by controlling the pressure to the stirred material to induce the entry and exit to the set space, while controlling the temperature at a separate temperature for each section from the entrance to the output; A cooling step (S400) of cooling in a direction corresponding to a flow direction of the corresponding material in order to minimize deformation of mechanical properties of the output material; A processing step of processing the shape of the cooled material into a shape corresponding to the production product and removing the residue on the surface (S500); It consists of a packaging step (S600) surrounding the product with a paper having a buffer force in order to exclude the possibility of damage to the surface of the product.

In the extruding step (S300), 70 mmhg of pressure is applied so that the agitated substance flows into a set space formed by five cylinders and an adapter from the entrance to the output, and the temperature of the first cylinder at the entrance is 230° C. The temperature of the 2 cylinder is 240℃, and the temperature of the 3rd cylinder is 245℃, but the temperature from the 3rd cylinder to the 5th cylinder is formed at the same temperature, and the temperature of the adapter associated with the 5th cylinder is the 5th cylinder. And isothermal formation to individually set the degree of deformation of each physical property, and the temperature of the final die, the extrusion die, is set to 250°C.

The cooling step (S400) is a cooling channel forming step (S410) in connection with the extrusion step (S300) to form a cooling channel for setting a path through which the output material passes while cooling water is supplied through a pair of supply pipes; A cooling water supply step (S420) of supplying cooling water at a rate corresponding to the output speed of the material to the cooling channel; It includes; cooling termination step (S430) for inducing the material to pass through the cooling channel to be introduced into the cooling water tank containing the cooling water.

The cooling channel of the cooling process (S400) is formed in an open spiral surrounding the output material, and the cooling water of the cooling water tank and the cooling channel is characterized by circulating in mutual connection.

According to the present invention having the above-described configuration, the method for manufacturing a diffusion plate for a vehicle display according to the present invention has an effect of providing a diffusion plate for a vehicle display that satisfies the properties of high flow, high impact, high heat resistance, and transmittance. . In addition, it is possible to actively prevent deformation of the properties when cooling.

In addition, the present invention has the effect of advancing into the global market through the development of high-tech materials and prevention of foreign spillage of wealth due to technological independence and dependence on imports through localization of vehicle display diffusion plate materials.

1 is a process of manufacturing a diffusion plate for a vehicle display according to the present invention.
2 is a flow chart for manufacturing a diffusion plate for a vehicle display according to the present invention.
3 is a flowchart of manufacturing a diffusion plate for a vehicle display according to the present invention.

Hereinafter, with reference to the accompanying drawings, the configuration of the present invention and the effects and effects thereof will be collectively described.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the person having the scope of the invention, and the present invention is only defined by the scope of the claims. And throughout the specification, the same reference numerals refer to the same components.

The present invention relates to a method for manufacturing a diffusion plate for a vehicle display, and according to the present invention, it is possible to provide a diffusion plate for a vehicle display with improved mechanical and physical properties such as high flow, high impact, high heat resistance, and transmittance. In addition, the cooling efficiency is maximized to minimize the defect rate to provide a diffusion plate for a vehicle display that actively improves conventional problems such as saving raw materials.

In detail, as shown in FIGS. 1 to 2, a raw material supply step (S100) of supplying at a separate set ratio by classifying the pure starting material of the product and impurities for controlling the chemical properties of the material; A raw material mixing step (S200) in which pure starting materials and impurities are introduced into a pre-prepared space to supply and stir the organic materials that regulate the attraction force between the molecular chains of the starting materials; Extruding step (S300) to induce physical property deformation by controlling the pressure to the stirred material to induce the entry and exit to the set space, while controlling the temperature at a separate temperature for each section from the entrance to the output; A cooling step (S400) of cooling in a direction corresponding to a flow direction of the corresponding material in order to minimize deformation of mechanical properties of the output material; A processing step of processing the shape of the cooled material into a shape corresponding to the production product and removing the residue on the surface (S500); It is characterized in that it consists of a packaging step (S600) surrounding the product with a paper having a buffering power to exclude the possibility of damage to the surface of the product.

The raw material supply step (S100) is a step of introducing a pure starting material of a product stored in a separate storage container and impurities for controlling the chemical properties of the material into a mixer according to the producer's choice. At this time, it is natural that the capacity of the starting material and impurities transferred from each storage should be precise, and a separate description will be omitted.

The starting material is a resin, which is generally referred to as polycarbonate (PC). Impurities are commonly used, and various kinds to improve the optical properties, colors, and physical properties of production products may be used, and any one of them may be mixed at a higher ratio to supplement the properties according to the choice of ordinary intellectuals in the field. Will be able to.

For example, an antioxidant, a release agent, a diffusion agent, and a coloring agent, which are impurities in 95% by weight of polycarbonate as a starting material, can be mixed in a limited amount of 5% by weight, and either one has a higher proportion or each impurity has the same proportion. Can be. Here, the weight percentage is made in a ratio that meets the producer's selection or the user's requirements. To make this more precise, it can be done through a meter.

The raw material mixing step (S200) is a step of supplying and stirring an organic material that regulates the attraction force between the molecular chains of the starting material while introducing the materials into the pre-prepared space.

This step is a step of injecting a plasticizer to improve the processability by lowering the melt viscosity while giving the elastic modulus and flexibility to process the starting material made of a polymer having a certain shape in a subsequent step. That is, the organic material refers to an additive called a plasticizer.

By adding the plasticizer to increase the thermoplasticity of the starting material polycarbonate, it facilitates molding at a high temperature, and at the same time, evenly mixes all the above materials to actively prevent variation in the product. It can be done through a blender (Blender Bin) to complete the operation more precisely.

In the extruding step (S300), pressure is applied to the agitated material to induce access to a set space while outputting a limited capacity to the outside, and controlling physical properties by controlling the temperature from entry to output at different sections.

This step is carried out through an extruder (Extruder) and the screw is rotated in the interior space of the extruder. The screw is a screw that rotates on a predetermined rotational axis and inserts the agitated material, that is, the gap between the blades constituting the helical surface of the entry point is larger than the output point, and the blade gap gradually narrows toward the output point.

When a material stirred at a speed corresponding to the rotation of the screw of the extruder is introduced into the extruder, a pressure of 70 mmhg is applied. This corresponds to the pressure to prevent the shrinkage at the time of output and to allow the adequacy of the subsequent plastic working.

As a result of confirming the shrinkage rate of the material by the pressure was as follows.

Pressure (mmhg) Shrinkage (%) 30 0.9 45 0.8 70 0.6 80 0.6

As shown in Table 1 above, it can be seen that the shrinkage is minimized when a pressure of 70 mmhg is applied. Therefore, it is preferable to apply a pressure of 70 mmhg in order to minimize the effect of the shrinkage rate later according to the applied pressure.

In this way, the stirring material is introduced into the set space, and the space is divided into five cylinders and an adapter associated with the fifth cylinder, the last cylinder. The five cylinders divide the areas through which the stirring material passes and have different temperatures.

In detail, in this step, the first cylinder, the second cylinder, the third cylinder, the fourth cylinder, the fifth cylinder, the adapter (adepter), and the extrusion die are connected in this order. The temperature of the first cylinder, starting with the temperature of the first cylinder, at which the stirring material is first introduced is 230° C., is 240° C., and the temperature of the third cylinder is 245° C., but the temperature from the third cylinder to the fifth cylinder is constant. In this way, the degree of deformation of the physical properties for each section is set differently, and the adapter connected to the outlet side of the fifth cylinder is isothermally formed with the fifth cylinder, and the temperature of the final die, the extrusion die, is 250°C. .

The material melted at the set temperature will be generated by rotation of the screw and viscous flow, and the shrinkage of the flow direction and the flow right angle direction according to the change in temperature is as follows.

Temperature (℃) Shrinkage (%) Flow direction Right-angle direction 240 0.55 0.84 250 0.56 0.85 260 0.61 0.91

As shown in Table 2 above, it is desirable to set the melting point or the melting temperature of the stirring material to a temperature of a line that does not greatly exceed the shrinkage rate for the flow direction and the right angle direction when the temperature is set excessively.

For example, if the temperature is rapidly increased, it may not melt properly. Therefore, it induces a stepwise temperature increase from the first cylinder to the final extrusion die of the fifth cylinder to minimize defects and loss of mechanical properties during processing.

Through this step, the solid stirring material is transformed into a liquid form with improved processability, and the molecular structure changes as the starting materials, impurities, and plasticizers are mixed. This process is a core process of the entire process, and it is natural that standard production conditions such as temperature and screw rotation speed can be individually set according to the properties of materials to be mixed.

As shown in Figure 3, the cooling step (S400) is a step for minimizing the deformation of the mechanical properties of the output material, it is preferable that the cooling should be performed simultaneously with the output of the molten material.

Specifically, the cooling step (S400) is a cooling channel forming step (S410) in connection with the extrusion step (S300) to form a cooling channel through which the output material passes while cooling water is supplied through a pair of supply pipes; A cooling water supply step (S420) of supplying cooling water at a rate corresponding to the output speed of the material to the cooling channel; Cooling termination step (S430) to induce the material that has passed through the cooling channel to be introduced into the cooling water tank in which the cooling water is accommodated; and the cooling channel of the cooling process (S400) is formed in an open spiral surrounding the output material, The cooling water of the cooling water tank and the cooling channel is characterized by circulating interconnectedly.

The stirring material whose physical properties are modified by the extrusion step (S300) has a viscous force, and thus, a material flow occurs, and the flow can be divided into a flow direction and a flow perception direction. Therefore, it is necessary to perform cooling for the same purpose as limiting the pressure and to actively compensate for shrinkage.

Conventionally, in order to cool the resin discharged from the extruder, a method of passing the resin through a cooling water tank in which water is accommodated at the end point discharged from the extruder was adopted. Accordingly, the cooling is unstable. It happened a lot.

Therefore, in this step, a cooling channel is provided to cool in the direction corresponding to the flow direction, and cooling is performed simultaneously with output. The cooling channel refers to a tube having a predetermined diameter, and the coolant is accommodated in the space inside the tube.

The cooling channel is connected to the extrusion die, which is the end point of the plastic working, and is formed in an open spiral corresponding to the flow direction of the stirring material, but may be configured to surround the surface of the material. After that, the initial temperature is rapidly cooled and then put into a cooling water tank. In this way, by rapidly cooling the temperature at the initial stage of output, it is possible to actively prevent the molecular chain from breaking during material shrinkage or cooling of the output. In addition, the cooling water in the cooling water tank and the cooling water in the cooling channel are circulated to each other, so that it can be used for a long time to induce a reduction in maintenance cost and manufacturing cost.

The material shrinkage of the preferred embodiment of the present invention and the embodiment cooled in the conventional manner is as follows.

Shrinkage (%) Conventional 1.8 Preferred embodiments of the invention 0.3

As shown in Table 2 above, when cooling is performed according to a preferred embodiment of the present invention, the problem of shrinkage itself in the flow direction and the flow perpendicular direction of the material is actively improved. Thus, the diffusion plate for a vehicle display manufactured by the present invention has improved mechanical and physical properties such as high impact, high heat resistance, and transmittance.

The processing step (S500) is a step of processing the shape of the cooled material into a shape corresponding to the production product and removing the residue on the surface. The elongated strand (noodle strand shape) is chipped (Chip (Pellet)) ) In the process of cutting in the form, the size of the cut chip is formed to a size of 2.5 to 3.0 pi X 3mm.

At this time, a residue on the surface is present by processing, which is usually referred to as dust. It can be made by a dust collector or the like to remove it. It is desirable to remove the surface residues as much as possible, as it may cause defects such as gas or yellowing during the production process of the final product, the diffusion plate.

The packaging step (S600) surrounds the product with a paper having a buffering power to exclude the possibility of damage to the surface of the product.

It is natural that a paper having a buffering force may be a paper with an air cap, and any paper may be packaged in multiple layers regardless of the purpose of achieving the purpose of preventing surface damage.

As described above, the method for manufacturing a diffusion plate for a vehicle display according to the present invention has an effect of providing a diffusion plate for a vehicle display that satisfies the properties of high flow, high impact, high heat resistance, and transmittance. In addition, the present invention has the effect of advancing into the global market through the development of high-tech materials and prevention of foreign spillage of wealth due to technological independence and dependence on imports through localization of vehicle display diffusion plate materials.

The present invention described above has been described with reference to one embodiment shown in the drawings, but this is only an example, and various modifications and equivalent other embodiments are possible from those skilled in the art. Should be clarified. Therefore, the true technical protection scope of the present invention should be interpreted by the appended claims, and all technical spirits within the equivalent scope should be interpreted as being included in the scope of the present invention.

S100: Raw material supply stage S200: Raw material mixing stage
S300: extrusion step S400: cooling step
S410: cooling channel formation step S420: cooling water supply step
S430: Cooling end step S500: Processing step
S600: packing step

Claims (3)

A raw material supply step (S100) of supplying at a separate set ratio by classifying the pure starting material of the production product and impurities for controlling the chemical properties of the material;
A raw material mixing step (S200) in which pure starting material and impurities are introduced into a pre-prepared space and supplied and stirred by supplying an organic material that regulates the attraction force between the molecular chains of the starting material;
Extrusion step (S300) to induce physical property deformation by controlling the pressure to the stirred material to induce the entry and exit to the set space while controlling the temperature at a separate temperature for each section from entry to output;
A cooling step (S400) of cooling in a direction corresponding to a flow direction of the corresponding material to minimize deformation of mechanical properties of the output material;
A processing step of processing the shape of the cooled material into a shape corresponding to the production product and removing residues on the surface (S500);
Packaging step to surround the product with a buffered paper to exclude the possibility of damage to the surface of the product (S600)
It consists of,
In the extruding step (S300), 70 mmhg of pressure is applied so that the agitated material flows into a set space formed by five cylinders and an adapter from the entrance to the output, and the temperature of the first cylinder at the entrance is 230°C. The temperature of the 2 cylinder is 240℃, and the temperature of the 3rd cylinder is 245℃, but the temperature from the 3rd cylinder to the 5th cylinder is formed at the same temperature, and the temperature of the adapter associated with the 5th cylinder is the 5th cylinder. And isothermal formation, individually setting the degree of deformation of each physical property, and setting the temperature of the final output point, the extrusion die, to 250°C.
delete According to claim 1,
The cooling step (S400) is a cooling channel forming step (S410) in connection with the extrusion step (S300) to form a cooling channel for setting a path through which the output material passes while cooling water is supplied through a pair of supply pipes;
A cooling water supply step (S420) of supplying cooling water at a rate corresponding to the output speed of the material to the cooling channel;
A cooling termination step (S430) inducing the material that has passed through the cooling channel to be introduced into a cooling water tank in which cooling water is accommodated;
Diffusion plate manufacturing method for a vehicle display comprising a.

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