KR20020048711A - Method for preparing a sheet for producing an article and method for producing the article using the sheet - Google Patents

Abstract

PURPOSE: A manufacturing method of a sheet used for the manufacture of molded articles and a molded article manufacturing method using the sheet are provided to simplify the manufacturing process of the molded articles, and to improve the strength and the appearance of the molded articles. CONSTITUTION: The sheet used for the manufacture of molded articles is manufactured by preparing a mixed state composite; mixing a desired amount of moisture to the composite; kneading the composite; and forming a sheet by passing the dough through rollers preheated to a desired temperature. The manufacturing method of molded article using the sheet comprises a compression molding step of the sheet using a set of male type and female type molds; and a step of adjusting the content of moisture of the molded articles by heating them.

Description

Method for preparing a sheet for producing an article and method for producing an article and method for producing the article using the sheet}

The present invention relates to a method for manufacturing a molded article for manufacturing a molded article and a method for manufacturing a molded article using the same, and more particularly, a molded article that is alleviated the molding conditions through a process of molding a sheet obtained after the sheet is first manufactured, and performed in a simplified process It relates to a manufacturing method for producing a sheet and a method for producing a molded article using the same.

Currently, plastic molded articles, such as household articles or various containers, which are commonly used in daily life, are filled with a resin composition that is heated and melted in a mold of convex and concave shapes, cooled in a mold, and then solidified. The manufacturing method of taking out the resin molded product in a metal mold | die is generally adopted. Then, by slightly modifying these methods, a so-called gas counter pressure method of adding a blowing agent to the resin and injecting the resin into a compressed mold and then depressurizing the inside to foam the resin, and a surface layer containing no blowing agent After the resin is injected, the so-called sandwich molding method of injecting the center layer resin containing the foaming agent to foam only the center layer resin, and the resin is injected into the mold, and then the high-pressure gas is injected into the mass of the resin. The method of obtaining a hollow shaped article, etc. are employ | adopted. These methods can produce plastics molded articles having sufficient strength, light weight and excellent appearance.

However, in the case of a plastic substitute material mainly based on the natural material, which has recently emerged, such a molding method cannot be adopted because it is difficult to be cooled and solidified due to the nature of the natural material. Therefore, these employ | adopt the method of compressing and shape | molding a powdery or liquid composition as it is in a molding machine. However, in this case, since high temperature and high pressure are required, a lot of expenses are required when the molding conditions are met, and there is a problem that deformation may occur in the form of deterioration and bending due to shrinkage during molding. In addition, it is not easy to control the thickness according to the bending of the inner and outer surfaces of the molded article, there is a problem such as producing an asymmetric container.

In order to solve the above problems, the present inventors studied a method of economically and easily manufacturing a molded article using materials of natural materials. In this process, when adopting a method of primary sheeting and then molding of natural materials, the molding method can be facilitated, the molding conditions can be alleviated, the thickness of the molded article becomes uniform, sufficient strength and light weight. And the finding that molded articles having an excellent appearance can be produced.

In order to solve the above-mentioned problems, there are technical problems of the present invention in order to alleviate various molding conditions necessary in the manufacturing process of the molded article, to have a uniform thickness, sufficient strength, light weight and excellent appearance, and to manufacture the molded article for achieving this. It is an object of the present invention to provide a method for producing a molded article for sheet forming the composition and a method for producing a molded article using the same.

1 is a flowchart illustrating a method for manufacturing a molded article for manufacturing a molded article and a method for manufacturing a molded article using the same according to the present invention.

2 is a schematic view showing an example of a molded article molded by the method according to the present invention.

3 is a schematic view showing another example of a molded article molded by the method according to the present invention.

Sheet manufacturing method for producing a molded article for achieving the above object of the present invention, (a) preparing a composition of the mixed phase by uniformly mixing the composition for producing a molded article; (b) adding a predetermined moisture to the mixed powder and then blending it; (c) kneading the blend containing the water and the mixed powder; And (d) sheeting the dough through a preheated roller at a predetermined temperature.

On the other hand, the molded article manufacturing method for achieving the other object of the present invention described above, by applying a predetermined pressure to the male and female molded article mold sandwiched between the sheet dough for manufacturing the molded article produced through the steps (a) to (d) Compression molding; And adjusting the moisture content of the compression molded article by applying a predetermined heat, or by changing the order of the compression molded article, the predetermined sheet dough prepared through the steps (a) to (d). Adjusting the moisture content by applying heat; And compression molding by applying a predetermined pressure to the male and female molded article mold having the sheet for preparing a molded article having a controlled moisture content interposed therebetween.

On the other hand, in the process for producing a molded article manufacturing method and a molded article manufacturing method using the same, the moisture added to the mixed powder in the (b) water mixing step is preferably 5 to 60% by weight, the (d) sheeting step Preheating temperature of the roller is preferably preheated to 20 to 180 ℃.

In addition, in the method for producing a molded article, a coating layer may be further formed on the outside or the inside of the molded body, particularly after the control of the moisture content and the compression molding step are completed. In addition, the compression molding step is preferably carried out at a molding time of 10 to 300 kg / cm 3 pressure and 1 second to 30 minutes at 100 to 200 ℃ temperature.

Hereinafter, the present invention will be described in detail with reference to Examples. However, embodiments according to the present invention can be modified in many different forms, the scope of the present invention should not be construed as limited to the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

The materials that can be molded through the molding method provided by the present invention described above are not specified, but are preferred when natural ingredients are the main ingredients. Specifically, carbohydrates such as flour, rice flour, starch, barley flour, corn flour, etc. It is preferable in the case of a composition for producing a molded article in which a binder and a functional strengthening agent are included as an auxiliary component in a conventional grain powder containing as a main component.

1 is a flowchart illustrating a process of molding according to the present invention.

As shown in Figure 1, first, in the method for producing a molded article of the present invention, the composition material is prepared in an appropriate content and mixed uniformly (S1). Here, it is preferable that the composition materials are once powder, and those that are not powder are preferably subjected to grinding in advance. In the course of mixing, it is also possible to mix via a stirrer if necessary to achieve even mixing.

In addition, the method may further include a colorizing step of selecting a pigment having a color to be expressed and adding a predetermined amount to the composition material during or after mixing, but this is an optional step in the process step. This colorization step is to determine the molding color.

Subsequently, the mixed composition is uniformly added by adding predetermined moisture (S2). At this time, the amount of water added may be directly linked to the preservation of the raw materials and the maintenance of the molding state of the finished product, so that it is necessary to control variously and precisely according to the specific use of the molded article, which is the final finished product. To 60% is preferred. Specifically, the process of homogenizing the size of the particles in the molded article composition to the fine powder primarily using the rotational force or stirring of the blade mixer at the time of mixing.

Subsequently, by applying a strong pressure while passing the blended dough through the roller having the irregularities formed on the surface of the kneader, the blended kneading process of grinding uneven particles not controlled even in the primary micropowdered kneading process is performed (S3). Since the kneading process that proceeds while applying such a high pressure also has the purpose of improving the viscosity of the dough composition containing water, it is sufficient through mechanical observation and visual observation to ensure sufficient viscosity for sheeting for the production of molded articles. It is preferable to proceed for time.

Subsequently, the dough having the improved viscosity through the dough is passed through a roller to form a sheet (S4). At this time, the roller is preferably preheated to 20 to 180 ℃. One reason for preheating the rollers is to prevent sticking to the rollers in the process of forming the sheet while the dough is flattened when rolling is performed without preheating. In other words, the dough is brought into contact with the surface of the roller, so that some moisture evaporates by the preheating temperature, so that the baking effect is generated. The dough is cured at the contact surface, so that the sheet is easily separated from the roller. There is a purpose. The sheet produced through the roller is then wound or cut into appropriate dimensions as the case may be.

Through these four steps, the manufacturing step of the sheet for manufacturing a molded article is completed first. Then, it is natural by the following description that such an intermediate product is used as a base material for the production of the final molded product. Since the considerable amount of the moisture included in the molded article sheeting process is still largely inherent in the molded article manufacturing sheet, which is an intermediate product, the process of excluding this, that is, drying will be essential. If the moisture is moist, the sheet state is weak, so that the molding is easy, but the deformation may occur in the appearance of the finished molded product. The process of excluding significant amounts of moisture, ie drying process for controlling moisture content, is essential.

However, there is no inevitable reason that the drying process for controlling the moisture content must be preceded or later than the compression molding process in the process of manufacturing a molded article. In some cases, the compression molding process (S5a) is first performed first. In addition, the drying process (S5b) for controlling the moisture content may proceed to the method later, on the contrary, after the drying process (S6a) for controlling the moisture content, the compression molding process (S6b) all proceeds later It is possible.

However, the moisture content is not solely controlled only in the drying process for controlling the moisture content, and part of the moisture content in the molded product may be dried and removed even during the compression molding process, and this should be sufficiently taken into account in the drying process.

In the compression molding process for forming the outer appearance of the molded article, the molded article manufacturing sheet is interposed between the upper and lower parts of the upper and lower parts forming a pair of male and female, and then the predetermined temperature, pressure and time are adjusted to achieve the desired final completion. Molded articles can be produced. Control of the molding conditions at this time relates to temperature, pressure and time, the molding temperature is 100 to 200 ℃, the molding pressure is 10 to 300kg / ㎠, the molding time is several seconds to several tens of minutes, preferably Is 1 second to 30 minutes, in particular, the limitation of temperature, pressure, and time will be said to be the core of a molded article manufacturing method that requires special attention because the molded article has a problem of burning or fading due to overheating. Here, it can be seen that there is an advantage that the molding is easy to handle, because the molding is molded once after the sheet. On the other hand, after the final finished product is manufactured, a coating layer may be formed on the inside or outside of the molded article, and if necessary, a color layer may be coated to implement a finished product of various colors. In some cases, it is obvious that the coating layer may be formed after the first step of coating the color layer.

On the other hand, for the purpose of enhancing the functionality of the coating layer formed on the outside or inside of the finished molded article, for example, it is possible to further form a functional surface layer for waterproofing, appearance improvement, strength improvement, fire resistance improvement, wear resistance improvement. The functional surface layer may be added a functional improving material required during the molding process, and after the molding process is completed, the functional surface layer as described above may be formed by coating or the like separately on the surface of the finished product. However, it is necessary to pay particular attention to the selection of the substance used and its content so that the formation of such a functional surface layer is not disposed for the purpose of producing the molded article of the present invention.

2 is a schematic view showing an example of a molded article manufactured through the molding method according to the present invention, Figure 3 is a schematic view showing another example of a molded article manufactured through the molding method according to the present invention.

As shown in Figure 2, it shows a cylindrical container of a predetermined depth or more. In the case of such a container, the sheet cut to a predetermined length is mounted on a molding machine, and then rolled and molded. In the case of a flat molded article as in the case of Figure 3 can be produced by pressing the sheet cut to a predetermined length directly with a molding machine.

2 and 3 illustrate an example of a molded article manufactured according to the method of manufacturing a molded article according to the present invention. In addition to this, for example, a cup ramen container, a disposable cup, a tray, a plate, a chopstick, a toothbrush, a razor, a knife Disposable items and plates, trays, containers, cups, gourds, delivery containers, including spoons, forks, hamburger cases, ice cream bins, coffee sticks, ice cream rods, ice cream spoons, toothpicks, straws, golf tees, food containers, etc. Multi-purpose items including dining containers, plates, solid food packaging, hangers, trash cans, picture frames, toys, legos, vases, flower pots, pencil cases, cutlery, ashtrays, wall / table clock cases, side dishes, diskette storage boxes, knitting needles Household goods including furniture, eyeglass frames, ballpoint pens, pencils, scotch tape cases, furniture reinforcement, office desks, wardrobes, bookshelves, etc. Interior and exterior materials, TV case, computer case, various home appliance case, cell phone case, mouse case, toy, life including switchboard, plywood, window frame, chock, door, kitchen furniture, interior molding material, MDF substitute, interior and exterior partition Agriculture, including various types of buffers, seedling containers, fish packaging boxes, fruit packaging boxes, etc., including plastic substitutes including tools, FRP substitutes, telephone cases, various food cases, egg boards, electronic product interior materials, various interior and exterior materials, etc. It can be seen that the industrial availability and its practical range of application can be used because it can be used to manufacture a general purpose molded article that can be used as a container material for fishing and interior and exterior materials of vehicles, aircraft, ships and the like.

The above-described molded article manufacturing method is not complicated, it can be molded in a cost-effective way by reducing the molding conditions, and the molded article obtained by such a molding method can ensure a uniform thickness, sufficient strength, light weight And excellent appearance.

Claims (7)

(a) uniformly mixing the composition for preparing a molded article to prepare a mixed phase composition; (b) adding a predetermined moisture to the mixed powder and then blending it; (c) kneading the blend containing the water and the mixed powder; And (d) passing through the roller preheated to a predetermined temperature to form a sheet; forming a sheet for producing a molded article, characterized in that the progress. Compression molding by applying a predetermined pressure to the male and female molded article mold sandwiched between the sheet dough prepared by using the sheet manufacturing method for producing a molded article of claim 1; And And applying a predetermined heat to the compression molded molded article to adjust its moisture content. Adjusting a moisture content by applying a predetermined heat to the sheet dough prepared using the method for producing a molded article of claim 1; And And compression molding by applying a predetermined pressure to the male and female molded part mold part having the molded article manufacturing sheet having the moisture content controlled therebetween. 2. The method according to any one of claims 1 to 3, The method of claim 1, wherein the water added to the mixed powder in the water mixing step is 5 to 60% by weight. The method according to any one of claims 1 to 3, The preheating temperature of the roller in the (d) sheeting step is preheated to 20 to 180 ℃ characterized in that the manufacturing method. The method according to claim 2 or 3, And forming a coating layer on the outside or the inside of the molded body after the compression molding step in which the moisture content is controlled. The method according to claim 2 or 3, The molding conditions in the compression molding step is a molded article manufacturing method, characterized in that the pressure of 10 to 300kg / ㎠ and 1 second to 30 minutes at a temperature of 100 to 200 ℃.