JPH02215501A - Rice hull molded product - Google Patents

Abstract

PURPOSE:To keep various essential properties of rice hull as they are and manufacture a molded product having required mechanical properties by using rice hulls as a main material, adding a binder of resin material to the rice hulls and mixed together, pressurizing, compressing and molding into an optional shape. CONSTITUTION:A small amount (approximately 20wt.% to rice hulls) of binder such as liquid urethane for bonding rice hulls together and shaping regularly is mixed with the rice hulls to pressurize the compression mold a sheet or the like of optional shape. As in the molded product gravity and heat conductiv ity after molding are proportional to each other, the pressurizing and compressing condition at the time of molding can be fixed selectively and the gravity and heat conductivity corresponding to the purpose of use can be pro vided, and also such essential properties of rice hull such as light weight proper ties, heat retaining properties, soundproof properties, cutting and processing properties can be kept as they are.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention is applicable to the use of plate-like molded products mainly made from rice husk, such as floors and walls of buildings, furniture, indoor and outdoor equipment, or The present invention relates to molded rice hulls that can be used as base materials for other everyday products, or can be directly molded into various products to be used as base materials and products in a wide range of fields.

``Prior art'' and ``7) 1 problem that the invention attempts to solve'' Traditionally, rice hulls, which are made from rice hulls, have been produced and disposed of in large quantities as a by-product of rice production. It has physical properties. Therefore, as a development that focuses on the use of the physical properties of rice husk, there is a ``building material made by mixing rice husk with water into cement and hardening'' disclosed in Japanese Utility Model Application Publication No. 186645/1983.

However, although this building material mixed with rice hulls has the advantage of excellent heat insulation and cutting workability, it has the disadvantage of being inferior in diversity of physical properties and mechanical properties, and its use is limited to a small range.

On the other hand, paddy hulls have been produced in large quantities as a by-product of rice cultivation since ancient times, but they cannot be used as building materials as mentioned above.

Only a very small amount of paddy husk is used as a heat-insulating bed for potatoes, etc., and most of the paddy husk is incinerated or discarded as unnecessary material, and there is a strong need in this field to develop technology for the effective use of this paddy husk. It is requested. For example, the current situation in this field is that proactive measures are taken to promote development, such as providing subsidies to those who propose the use of rice hulls to commercialize their technology.

It is an object of the present invention to overcome the drawbacks of the prior art described above, as well as to solve the technical problems in the field described above.

A molded product of the present invention that solves the above-mentioned technical problems is made by adding and mixing a resinous binder to the main material, the paddy husk. , a rice hull molded product that is pressurized and compressed into an arbitrary shape.

Specifically, the rice hull molded product of the present invention is intended to preserve various physical properties unique to rice hull, and to be made into a molded product that has required mechanical properties and various physical properties. The main material is rice hulls, and a small amount of a binder (hereinafter referred to as resin binder) of a resin material (such as liquid urethane) is mixed in to fix the rice hulls together and give them a regular shape. It is characterized by a molded product that is pressurized and compressed into an arbitrary shape.

Hereinafter, referring to the basic manufacturing method, a rice husk molded product is formed by the following steps and means.

・First, some amount is added to the main material, paddy shell (approximately 20% of the paddy shell)
(wt%)) of the resin binder is mixed and stirred. 6. Paddy husk mixed with the above binder is poured into the required mold and compressed under pressure under heat, and the paddy is molded by the binder. The shells are fixedly connected to each other to form a single piece, and after hardening, they are molded.

- After demolding, cure at room temperature to obtain a rice hull molded product solidified into a predetermined shape.

The rice husk molded product having the above structure and manufacturing method can be molded into a variety of products using the application methods described below, depending on the physical properties such as specific gravity, thermal conductivity, and compressive strength that should be imparted to the molded product. In other words, for rice hull molded products, there is a proportional correlation between the specific gravity and thermal conductivity after molding, so the pressurization and compression conditions during molding must be selectively determined to give specific gravity and thermal conductivity appropriate to the intended use. .

- In order to add other physical properties to the rice husk molded product other than the inherent physical properties of rice husk, for example, glass fiber or metal fiber may be added and mixed in advance to improve mechanical strength.

Alternatively, it is formed into a composite rice hull molded product by polymerization with metal plates or plywood plates, or by adding and mixing far-infrared ceramic powder or ordinary ceramic powder in advance.

・Additionally, resin materials, ceramic powder, paint, etc. are applied to one surface or the surface layer depending on the functionality and appearance requirements of the application, in order to improve the unique surface properties and appearance.

・Furthermore, depending on the purpose, waterproofing materials, antibacterial materials, antifungal agents, insect repellents, etc. are mixed in small quantities in advance.

Waterproof properties etc. are imparted based on these factors.

[Function] The rice hull molded product of the present invention has the main material, the rice hull, which is bonded between the shells by a resin binder and is compressed under pressure to solidify into a fixed shape. It has properties such as soundproofing, soundproofing, and cutting workability, and is also moldable into any solid shape.

Furthermore, the above-mentioned correlation characteristics between specific gravity and thermal conductivity.

There is a correlation between the compression processing conditions and the mechanical strength of the molded product, so by quantitatively selecting the compression processing conditions during molding, specific gravity, thermal conductivity, and mechanical properties can be harmonized or intentionally adjusted. It has physical property flexibility that allows molded products to be formed freely.

Furthermore, as the shells are firmly bonded using a resin binder, and the paddy hull itself leaves voids depending on the degree of compression, the molded product has elasticity and will not crack or deform even if used as a building material for a long period of time. There is a characteristic that there is little risk of

"Example" Hereinafter, a detailed explanation will be given with reference to an example. In this example, a plate-shaped rice husk molded product to be used as a heat insulating material or building flooring/wall material was processed under the following molding conditions, and the compression processing conditions during processing were changed. We confirmed various physical properties that correlate with

(A) Molding conditions: Mix the main material and resin binder at a ratio of "-weight of the liquid urethane resin binder 1" to "5" of the weight of the main material, rice husk, and inject it into the mold. Compressed under pressure at 80℃ for 60 minutes,
It was molded into a board with a thickness of 15 mm.

Then, several types of rice husk molded products with different specific gravities were produced by changing the pressurization conditions in stages.

(B) Physical properties of the molded product The correlation between the specific gravity and thermal conductivity of the rice husk molded product under molding conditions that are higher than the physical properties, and the respective numerical values are as shown in Table 1 above.

As shown in Table 1, the rice hull molded product of the present invention is lightweight, has low thermal conductivity, and has excellent heat retention and insulation properties.

In addition, in relation to specific gravity (correlation with compression processing conditions), lightness and heat insulation properties can be harmonized or adjusted.

In addition, the mechanical properties of this rice husk molded product are as follows: The specific gravity is 20.6 in the table above, and the compressive strength is approximately 80 kg/c.
d. Bending strength: 43 to 45 kg/cd was confirmed, indicating that it had sufficient mechanical strength to be used as a building flooring material, wall material, etc.

"Effects of the Invention" As explained above, the rice hull molded product of the present invention preserves the lightness and heat insulation properties of the main material, rice hull, and has appropriate mechanical properties. By adjusting the compression conditions and adding other materials, the physical properties can be intentionally harmonized or other unique physical properties can be added, and the material can be molded with a mold. Since it can be easily and inexpensively molded from discarded rice hulls, it can be usefully applied to a wide range of fields such as new building materials, furniture materials, indoor equipment, etc. Furthermore, it provides a new technology for effective utilization of rice hulls, and has great effects such as meeting the needs of the field.

Claims (1)

[Claims] (1) A molded product of rice husk, characterized in that the main material is rice husk, the rice husk is mixed with a resin binder, and the mixture is pressurized and molded into an arbitrary shape.