Construction material and method for manufacturing same

Abstract

In one aspect, a method for manufacturing a composite material for structural applications may include steps of sawing and arranging bamboo woods into bamboo bundles; heating the bamboo bundles; dipping the bamboo bundles in phenolic resin; drying the bamboo bundles; arranging the bamboo bundles with the green surface facing outside and the yellow surface facing inside; and forming bamboo beams with a hot-pressing process.

Claims

1. A method for manufacturing a composite material for structural applications comprising steps of: sawing and arranging bamboo woods into bamboo bundles; heating the bamboo bundles; dipping the bamboo bundles in phenolic resin; drying the bamboo bundles; arranging the bamboo bundles with the green surface facing outside and the yellow surface facing inside; and forming bamboo beams with a hot-pressing process, wherein the step of forming bamboo beams with a hot-pressing process include steps of first hot pressing the bamboo bundles at 145? C. and under the pressure of 0.35-0.40 mpa with the holding time 1.0 min/mm; and second hot pressing the bamboo bundles at 55-60? C. to 18 mm, and the density thereof is controlled at 1.1 g/cm.sup.3.

2. The method for manufacturing a composite material for structural applications of claim 1, wherein the step of sawing and arranging bamboo woods into bamboo bundles include steps of sawing the bamboo woods to long bamboo tubes of 2.6 meter, and putting together a predetermined amount of bamboo tubes into a bamboo bundle.

3. The method for manufacturing a composite material for structural applications of claim 1, wherein the step of heating the bamboo bundles include steps of heating the bamboo bundles at 200? C. for two hours with water vapor; and drying the bamboo bundles to 6% to 8% moisture content.

4. The method for manufacturing a composite material for structural applications of claim 1, wherein the step of dipping the bamboo bundles in phenolic resin include a step of immersing the bamboo bundles in 20% phenolic resin for 4 to 6 minutes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram for a cross section of a bamboo.

(2) FIG. 2 is a block diagram of a method for manufacturing a composite material for structural applications in the present invention.

(3) FIG. 3 illustrates basic properties of Zunanmu including moisture content, compressive strength, bending strength, elasticity, shear strength, cross gram compression, and formaldehyde emission.

(4) FIG. 4 illustrates the flammability and burning tests results of Zunanmu in the present invention.

(5) FIG. 5 illustrates the test results of corrosion resistance of Zunanmu in the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(6) The detailed description set forth below is intended as a description of the presently exemplary device provided in accordance with aspects of the present invention and is not intended to represent the only forms in which the present invention may be prepared or utilized. It is to be understood, rather, that the same or equivalent functions and components may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.

(7) Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices and materials similar or equivalent to those described can be used in the practice or testing of the invention, the exemplary methods, devices and materials are now described.

(8) All publications mentioned are incorporated by reference for the purpose of describing and disclosing, for example, the designs and methodologies that are described in the publications that might be used in connection with the presently described invention. The publications listed or discussed above, below and throughout the text are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention.

(9) As used in the description herein and throughout the claims that follow, the meaning of a, an, and the includes reference to the plural unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the terms comprise or comprising, include or including, have or having, contain or containing and the like are to be understood to be open-ended, i.e., to mean including but not limited to. As used in the description herein and throughout the claims that follow, the meaning of in includes in and on unless the context clearly dictates otherwise.

(10) It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the embodiments. As used herein, the term and/or includes any and all combinations of one or more of the associated listed items.

(11) In recent years, environmental friendly building and decoration materials have been highly recognized, and environmentally friendly materials such as wood and bamboo have gained much attention. Bamboo and wood structures are superior to reinforced concrete and brick structures in insulation, energy saving, environmental protection, comfort, earthquake resistance, material regeneration and recycling. This has aroused positive attentions from experts, scholars, designers, architects, manufacturers and the public.

(12) Bamboo has excellent mechanical properties due to its unique biological characteristics of bamboo fibers. Bamboo fibers can be divided into primary cell walls and secondary cell walls. These cell layers are mostly composed of cellulose, hemicellulose, lignin, etc. The ratio of these elements is about 2:1:1 and account for about 95% of the total weight. In each layer of cellulose, there are crystalline components of cellulose microfibrils arranged in a spiral manner. The structure of the hollow, multi-layer helix of the bamboo fiber is very reasonable. Crystalline cellulose is arranged in disorder on the primary cell wall and in longitudinal parallel arrangement along the secondary cell wall. This structure is an important reason for the high strength of bamboo fibers. The comparison of the characteristics of bamboo, spruce, concrete and steel is shown as below:

(13) TABLE-US-00001 Bamboo Spruce Concrete Steel Tensile Strength 35-300 90 1.26-12.6 250-350 (N/mm.sup.2) Compressive 64-110 43 12.6-126 250-350 Strength (N/mm.sup.2) Density 600 43 2400 7800 (Kg/m.sup.3) Regeneration 80-300% 3-6% N/A N/A Capacity Ripening Time 7-9 60-80 N/A N/A (Year) Re-ripening 1 60-80 N/A N/A after being cut (Year) Pollution Level Slight Slight Severe Medium Waste Disposal Easy Easy Construction Reusable Waste

(14) Also, bamboo is a material with great environmental and ecological benefits. It is of great ecological significance to use it in architecture. The urban construction may have requirements on the environmental performance of building materials, and according to the ecological properties of the material, every ton of bamboo releases 1.07 tons of oxygen and absorbs 1.47 tons of carbon dioxide during the growth process. The production of 1 ton of ordinary Portland cement clinker emits 1 ton of carbon dioxide, 0.74 tons of sulfur dioxide and 130 kg of dust. The production of 1 square meter of steel, the emission of 5320 kilograms of carbon dioxide. In the production of ordinary Portland cement and steel, it also needs to consume a large number of stone and minerals and other non-renewable resources. The following table is the impact factor to the environment of the life cycle of the construction materials.

(15) TABLE-US-00002 Water Greenhouse Air Solid Pollution Effect Pollution Waste Bamboo 1 1 1 1 Steel 1.2 1.47 1.44 1.37 Cement 0.9 1.88 1.69 1.95

(16) In one aspect, a method for manufacturing a composite material for structural applications may include steps of sawing and arranging bamboo woods into bamboo bundles 110; heating the bamboo bundles 120; dipping the bamboo bundles in phenolic resin 130; drying the bamboo bundles 140; arranging the bamboo bundles with the green surface facing outside and the yellow surface facing inside 150; and forming bamboo beams with a hot-pressing process 160.

(17) In one embodiment, the step of sawing and arranging bamboo woods into bamboo bundles may include steps of sawing the bamboo woods to long bamboo tubes of 2.6 meter, and putting together a predetermined amount of bamboo tubes into a bamboo bundle.

(18) In another embodiment, the step of heating the bamboo bundles may include steps of heating the bamboo bundles at 200? C. for 2 hours with water vapor; and drying the bamboo bundles to 6% to 8% moisture content. In still another embodiment, the step of dipping the bamboo bundles in phenolic resin may include a step of immersing the bamboo bundles in 20% phenolic resin for 4 to 6 minutes.

(19) In a further embodiment, the step of forming bamboo beams with a hot-pressing process may include steps of first hot pressing the bamboo bundles at 145? C. and under the pressure of 0.35-0.40 mpa with the holding time 1.0 min/mm; and second hot pressing the bamboo bundles at 55-60? C. to 18 mm, and the density thereof is controlled at 1.1 g/cm.sup.3.

(20) It is noted that the finished product can be named Zunanmu, which is considered a bamboo fiber composite and imitation wood material. It can also be considered a reconstituted bamboo.

(21) According to the manufacturing process stated above, Zunanmu has been made through high-temperature carbonization and high pressure, which make Zunanmu a fire-resistant construction material achieving the BI antifire safety standard. The antifire materials like Zunanmu can be flame-retardant, meaning when fire is close to the material, the material will not easily be burned and even when the material is burned, it would not cause serious damages thereon and when the fire is moved away, the burning on the material will immediately stop.

(22) FIG. 3 illustrates basic properties of Zunanmu including moisture content, compressive strength, bending strength, elasticity, shear strength, cross gram compression, and formaldehyde emission; and Zunanmu can meet all requirement to be an excellent constructional material. FIG. 4 shows that Zunanma has passed a flammability test and a burning test for building materials; and FIG. 5 shows Zunanmu shows good corrosion resistance (Grade II).

(23) As stated above, in recent years, environmental friendly building and decoration materials have been highly recognized, and environmentally friendly materials such as wood and bamboo have gained much attention. Bamboo and wood structures are superior to reinforced concrete and brick structures in insulation, energy saving, environmental protection, comfort, earthquake resistance, material regeneration and recycling, which has aroused the positive attention of experts, scholars, designers, architects, manufacturers and the public.

(24) Zunanmu that made by bamboo is free of chemical and radioactive materials and is not harmful to humans. Also, it has the natural aroma and can reduce the environmental pollution of the construction project. Furthermore, Zunanmu is a very stable, long life, durable and renewable non-polluting materials. Century-old wooden houses are common, dating back as far as the 18th century.

(25) Zunanmu can also be used for beams for structural design for either interior or exterior decoration of the construction project. For the interior design, if Zunanmu is not used for load-bearing, it can be positioned in different locations inside the house according to the house owner's preference.

(26) Furthermore, Zunanmu has good thermal insulation so the house built with Zunammu can keep warm in winter and cool in summer. The house frame structure made by Zunanmu is strong enough even for earthquake. In the Kobe earthquake in Japan and Sichuan earthquake in China, there was less damage to the wooden structure buildings, which provided a basis for the earthquake resistance of the wooden structure houses. Also, bamboo has a moisture content of only 17%, so the building made by bamboo/Zunanmu keeps the building materials dry.

(27) Having described the invention by the description and illustrations above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Accordingly, the invention is not to be considered as limited by the foregoing description, but includes any equivalent.