Method for manufacturing reconstituted bamboo lumber for outdoor bamboo flooring

Abstract

In one aspect, a method for manufacturing outdoor bamboo flooring may include steps of: (i) cutting one or more pieces of bamboo lumbers into a predetermined length; (ii) splitting and defibering the bamboo lumbers into reticular fiber bundles; (iii) conducting a high-temperature treatment to dry the bamboo lumbers in step (ii), immersing them with glues, and then conducting a second drying; (iv) performing pressing and curing on the bamboo lumbers treated in step (iii); and (v) cutting the bamboo lumbers in step (iv) into a predetermined of pieces.

Claims

1. A method for manufacturing outdoor bamboo flooring comprising steps of: (i) cutting one or more pieces of bamboo lumbers into a predetermined length; (ii) splitting and defibering the bamboo lumbers into reticular fiber bundles; (iii) conducting a high-temperature treatment to dry the bamboo lumbers in step (ii), immersing them with glues, and then conducting a second drying; (iv) performing pressing and curing on the bamboo lumbers treated in step (iii); and (v) cutting the bamboo lumbers in step (iv) into a predetermined number of pieces, wherein the step of conducting a high-temperature treatment further includes a high-temperature carbonization of fiber bundles in a carbonization equipment after drying, the temperature of high-temperature carbonization is between 150° C. and 250° C., and the time is 6 to 15 hours.

2. The method for manufacturing outdoor bamboo flooring of claim 1, wherein the bamboo lumber in step (i) is raw bamboo of more than two years' growth, and cutting of the bamboo lumber should avoid bamboo joints.

3. The method for manufacturing outdoor bamboo flooring of claim 1, wherein the step of defibering the bamboo lumbers further includes steps of placing split bamboo lumbers into a teeth-engaged defiberer to physically decompose bamboo fibers of the bamboo lumbers into fiber bundles with reticular structure.

4. The method for manufacturing outdoor bamboo flooring of claim 1, wherein the step of conducting a high-temperature treatment further includes steps of a high-pressure steam cooking, and the high-pressure steam pressure is 0.1˜0.6 mPa, the time of high-pressure steam cooking is 0.5˜6 hours, and the drying effect is that the moisture content of fiber bundles is 15% or less, the drying methods may be drying by a dryer or drying under sunshine or air-drying.

5. The method for manufacturing outdoor bamboo flooring of claim 1, wherein the glue immersion step further includes steps of immersing the bamboo fiber bundles to fully absorb the glue; the glue solid content in the bamboo fiber bundles after immersion can reach 5% to 20%, and for the second drying, the average water content of the bamboo fiber bundles immersed with glue drops to less than 20%.

6. The method for manufacturing outdoor bamboo flooring of claim 1, wherein the glue used in step (iii) is a water-soluble phenol glue generated by the reaction of a formaldehyde solution with phenol in an alkaline environment, and the formaldehyde solution is solution of formaldehyde containing 0.5% to 15% methanol, then the water-soluble phenol glue prepared is modified with resorcinol, or modified with organic silicone, or modified with polyethylene, or modified with nano-silicon or modified with melamine, with the ratio of modifier at 0.5% to 10%.

7. The method for manufacturing outdoor bamboo flooring of claim 1, wherein the step of pressing and curing described in step (iv) further includes steps of placing the glued bamboo fiber bundles after pretreatment into a mold; the mold volume is established according to the density of 1.1 to 1.5 g/cm.sup.3, delivering the mold to a hot pressing machine to perform hot pressing and curing by controlling the board surface contact pressure at 5˜15 MPa; the hot pressing temperature is between 120° C. and 160° C., the curing time is 1.1 to 1.6 min/mm, and after curing, cooling the mold down until the board core temperature is below 80° C.

8. The method for manufacturing outdoor bamboo flooring of claim a, wherein before the cutting in step (v), the bamboo lumbers treated in step (iv) after hot pressing should be stored for more than three days to release internal stress, and then cut.

9. The method for manufacturing outdoor bamboo flooring of claim 1, wherein the pressing is cold pressing, the cold pressing is to place the glued bamboo fibers in a mold firstly, then securing them by lock pins after pressing, and then place them with the mold to a heating device for heating and curing, and perform demolding after fully curing and cooling.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

(1) The detailed description set forth below is intended as a description of the present 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.

(2) 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.

(3) 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.

(4) 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.

(5) 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.

(6) The present invention is further described in with the following examples:

Example 1

(7) In one aspect, a method of making reconstituted bamboo lumber used for outdoor bamboo flooring, comprising the steps of (1) select the material, cut into the required length; (2) split, defiber into reticular fiber bundles; (3) conduct high-temperature treatment, dry the treated materials and immerse into glues, and then conduct the second drying; (4) perform pressing and curing; and (5) cut into pieces.

(8) In one embodiment, the raw material taken from step (1) is raw bamboo of more than two years' growth, and the cutting of the bamboo segments at the required length should avoid the bamboo joint. The defibration process described in step (2) is to place split bamboo strips into a teeth-engaged defiberer and the defiberer compresses the bamboo to physically decompose bamboo fibers into fiber bundles. The fiber bundles present a reticular structure due to the compression and distortion.

(9) In another embodiment, the high-temperature treatment in step (3) is high-pressure steam cooking, and the high-pressure steam pressure is 0.1˜0.6 mPa, the time of high-pressure steam cooking is 0.5 to 6 hours, and the drying effect is that the moisture content of fiber bundles is 15% or less. The drying methods may be drying by a dryer or drying under sunshine or air-drying. The glue immersion process in step (3) is to make all small units of bamboo fiber bundles to fully absorb the glue. The glue solid content in the bamboo fiber bundles after immersion can reach 5% to 20%, and for the second drying, the average water content of the bamboo fiber bundles immersed with glue drops to less than 20%. The glue-containing bamboo fiber bundles after second drying should be set aside for more than 24 hours until the moisture is even. In still another embodiment, the glue used in step (3) is a water-soluble phenol glue generated by the reaction of a formaldehyde solution with phenol in an alkaline environment, and the formaldehyde solution is a solution of formaldehyde containing 0.5% to 15% methanol. Then the water-soluble phenol glue prepared is modified with resorcinol, or modified with organic silicone, or modified with polyethylene, or modified with nano-silicon or modified with melamine, with the ratio of modifier at 0.5%˜10%. The prepared glue is the glue used for immersion in step (3) in the present invention.

(10) For the hot pressing and curing described in step (4), the glued bamboo fiber bundles after pretreatment are placed to a mold, and the mold volume is established according to the density of 1.1 to 1.5 g/cm.sup.3, and then delivered to a hot pressing machine, to perform hot pressing and curing by controlling the board surface contact pressure at 5 to 15 MPa. The hot pressing temperature is between 120° C. and 160° C., the curing time is 1.1 to 1.6 min/mm. After curing, the boards are cooled down until the board core temperature is below 80° C. The mold is then ready for assembling, and the assembling process is to place all fiber bundles to the mold by layers according to longitudinal or crisscross direction. Before the cutting in step (5), and after the boards have been hot pressed, the boards should be stored for more than three days to release internal stress, and then cut.

Example 2

(11) A method of making reconstituted bamboo lumber used for outdoor bamboo flooring, comprising the steps of (1) select the material, cut into the required length; (2) split, defiber into reticular fiber bundles; (3) conduct high-temperature treatment, dry the treated materials and immerse into glues, and then conduct the second drying; (4) perform pressing and curing; and (5) cut into pieces.

(12) In one embodiment, the raw material taken from step (1) is raw bamboo of more than two years' growth, and the cutting of the bamboo segments at the required length should avoid the bamboo joint. The defibration process described in step (2) is to place split bamboo strips into a teeth-engaged defiberer and the defiberer compresses the bamboo to physically decompose bamboo fibers into fiber bundles. The fiber bundles present a reticular structure due to the compression and distortion.

(13) In another embodiment, the high-temperature treatment in step (3) is high-temperature carbonization of fiber bundles in a carbonization equipment after drying. The temperature of high-temperature carbonization is between 150° C. and 250° C., and the time is 6 to 15 hours. The glue immersion process in step (3) is to make all small units of bamboo fiber bundles to fully absorb the glue. The glue solid content in the bamboo fiber bundles after immersion can reach 5%˜20%, and for the second drying, the average water content of the bamboo fiber bundles immersed with glue drops to less than 20%. The glue-containing bamboo fiber bundles after second drying should be set aside for more than 24 hours until the moisture is even. More specifically, the glue used in step (3) is a water-soluble phenol glue generated by the reaction of a formaldehyde solution with phenol in an alkaline environment, and the formaldehyde solution is solution of formaldehyde containing 0.5% to 15% methanol. Then the water-soluble phenol glue prepared is modified with resorcinol, or modified with organic silicone, or modified with polyethylene, or modified with nano-silicon or modified with melamine, with the ratio of modifier at 0.5% to 10%. The prepared glue is the glue used for immersion in step (3) in the present invention.

(14) For the hot pressing and curing described in step (4), the glued bamboo fiber bundles after pretreatment are placed to a mold, and the mold volume is established according to the density of 1.1 to 1.5 g/cm.sup.3, and then delivered to a hot pressing machine, to perform hot pressing and curing by controlling the board surface contact pressure at 5 to 15 MPa. The hot pressing temperature is between 120° C. and 160° C., the curing time is 1.1 to 1.6 min/mm; after curing, cool down until the board core temperature is below 80° C. before taking out the boards. The mold is ready to be assembled, and the assembling is to place all fiber bundles to the mold by layers according to longitudinal or crisscross direction. Before the cutting in step (5), the boards after hot pressing should be stored for more than three days to release internal stress, and then cut.

Example 3

(15) In a further aspect, a method of making reconstituted bamboo lumber used for outdoor bamboo flooring, comprising the steps of (1) select the material, cut into the required length; (2) split, defiber into reticular fiber bundles; (3) conduct high-temperature treatment, dry the treated materials and immerse into glues, and then conduct the second drying; (4) perform pressing and curing; and (5) cut into pieces.

(16) In one embodiment, the raw material taken from step (1) is raw bamboo of more than two years' growth, and the cutting of the bamboo segments at the required length should avoid the bamboo joint. The defibration process described in step (2) is to place split bamboo strips into a teeth-engaged defiberer and the defiberer compresses the bamboo to physically decompose bamboo fibers into fiber bundles. The fiber bundles present a reticular structure due to the compression and distortion.

(17) In another embodiment, the glue immersion process in the step (3) is to make all small units of bamboo fiber bundles to fully absorb the glue. The glue solid content in the bamboo fiber bundles after immersion can reach 5% to 20%, and for the second drying, the average water content of the bamboo fiber bundles immersed with glue drops to less than 20%. The glue-containing bamboo fiber bundles after second drying should be set aside for more than 24 hours until the moisture is even. The pressing is cold pressing, the cold pressing is to place the glued bamboo fibers in a mold firstly, then lock them by lock pins after pressing, and then place them with the mold to a heating device for heating. Before the cutting in step (5), the boards after hot pressing should be stored for more than three days to release internal stress, and then cut.

(18) 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.