EP0907503B1

EP0907503B1 - Parallel randomly stacked, stranded, bamboo beams

Info

Publication number: EP0907503B1
Application number: EP96921801A
Authority: EP
Inventors: Jay Plaehn
Original assignee: B3 TECHNOLOGIES Inc
Current assignee: A & A PUCHY FAMILY TRUST
Priority date: 1996-06-26
Filing date: 1996-06-26
Publication date: 2002-08-28
Anticipated expiration: 2016-06-26
Also published as: DE69623346T2; EP0907503A4; DE69623346D1; ES2184877T3; WO1997049547A1; ATE222846T1; BR9612688A; EP0907503A1; AU6292296A

Abstract

A composite bamboo beam for use as a substitute for natural wood beams. Segments of bamboo stalk, either split or whole, are longitudinally aligned and randomly stacked. The bamboo segments are compressed and bonded together to form a cohesive bamboo composite structure from which beams of the desired dimension may be cut.

Description

The present invention relates to parallel randomly stacked, stranded, bamboo beams.

Wood beams are generally cut from naturally grown trees. However, trees are limited in supply due to the long time necessary for a tree to reach maturity. Also, the supply of natural wood is limited by the deforestation that is now occurring in many parts of the world.

One approach to this problem has been to resort to producing composite lumber formed out of wood products, lignocellulosic materials or reconsolidated wood products, to make lumber products. Generally, producing composite lumber involves splitting, mashing, gluing and manufacturing artificial wood from wood products to manufacture lumber products such as plywood, particle boards and chip boards.

Additionally, US Patent No. 4,810,551 shows a plywood made from sheets of bamboo comprising strands of bamboo glued together side by side to make bamboo sheets of laminated strips where each sheet of bamboo runs perpendicular to the one below or above it, creating the conventional plywood cross grain layered design. It also claims a layered bamboo board made from sheets of bamboo stacked with the grain running in the same direction and glued together.

Therefore, there is a need for a natural wood beam substitute which is less expensive and at least as equally strong as natural wood beams. The beam must be composed of a material which is readily available and easily replenished, and which is not a threat to the environment.

According to the present invention, there is provided a bamboo beam comprising, in combination: a plurality of bamboo segments, each of said bamboo segments having a length, width and a longitudinal axis, the longitudinal axes of said segments being generally parallel to one another, said segments having a random horizontal and vertical orientation about the length and width of each of said segments, respectively, said segments also having a random rotational orientation with regard to the longitudinal axis of each said segments and said segments being compressed and bonded together to form a single integral structure.

The bamboo beam may further comprise wood fillers between said bamboo segments, wherein said wood fillers eliminate gaps within said bamboo beam created by said random horizontal, vertical and rotational orientation of said bamboo segments.

Said bamboo segments may have a width from 6.35 to 19.05 mm (¼ to ¾ inch), a majority of said bamboo segments having a length from 1.52 to 6.10 m (5 to 20 feet).

Said bamboo segments may be longitudinal segments of whole bamboo stocks.

The bamboo beam may have a length, width and height, the longitudinal axes of said segments being generally parallel with the length of the bamboo beam and said segments being otherwise randomly oriented with respect to each other about the width and height of the bamboo beam.

The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:-

FIG. 1 is a front view of a composite bamboo beam;

FIG. 2 is an exploded view of a corner of the composite bamboo beam to show more clearly the end grain and the flat surface of the beam which is consistent on all sides and ends of the composite bamboo beam;

FIG. 3 is a side view of the composite bamboo beam; and

FIG. 4 is a top view of the composite bamboo beam.

Referring to Fig. 1, a bamboo beam is generally designated as 10 and has a core 1 and an outer surface 2.

The core 1 consists of bamboo segments 3 which have been bonded and compressed together to form an adhesive structure. As shown more clearly in Fig. 2, the core 1 may contain gaps due to the cross-sectional shapes of the bamboo segments 3 and the randomness of the stacking of the segments 3.

The outer surface 2 is prepared by milling the adhesive structure to a desired dimension. In Figs. 1, 3 and 4, the beam 10 is shown as having four side surfaces and two end surfaces, defining a conventional beam dimension.

In the preferred embodiment, bamboo stalks are split open and dried in segments 3 ranging from 6.3 5 to 19.05 mm (¼ to ¾ inch) in width to approximately 1.52 to 6.10 m (5 to 20 feet) in length. The segments 3 can be as short as 1.52 m (5 feet) or less in small percentages. An adhesive suitable for bamboo is evenly applied to the dried segments 3 and the segments 3 are aligned in parallel fashion and stacked randomly. The stack is then fused under pressure until it results in a cohesive structure. When the stack has dried and is cohesive, it is milled into the desired beam dimensions.

It has been discovered that the resulting beams, regardless of variations in dimension, exhibit a uniform structural consistency which is highly desirable in lumber products. It was also discovered that a bamboo beam according to this invention produced a beam which is lighter and oftentimes stronger than conventional construction grade lumber.

Additionally, suitable wood fillers 4 can be introduced into the stack before compression to eliminate any gaps which may exist in the core 1 of the bamboo beam 10.

Claims

A bamboo beam (10) comprising, in combination: a plurality of bamboo segments (3), each of said bamboo segments having a length, width and a longitudinal axis, the longitudinal axes of said segments (3) being generally parallel to one another, said segments (3) having a random horizontal and vertical orientation about the length and width of each of said segments (3), respectively, said segments (3) also having a random rotational orientation with regard to the longitudinal axis of each said segments and said segments (3) being compressed and bonded together to form a single integral structure.
A bamboo beam (10) according to claim 1, further comprising wood fillers (4) between said bamboo segments (3), wherein said wood fillers eliminate gaps within said bamboo beam (10) created by said random horizontal, vertical and rotational orientation of said bamboo segments (3).
A bamboo beam according to claim 1 or 2, wherein said bamboo segments (3) have a width from 6.35 to 19.05 mm (¼ to ¾ inch), a majority of said bamboo segments (3) having a length from 1.52 to 6.10 m (5 to 20 feet).
A bamboo beam (10) according to any preceding claim, wherein said bamboo segments (3) are longitudinal segments of whole bamboo stocks.
A bamboo beam (10) according to any preceding claim, having a length, width and height and wherein the longitudinal axes of said segments (3) are generally parallel with the length of the bamboo beam (10) and said segments (3) are otherwise randomly oriented with respect to each other about the width and height of the bamboo beam (10).