PLASTIC COATED LUMBER AND LOGS

BOIS D'OEUVRE ET GRUMES ENDUITS DE PLASTIQUE

English Abstract

A building element having a core of compressed fibrous
material and a sheathing of plastic molded over the core.

Claims

6
I CLAIM:
1. A building element, comprising:
(a) a core of compressed fibrous material;
(b) a sheathing of plastic molded over said core.
2. A building element according to claim 1, wherein said core
is made of scrap wood.
3. A building element according to claim 1, wherein said
plastic is recycled plastic.
4. A building element according to claim 1, wherein said core
and sheath are elongated and round having an elongated concavity
along a bottom and a semi-circular recess with an axis
perpendicular to an axis of said core and sheath.
5. A method of forming a building element, comprising:
(a) bundling fibrous material into an elongated rounded
cross section
(b) compressing said bundled fibrous material; and
(c) molding plastic around said bundled fibrous material to
form a plastic sheath.
6. A method according to claim 5, wherein said fibrous material
is scrap wood.

7
7. A method according to claim 5, wherein said plastic is
recycled plastic.

Description

CA 02383867 2002-04-29
PLASTIC COATED LUD~ER AND LOGS
FIELD
The present invention relates to building product made from
acrap wood or other fibrous material and over molded with a
:recycled low grade plastic.
Currently, the type of structure that is erected in third
world countries to house the poor range from mud huts with leaves
and grass on the roof to structures made from bamboo or whatever
:indigenous material is available. Often such structures are dark
and easily penetrated by snakes and insects and do not provide
ample weatherability. Occasionally material such as stone is
available but unless it is close by it usually involves heavy
:Lifting and a mode of transport. In refugee camps, shelter is
provided by various tents ranging from military style to plastic
sheets fastened over poles. In large slums around cities such as
Cairo, Rio, Bogota, empoverished families live in shelters that
<~re made from anything that can be found in the landfills or
dumped by the roadside. Consequently, there is a need for a
building element that can be manufactured locally, is inexpensive
<~nd can be easily transported and erected.
SUi~ARY OF THE INVENTION
According to the invention there is provided a building
Eslement having a core of compressed fibrous material and a
:sheathing of plastic molded over the core.

CA 02383867 2002-04-29
2
Preferably the core is made of scrap wood and the plastic is
:recycled plastic.
Advantageously, the core and sheath may be elongated and
:round having an elongated concavity along a bottom and a semi-
circular recess with an axis perpendicular to an axis of the core
<~nd sheath.
In an alternative aspect of the invention there is provided
;~ method of forming a building element, namely, bundling fibrous
material into an elongated rounded cross section, compressing the
bundled fibrous material; and molding plastic around the bundled
:Fibrous material to form a plastic sheath.
The composite lumber or log is both durable and long-lived
:Lasting up to 50 years without maintenance. It has excellent
structural characteristics, thermal properties and a pleasing
appearance. Provided in the form of a pre-cut kit, it can be
assembled within a few days with minimal expertise.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages will be apparent from the
:Following detailed description, given by way of example, of a
~~referred embodiment taken in conjunction with the accompanying
drawings, wherein:

CA 02383867 2002-04-29
3
Fig. 1 is a perspective view of a log consisting of a
fibrous material encased in plastic;
Fig. 2 is a perspective view of three logs being fitted
together at a corner of a structure being assembled;
Fig. 3 is an assembled log structure without a door, window
or roof; and
Fig. 4 is a partial perspective view of an alternative log
:in which long pieces of waste wood are encased in plastic.
D$TAILED DESCRIPTION TnTITH RLl'~SRENCE TO TH8 DRAWINGS
Referring to Fig. 1 a log 10 is formed by first bundling
;acrap wood and lumber material and then over molding it with
=recycled mixed plastic being mainly high and low density
polyethylene. The log 10 is formed with semi-circular recess 18
at ends, which are to intersect at right angles with another log
10. A pinhole 11 is formed vertically so that it passes into the
center of the recess and permits the passage of a retaining pin
(not shown). The bottom of the log 10 has a slight elongated
concavity 16, which conforms to the curvature of an underlying
:Log 10. The wood is bundled by first filling an elongated mold
with scrap wood, compressing the mixture into the shape shown,
:inserting this core bundle into a a second mold which has a
:Larger cross section and then injecting the plastic between the
mold and the compressed wood core. Optionally, a wood-bonding

CA 02383867 2002-04-29
4
agent can be mixed with the wood in order to enhance the strength
of the log.
Fig. 2 shows how several logs are stacked at an intersection
of two walls. In this case log 10A is laid down first and then
log 10B is fitted at its recess over log 10A. Next log 10C is
fitted over log 10B and log 10A. This methodology is continued
until both walls are erected. A final structure 20 is shown in
:fig. 3 complete with doorway 22, window openings 24 and roof
beams 26. A roof is built atop logs 26 which are thicker at one
~=nd than the other to allow for water drainage. The roof can be
completed using whatever materials are available such as bamboo,
grass, or branches. Similarly, the door and windows can be made
From bamboo tied with soft. reeds or totally from a material
;similar to that which is used to make baskets. Alternatively, for
<~. higher grade permanent housing, regular doors and windows can
be fitted into the openings as they would be in a traditional log
cabin or a prefabricated laminated log building.
Referring to Fig. 4 an alternative high strength log 30 is
made by bundling elongated wood scraps 32, compressing them and
i~hen over molding with a plastic sheath 34. The elongated wood
32 provides considerable additional bending strength.
While logs have been formed using this method, it is obvious
that there are a wide variety of shapes that can be made such as

CA 02383867 2002-04-29
'S
rectangular lumber and square posts. A coloring pigment can be
.added to the plastic if desired.
It is also obvious that while scrap wood has been recited,
many other types of fibrous materials could be used such as
bamboo, logging debris, branches, reeds, cardboard tubes and the
like.
Accordingly, while this invention has been described
with reference to illustrative embodiments, this description is
not intended to be construed in a limiting sense. Various
modifications of the illustrative embodiments, as well as other
embodiments of the invention, will be apparent to persons skilled
:in the art upon reference to this description. It is therefore
contemplated that the appended claims will cover any such
modifications or embodiments as fall within the true scope of the
:invention.

Representative Drawing