Note: Descriptions are shown in the official language in which they were submitted.
CA 02582817 2007-03-27
NON-ORGANIC COMPOSITE LUMBER
BACKGROUND
[0001] The present invention relates to composite lumber manufactured from non-
organic
materials.
[0002] Composite lumber made from both natural and synthetic materials is
known in the art.
When natural organics such as wood fillers and the like are utilized, this
composite lumber
material is susceptible to color fading, rotting and molding. When such
composite lumber
material absorbs moisture, it has the potential to behave like wood leading to
serious problems
like cracking, fading, rotting, warping and loss of strength. Most synthetic
composite lumber
materials fade dramatically over the first few years and some start to lose
their original color
within sixty days due to their organic materials.
SUMMARY
[0003] In one embodiment, the invention includes a composite lumber material
comprising at
least one plastic in an amount by weight less than 90% and at least one
mineral in an amount by
weight greater than 10%. In another embodiment, the invention includes a
composite lumber
material comprising at least one plastic in an amount by weight in the range
of 50-60% and at
least one mineral in an amount by weight in the range of 40-50%. In another
embodiment, the
invention includes a composite lumber material comprising HDPE in an amount by
weight in the
range of 50-60% and at least one mineral in an amount by weight in the range
of 40-50%, said
mineral including at least one of talc, calcium carbonate and wollastonite. In
another
embodiment, the invention includes a composite lumber material comprising HDPE
in an
amount by weight in the range of 50-60%, at least one mineral in an amount by
weight in the
range of 40-50%, a coupling agent, a blowing agent and a pigment.
[0004] Other aspects of the invention will become apparent by consideration of
the
accompanying drawings and detailed description.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Fig. 1 is a perspective view of a piece of composite lumber of the
present invention.
[0006] Fig. 2 is an end view of the composite lumber.
DETAILED DESCRIPTION
[0007] Before any embodiments of the invention are explained in detail, it is
to be
understood that the invention is not limited in its application to the details
of construction and the
arrangement of components set forth in the following description or
illustrated in the following
drawings. The invention is capable of other embodiments and of being practiced
or of being
carried out in various ways. Also, it is to be understood that the phraseology
and terminology
used herein is for the purpose of description and should not be regarded as
limiting. The use of
"including," "comprising," or "having" and variations thereof herein is meant
to encompass the
items listed thereafter and equivalents thereof as well as additional items.
Unless specified or
limited otherwise, the terms "mounted," "connected," "supported," and
"coupled" and variations
thereof are used broadly and encompass both direct and indirect mountings,
connections,
supports, and couplings. Further, "connected" and "coupled" are not restricted
to physical or
mechanical connections or couplings.
[0008] Turning to Figs. 1 and 2, the composite lumber 10 of the present
invention is shown.
The composite lumber is shown in the form it exits the manufacturing process.
However, it
should be noted that other forms can be utilized and the manufactured product
can be cut into
various shapes as need for any given application.
[0009] The composite lumber includes no organic components. By weight, the
composite
lumber is primarily comprised of at least one plastic and at least one
mineral. Other components
can include a blowing agent, a coupling agent and pigments. It should be noted
that other
components and additives can be added as desired.
[0010] Preferably, the plastic component is a polymeric compound such as a
high density
polyethylene (HDPE) and, by weight, makes up less than 90% of the composite
lumber, and
more preferably makes up in the range of 50-60% by weight of the composite
lumber. The
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source of the plastic can either be virgin or recycled as are available from
many commercial
sources. It should be noted that other types of plastic or more than one
plastic can also be
utilized.
[0011] Preferably, the mineral component makes up more than 10% by weight of
the
composite lumber, and more preferably makes up in the range of 40-50% by
weight of the
composite lumber. For example, at least one of the following minerals can be
utilized in the
instant invention: talc, calcium carbonate and wollastonite. All three of
these minerals can be
used and in the following ranges: 0-5% wollastonite, 0-35 % calcium carbonate
and the
remainder talc. The mineral component of the composite lumber enhances the
manufacturing
process due to increased flowability and addition to the strength of the
composite lumber. It
should be noted that minerals other than the three examples set forth above
can also be utilized in
the present invention. The minerals are available from many commercial
sources.
[00121 A blowing agent such as nitrogen is preferably added to lighten the
composite
lumber. For example, the end weight of the composite lumber is less than or
equal to about 2.4
lb/ft for a 5'/a inch board. Preferably, the blowing agent makes up 0-3% by
weight of the
composite lumber. The blowing agent is available from many commercial sources.
[0013] A coupling agent is preferably added to the composite lumber. An
example of such a
coupling agent is Epolene G-2608 polymer available from the Eastman Chemical
Company. The
coupling agent aids in thoroughly mixing the components prior to manufacture
of a finished
product. Preferably, the coupling agent makes up 0-3% by weight of the
composite lumber. The
coupling agent is available from many commercial sources.
[0014] The composite lumber can include pigments as are well know in the art
and available
from many commercial sources. The amount of pigment added can vary as is
desired for a given
finished product.
[00151 The composite lumber can be manufactured using many traditional
processes such as
extrusion and blow molding. Preferably, the composite lumber is extruded as is
known in the
art. Prior to extrusion, the plastic and mineral components are mixed and
pelletized. The
resulting pellets are dried to remove moisture to approximately 0.02%
moisture. The pellets are
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then mixed with the blowing agent, the coupling agent and the pigment and then
fed to the
extruder. The dimensions of the composite lumber exiting the extruder can be
changed as
desired. Further, any pattern 12 can be included on the surface of the
composite lumber as is
shown in Fig. 1. The pattern can be incorporated such as through the use of a
die during the
manufacturing process.
[0016] The composite lumber is entirely non-organic. As such, it cannot absorb
moisture
and is 100% moisture proof. As such, its color retention is superior to
organic based composite
lumber materials. The composite lumber of the present invention will not rot,
absorb moisture,
mold nor become termite infested.
[0017] As an example, one formulation of the composite lumber includes the
following
components:
55% plastic (HDPE)
40% minerals (of which 100% is talc)
3% additives (of which 2.0% is a coupling agent and 1.0% is a bonding agent)
2% pigment.
[0018] This formulation of a composite lumber of the present invention meets
or exceeds all
ICC test requirements. Technical data on this specific formulation is as
follows.
Table 1
PROPERTIES TEST METHOD UNIT TEST RESULT
Modulus of Elasticity 720 F ASTM D6109 PSI 245,419
Modulus of Elasticity -201 F ASTM D6109 PSI 584,860
Compression Strength 72 F ASTM D6108 PSI 3,000
Compression Strength -30 F ASTM D6108 PSI 4,000
Modulus of Rupture ASTM D6109 PSI 3,327
Specific Gravity ASTM D6111-97 1.13
Flexural Strength ASTM D790 PSI 3,500.00
Falling Dart Impact Strength 72 F ASTM D5420 Lbs 350.00
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PROPERTIES TEST METHOD UNIT TEST RESULT
Falling Dart Impact Strength -30 F ASTM D5420 Lbs 550.00
Nail Retention ASTM D6117 Lbs 350.00
Screw Retention ASTM D6117 Lbs 600.00
Tensile Strength ASTM D638 PSI 2,100.00
Coefficient of Linear Thermo ASTM D6341 3.5x10-5
Expansion & Contraction
Shear Test Strength ASTM D6435 PSI 1,200.00
Water Absorption ASTM D1037 0.05%
Flame Spread Index ASTM E84 Class 2(B)
Smoke Index ASTM 750
100191 The uses of the composite lumber of the present invention are numerous
and include,
for example, as decking, patios, piers, docks, fencing, stair cases, spindles,
railings, trailers,
picnic tables, pool decks and many other applications in which a traditional
wood product can be
used.
[00201 Various features and advantages of the invention are set forth in the
following claims.
