U.S. patent number 3,908,902 [Application Number 05/410,171] was granted by the patent office on 1975-09-30 for molded or extruded synthetic railroad ties, beams and structural members.
This patent grant is currently assigned to Collins Synthetics, Inc.. Invention is credited to Benjamin P. Collins, John J. Novello.
United States Patent |
3,908,902 |
Collins , et al. |
September 30, 1975 |
Molded or extruded synthetic railroad ties, beams and structural
members
Abstract
This invention relates to railroad ties and the like, such as
beams and structural members, and particularly to articles of
recycled wood and to the process of making the same.
Inventors: |
Collins; Benjamin P. (Turners
Falls, MA), Novello; John J. (Weston, CT) |
Assignee: |
Collins Synthetics, Inc. (New
Haven, CT)
|
Family
ID: |
23623539 |
Appl.
No.: |
05/410,171 |
Filed: |
October 26, 1973 |
Current U.S.
Class: |
238/83; 264/109;
524/16; 524/14; 524/34 |
Current CPC
Class: |
E01B
3/44 (20130101) |
Current International
Class: |
E01B
3/00 (20060101); E01B 3/44 (20060101); E01B
003/02 () |
Field of
Search: |
;260/17,16,9
;238/83,84,37,29 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wood, Jr.; M. Henson
Assistant Examiner: Bertsch; Richard A.
Attorney, Agent or Firm: Smythe & Moore
Claims
What is claimed is:
1. A waste wood structural member composed of:
2. A waste wood structural member as claimed in claim 1 wherein the
structural member is a railroad tie.
3. A waste wood structural member composed of:
4. A waste wood structural member as claimed in claim 3 wherein the
structural member is a railroad tie.
Description
This invention relates to railroad ties, beams and structural
members made from waste wood.
Railroad ties have been made of wood for many years, the ties being
placed on rock ballast and having the steel rails carried thereon
and fastened thereto, such as by spikes or the like. Wood
deteriorates in spite of being impregnated with a preservative,
such as creosote. The ties are of such a size that wood must be
obtained from large size trees without defects, such as splits, and
suitable lumber or wood is becoming scarce. Other types of
material, such as concrete or metal, have not been satisfactory
because of weight and improper resiliency. Also, concrete is
subject to cracking because of water freezing. Due to the
aforementioned scarcity of lumber, beams and similar structural
members of high strength also have been expensive and difficult to
obtain. It is known to make thin particle board from wood chips and
thermosetting resins, such as in U.S. Pat. No. 3,463,746.
One of the objects of the invention is to provide an improved
railroad tie, structural member, or the like, which is relatively
inexpensive and yet will perform satisfactorily in service and the
method of making the same.
In one aspect of the invention, recycled comminuted railroad ties,
as well as waste wood, such as wood chips or bark, can be mixed
with thermoplastic polyester resin and catalyst and subjected to
high pressure and heat to form a railroad tie, structural beam or
the like. The term "structural beam" is meant to include load
bearing members for buildings or other structural use. The mixture
also can include fire retardants and reinforcing means, such as
wood slabs as obtained in lumber milling operations. The waste wood
has its moisture content controlled so as to have a moisture
retention of at least 30 percent by weight. The ties and beams have
a relatively high density in the range of 50 to 70 lbs. per cu. ft.
and with a high strength.
Other objects, advantages and features of the present invention
will become apparent from the accompanying description and
drawings, which are merely exemplary.
IN THE DRAWINGS
FIG. 1 is a fragmentary perspective view of a tie with rails
thereon;
FIG. 2 is a schematic view of one manner of making a tie; and
FIG. 3 is a fragmentary perspective sectional view of a tie showing
the chips therein.
Referring to FIG. 1, a railroad tie 10 is normally partially
embedded or laid on crushed rock ballast 11. Rails 12, 13 are laid
on top of tie 10 and can be held in place in various known manners,
such as by spikes 14, 15.
Old or used railroad ties can be cut or comminuted or made into
wood chips for use in producing the tie of the present invention.
If the tie has creosote therein and it is deemed necessary, the
creosote can be removed in any known manner, such as acetone or the
like.
Other waste wood products, such as bark resulting from lumber
milling or chips produced in milling, can be used as will appear
hereafter. Merely by way of example, the chips can be 1/4 to 1/2
inch in length and the comminuted tie fibers can be 3/4 inch
long.
The recycled tie chips or fibers and/or the waste wood is mixed
with thermoplastic polyester resin and then placed in a mold and
pressed under heat and pressure.
Alternatively, the mixture can be extruded as shown in FIG. 2. The
waste wood to be extruded along with the resin and additives are
placed in hopper 16 and extruded through dies 17 by screw 18 to a
receiving station 19. Heat is applied as is known in the extrusion
art. The finished tie 20 or structural member is sized as desired.
Other suitable catalysts can be used, including those which do not
require external heat for action.
The waste wood should be dried or treated before molding or
extrusion so that it has a moisture retention of at least
approximately 30 percent by weight and preferably about 35
percent.
As one specific example, a tie or beam can be produced which is
composed of:
Percentage by Weight ______________________________________ Waste
wood 50% Polyester resin, GR 117 25% Aluminum hydrate, Alcoa 331
23% Benzyl peroxide powder catalyst 1% Dimethyl aniline catalyst 1%
______________________________________
The thermoplastic resin is that furnished by W. R. Grace Co. under
the identification of GR 117. Greater flexibility in the ties and
beams was obtained by using a polyester resin furnished by W. R.
Grace under the identification of GR 14010.
Aluminum hydrate can be added to the mix together with the catalyst
for the polyester resin.
The structural member can have a composition in accordance with the
following approximate ranges:
Percentage by Weight ______________________________________ Waste
wood 38% - 65% Aluminum hydrate 25% - 23% Polyester resin GR 117 or
GR 14010 35% - 10% Dimethyl aniline 1% -- 1% Catalyst Benzyl
peroxide powder 1% -- 1% mixed with
______________________________________
When placed in a mold, a pressure of 300 to 800 p.s.i. can be
applied for 15 to 30 minutes at 250.degree.F. to 300.degree.F. A
density of 50 to 70 lbs. per cu. ft. is obtained.
As a reinforcing means, slabs of wood also could be included in the
mix. As an example, ties are normally 8 feet 6 inches to 9 feet 0
inch in length and are approximately 6 inches .times. 8 inches or 7
inches .times. 9 inches in cross section. The slabs can extend
longitudinally in the member to within about 2 inches of each end,
there being a single slab, more than one slab, or overlapping
slabs.
It should be apparent that changes in details of construction and
arrangement of parts may be made without departing from the spirit
of the invention except as defined in the appended claims.
* * * * *