System and process for recycling waste material produced by a glass fiberizing process

The waste material processing system of the present invention includes a (1) waste material supply; (2) shredder; (3) moisture reducing device; (4) crusher having a rotatable screw auger positioned within a cavity of the crusher for crushing and conveying waste material and a pressurizing device such as a conduit attached to the discharge end of the cavity for exerting a backpressure upon a portion of the waste material positioned about the second end of the auger such that a portion of the scrap glass fibers in the waste material is crushed; (5) dryer; and (6) separating device for separating waste material having a mean average length of less than about 5 millimeters from oversized dried waste material. Also provided by the present invention is a process for recycling waste material using the system.

CROSS REFERENCE TO RELATED APPLICATION 
This patent application is related to the copending U.S. Patent Application 
of Curtis L. Hanvey, Jr. entitled "SYSTEMS AND PROCESSES FOR RECYCLING 
GLASS FIBER WASTE MATERIAL INTO GLASS FIBER PRODUCT", filed concurrently 
with the present patent application. 
FIELD OF THE INVENTION 
The present invention relates to recycling waste material produced by a 
glass fiberizing process and, more particularly, to processing waste glass 
fibers for reuse as a glass fiber batch melt ingredient. 
BACKGROUND OF THE INVENTION 
As raw material and waste disposal costs for glass fiber production 
escalate and environmental concerns regarding waste disposal increase, 
recycling waste glass fibers provides a cost effective means to decrease 
such costs and alleviate associated environmental concerns. 
In the fiber glass industry, waste glass fibers can be produced in the 
fiber forming process and in subsequent processing operations, such as in 
the formation of yarns, fabrics, roving, chopped reinforcement and mat 
products. Various approaches have been used to process and recycle such 
waste glass fibers. 
U.S. Pat. No. 5,352,258 discloses a process and apparatus which shred scrap 
glass fibers, dry the shredded glass fibers, remove contaminants such as 
metallic materials, and feed the shredded glass fibers to a glass melter. 
The feeder is preferably an auger feeder having a dead space at the end of 
the auger adjacent the melter. The dead space permits build up of shredded 
glass fiber material to insulate the metal auger from the heat of the 
melter, as discussed at column 11, lines 31-35 of the patent. The dead 
space has a length of around 1 to 12 inches along the longitudinal axis of 
the auger and before the interior of the melter, as discussed at column 
13, lines 5-11. 
U.S. Pat. No. 4,145,202 discloses a method for processing waste glass 
strands which includes the steps of cutting and draining free water from 
the glass strands, removing metal from the strands, drying and 
incinerating the strands, sieving the strands and, if the particles are 
too large, grinding or milling the strands to 60 to 325 mesh range. 
Typical grinding and milling operations are energy-intensive, have high 
maintenance costs and therefore are not economically desirable to include 
in a recycling process. Also, it is often difficult to pneumatically 
convey recycled glass fibers. There is a need for a system and process for 
recycling glass fibers which requires minimal energy input, is efficient, 
durable, inexpensive, and provides glass fiber material which is 
conveyable by pneumatic transport and compatible with the glass melt. 
SUMMARY OF THE INVENTION 
The present invention provides a waste material processing system 
comprising: (a) a waste material supply, the waste material being produced 
by a glass fiberizing process and comprising scrap glass fibers; (b) a 
shredder positioned to receive waste material from the waste material 
supply, the shredder for shredding the waste material to form shredded 
waste material; (c) a moisture reducing device positioned to receive 
shredded waste material from the shredder, the moisture reducing device 
for reducing the mean average moisture content of the shredded waste 
material to form moisture-reduced waste material; (d) a crusher 
comprising: (1) a body comprising a cavity having a first end positioned 
to receive the moisture-reduced waste material from the moisture reducing 
device, a second end distal to the first end, and a length therebetween; 
(2) a rotatable screw auger positioned within the cavity of the body for 
crushing and conveying the moisture-reduced waste material from the first 
end of the cavity in a first direction toward the second end of the 
cavity, the auger having a first end proximate the first end of the 
cavity, a second end proximate the second end of the cavity, and a length 
therebetween; and (3) a pressurizing device for exerting a pressure 
ranging from about 1.38.times.10.sup.4 to about 5.51.times.10.sup.6 
pascals upon at least a portion of the moisture-reduced waste material 
positioned about the second end of the auger in a direction generally 
opposite to the first direction in which the auger conveys the 
moisture-reduced waste material such that the portion of the scrap glass 
fibers in the moisture-reduced waste material is crushed to form crushed 
glass fibers; (e) a dryer positioned to receive the moisture-reduced waste 
material from the crusher, the dryer for drying the moisture-reduced waste 
material to form dried waste material having a mean average moisture 
content of less than about one weight percent; and (f) a separating device 
positioned to receive the dried waste material from the dryer, the 
separating device for separating the dried waste material into a first 
portion of dried waste material having a mean average length of less than 
about 5 millimeters from oversized dried waste material. 
Also provided by the present invention is a waste material processing 
system comprising: (a) a waste material supply comprising waste material 
produced by a glass fiberizing process and comprising scrap glass fibers; 
(b) a shredder positioned to receive waste material from the waste 
material supply, the shredder for shredding the waste material to form 
shredded waste material; (c) a moisture reducing device positioned to 
receive shredded waste material from the shredder, the moisture reducing 
device for reducing the mean average moisture content of the shredded 
waste material to form moisture-reduced waste material; (d) a pulverizer 
positioned to receive the moisture-reduced waste material from the 
moisture reducing device, the pulverizer for pulverizing a major portion 
of the moisture-reduced waste material into pulverized waste material 
having a mean average length of less than about 20 mesh; (e) a dryer 
positioned to receive the moisture-reduced waste material from the 
pulverizer, the dryer for drying the moisture-reduced waste material to 
form dried waste material having a mean average moisture content of less 
than about one weight percent; and (f) a separating device positioned to 
receive the dried waste material from the dryer, the separating device for 
separating the dried waste material into a first portion of dried waste 
material having a mean average length of less than about 3 millimeters 
from oversized dried waste material. 
Also provided by the present invention is a process for recycling waste 
material produced by a glass fiberizing process, the waste material 
comprising scrap glass fibers, the process comprising the steps of: (a) 
shredding glass fiber waste material; (b) drying the glass fiber waste 
material to form moisture-reduced waste material; (c) crushing the 
moisture-reduced waste material in a crusher comprising: (1) a body 
comprising a cavity having a first end positioned to receive the 
moisture-reduced waste material from the moisture reducing device, a 
second end distal to the first end, and a length therebetween; (2) a 
rotatable screw auger positioned within the cavity of the body for 
crushing and conveying the moisture-reduced waste material from the first 
end of the cavity in a first direction toward the second end of the 
cavity, the auger having a first end proximate the first end of the 
cavity, a second end proximate the second end of the cavity, and a length 
therebetween; and (3) a pressurizing device exerting a pressure ranging 
from about 1.38.times.10.sup.4 to about 5.51.times.10.sup.6 pascals upon 
at least a portion of the moisture-reduced waste material positioned about 
the second end of the auger in a direction generally opposite to the first 
direction in which the auger conveys the moisture-reduced waste material 
such that the portion of the scrap glass fibers in the moisture-reduced 
waste material is crushed to form crushed glass fibers; (d) drying the 
moisture-reduced waste material received from the crusher; (e) separating 
a first portion of dried waste material having a mean average length of 
less than about 5 millimeters from oversized dried waste material; and (f) 
feeding the first portion of the dried waste material to a glass melter.

DETAILED DESCRIPTION OF THE INVENTION 
The system and process of the present invention represent an economical, 
durable and environmentally beneficial advance in glass fiber recycling 
technology which provides efficient recycling of glass fiber to a glass 
melting and fiber forming (drawing) operation. Advantages of the system 
and process of the present invention include that the resulting glass 
fiber product can be readily pneumatically transported to facilitate 
recycling of the product to the glass melter and that the system can 
easily accommodate waste from other glass fiber forming and processing 
facilities. Recyclable glass fibers produced using the system and process 
of the present invention surprisingly can have relatively smooth ends and 
low surface organic levels. The system and process of the present 
invention also provide the capability to consolidate waste from different 
glass fiber forming facilities. 
In the manufacture and processing of glass fibers, several different types 
of waste or scrap glass materials suitable for recycling are generated, 
including vitrified glass forming materials such as cullet, frit, glass 
marbles and glass beads; glass fibers which break during winding or 
payout, do not meet size or composition specifications or contain defects 
such as seeds; waste strands of glass fibers generated at the beginning or 
end of the winding process; strands which are not properly coated to 
specification; fibers which are fed through the pull roller device when 
forming packages are not being wound; and discarded forming packages which 
do not meet specifications. Other sources of glass fiber waste material 
include fabrication operations such as drying, twisting, weaving, roving 
and mat fabrication operations, to name a few. 
Glass fibers are a class of fibers generally accepted to be based upon 
oxide compositions such as silicates selectively modified with other oxide 
and non-oxide compositions. Useful glass fibers can be formed from any 
type of fiberizable glass composition known to those skilled in the art, 
and include those prepared from fiberizable glass compositions such as 
"E-glass", "A-glass", "C-glass", "D-glass", "R-glass", "S-glass", and 
E-glass derivatives that are fluorine-free and/or boron-free. As used 
herein, the term "fibers" means a plurality of individual glass filaments. 
As used herein, the term "fiberizable" means a material capable of being 
formed into a generally continuous filament, fiber, strand or yarn. The 
preferred glass fibers to be recycled using the system and process of the 
present invention are E-glass fibers. 
Such compositions and methods of making glass fibers therefrom are well 
known to those skilled in the art and will be discussed in greater detail 
below. If additional information is needed, such glass compositions and 
fiberization methods are disclosed in K. Loewenstein, The Manufacturing 
Technology of Glass Fibres, (3d Ed. 1993) at pages 30-44, 47-60, 115-122 
and 126-135, which are hereby incorporated by reference. 
The waste material preferably includes glass fibers of the same composition 
as the glass melt. For example, it is preferred to use waste material 
containing E-glass fibers as a recycle material for an E-glass melt. 
However, glass fibers of different compositions can be used if any 
imbalance in components is compensated for by adjusting the proportions of 
the non-vitrified batch materials and adding any other components as 
necessary. 
One or more coating compositions can be present on the surfaces of the 
glass fibers to be recycled, although preferably the glass fibers are 
essentially free of any coating compositions. Such coating compositions 
can be applied, for example, by sizing applicator in a manner discussed 
below. Although the glass fibers are preferably washed prior to shredding, 
a portion of the sizing composition can remain on the surfaces of the 
glass fibers. As used herein, "essentially free of any coating 
compositions" means that the glass fibers typically have less than about 
10 weight percent of a coating upon the surfaces thereof and can have less 
than about 2 weight percent of a coating thereon. Preferably, the glass 
fibers have less than about 0.5 weight percent of a coating upon the 
surfaces thereof and are more preferably free of any coating composition. 
Examples of coating compositions typically present on waste glass fibers 
include sizing compositions and secondary coating compositions. As used 
herein, the terms "size", "sized" or "sizing" refer to the aqueous coating 
composition applied to the filaments immediately after formation of the 
glass fibers. The term "secondary coating" refers to a coating composition 
applied secondarily to one or a plurality of strands after the sizing 
composition is applied, and preferably at least partially dried. 
Typical sizing compositions can include as components film-formers such as 
starches, thermoplastic materials and/or thermosetting materials, 
lubricants, coupling agents, emulsifiers and water, to name a few. 
Examples of suitable sizing compositions are set forth in Loewenstein at 
pages 237-287 and U.S. Pat. Nos. 4,390,647, 4,681,802 and 4,795,678, each 
of which is hereby incorporated by reference. 
The waste materials can include not only glass fiber materials, but also 
non-glass materials typically discarded during a glass fiber forming 
operation, such as cardboard forming tubes, graphite gathering shoes, 
refractory materials from the glass melting furnace such as chrome oxide, 
zircon and mullite, steel knives which are used to sever the strand during 
forming and chunks of hardened sizing composition. 
Preferably, the waste materials are essentially free of, and more 
preferably free of, cured matrix materials from reinforced composites. As 
used herein, the phrase "essentially free of cured matrix materials from 
reinforced composites" means that the waste materials utilized in the 
present invention preferably comprise less than about 5 weight percent and 
more preferably less than about 1 weigh percent of cured matrix materials 
from reinforced composites on a total solids basis. 
Referring to the drawings, wherein like numerals indicate like elements 
throughout, there is shown in FIG. 1 a waste material processing system, 
generally designated 10, comprising one or more waste material supplies 
12. The waste material supply 12 comprises waste material 14 produced by a 
glass fiberizing process, which will be discussed in detail below. As 
shown in FIGS. 10-12, the waste material 14 comprises scrap glass fibers 
16 and non-glass materials 18 such as are discussed in detail above. 
The amount of waste material 14 to be processed by the system 10 can be 
about 0.2 to about 10 metric tons per hour (about 500 to about 22,000 
pounds per hour, and is preferably about 3 to about 7 metric tons per hour 
(about 6500 to about 15,000 pounds per hour). The moisture content of the 
waste material 14 can range from about 1 to about 50 weight percent on a 
total weight basis. 
The mean average length of the scrap glass fibers 16 of the waste material 
supply 12 can be about 0.025 to about 200 meters and preferably about 0.5 
to about 50 meters. More preferably, the mean average length of the scrap 
glass fibers 16 ranges from about 0.5 to about 5 meters. 
The nominal filament diameters of suitable scrap glass fibers 16 (shown in 
FIG. 16) can range from about 3.5 micrometers (filament designation B) to 
about 24 micrometers (filament designation U) or larger. Other suitable 
nominal filament diameters are disclosed in Loewenstein at page 25which is 
hereby incorporated by reference. 
Referring to FIG. 16, other useful scrap glass fibers 16 for recycling 
include those which are gathered together by a pull roll 300 during the 
glass fiber forming process, for example when a winding operation is not 
in progress. When coated with a sizing composition, such scrap glass 
fibers 16 tend to clump into bundles having a mean average diameter 
ranging from about 0.001 to about 0.025 meters. 
Also useful for recycling by the present system and process are waste glass 
beads and pieces of frit produced during glass fiber formation, which 
typically have diameters ranging from about 0.001 to about 0.125 meters. 
Bands of glass fibers which are wound about the endcap of a glass fiber 
forming collet 302 during the initial and final stages of the winding 
process, incomplete forming packages and/or forming packages 304 which do 
not meet specifications are also useful as waste materials 14 for 
recycling by the present system and process. Such bands typically have a 
width of about 0.05 meters, a length of about 0.4 to about 1 meters and a 
thickness of about 0.1 meters. Waste forming packages 304 useful in the 
present invention can have a width of about 0.4 meters, a length of about 
0.4 to about 0.75 meters and a thickness of about 0.1 meters when 
flattened. 
The waste material supply 12 can be obtained directly from a glass 
fiberizing operation 316 by collecting waste material 14 emanating from 
the bushings 306 of the glass melter 20 when the winding process is not in 
operation or by gathering the waste material 14 from other glass fiber 
product fabrication processes, such as roving 308, twisted strands 310 or 
mat 312, as discussed above. The waste material 14 can be collected 
continuously or batchwise as waste material 14 is accumulated. For 
example, the waste material supply 12 can be drawn directly from glass 
fibers 16 which are diverted through a pull roll 300 (shown in FIG. 16) 
and conveyed to the waste material processing system 10. Additionally or 
alternatively, one or more conventional storage containers 314 or bins can 
be used to accumulate material from a variety of different sources within 
glass fiberizing and product fabrication processes, such as are discussed 
above, and transported to the waste material processing system 10. 
Referring now to FIGS. 1 and 2, the waste material processing system 10 
preferably further comprises one or more conveyors 24 positioned between 
any of the system components for conveying the waste material 14 through 
the waste material processing system 10. 
Preferably, the conveyor 24 is sufficiently wide and thick to stably 
accommodate the waste material 14 on the conveyor 24 and to prevent the 
waste material 14 from spilling from the conveyor 24 during transport. The 
width of the conveyor 24 can be about 0.3 to about 1.5 meters. The 
preferred conveyor 24 is about 1.3 meters (about 54 inches) wide. The 
length of the conveyor 24 can be any length suitable to convey the waste 
material 14 between components of the system 10. The thickness of the 
conveyor 24 can be about 0.005 to about 0.025 meters and can vary based 
upon such factors as the material from which the conveyor 24 is formed, 
dimensions and weight of the waste material 14 to be transported. 
Non-limiting examples of suitable conveyors include vibratory conveyors, 
belt conveyors, screw conveyors, horizontal conveyors, and batch conveyors 
which transport a plurality of individual containers, each container 
holding a portion of waste material 14. The preferred conveyor 24 for use 
in the present invention has a double V-shaped trough which can be 
perforated to permit drainage, such as is commercially available from 
General Kinematics of Barrington, Ill. Screw and horizontal conveyors are 
also preferred for use in the present invention. Suitable screw conveyors 
are commercially available from Thomas Conveyor Co. of Fort Worth, Tex. 
The conveyor 24 can be inclined with respect to horizontal to facilitate 
drainage of the waste material 14. Preferably, the conveyor 24 is inclined 
at about a 5 to about a 20 degree angle with respect to horizontal, and 
more is preferably about 15 degrees. 
The conveyor 24 comprises a drive device 26, such as an eccentric direct 
drive motor. Preferably, the motor is a conventional AC eccentric direct 
drive motor of about 5 to about 50 horsepower. One skilled in the art 
would understand that any suitable motor and drive capable of providing 
power to move the waste material 14 from a first position to a second 
position spaced apart from the first position would be useful in the 
present invention. The conveyor 24 is preferably moved at a speed of about 
4.5 to about 30 meters/minute, and more preferably about 12 meters/minute. 
One skilled in the art would understand that one or a plurality of 
conveyors 24 can be used in the present system 10. Also, the conveyor 24 
can be enclosed and/or heated, if desired. 
Alternatively, some or all of the system components can be positioned such 
that the waste material 14 being discharged from a given component enters 
the inlet of the next component of the system 10 without intervening 
conveyors 24. 
The waste material processing system 10 can further comprise one or more 
washers 28 positioned between the waste material supply 12 and the 
shredder 30 for washing the waste material 14 prior to shredding. 
Preferably, the waste material 14 is washed by spraying water upon the 
conveyor 24 using a conventional spray nozzle before the waste material 14 
enters the shredder 30. The amount of water sprayed should be sufficient 
to remove at least a portion of any coating compositions present upon the 
glass fibers 16. The moisture content of the washed waste material 32 can 
be about 25 to about 50 weight percent on a total solids basis. 
The waste material processing system 10 comprises one or more shredders 30 
positioned to receive waste material 14 from the waste material supply 12, 
preferably by conveyor 24. The shredder 30 shreds the waste material 14 to 
form shredded waste material 34. 
The shredder 30 can be any conventional shredder 30 useful for shredding 
glass fibers, such as are well known to those skilled in the art. 
Preferably the shredder 30 is capable of shredding about 0.5 to about 7 
metric tons (about 1000 to about 15500 pounds) per hour of waste material 
14. The shredder 30 preferably has a plurality of intermeshing disks, each 
disk having two or more cutting prongs. An example of a shredder 30 which 
is useful in the present invention is a SSI Model 3400H shredder having a 
direct hydraulic drive, which is commercially available from Shredder 
Systems, Inc. of Wilsonville, Oreg. 
The mean average length of the scrap glass fibers 16 of the shredded waste 
material 34 is preferably about 0.05 to about 0.3 meters (about 2 to about 
12 inches) or less, and more preferably is about 0.05 to about 0.15 meters 
(about 2 to about 6 inches). The non-glass waste materials 18 are 
preferably also shredded into similar lengths. 
The waste material processing system 10 preferably further comprises one or 
more storage systems 36 for storing excess waste material 14, for example 
if one or more components of the system 10 are temporarily disabled. The 
storage system 36 can be, for example, a bunker or other conventional 
storage area well known to those skilled in the art. The capacity of the 
storage system 36 is preferably about 0.5 to about 250 metric tons. The 
storage system 36 preferably permits drainage and evaporation of excess 
moisture from the waste material 14. 
The waste material processing system 10 preferably further comprises one or 
more feeders 38 for returning the waste material 14 in the storage system 
36 to the system 10. The feeder 38 can be automatic or manual. The feeder 
38 can be a bucket material handler or volumetric feeder and a conveyor 
24, examples of which are discussed above. Preferably, the feeder 38 is a 
Bobcat bucket material handler. 
The waste material processing system 10 comprises one or more moisture 
reducing devices 40 positioned to receive shredded waste material 34 from 
the shredder 30. The moisture reducing device 40 reduces the mean average 
moisture content of the shredded waste material 34 to form 
moisture-reduced waste material 42. The mean average moisture content of 
the moisture-reduced waste material 42 preferably ranges from about 5 to 
about 30 weight percent moisture on a total weight basis, and more 
preferably about 10 to about 25 weight percent. 
The moisture reducing device 40 can be selected from dewatering devices, 
dryers, perforated screens, vibratory screens, centrifuges, presses or 
calciners, and combinations thereof. Preferably the moisture reducing 
device 40 is a dewatering device such as a rotary bulk dewaterer which is 
commercially available from General Kinematics. The preferred dewatering 
device is formed from stainless steel, has dimensions of about 3 meters 
(about 10 feet) long and about 1.5 meters (about 5 feet) wide, and is 
rotated by a conventional drive device such as a 30 horsepower (hp) motor. 
The rotational speed of the dewatering device is preferably about 10 to 
about 50 revolutions per minute. Suitable motors for rotating such 
dewatering devices at such speeds are well known to those skilled in the 
art. 
The moisture reducing device 40 preferably further comprises one or more 
moisture separating devices 44 for receiving a moisture-laden stream 46 
separated from the waste material 14 by the moisture reducing device 40 
and separating moisture from any residual solids such as glass fibers in 
the moisture-laden stream 46, which can be recycled to the moisture 
reducing device 40, if desired. Non-limiting examples of suitable moisture 
separating devices 44 include hydrosieve metal fabric filter screens and 
settlers. 
The waste material processing system 10 can further comprise one or more 
storage devices 48 positioned between the moisture reducing device 40 and 
the crusher 50 for receiving moisture-reduced waste material 42 from the 
moisture reducing device 40 and supplying the moisture-reduced waste 
material 42 to the crusher 50. The storage device 48 can be a conventional 
cascade storage system which comprises multiple storage units 52 arranged 
in parallel such that when a first storage unit 54 is filled with a 
portion of the moisture-reduced waste material, another portion of the 
moisture-reduced waste material subsequently received from moisture 
reducing device 40 is diverted to another storage unit 56. The capacity of 
each storage unit 52 depends upon such factors as the total waste material 
14 to be processed by the system 10, and is preferably about 0.5 to about 
5 metric tons. 
The storage device 48 preferably has at least as many storage units 52 as 
crushers 50 in the system 10, such that each storage unit 52 is aligned to 
feed moisture-reduced waste material 42 into the corresponding crusher 50. 
The discharge chutes are preferably tubular and can be operated manually 
or preferably automatically as the level of waste material 14 in the 
corresponding crusher 50 decreases. Preferably the discharge chutes have a 
diameter ranging from about 0.25 to about 0.75 meters. 
As discussed above, the waste material processing system 10 comprises one 
or more auger crushers 50 discussed below. Preferably, the waste material 
processing system 10 comprises six auger crushers 50, each auger crusher 
50 accommodating about 1 metric ton per hour of material to be processed. 
Referring now to FIG. 3, the crusher 50 comprises a body 58 comprising a 
cavity 60 having a feed chute or first end 62 positioned to receive the 
moisture-reduced waste material 42 from the moisture reducing device 40, a 
second end 64 distal to the first end 62 in which at least the glass 
fibers of the moisture-reduced waste material 42 are crushed, and a length 
66 therebetween. The walls of the feed chute are preferably angled to 
facilitate the flow of moisture-reduced waste material 42 into the cavity 
60. 
As shown in FIG. 3, the length 66 of the cavity 60 ranges from about 0.6 to 
about 1.8 meters, and is preferably about 1.5 meters. The cavity 60 has a 
width at the inlet 68 ranging from about 0.25 to about 1.25 meters, and is 
preferably about 0.75 meters (about 30 inches). The cavity 60 has a depth 
70 ranging from about 0.75 to about 1.5 meters, and is preferably about 
0.75 meters (about 30 inches). 
Referring to FIG. 3, the crusher 50 comprises a rotatable screw auger 72 
positioned within the cavity 60 of the body 58 for crushing and conveying 
the moisture-reduced waste material 42 from the first end 62 of the cavity 
60 in a first direction 74 toward the second end 64 of the cavity 60. The 
auger 72 has a first end 76 proximate the first end 62 of the cavity 60, a 
second end 78 proximate the second end 64 of the cavity 60, and a length 
80 therebetween. 
The auger 72 is preferably formed from a metallic material such as carbon 
steel and can have a striated hard alloy coating on the faces of the 
flights 86, such as STOOL 101 flexcore MIG wire. 
As shown in FIG. 3, the length 80 of the auger 72 preferably ranges from 
about 0.5 to about 1.75 meters, and is preferably about 1.4 meters (about 
56 inches). The diameter 82 of the auger shaft 84 preferably ranges from 
about 0.075 to about 0.2 meters, and is preferably about 0.075 meters 
(about 3 inches). 
The auger 72 includes a flight 86 having a plurality of peaks 88 along the 
length 80 of the auger 72, the distance 90 between adjacent peaks 88 
ranging from about 0.35 to about 0.6 meters (about 14 to about 24 inches). 
Preferably, the first end 76 of the auger 72 has a right-handed pitch of 
about 0.55 meters (about 22 inches) and the second end 78 of the auger 72 
has a right-handed pitch of 0.4 meters (about 16 inches). Including the 
flight 86, the auger 72 has an outer diameter 92 ranging from about 0.2 to 
about 0.4 meters, and is preferably about 0.2 meters. The height 87 of 
each flight 86 is preferably about 0.025 to about 0.1 meters (about 1 to 
about 4 inches), and is preferably about 0.038 meters (about 1.5 inches). 
The thickness of the flight is preferably about 0.006to about 0.025 
meters. 
The flight 86 is positioned at an angle ranging from about 80.degree. to 
about 100.degree., and preferably about 90.degree., with respect to a 
longitudinal axis of rotation 79 of the auger 72. The distance 81 between 
edge of the flight 86 and the cavity 60 is preferably about 0.025 to about 
0.075 meters (about 1 to about 3 inches). 
The auger 72 is rotated by a drive device 73 which comprises a motor 75 and 
a drive 77. The motor 75 can be any conventional motor for rotating an 
auger, such as about a 5 to about 40 horsepower AC motor having a variable 
speed gear reducer, such as a Baldor TEFC (totally enclosed fan cooled) 
motor. The speed of rotation of the auger 72 can range from about 5 to 
about 150 revolutions per minute, and is preferably about 5 to about 30 
revolutions per minute. 
The crusher 50 comprises a pressurizing device 94 proximate the second end 
64 of the cavity 60 and the second end 78 of the auger 72 for exerting a 
pressure ranging from about 1.38.times.10.sup.4 to about 
5.51.times.10.sup.6 pascals (about 2 to about 800 pounds per square inch) 
upon at least a portion 96 of the moisture-reduced waste material 42 
positioned about the second end 78 of the auger 72 in a direction 98 
generally opposite to the first direction 74 in which the auger 72 conveys 
the moisture-reduced waste material 42 such that the portion 96 of the 
scrap glass fibers 16 of the moisture-reduced waste material 42 are 
crushed to form crushed glass fibers 100 having a mean average dimension, 
such as length or width, of less than about 0.09 meters (about 3.5 
inches), and preferably ranging from about 0.003 to about 0.006 meters 
(about 1/8 to about 1/4 inches) or less. 
Preferably, the pressurizing device 94 is a conduit 102 comprising a first 
end 104 positioned adjacent to, and preferably connected to, the second 
end 64 of the cavity 60 for receiving crushed glass fibers 100 from the 
second end 64 of the cavity 60. The conduit 102 also has a discharge or 
second end 106 and a length 108 between the first end 104 and the second 
end 106. 
The crushed glass fibers 100 received from the second end 64 of the cavity 
60 accumulate within the conduit 102 to exert backpressure upon at least 
the portion 96 of the moisture-reduced waste material 42 positioned about 
the second end 78 of the auger 72 in the direction 98 generally opposite 
to the first direction 74 in which the auger 72 conveys the 
moisture-reduced waste material 42 to provide resistance to the flow of 
the portion 96 of the moisture-reduced waste material 42 being conveyed 
through the cavity 60 and conduit 102 such that the portion 96 of the 
scrap glass fibers 16 in the moisture-reduced waste material 42 are 
crushed to form the crushed glass fibers 100. 
The conduit 102 can be formed from a durable material such as a 
thermoplastic material, thermosetting material, or metallic material such 
as steel. Preferably, the conduit 102 is formed from a thermoplastic 
material such as polyvinyl chloride or acrylonitrile-butadiene-styrene 
polymer. 
The conduit 102 is preferably generally circular in cross-section, although 
the conduit 102 can be generally oval, square, rectangular, or have any 
shape cross-section desired. Preferably, the cross-section of the conduit 
is generally uniform along the length 108 of the conduit 102, although the 
cross-section can vary, as discussed below. 
The length 108 of the conduit 102 can range from about 0.9 to about 6 
meters (about 3 to about 20 feet), is preferably about 0.9 to about 5 
meters (about 3 to about 17 feet), and is more preferably about 1.8 to 
about 2.1 meters (about 6 to about 7 feet). The internal diameter 110 of 
the conduit 102 can range from about 0.15 to about 0.6 meters (about 6 to 
about 24 inches), and is preferably about 0.35 to about 0.4 meters (about 
14 to about 16 inches). The thickness of the wall of the conduit 102 can 
range from about 0.01 to about 0.025 meters. 
Preferably, the interior surface 112 of the conduit 102 is generally smooth 
as shown in FIG. 3, although the interior surface 112 can comprise one or 
more cross-sectional area restrictions to flow or protrusions 114 which 
project into the interior 115 of the conduit 102, as shown in FIGS. 4-7, 
which increase the resistance to flow of the crushed fibers 100 and other 
waste material through the conduit 102. Other useful flow restrictions 
include dies or irregularities such as ridges, rifling counter to the 
direction of rotation of the screw and roughening of the interior surface 
112 of the conduit 102. The use of protrusions 114 or irregularities in 
the interior surface 112 can provide adequate resistance to flow using a 
shorter conduit 102. 
Referring now to FIGS. 4 and 5, in an alternative embodiment the interior 
surface 112 of the conduit 102 can comprise one or more protrusions 114 
such as screws or bolts 116 which provide increased resistance to flow of 
the crushed glass fibers 100 and other waste material through the conduit 
102. Each screw or bolt 116 can have a width 118 of about 0.006 to about 
0.075 meters (about 0.25 to about 3 inches) and a length 120 within the 
conduit of about 0.006 to about 0.2 meters. Preferably, the number of 
bolts 116 used as protrusions 114 can be about 1 to about 10, and is 
preferably 6, although the number and dimensions of the bolts 116 can vary 
based upon such factors as the dimensions of the conduit 102, bolts 116 
and the desired resistance to flow of the waste material. The bolts 116 
are preferably evenly spaced about the circumference of the conduit 102, 
although the bolts 116 can be spaced at any position desired. 
Referring now to FIGS. 6 and 7, in another alternative embodiment the 
protrusion 114 can be one or more rods 122. Each rod 122 can have a width 
124 of 0.006 to about 0.075 meters (about 0.25 to about 3 inches) and an 
average length 126 within the conduit of about 0.25 to about 0.55 meters. 
Preferably, the number of rods 122 used as protrusions 114 can be about 1 
to about 10, and is preferably 1, although the number and dimensions of 
the rods 122 can vary based upon such factors as the dimensions of the 
conduit 102 and the desired resistance. The rods 122 can be positioned 
within the interior of the conduit 102 as desired. 
Referring now to FIG. 8, in another alternative embodiment, the diameter 
110 of the conduit 102 can be greater at the first end 104 of the conduit 
102 than at the second end 106 of the conduit 102. The diameter 110 can be 
decreased uniformly along the length of the conduit 102 or by one or more 
progressions, as desired. For example, if the diameter of the conduit 102 
at the first end 104 is about 0.35 meters (about 14 inches), the diameter 
at the second end 106 of the conduit 102 can be about 0.2 meters (about 8 
inches). 
The pressure exerted by the pressurizing device 94 of the crusher 50 upon 
the portion 96 of the moisture-reduced waste material 42 positioned about 
the second end 78 of the auger 72 can range from about 1.38.times.10.sup.4 
to about 5.51.times.10.sup.6 pascals (about 2 to about 800 pounds per 
square inch), and preferably ranges from about 1.38.times.10.sup.4 to 
about 1.03.times.10.sup.6 pascals (about 2 to about 150 pounds per square 
inch). 
In an alternative embodiment shown in phantom in FIG. 1, the 
moisture-reduced waste material 42 can be pulverized in a pulverizer 51 
for pulverizing a major portion of the moisture-reduced waste material 42 
into pulverized waste material having a mean average length of less than 
about 20 mesh, and preferably between about 20 mesh and about 60 mesh. 
Non-limiting examples of suitable pulverizers include ring roller mills, 
hammer mills, grinding mills, rotary mills, ball mills, vibratory mills 
and pin mills such as are disclosed in the Chemical Engineers' Handbook at 
pages 8-33 through 8-40, which are hereby incorporated by reference. 
Non-limiting examples of suitable pulverizers include the SIMTOR.RTM. 
rotary mills which are commercially available from Sturtvant of Boston, 
Mass. and the Buffalo WA Series vibratory mills which are commercially 
available from Hammer Mill Corp. Of Buffalo, N.Y. 
Referring now to the preferred embodiment shown in FIG. 1, the waste 
material processing system 10 can further comprise a metal detector and 
removal device 128 positioned between the crusher 50 and the dryer 130 for 
removing contaminants such as metallic material and graphite from the 
moisture-reduced waste material. Suitable metal detector and removal 
systems are well known to those skilled in the art and include metal 
detectors which determine the presence of metallic materials by 
fluctuations in the spatial location and amplitude in a field of fixed 
frequency which can be generated using an inductor of fixed inductance and 
a capacitor of fixed capacitance. A non-limiting example of a suitable 
metal detector 128 is E-Z Tech Model III synchro magnetic detector, which 
is commercially available from Eriez Manufacturing Co. of Erie, Pa. The 
contaminants can be removed or separated from the waste material 14 by a 
diverter, slot or gate in the conveyor 24 which is opened in response to a 
signal received from the metal detector 128, for example. 
The waste material processing system 10 can further comprise a coarse waste 
material separating device 132 positioned between the crusher 50 and the 
dryer 130. The coarse waste material separating device 132 receives the 
moisture-reduced waste material 42 including crushed glass fibers 100 from 
the crusher 50 and separates (1) waste material 134 having a dimension 
136, such as length or width, less than about 0.025 meters (about 1inch) 
and preferably between about 0.01 to about 0.025 meters (about 0.5 to 
about 1 inches) from (2) coarser waste material 138. Non-limiting examples 
of such coarse waste material 138 include pieces of forming packages, 
forming tubes, graphite gathering shoes and refractory materials from the 
glass melter. Typically, the coarse waste material 138 comprises about 1 
to about 10 weight percent of the waste material 14. 
The separating device 132 is preferably a screening device 140 such as is 
shown in FIG. 1. Preferably the screening device 140 does not lift the 
crushed waste material vertically to prevent coarser waste material 136 
from reorienting such that the length of the coarse waste material 136 is 
generally perpendicular to the plane of the screen and which can permit 
coarser waste material 136 to pass the screen. 
Useful screening devices 140 include mechanical shaking screens and 
vibrating screens such as are disclosed in R. Perry et al., Chemical 
Engineers' Handbook, (5th Ed. 1973) at pages 21-39 through 21-45, which 
are hereby incorporated by reference. The preferred screening device 140 
is a scalping vibratory screener having 0.025 meter (one inch) opening 
wire cloth screen such as a Series 80 screener with a DX 2000 
counterbalanced drive which is commercially available from Rotex of 
Cincinnati, Ohio and such as are available from Heyl & Patterson, Inc. of 
Pittsburgh, Pa. and S. Howles of Silver Creek, N.Y. 
The preferred waste material processing system 10 which comprises the auger 
crusher 50 discussed above can further comprise a pulverizer 142, if 
necessary. The pulverizer 142 preferably reduces the size of the waste 
material 134 to about 20 to about 200 mesh and more preferably about 20 to 
about 50 mesh. Suitable pulverizers are discussed above. 
The waste material processing system 10comprises one or more dryers 130 
positioned to receive the moisture-reduced waste material 42 from the 
crusher 50 (or metal removal device 128 and/or screening device, if 
present). The dryer 130 drys the moisture-reduced waste material 42 to 
form dried waste material 144 having a mean average moisture content of 
less than about one weight percent, and preferably about 0.3 to about 0.5 
weight percent moisture on a total weight basis. Preferably the dryer 130 
is combined with one or more cooling devices 146 for cooling the dried 
waste material 144 received from the dryer. 
The dryer 130 preferably drys the waste material 15 by exposure to heated 
air at a temperature ranging from about 120.degree. C. to about 
815.degree. C. (about 250.degree. F. to about 1500.degree. F.), and more 
preferably about 205.degree. C. to about 500.degree. C. (about 400.degree. 
F. to about 925.degree. F.). The time period for drying preferably ranges 
from about 5 to about 30 minutes, and more preferably about 7 to about 15 
minutes. Preferably the dried waste material 144 is cooled to about 
25.degree. C. upon exiting the cooler 146. 
Suitable dryers 130 can be selected from rotary dryers (preferred), 
fluidized bed dryers, forced air dryers, infrared dryers, radio frequency 
dryers, hot air resistance dryers and other suitable direct fired dryers 
for glass fibers which are well known to those skilled in the art. 
Non-limiting examples of useful dryers 130 include Rotor-Louvre Precision 
dryers/coolers which are commercially available from FMC Corporation of 
Chalfont, Pa. and rotary calciners/coolers which are commercially 
available from Heyl & Patterson, Inc. 
As shown In FIG. 1, the waste material processing system 10 can further 
comprise one or more baghouses 190 for separating and recovering fine 
dried waste material 144 from the air stream 192 received from the dryer 
130. Suitable baghouses are well known to those skilled in the art and are 
commercially available from Nol-Tec Systems Inc. of Forest Lake, Minn. The 
fine waste material can be recombined with the dried waste material 144 
for further processing. 
As shown In FIG. 1, the waste material processing system 10 can further 
comprise one or more secondary crushers 150 positioned to receive dried 
waste material 144 from the dryer 130 and crush the scrap glass fibers in 
the dried waste material 144 to form crushed glass fibers 152. 
Referring now to FIGS. 9-12, the secondary crusher 150 comprises at least 
one pair of rotatable, intermeshing rollers 154 and one or more drive 
devices 156 for rotating at least one of the rollers 154 such that each 
pair of rollers 154 rotate at essentially the same speed, and preferably 
the same speed. As used herein, "essentially the same speed" means that 
that each of the rollers 154 of a pair rotate within about 5 percent of 
the speed of the other roll of the pair, and preferably less than about 1 
percent. 
Preferably the rollers 154 are configured to reduce shearing effects upon 
the fibers to provide fibers having generally smooth ends. 
As shown in FIGS. 1 and 11-12, the secondary crusher 150 can comprise a 
plurality of pairs of intermeshing rollers 154. Preferably the secondary 
crusher 150 comprises 2 to 4 pairs of rollers 154. Each of the rollers 154 
has an axis of rotation 158, the axes of rotation 158 of each pair of 
rollers 154 preferably being offset, as shown in FIG. 12. In an 
alternative embodiment, the axes of rotation 158 of each pair of rollers 
154 are generally parallel, as shown in FIGS. 9-11. 
Preferably, the rollers 154 are formed from a material selected from the 
group consisting of resilient thermoplastic materials and thermosetting 
materials, preferably a urethane polymer. Although not preferred, the 
rollers 154 can be formed from a metallic material such as steel, if 
desired. 
The length 160 of each roller 154 can range from about 0.125 to about 0.75 
meters (about 5 to about 30 inches) and preferably about 0.5 to about 0.6 
meters (about 20 to about 24 inches). The diameter 162 of each roller 154 
can range from about 0.1 to about 0.5 meters (about 4 to about 20 inches) 
and preferably about 0.2 to about 0.3 meters (about 8 to about 12 inches). 
The length 160 and diameter 162 of each roller 154 of a pair of rollers 
can be different, if desired. 
Each roller 154 has an outer surface 162 comprising a plurality of 
protuberances 164 which are essentially free of serrations. As used 
herein, "essentially free of serrations" means that the outer surface 162 
of each roller 154 has less than about 5 percent by surface area, and is 
preferably free of, serrations having a cross-sectional shape in the form 
of a pointed tooth. Preferably the rollers 154 of a pair of rollers 154 
have about the same pitch. 
Preferably, the protuberance 164 is a ridge or corrugation 166 having a 
longitudinal axis 168 which is generally parallel to the axis of rotation 
158 of the roller 154, the edges 170 of the corrugation 166 preferably 
being generally rounded. 
The width 172 of the corrugation 166 can range from about 0.0016 to about 
0.025 meters (about 1/16 to about 1 inches), and is preferably about 0.003 
to about 0.006 meters (about 1/8 to about 1/4 inches). The length 174 of 
the corrugation 166 is preferably about the same as the length 160 of the 
roller 154. One or more ridges 166 can be positioned along the length 160 
of the roller 154, as desired. The height 176 of the corrugation 166 is 
preferably greater than or equal to the width 172 of the corrugation and 
can range from about 0.0016 to about 0.025 meters (about 1/16 to about 1 
inches). The height 176 of the corrugation 166 can vary along the length 
160 of the roller 154, as desired. Alternatively, a knurled or smooth 
surface roll can be used. 
At least a portion 178 of a protuberance 164 of a first roller 180 of the 
pair of rollers 154 contacts a corresponding mating portion 182 of at 
least one protuberance 164 of a second roller 184 of the pair of rollers 
154 for crushing scrap glass fibers 16 passing therebetween to form 
crushed glass fibers 152. One or more biasing members 200, such as springs 
or hydraulic cylinders, are used to bias the rollers 180, 184 into 
contact. Non-limiting examples of suitable air cylinders for biasing the 
rollers 180, 184 into contact are spring-loaded hydraulic cylinders which 
are commercially available from Bimba Inc. of Monel, Ill. The biasing 
force provided by the biasing member 200 should be sufficient to maintain 
the rollers 180, 184 in contact when crushing glass fibers, but should 
permit the rollers 180, 184 to separate to permit uncrushable materials 
such as refractory materials to pass therethrough. 
The waste material processing system 10 comprises one or more separating 
devices 186 positioned to receive the dried waste material 144 from the 
dryer 130 (or the secondary crusher 150, if present). The separating 
device 186 separates the dried waste material 144 into a first portion 188 
of dried waste material 144 having a mean average dimension, i.e., length 
and width, of less than about 5 millimeters from oversized dried waste 
material 194. Typically, the first portion 188 of dried waste material 144 
comprises about 80 to about 90 weight percent of the dried waste material 
144. 
The separating device 186 can be one or more screening devices, mills 
and/or air classifiers. The separating device 186 is preferably two 
screening devices 196 and 198, respectively, such as are shown in FIG. 1. 
Preferably the screening devices 196,198 do not lift the dried waste 
material 144 vertically to prevent oversize waste material 194 from 
reorienting such that the length of the oversize waste material 194 is 
generally perpendicular to the plane of the screen which can permit 
oversize waste material 194 to pass through the screen. 
Useful screening devices 196,198 include mechanical shaking screens and 
vibrating screens such as are discussed above. The preferred screening 
devices 196,198 are scalping vibratory screeners such as Series 80 
screeners with a DX 2000 drive which are commercially available from 
Rotex. The first screening device 196 preferably has about 0.005 to about 
0.02 meters (about 3/16 to about 3/4 inch), and more preferably about 
0.006 meters (1/4 inch) opening wire cloth screen and the second screening 
device 198 preferably has about 0.0008 to about 0.005 meters (about 1/32 
to about 3/16 inch), and more preferably about 0.003 meters (1/8 inch) 
opening perforated plate when the screened material is to be pneumatically 
conveyed. The openings can be slightly larger, i.e., about 0.006 meters 
(1/4 inch) if the material is to be mechanically conveyed. 
In an alternative embodiment shown in FIG. 2, dried waste material 444 
received from the dryer 430 can be pulverizer using a pulverizer 400 such 
as are discussed in detail above. The pulverized material 402 can be 
passed through a metal detector and removal system 404 to remove metallic 
materials and graphite and transported to a storage bin 406 for recycling 
to the glass melter 420 as discussed below. 
As shown in FIG. 1, the preferred system 10 can further comprise one or 
more pneumatic transports 201. The pneumatic transport 201 is preferably a 
batch-loaded, dense phase transport system capable of transporting loads 
of about 0.5 metric tons (about 1000 pounds) such as are commercially 
available from Nol-Tec Systems, Inc. and Dynamic Air of St. Paul, Minn. 
and as are disclosed in Loewenstein at pages 45-46, which are hereby 
incorporated by reference. 
The system 10 can also further comprise a metal detector and removal system 
203 positioned to receive the first portion 188 of dried waste material 
from the separating device 186 and detect and remove metallic materials 
and graphite from therefrom. Suitable metal detector and removal systems 
are discussed in detail above. 
As shown in FIG. 1, the system 10 can further comprise one or more air 
separating devices 202 positioned to receive the first portion 188 of 
dried waste material from the separating device 186 (and the metal 
detector and removal system 203, if present) which is suitable for 
conveying to the glass melter 20. The air separating device 202 separates 
a portion 204 of crushed glass fibers 240 having a mean average length of 
less than about 5millimeters (about 3/16 inches), and preferably between 
about 0.0008 and about 0.003 millimeters (about 1/32 to about 1/8 inches) 
from a second portion 206 of oversize glass fibers and other waste 
material. The portion 204 is preferably sized such that it can be 
pneumatically transferred to a storage bin 226 by a pneumatic air 
transport such as are discussed in detail above. 
Preferably, the air separating device 202 subdivides the second portion 206 
of oversize glass fibers and other waste material into heavy, non-glass 
waste 208 which is discarded and oversize glass fibers, glass beads and 
frit materials 210 which can be screened by a metal detector and removal 
device 212 (such as are discussed above). The fines 214 entrained in the 
air stream can be recovered by passing the air stream 216 through a 
baghouse 218, examples of which are discussed in detail above. 
The separation of the different fractions of waste material depend upon 
such factors as the air velocity, particle size, configuration, weight and 
inertia. By varying the air velocity, configuration and number of 
separation chambers or separating devices, the grouping of desired 
fractions can be achieved. Preferably, the air velocity within an uplift 
air separating device 202 can be about 0.6 to about 60 meters per second 
(about 2 to about 200 feet per second), and is preferably about 6 to about 
48 meters per second (about 20 to about 160 feet per second) and more 
preferably about 39 to about 45 meters per second (about 130 to about 150 
feet per second). 
The air separating device 202 is preferably an uplift air separator, such 
as is shown generally in FIG. 13. Examples of suitable uplift air 
separators are Models CEX2 and CEY2 fractionating aspirators which are 
commercially available from Carter Day of Minneapolis, Minn. The attached 
blower can be powered by any conventional motor such as are discussed 
above, for example a 5 horsepower motor such as are commercially available 
from Baldor. The CEY2 air separator has a 1.2 meter (48 inch) wide 
air/material contact width and three product collection chambers which 
permit collection of several fractions of product. See "Carter Day 
Fractionating Aspirator 24" & 48" Instruction Manual", Carter Day 
(Minneapolis, Minn.) 
Preferably, the first collection chamber 220 separates and accumulates 
dried waste material 144, such as cardboard forming package tubes, which 
is larger than about 16 mesh, and more preferably about 20 mesh. This 
waste material 208 is preferably discarded. 
The second collection chamber 222 separates and accumulates dried waste 
material 144 which is ranges from about 16 to about 65 mesh, and more 
preferably about 20 to about 60 mesh. This oversize waste material 210 can 
be treated with a lubricant such as water and passed through a mill or 
pulverizer 224 such as are discussed above and a second air separating 
device 228. 
One skilled in the art would understand that the number of collection 
chambers can be varied as desired, and the portion of waste material being 
diverted to a particular chamber can be influenced by such factors as the 
air velocity within and the configuration of the air separating device 
202. 
Alternatively, the air separating device 202 can be a series of cyclone 
separators or tapered pipes (shown in FIG. 14), each pipe 500 having a 
first side entry inlet 504 for regulating air, a main air bottom inlet 510 
and a second side entry inlet 502 below the air inlet 504 for receiving 
the first portion 188 of dried waste material from the separating device 
186. The light fraction is entrained by the airstream and exits the top 
506 of the pipe 500 and the portion 204 of crushed glass fibers exits from 
the bottom 508 of the pipe 500. Other useful air separating devices or air 
classifiers are disclosed in the Chemical Engineers' Handbook at pages 
8-31 through 8-32, which are hereby incorporated by reference. 
The crushed glass fibers 240 in the storage bin 226 can be transported by a 
pneumatic transport 230 to another storage bin 232 in the batch house (not 
shown). The crushed glass fibers can be mixed with batch materials 234 in 
a blender 236 and fed by a feeder 242 to the glass melter 20 or directly 
to the glass melter 20 as a separate batch ingredient. The blender 236 can 
be a conventional mixer for glass fibers which are well known to those 
skilled in the art, such as are commercially available from Nol-Tec 
Systems, Inc. and as are disclosed in Loewenstein at pages 45-46. Suitable 
feeders 242 for glass fibers include loss-in-weight feeders and the auger 
feeder disclosed in U.S. Pat. No. 5,352,258 at column 6, line 64 through 
column 7, line 25 and column 11, lines 5-38, which are hereby incorporated 
by reference. Other suitable feeders are well known to those skilled in 
the art. 
Alternatively, the crushed glass fibers can another glass melter 238 which 
operates on 100 percent recycled scrap glass. 
The recycled waste material is useful as an ingredient in a glass 
fiberizing or forming operation 316, shown in FIG. 16. In a typical glass 
fiber forming operation, particulate batch materials of from less than 
about 325 to about 100 mesh (U.S. sieve series) are mixed, melted in a 
glass furnace or melter 20, 238 and drawn into glass fibers 318. 
The glass melter 20, 238, also referred to as a glass furnace or 
forehearth, contains a supply of molten glass 320 and has a precious metal 
bushing 306 or spinneret attached to the bottom of the glass melter 20. 
The bushing 306 is provided with a series of orifices in the form of tips 
322 through which molten glass 320 is drawn in the form of individual 
fibers 318 or filaments at a high rate of speed. 
The glass fibers 318 can be cooled by spraying with water (not shown) and 
then coated with a sizing composition by an applicator device 324 which 
contacts the fibers 318 prior to entering the alignment device 326. 
Examples of suitable applicator devices are disclosed in Loewenstein at 
pages 165-172, which are hereby incorporated by reference. Non-limiting 
examples of suitable alignment devices 326 include rotatable or stationary 
gathering shoes or a comb, as discussed in Loewenstein at page 173, which 
is hereby incorporated by reference. 
Referring to FIG. 16, the fiber forming operation 316 also comprises a 
winder 328 for receiving the fiber strands 330 from the alignment device 
326, advancing and applying a tension to the strands 330, and forming the 
strands 330 into a wound forming package 304. 
The process according to the present invention for processing waste 
material for recycling will now be described generally. 
With reference to FIG. 16, the process generally comprises the initial step 
of supplying waste material 14 to a shredder 30. The waste material 14 can 
be washed by a washer 28, as discussed above, to remove at least a potion 
of any coatings upon the glass fibers and other waste material. 
The next step in the process involves shredding the glass fiber waste 
material 14. The shredded waste material 34 can be stored in a storage 
system 36, for example when one or more of the components of the system 10 
is not properly operating. 
The moisture in the shredded waste material is reduced by using a 
moisture-reducing or dewatering device as discussed above to form 
moisture-reduced waste material. The moisture-reduced waste material is 
crushed in an auger crusher 50, such as is discussed in detail above, by 
feeding the moisture-reduced waste material into the feed chute and first 
end 62 of the cavity 60 and through the auger crusher 50 having a pressure 
device such as conduit 102 connected thereto to apply backpressure to the 
material advancing through the auger crusher 50 sufficient to crush the 
glass fibers in the moisture-reduced waste material. 
The crushed glass fibers and waste material is separated by a separating 
device, such as one or more screeners, into coarse waste material and 
screened recyclable glass fibers, for example by shaking the screens. 
If the screened glass fibers are still too large for proper recycling after 
screening, the glass fibers can be pulverized. The screened or pulverized 
glass fibers can be dried in a dryer 50, cooled and, if necessary, crushed 
in a secondary crusher 150 as discussed above. Alternatively or 
additionally, the glass fibers can be rescreened using a finer mesh screen 
to separate and recover smaller glass fibers. 
After removing any metal or graphite from the smaller glass fibers, they 
can be milled and/or air classified to further reduce or capture a desired 
fraction having a smaller average particle size. The suitable fraction of 
glass fibers can be conveyed pneumatically to storage bins, a blender for 
blending with other batch materials or directly to a glass melter. 
The operation of the waste processing system 10 to perform the process 
according to the present invention will now be described. However, other 
systems than that shown and described herein could be used to perform the 
process of the present invention, if desired. 
In the initial sequence of operation of the preferred embodiment, waste 
material 14 is gathered as discussed above and supplied by a conveyor 24 
to a shredder 30. Preferably, the waste material 14 is washed by water as 
it is conveyed to remove at least a portion of any coating compositions 
thereon. 
The shredder 30 is activated to shred waste material 14 passing 
therethrough. If necessary, the shredded waste material 34 can be conveyed 
to a storage system 36 such as a floor bunker and returned to the system 
10 by a feeder as discussed above. The shredded waste material 34 is 
conveyed to an activated dewatering device 40 which removes excess 
moisture from the shredded waste material 34 to form moisture-reduced 
waste material 42. 
The moisture-reduced waste material 42 is conveyed to the activated auger 
crusher 50 and crushed as discussed above. The crushed glass fibers 100 
and other waste material are screened using a 1 inch opening stainless 
steel mesh vibrating screen to separate coarse waste material 138 from 
smaller waste material which pass through the screen. 
The dryer 130 preferably drys the waste material 15 by exposure to heated 
air at a temperature ranging from about 120.degree. C. to about 
815.degree. C. (about 250.degree. F. to about 1500.degree. F.), and more 
preferably about 205.degree. C. to about 500.degree. C. (about 400.degree. 
F. to about 925.degree. F). The time period for drying preferably ranges 
from about 5 to about 30 minutes, and more preferably about 7 to about 15 
minutes. Preferably the dried waste material 144 is cooled to about 
25.degree. C. upon exiting the cooler 146. 
The dried waste material 42 can be crushed in a secondary crusher 150 
preferably having 3 pairs of rollers 154 as discussed in detail above. The 
crushed glass fibers and waste material not previously separated are 
screened through a series of vibrating screeners, the first screener 
having a 0.006 meter (1/4 inch) opening stainless steel mesh screen and 
the second screener having a 0.003 meter (1/8 inch) opening stainless 
steel perforated plate to separate oversize dried waste material 194 from 
glass fibers and waste material which pass through the screens. 
A metal detector and removal system 212 can activated to separate metallic 
and graphite materials from the glass fibers and waste material which 
passed through the 0.006 meter (1/4 inch) and 0.003 meter (1/8 inch) 
screens. 
After removing any metal or graphite, the residual glass fibers and waste 
material can be milled and/or air classified to further reduce or capture 
a desired fraction having a smaller average particle size. The suitable 
fraction of glass fibers can be conveyed pneumatically to storage bins, a 
blender for blending with other batch materials or directly to a glass 
melter, as discussed above. 
The process and system 10 of the present invention will now be illustrated 
by the following specific, non-limiting examples. 
EXAMPLE 1 
About 0.27 metric tons (about 600 pounds) of waste material from an E-glass 
fiber forming operation was processed in the following manner. The waste 
material was then shredded into lengths ranging from about 1.5 meters 
(about 5 inches) to about 3.6 meters (about 12 inches) using a SSI Model 
3400H shredder having two prongs per cutting head, as discussed above. The 
waste material was stacked into a pile and drained at a temperature of 
about 25.degree. C. for about 4-5 days, such that the drained waste 
material had about 4 to about 5 weight percent moisture on a total weight 
basis. 
The drained shredded waste material was fed into an auger crusher having a 
cavity which was about 1.45 meters (about 58 inches) long and about 0.75 
meters (about 30 inches) deep. The auger in the crusher was about 1.4 
meters (about 56 inches) long, had a shaft diameter of about 0.075 meters 
(about 3 inches), a 0.55 meter (22 inch) right handed pitch at the first 
end and a 0.4 meter (16 inch) pitch at the second end thereof, a flight 
width of about 0.04 meters (about 1.5 inches) and an outer diameter of 
about 0.25 meters (about 9 inches). The flights were coated with STOOL 101 
alloy as discussed above. 
A standard 0.25 meter (10 inch) long extension having about a 0.25 meter 
(10 inch) diameter was attached to the second, discharge end of the cavity 
proximate the second end of the auger. Conduits of varying lengths, set 
forth in Table 1, were attached to the discharge end of the extension. 
TABLE 1 
______________________________________ 
CONDUIT LENGTH 
METERS FEET 
______________________________________ 
0.9 3 
1.8 6 
3 10 
4.5 15 
5.1 17 
______________________________________ 
The auger was rotated at a speed of about 7 revolutions per minute using a 
Baldor 5 horsepower motor. It was observed that the mean particle size of 
the waste material was reduced as the length of the conduit was increased. 
No noticeable reduction in mean particle size from the feed waste material 
was observed when only the standard 0.25 meter (10 inch) batch feeder 
extension was attached to the crusher. 
EXAMPLE 2 
The crushed waste material produced using the 1.8 meter (6 foot) conduit 
attached to the auger crusher was conveyed through an 0.45 meter (18 inch) 
screw auger conveyor at about a 45.degree. angle to horizontal. The 
crushed waste material was screened using a 1 inch opening stainless steel 
mesh vibrating screen to separate coarse waste material from smaller waste 
material which passed through the screen. 
The smaller waste material was passed through a Carter Day Model CEY2 
fractionating aspirator (air classifier) at an air velocity of about 40.5 
to about 45 meters per second (about 135 to about 150 feet per second). 
The damper was set to setting number 4 and the flange was set to setting 
number 5. The feeder roll was not used. 
The air classifier had three product collection chambers, one oversize 
material collection port and a fines removal port. The material collected 
in the three center chambers of the air classifier was consolidated. This 
material was screened using a 0.006 meter (1/4 inch) opening stainless 
steel mesh and 0.003 meter (1/8 inch) vibrating screens to separate 
oversize waste material from acceptable waste material which passed 
through the screens. The coarse material was recirculated through a 0.006 
meter (1/4 inch) opening stainless steel mesh screen and through a 
secondary crusher having a pair of 0.1 meter (4 inch) long and 0.09 meter 
(3.5 inch) diameter intermeshed rollers having 18 rounded corrugations 
along the length of each roll, as discussed above. One roller was rotated 
by a drive at a speed of about 90 revolutions per minute. The crushed 
waste material was recirculated through the 0.025 meter (1 inch) opening 
screen and the air classifier. About 440 kilograms (about 200 pounds) of 
acceptable waste material which passed through the 0.003 meter (1/8 inch) 
opening screen was collected and samples of which were analyzed. 
The loss on ignition (LOI) of the first sample was determined to be 0.35 
mass weight percent. 
FIG. 18 is a bar chart of number of occurrences of specified fiber lengths 
in a 250 count fiber sample and FIG. 19 is a bar chart of number of 
occurrences of specified filament diameters in a 250 count fiber sample as 
determined by transmitted light optical microscopy using the commercially 
available OPTIMAS image analysis package. 
The average fiber diameter was determined to be 1.94.times.10.sup.-5 meters 
(77.6.times.10.sup.-5 inches). The filament diameter ranged from 
8.5.times.10.sup.-6 meters (34 .times.10.sup.-5 inches) to 
1.1.times..sup.10-4 meters (427.times.10.sup.-5 inches). Fifty percent of 
the fibers had diameters of less than 1.4.times.10.sup.-5 meters 
(56.times.10.sup.-5 inches). 
The average fiber length was determined to be 6.5.times.10.sup.-4 meters 
(0.026 inches). The filament diameter ranged from 7.5.times.10.sup.-5 
meters (0.003 inches) to 3.2.times.10.sup.-3 meters (0.127 inches). Fifty 
percent of the fibers had diameters of less than 5.times.10-4 meters 
(0.020 inches). The aspect ratio of the average fiber length to diameter 
was 33. 
Approximately 500 milliliters of a second sample of the collected material 
was placed onto a U.S.A. series sieve having 2 millimeter (mm) openings 
and over a stack of five additional screens having successively smaller 
openings as follows: 1 mm, 0.5 mm, 0.25 mm, 0.15 mm and 0.075 mm and a 
collection pan. The set of six screens was vigorously shaken for about 
five minutes and disassembled. The material trapped on each screen and the 
collection pan was collected and weighed. The results of this analysis are 
shown in Table 2 below. 
TABLE 2 
______________________________________ 
WEIGHT 
SCREEN OPENING PERCENTAGE OF 
(mm) SAMPLE 
______________________________________ 
2.0 0.2 
1.0 0.2 
0.5 7.4 
0.25 56.6 
0.15 22.0 
0.075 13.0 
&lt;0.075 0.6 
______________________________________ 
The loss on ignition (LOI) of the second sample was determined to be 0.0 
mass weight percent. The second sample had 0.1 weight percent moisture, 
0.3 weight percent organics and 0.4 weight percent volatiles. The percent 
moisture was calculated as the percent mass loss upon heating at 
110.degree. C. overnight (about 8-10 hours). The volatiles were calculated 
as the percent mass loss upon heating at 650.degree. C. and the percent 
organics was calculated as the difference between the percent volatiles 
and the percent moisture. 
The bulk density (natural fill) of the second sample was determined to be 
0.985 grams per cubic centimeter. The natural fill bulk density was 
determined by pouring the sample into a 50 milliliter graduated cylinder 
to the 50 milliliter level. The bulk density (tamped) of the second sample 
was determined to be 1.248 grams per cubic centimeter. The tamped bulk 
density was determined by pouring the sample into a 50 milliliter 
graduated cylinder and tamping the cylinder until the material settled to 
the 50 milliliter level. According to ASTM Method E688, the sample 
displayed incomplete flow. 
From the foregoing description, it can be seen that the present invention 
provides a simple, economical, durable system and process for reducing 
waste disposal costs and increases efficiency and productivity. The 
resulting glass fiber product can have relatively smooth ends, low surface 
organic levels and can be readily pneumatically transported to facilitate 
recycling of the product to the glass melter. The system and process of 
the present invention also provide the capability to consolidate waste 
from different glass fiber forming facilities. 
It will be appreciated by those skilled in the art that changes could be 
made to the embodiments described above without departing from the broad 
inventive concept thereof. It is understood, therefore, that this 
invention is not limited to the particular embodiments disclosed, but it 
is intended to cover modifications which are within the spirit and scope 
of the invention, as defined by the appended claims.