CA2358628A1

CA2358628A1 - Non-woven web made with untreated clarifier sludge

Info

Publication number: CA2358628A1
Application number: CA 2358628
Authority: CA
Inventors: Philip Bush; Ricky Burkeen; Robert H. Blanpied
Original assignee: Individual
Current assignee: Atlas Roofing Corp
Priority date: 2000-10-10
Filing date: 2001-10-10
Publication date: 2002-04-10
Also published as: GB2367837A; GB2367837B; US6572736B2; US20020062934A1; GB0124318D0

Abstract

The non-woven web of the present invention is comprised of recycled cellulose fiber and untreated Clarifies Sludge, and optionally, recycled glass fiber.
Unlike uses of reclaimed Clarifies Sludge whereby the material has been treated in some fashion to improve its quality, the non-woven web of the present invention utilizes untreated Clarifier Sludge. The Clarifies Sludge of the present invention is dry enough to handle, and in one example varies between about 30% and about 45% solids. The Clarifier Sludge can be added to web-forming equipment (e.g., papermaking equipment) either in a waste paper disintegrator or into a recycling apparatus (e.g., broke pulper) whose output is metered into a refiner tank of the web-forming equipment. In an embodiment utilizing a broke pulper for introduction of the Clarifier Sludge, the broke pulper is filled with clarifier sludge and water to a consistency of about 3.5% solids.

Description

~.... ..~.

NON-WOVEN WEB IvIAD~ WITH UNTREATED
CLARIFIER SLUDGE
BtICKGROLiND
This application claims the priority and benefit of United States Provisional p Patent Application Serial Number 60/?38,4?0, filed October 10, ?000, which is incorporated by reference herein in its entirety.
1. FIELD OF THE XNVENTION
The present invention pertains to low cost moisture resistant and dimensionally arable non-woven continuous webs, and the use of ine;cpensive furztish for producing to such webs.

2. RELATED ART AND OTHER CONSIDERATTONS
Non-woven continuous web materials have been known in the art at least since the 19'" Century, when the English papermaking brothers Sealy and Henry Fourdrinier started their Lust machine. Over the years many fibers have been used to make is various types of webs, includinC asbestos. bagasse, cotton, jlass, hemp, jute, kenaf, sisal, various types of wood cellulose pulp. and many forms of synthetic plastic fibers.
FOr example, U.S. Patent Nos. 3,773,513 and 3,885,9b2 to l~IacClaren teach the use of glass fiber and latex to stabilize a photographic paper.
When health concerns made asbestos fiber obsolete, web makers turned to 2o glass fibers and synthetic fibers made of various plastics. For erample, common vinyl floor backinb webs which had been made with asbestos fibers were subsequently made of a combination of 'lass and plastic fibers using a polymer latex as a binder. US Patent =I,?74,9I 6 and US Patent =1,;73,992 both disclose a dimensionally stable backing web usin' polypropylene fibers for stabilisation.
US
z~ Patent 4,373.992 further teaches the adding of glass fibers. US Patent ~,269,6~7 pertains to an asbestos-free web that uses slightly refined virgin cellulose fiber in~orporatind a Iow percentage of ~lasS fiber.

The art of '~sizin~" non-woven webs is nearly as old as the continuous formation mode. For the purpose of defining "sizing," see simultaneously-filed United States Patent Application Serial No. O~)/-,- (attorney docket. 2334-195) and United States Provisional Patent application 6()/338,457 , both entitled "NON-WOVEN WEB H~A VING UNIQUE LIQUID RESISTANCE AND
DIMENSIONAL STABILITY", which are incorporated herein by reference in their entirety. Products using the materials of the present invention can be either sized, or not sized. The current invention pertains to types of fiber utilized rather than any form of sizing against moisture resistance.
to A sampling of prior art directed toward various different types of fibers used in non-woven webs can be found in the following list of US Patents, all of which are incorporated hexein by reference.

3,773,5 .l 3 3,885,962 4,174,415 4,188,353 4,245,689 4,269,657 4,'.?74,916 4,373,99?
15 4,426,470 4,445,972 4,457,785 4,472.?43 4,481,075 4,510,019 4,513,045 4,536.44:7 4,543,158 4,545,85:1 4,591.:11? 4,609,431 4,618,401 4,626,389 4,680,?23 4,681,658 4,749,4=~ 4,789,43() 4,956,049 4,964,954 ?0 4,969,975 5,?36,757 5,236,778 5,393,379 5,409,574 5,501,771 5,501,7'14 5,536,370 An ordinary 100%a cellulose non-woven continuous web material known as "felt" has been used for many years in the production of asphalt saturated roofing felt.
This material is used to cover and protect the plywood or composition board ~S comprising the stnictural part of a sloped roof prior to adding exterior protection.
Sloped roof construction is normally used on residential buildings, churches, and schools. The exterior covering over the saturated asphalt felt can be shin~Ies, tiles, slate, or newer materials such as standing ridge steel panels. The layer of asphalt saturated cellulose felt between the structural deck and exterior membrane is often 3o called ''underlayment."

A particular class fiber reinforced nun-woven continuous web material has been used for many years in the production of polyisocvanurate (polyiso) foam board insulation. This rigid plastic foam insulation board has become the most popular type of commercial roofing insulation. It is manufactured by pouring liquid chemical streams on the continuously moving b~tt~m felt. known as the bottom''Facer,"
with a second Fscer being placed on top of the foaming streams. The polyiso foaming liquid is deposited between two webs of the Facet felt, cured into a unified foamed board, and then cut into insulation board lengths. The lartrest producer of this Pacer felt, Atlas Rooting Corporation, developed a glass fiber-utilizing facet which Atlas refers io to as "Glass Reinforced Felt" (GRF) Facet. Certain aspects of this facet product are disclosed in US Patent Application, Serial No. 09/425.051, which is incorporated herein by reference in its entirety. The GRF Facet has a higher degree of dimensional stability than 100~7c cellulose felt. .as an integral part of an insulation board. GRF
Facet adds strength and durability to a lightweight .insulation board that is used in s i5 severe environment. Strength and durability are important because commercial roofing products suffer some of the most intense punishment experienced by building construction products.
Historically, asphalt saturated roofing felt and G12F Facets have primarily used recycled waste paper as the raw material source for fiber. In most cases, OCC
(Old zo Corrugated Container) is the main source of fiber. OCC is normally the highest cost matezial used in a paper mill that uses nothing but recycled waste paper.
Mixed waste, or office waste, or newsprint, or wood flour, or some mixture of these has been the lower cost fiber source to augment the OCC. The successful use of recycled glaos fiber has irrxproved. the properties of the Pacer web while keeping the cost reasonable.
?5 The cost of either virgin glass fiber or virgin cellulose fiber is much too high for this facet.
For the purpose of describing this invention, the term "Clarifies Sludge"
refers to the rejected solids that are separated from the post-processing water by the cleaning and recycling systems in paper and pulp mills. Thus. "Clarifies Sludge"
encompasses 3o but is not limited to the mixture of short fibers, extremely large fibers, and inorganic contaminates that are separated from the recycling water of a pulp andlor paper mill.
Clarifer Sludge is sometitttes sent to an approved landfill. Most of it is burned as boiler fuel after some water has been removed. Several solid/liquid separation systems in use have trade names, but herein they are collectively and generically called ''clarifiers." Both pulp mills and paper mills have a need to clean their post-processing water, especially if it is an zffluent joing back into the public sewer or watershed systems. Llntreated Clarilier Sludge is notoriously unacceptable as a paper mill furnish.
Thus, the owner of the pulp and/or paper mills primarily direct their efforts to the clarifcation of the water, rather than emphasizing the collection of solids (e.;., Claririer Sludge). The collection of solids is an onerous but necessary part of the cleaning of pulp and paper mill effluent water. Disposal of Clarifter Sludge is often 1o hampered by environmental concerns. The quality of the fiber found in this recovered solids mass will depend upon the source of the fiber used by the paper mill.
If a pulp mill is integrated with a paper mill, these recycling water streams are usually mixed prior to clarifier treatment. In this case, the fiber quality of these mixed streams will be higher than most any other situation. The reason is that some of this fiber has is never been through a retiner. Even the relatively high quality C:laritier Sludge from a de-inking plant will have no unrefined fibers. The highest quality sludge is found where a pulp mill treats their own recycling water, separate from a paper trill.
Many attempts have been made at improvi:n~ wet Claritier Sludge to a state of being useful. At least by the mid-1970s a company developed a system for recovery ~o of fiher from paper mill effluent. US Patent No. 3,833,468 to Boniface teaches such a system. Other US Patents concentratin' on either the apparatus to improve, or the method of izz~.provina, waste Clarifier Sludge include the following:
4,983,?58 ~,00?,633 5,137,99 ,?97,742 5,332,474 5,23,993 5,527,432 5,536,371 LS x,772,847 The various processes to improve quality of Clarifier Sludge are relatively e:cpensive, raising the cost ~f acceptable fiber furnish. In some instances, the freight costs to transport this type of reclaimed fiber are prohibitive. Excessive freight costs 3o can be due to the large percentage of water usually found in this material, or the distance from the source to the paper mill using the material, or both.

The quality of untreated Clarifier Sludge has heen so low- that it has not been considered suitable as a substitute for waste paper. Only after bein; treated by one or more of the various schemes noted above has it been useful. One example, US
Patent ~,=123,993, teaches a method using a fiber recovery system inside a paper mill. It 5 appears that no paper mill has heretofore successfully used untreated Claritier Sludge.
The quality of waste paper is lower now than at any time in the past, primarily due to more recycling. Some experts estimate that any given Kraft fiber originally used in a cardboard box can be reused ai least love different times in five different waste paper mills. Another major reason waste paper quality has dropped is that the to suppliers allow more contamination from metals and plastics. A further problem is the large increase in coated papers being recycled. Coated paper means high levels of mineral pigments as ash. Wide fluctuations in the annount of coated paper in "I~.Iixed Waste" causes a loss of control ovex the percent ash in felt. The lack of consistent properties causes CntiICSS problems for s paper mill using 100~''o recycled waste paper.
~s Any Given truckload of any trade of waste paper will contain significantly different materials than any ocher truckload of the Supposedly same grade. In today's market, it is virtually impossible to purchase consistent properties in any grade of waste paper.
This makes it difficult to manufacture s web of felt, with or without glass fibers, with uniform properties.
?o Thus, there remains a need for a more consistent source of secondary cellulose fibers to make dry felt both for asphalt saturated underlayment :and for facets (e.~., glass reinforced felt facets) for polyiso foam boards. Therefore it is an object of the present invention to provide an economic;~l dry felt having more consistent properties by utilizing a more unikorm source of cellulose fiber.
2s BRIEF SUMNIARY OF TIDE INVENTION
The non-woven web of the present invention is comprised of recycled cellulose fiber and untreated Clarifies Sludge, and optionally, recycled glass fiber.
Unlike uses of reclaimed Clarifies Sludge whereby the material has been treated in some fashion to irtoprovc its quality, the non-woven web of the present invention utilizes untreated Clarifies Sludge, The Clarifies Sludge used in the present invention is dry enough to handle, e.g., with a front-loader, and in one ex;irnple varies between about 3U% and about 45% solids. The Clarilier Sludge can be added to web-forming equipment (e.g., papermakinD equipment) either in a waste psper disintegrator or into a recycling apparatus (e.g., broke pulper) whose output is metered into a refiner tank of the web-forming equipment. In an embodiment utilizing .1 broke pulper for introduction of the Clarifter Sludge, a broke pulper is filled with Clarifies Sludge and water to a consistency of about 3.5% solids. In a practical example, over fifty percent (50%) of the total paper making furnish (i.e., paper making solids] is Clarifies Sludge-io The use of the Clarifies Sludge of the present invention for papermaking involves selection of proper retention and drainage agents. In particular, the retention and drainage agents must enable solids (e.g., the impurities) of the Clarifies Sludge to stay in a sheet formed in the papermakinc machine 9Q and still permit Good liquid drainage. Proper agent selection enables a bundling of the short fibers and the impurities of the Clarifies Sludge with the loner fibers in the wastepaper, and at the s3tne time permits quick liquid drainage between the korrning bundles; e_g., "pin flocs" .
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects. features, and advantages of the invention will ?o be apparent from the following more particular description of preferred embodiments as illustrated in the accompaztyinb drawings in which reference characters refer to the same parts throughout the various views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
Fig. 1 is a schematic view showing apparatus and process steps for producing a zs nutx-woven continuous web, specifically "Dry Felt", in accordance with a k~xst Example of an embodiment of the present invention.
Fig. 2 is a schematic view showing apparatus znd process steps for producing a non-woven continuous glass reinforced web (e.g., facet) in accordance with a Second Example of an embodiment of the present invention.

FiQ. 3 is a schematic view showing apparatus and process steps for utilizing the glass reinforced non-woven continuous web (e.g.. facet) of the Second Example in production of a polyisocyanurate foam board in accordance with a Third Example of the invention.
DETAILED DESCRIPTrON
In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular compositions, processes, techniques, etc. in order to provide a thorough understanding of the present invention.
However.
it will be apparent to those skilled in the art that the present invention may be io practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known ingredients, steps, or operations are omitted so as not to obscure the description of the present invention with unnecessary detail.
As used in this invention, the term "recycled cellulose fiber" means either ( 1 ) 15 post-consumer recycled waste paper and cardboard. or (Z) pre-consumer but post-industrial recycled waste paper and cardboard, which is obtained from factories, or a combination of (1) and (?). An example of pre-consumer but post-industrial recycled waste paper and cardboard is the side-trim and clippings that come from paper converters. post-consumer paper and cardboard is the lamest source available.
zo For the purpose of describing this invention, the term "recycled glass fiber" is exemplified by the synthetic binder-impregnated waste material not usable by the producers of glass-fiber mats. Due to the synthetic hinders char are added duriztg the formation of glass mats, only a limited amount of waste glass mat can be recycled within the mat-forminn process. Too much recycled binder interferes with the ?5 acceptable formation of glass fibers on a forming wire. Owing to the high expense of cleaning the binder from mat trimmings, or rejected mat, this material has instead been sent to landfill sites. But by sellinb this scrap glass mat and trimmings (e_g., recycled glass fiber) to GRF Facet manufacturers for facet production in accordance with the techniques of the present invention, the glass mat producers can avoid the ~o added cost of plying for landfill. Moreover, the GRF Facet producer enjoys lower costs for 5lass fiber.

In general, there are two drawbacks to using recycled Glass fiber. ~ tirst drawback is that. after the recycled glass fiber has been subjected to the intense mechanical enemy needed to break up the mat (especially if the mat is in the form of a roll), most of the fibers are shorter than any virgin fibers commercially available. .~
second drawback is that, due to the much shorter fiber lengths, the first-pass retention is lower than if virgin fiber had been used. However. recycled glass fiber lengths in glass reinforced felt Eaters can ranGe from less than 1-mm up to over 13-mm, due to the wide range of recycled class fibers employed and the varied conditions found in preparing the glass tibers for use.
to The non-woven web of the present invention is comprised of recycled cellulose fiber and untreated Clarifier Sludge, and optionally, recycled glass fiber.
Unlike uses of reclaimed Clarifxer Sludge whereby the material has been treated in some fashion to improve its quality. the non-woven web of the present invention utilizes untreated Clarifier Sludge. That is. prior to its introduction into the apparatus t5 of the present invention, the Clarifies Sludge has not been treated with fiber cleaning or reclamation equipment.
The Clarifies Sludge utilized in the present invention is preferably dry enough to handle, e.g., with a front-loader, and in one example varies between about 30% and about ~5% solids. The Clarifies Sludge can be added to web-forming equipment ?o (e.g., papermaking equipment) either in a waste paper disintegrator or into a recycling arparatus (e.g., broke pulper) whose output is metered into a refiner tank of the web-forming equipment. In an ennbodiment utilizing a broke pulper for introduction of the Clarifies Sludge, the Broke Pulper is filled with Clarifies Sludge and water to a consistency of about 3.S°lo solids. In, the present invezttion, a practical e:cample (see ?5 EXANIPLE 1 below) uses over fifty percent (~0%) of the total paper making furnish (i.e., paper making solids) as Clarifies Sludge.
The non-woven web also comprises chemical additives to enhance paper machine processing; and, optionally, to enhance final web performance. The preferred embodiments cast more easily be described using the following examples 3o shown below.

y EXAuIPL>r 1 Basic sltucture and certain process steps involved in Example 1 are illustrated in Fig. 1. which shows the papermakina system of the present invention. The papermaking system includes a waste paper disintegrator 20; cleaning 3z clump removal screens 30; stock holding chest ~0: refiner tank ~0; machine chest (for stock mixitag and holding) 60: selectifier screen and cleaners 70; tan pump 80; and papermaking machine 90.
Process steps performed in waste paper disintegrator 20 are labeled as steps/blocks S-1.1 through S- l.~ in Fig. 1. ~1s step S-1.1, the disintedrator ?0, being a io large type waste paper disintegrator as used by any waste-paper mill (such as a Hydrapulper~ type waste paper disintegrator, for example), is charged with about X000 gallons of wafer, to which is addet~ ah~ut 1 R00 Pounds of OCC (Old Corrugated Container). The water/OCC mixture is pulped (step S-1.3) until the big clumps are disinte~'ated. To the pulped mixture is added (as 3iep S-1.3) another 1?09 pounds of 1~ OCC and another 5000 gallons of water. The resulting stock is now at about 3.~','o consistency (% solids). As soon as this blend is well mi.~ted (step S-1.~), it is passed through cleaning and clump removal screens 30.
As a routine practice, in a parallel operation, items such as side trim, deckle edge, reject rolls, and other paper machine waste are recycled using recycling zo apparatus t OO. Typically paper machines have such a recycling apparatus (such as a broke pulper of one type or another, or beater) to recycle in-house fibers that are too dry to pump. The recycle matccial from recycling apparatus 100 is added to the stock furnish coming from waste paper disintegrator 20 in reFtner tank 50.
In Example 1 of the present invention, and as a radical departure from the prior ?5 art practice, untreated Claritier Sludge (represented by arrow "CS" in Fig.
1) is introduced into the recycling apparatus 100, which in the illustrated embodiment is a Broke Pulper. Prior to this point, the Clarifier Sludge has not been treated with fiber cleaning or reclamation equipment. and thus includes as its solids impurities such as one or more of plastic, wood particles, sand, ash, and grit. for example. The Clarifier 3o Sludge of this example varies between about 30~o arid about =15% solids;
e.g., dry enough to handle with a front-luarlor. It is a must preferred method within ih~

teachinb of this invention to primarily use the Broke Pulper 100 as the place to add incoming Clarifier Sludge which has not been specially treated or cleaned.
However, if the Waste Paper Disinte~rator ?0 is easily accessible, this location is another point at which the Clarifier Sludge can be added in another mode of the invention.
s The Broke Pulper 100 is filled with Claritier Sludge and water to a consistency of about 3.5% solids, whereupon it is pumped to a meterinC device :~S situated immediately above the refiner tank ~0. This metering device 45, in one embodiment, is or has simple double weir-gates with return and flow-ahead ports. This metering device 45 is used to regulate the amount of Clarifier Sludge being added to the OC;C
to system. The output of Broke Pulper 100 is metered at about »%. The OCC
stock from disinter razor 20 is metered at about -1~ %. 'The outputs from Broke Pulper 100 and disintearator 20 are thus combined and well mixed in refiner tank 50 prior to passing through refiner ~~, and afterwards mixed well in machine chest 60.
After stock dilution with mill water, various processing aids such as retention t5 aids, drainage aids, and defoamers are added as needed in paper making machine 90.
The use of the Clarifier Sludge of the present invention for papermaking involves selection of proper retention and drainage :~Qents. In particular, the retention and drainage agents must enable solids (e.'., impurities) of the Claritier Sludge to stay in a sheet formed in the papermakinQ machine 90 and still permit food liquid drainage.
~o Proper agent selection enables a bundling of the short fibers and the solids (e.g impurities) in the Clarifier Sludge with the lonser fibers in the OCC and other wastepaper, and at the same time permits quick liquid drainage between the forming bundles; e.g., "pin-flocs".
One example of such appropriate agents involves utilizing an acrylamide 25 modified cationic copolymer such as Nalco 720 at about two pounds l?.0-lbs.
as-received liquid basis) per ton of paper in conjunction with about one (1) pound (dry basis per ton) of a stron~ly anionic amorphous silica such as Nalco 8692. (n accordance with such example, the first pass retention can be maintained above 90'0.
plus providing an increase in drainage rate. Not many years a?o it was impossible to 30 obtain a first-pass retention of over ninety percent (90 %) of any type of incoming stock retained on a 14-mesh wire cylinder. Faster drainage plus higher percent retention is made possible by creating pin-flocs in the low consistency (below 0.80%

solids) vat stock. Even though proper retention and drainage agents such a5 those mentioned above have been commercially available, heretofore the Vreatly dista~ored Clarifies Sludge has not been successfully utilized in papezmakinQ in view of its perceived contamination issues.
> In paper makinc machine 90, the sheet formed is pressed by a standard mechanical paper wet-press section before introducing the web to a typical stcam-heated dryer section.
Because enough material is available, it has been discovered that the quality requirements of Dry Felt are not compromised by using over ~0~70 of the total paper io making furnish (i.e., paper making solid constituents) as Clarifies Sludge.
F~owever, not enough material is available to determine how much Clarifies Sludge can be used without hurting desired properties. Of course, anv minimum amount helps the cost.
With regard to Tables 1, ?, and 3, all the tests are familiar to all persons skilled in the art of papermakin; and/or are understood in the context of the present m disclosure. In this regard, the Solvent of the Penetration Test is comprised of Stepan polyol S-2352 at 100-parts-by-weight (pbw) mixed with 30-pbw HCFC-141b. The polyol is obtained from Stepan Company. Northtield, IL 6UU93, and HCFC-141b can be obtained from Atochem or Aldrich. The Test is rt~ade by holding an elevated 1''-inch square sample horizontal, dropping 10-grams of Solvent in the center. and recording the seconds required for the first small circle of "show-throu'h" to appear.
These test results represent the Quality Control Tests made within ?4 hours of production_ The single cylinder vat machine web produced by Example 1 is usually called ''Dry Felt", which is used to make asphalt saturated roofing felt. This type of felt 2s must be able to pick up (absorb) at least its own weight in asphalt. If a Dry Felt absorbs asphalt in exactly the same weight as the felt, it is said to ''Pick Up 100°70."
The Dry Felt of Example 1 exhibits the test characteristics shown in Table 1.

CHARa\CTERISTICffEST i MEAS>;IRENIENT

Basis Weight ?S-pounds per 480-tt~

Tensile Test, M.D. ~ 3?-pounds per linear inch (1-inch by ~-inch test strip) Percent Asphalt Saturation~ lOS"~ pick-up by weight The test results for the web of Ex:unple 1 are essentially as good as those of the prior art, and yet advantageously the felt of Example 1 is more economical to produce. Furthermore, personnel operating paper machines which use 100%
recycled waste paper but not the untreated Clarifies Sludge of the present invention spend more time making adjustmer~ts_ With enough volume, it may be possible to eliminate one person from a papermakin~ machine crew when using Clarifies Sludge.
EXAMPLE
io Example ? shows a method of making a Mass reinforced felt facet for polyiso foam boards in accordance with a mode of the present invention. The method of Example 2 is depicted in Figure ?. ;~s understood from the ensuing discussion, initial steps of the method of Example ? resemble those of the method of Example 1 with it use of Clarifies Sludge, but additionally the Eater of Example ? includes recycled is glass (e.g., waste blass mat).
As step S-l.l, at step S-Z.I a large type waste paper disintegrator 20 is charged with about 5000 gallons of water, to which is added about 19U0 pounds of OCC
(Old Corrugated Container). The water/OCC mixture is pulped (step S-?.2) until the bis clumps are disinters aced. To the pulped mixture is added (as step S-?.3) about 6~0 ?o pounds of Mixed Waste paper, another 5000 gallons of water, and 5~0 pounds of waste glass that. The resulting stock is now at about 3.6% consistency (percent solids).
When the blend is well mixed (step S-?.4), it is passed through clump removal screens 30. As the stock enters the tirst stunk chest :10, Basazol Black PR-376-L dye from BASF is added in an amount sufficient to obtain the desired shade of gray, usually about four (4) pounds of full strength dye per ton of jlass reinforced felt facet.
In the papermaking industry, chemical addition rates are normally measured in the liquid form, but reported using dry weight basis of the chemical per ton, or 2000 pounds, of finished paper. As an example, following the dye addition comes the addition of cationic resin polymer, such as a polyanude wet-strength a~enl.
The liquid polymer is pumped into the system at a rate which Will provide 30 dry pounds per ton of finished paper. Instead of reporting this as an add-on rate of 30 dry pounds to per ton, this rate can be expressed as an add-on rate of about 1.~% dry basis (d.b.).
The polymer is added to the thick stock in refiner tank 50.
After passing through stoclt refiner », the stock is pumped to holdin' chest whew about 3.~% d_b. dispersed carboxylated SBR latex is added- All the active chemicals (e_g_, the cationic dye, sizing agent(s), resin polymer and SBR
latex) are is pumped to their respective addition points as full strength liquids, but then mixed with a stream of mill water to greatly reduce the concentration- This dilution substantially aids in product distribution.
As in Example 1 of Fig. l, Clarifier Sludge is inaoduced into the Broke Pulper 100. The CIarifier Sludge of this example varies between about 30% and about 45%
2o solids. The Broke Pulper 100 is filled with Clarifier Slud~e and water to a consistency of about 3.5% solids, whereupon, as in Example 1, it is pumped to a metering device 45 immediately above the Refiner Tank ~0.
Then the stock is diluted somewhat before passing through a Selectifiei~
screen and several cleaners 70. A good quality glass reinforced felt Eater requires zs substantial liquid resistance, and this is provided by a synthetic sizing agent being added. One preferred synthetic sizing abent is Alkenyl Succinic Anhydride, which is added at the rate of about 0.?% to abouC 0.~°,'o dry basis weight [See simultaneously-filed United States Patent Application Serial No. 09/-, - (attorney docket:

194) and United States Provisional Patent Application No. 60/?38,~57 , both entitled ~o "NON-WOVEN WEB H~VINC'T 1JNIQUE LIQUID RESISTANCE AND
DIhIENSIONAL STABILITY", which are incorporated herein by reference in their entirety.] Following this addition, another dilution is made at a fan-pump 8U
to about l~
0.8°~o consistency. The stock i5 then introduced to the paper making machine 9U.
Paper making machine 90 can comprise any suitable apparatus, such ss a Fourdrinier, a single cylinder, or multiple cylinder vat machines, for example. The retention and drainage agents of Example 1 are also utilized in papermaking machine 90 for Example ?.
The sinble cylinder vat machine web produced by Example 2 exhibits the test characteristics shown in Table 2. Again. if the percent Claritier Sludge utilized is not excessive, there will be no loss of properties appearing. At worst, a 10~'o reduction in the tensile strength may be observed; however, that amuunt is not significant in this io grade_ T.~BLE 2 CHARACTERISTICITEST VIEASUREMEl~T

Basis Weight 25-pounds per 4$U-ft' Tensile Test, M.D. ?8-pounds per Linear inch (1-inch by 8-inch test strip) Ash Content 17~c Organic Solvent Penetration1~--seconds to i8 seconds to First Test Penetration Two minute Cobb Test 6.7~'o weight increase from Water absocpcion v s Also provided is a rigid cellular foam insulation board made with the lower cost web material (e.g., the glass reinforced felt facet of Example ?), and method of making the same. Such boards can be made on a typical continuous restrained-rise double steel belt foam board laminator, or on any other board producing machinery such as a continuous free-rise foam board machine. Fig_ 3 shows a representative Zo generic type restrained-rise laminator that can use facets of the present invention (e.g., the facets of Example 2 j. While Fig. 3 illustrates a generic type restrained-rise laminator, it should be kept in mind that a free-rise machine may be employed.

l~
Basic structure and process steps involved in a foam board production are also illustrated in Fig. 3. Two (.?) rolls 110 and 130 of GRF Facet of the invention are unwound and pulled into the laminator. On s free-rise machine, motor-driven pull-rolls grip the facets to provide the means to feed the machine, whereas on a > restrained-rise machine, scrap boards I30 are used drip the two facets between the double belts 320, 230. Prior to the machine starting, the bulk polyol in storage tank 140 is mixed will other ~henucals such as catalysts, surfactants, bluwino agents, and (optionally) flame retardants. These additives are stored as shown in storage tanks 150, 160, 170, and 180 respectively. The above mentioned chemicals from storage to tanks 1~0, 160, 170, and 180 are completely mixed in mi.cin~ tank 19U. As the machinery is started the polymeric polyisocyanate in storage tank 200 is pumped to the mixing device ? 10 at the same instant that the mixed materials in miring tank 190 are fed to the mixin~ device 210. At this point, all the chemicals needed have been mixed and are laid on the bottom facet before the top facet is lowered into place on is top of the chemicals. These mixed chemicals begin to react and expand in preplanned rates (See U.S. Patent 5,252,625; U.S. Patent .5,?54,600: and U.S. Patent 5,294,647;
all incorporated herein by reference in their entirety). As the liquid turns into foam it expands to fill the cavity between the top laminator belt ??0 and the bottom laminator belt 230. both motorized parts of the machine. A solid board is created and viewed ?o for quality at the end of the laminator. A crosscut saw 2~0 cuts the solid boards 250, and 250 into planned lengths, which are then carried away from the crosscut saw ?40 by a motorised conveyor ?60 that runs fastex than the laminator belts ?30 and ?30.
The rigid boards are stacked and wrapped, compleun~ the process.
Thus, in accordance with the present invention, and as poor as Clarifies Sludge is quality is, when used in a 100% recycled paper trill, there is no need to sdd special fiber recovery equipment.
Through the use, e.a., of modern flocculating and draina;e polymers such as described above, inorganic contaminants and the large amount of extremely short fibers ("fines") included in the Clarifies Sludge can be held in the web, thereby 3o keeping the recycled water relatively clean. As long as fines are not lost to the recycled water system, the effluent quality is not impaired. In some ways, the additional fines improve the characteristics of the felt product. Often times, the running speed of a paper machine will be slowed due to the sluwer water drainage caused by excessive fines. However, the running speed can be maintained as long as the fines are flocculated into small bundles of fiber, which do not slow drainage-Advantageously, the quality requirements of GRF Faces are not compromised by using about 40% of the total paper making furnish (i.e., paper making solid s constituents) as Clarifies Sludge: and, in making Dry Felt by using over about 50% as Clarifies Sludge.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment. but cm the to contrary, is intended to cover various cziodifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A method of manufacturing a non-Woven web using a papermaking system, the method comprising:

forming a web in the papermaking system using a mixture of recycled cellulose fiber and Clarifies Sludge, the Clarifies Sludge being introduced directly into the paper making system without the use of fiber cleaning or reclamation equipment;
introducing into the papermaking system a retention agent and a drainage agent chosen collectively to enable solids in the Clarifier Sludge to be included in a sheet forming in the papermaking system while permitting liquid drainage.

2. The method of claim 1, further comprising forming the web additionally using recycled glass fiber.

3. The method of claim 1, wherein the Clarifier Sludge comprises between about 30% and about 45% solids.

4. The method of claim 1, further comprising adding the Clarifier Sludge to the paper making system in one of a waste paper disintegrator or a recycling apparatus.

5. The method of claim 4, further comprising adding the Clarifier Sludge to a broke pulper.

6. The method of claim 5, further comprising adding the Clarifier Sludge to a broke pulper filled with clarifier sludge and water to a consistency of about 3.5% solids.

7. The method of claim 1, wherein the Clarifier Sludge comprises over about fifty percent (50%) of the solid material of the web.

8. A web produced by the method of claim 1.

9. A web produced by the method of claim 2.

10. A web produced by the method of claim 3 .

11. A web produced by the method of claim 4.

12. A web produced by the method of claim 5.

13. A web produced by the method of claim 6.

14. A web produced by the method of claim 7.

15. A rigid cellular foam board utilizing the web of claim 2.

16. A rigid cellular foam board comprising:

a first facer and a second facer;
a rigid cellular foam formed between the first facer and the second facer;

wherein at least one of the first facer and the second facer comprise:

recycled cellulose fiber;
recycled glass fiber, and untreated Clarifier Sludge.