CA1262231A - Resin impregnated fibre batt - Google Patents

Abstract

ABSTRACT

A bonded fibre insulation batt is produced by ragging, teasing and otherwise doffering fibres of wool and/or synthetic or other natural fibres such as monoacrylic, acrylic, polyamide, polyester or cotton fibres, so as to form a sliver with said fibres randomly dispersed and lapping the sliver to produce a mat of the desired thickness. The mat is then impregnated with a resin, such as a fireproofing resin, and preferably with a pesticide and a smoke retardant. The impregnated mat is placed in an oven to cure the resin thus forming the insulating batt which can be cut to desired size.

Description

KG - DND nF TUE INV~NTION

Ths pre~nt invention relate~ to improvement~ in insula~ion, and in particular to the u~a of bonded mono-acrylic, ac.rylic or polyamide, polyester and like synthetic or cellulose fibres either alone or in combination with animal fibres and either in batt form or a~ ' blow inl in~ulation.
With the pre~ent energy cost~, con~ervation of heat is highly d~rabl~. One m~thod of con~erving heat in the dome~ia scene i~ to insulate th~ dwelling. Fibregla~s in~ula-tion l~ u~ed exten~lvely in thi~ ld, although it is hazardous to health, and di~ficult *o handle in batts by reason of the gla~s ~ibxe~. Use o~ chemlcala to ran~er 'blow in' ~ibreglass fire-retarding i~ also h~alth hazardous.

BACKGROUND MT

In the Australian Patent No. 527,843 granted to Richard L. Lewellin there is disclosed a me~hod o~ forming an insulation batt of bonded fibres, at l~a~t 95% of which are wool fibres.
The method involves ragging and teasi~g wool ~ibres o~ waste wool, wool ~econd~ and ~he like, and matting tha randomly dispersed wool fibre~ to produae a b~tt o~ ~he required thickness. The bat~ i3 then ~prayed wlth ~ira r~tardant, resin~, pe~ticides, etc. a~d the rasin~ are ~t by cu~ing.
However, it l8 o~t0n di~ficult to obtain wa~te products having a hiyh wool aont~nt. I~ ha~ ~ee~ found, however, that other fibre~, whe~ ~ui~bly .troated and fo~med into a batt:, will bond tvgether ~nd with wool ~ibre~ to ~nable a ~uitable in~ulating batt to be ~oxmed.
.~acordingly, ~ a~ object o~ th0 i~ventlon to provide an improved ~eth~d o~ producing an in~ulating b~t~ or an insulating loose material formed o~ wa~te tex ile a~d o~her matarials which do not nece~arll~ includ~ a high ~mount af wool fibres.
A ~urther obja¢t of the pre~ent invention i8 to provide an in~ulation which i~ not hazardous ~o the health, but yet has all the proper~ie~ o~ ~xisting ins~lation.

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S AE~Y OF THE :[NVENTIOM

According:Ly, the presen-t invention provides a method of formi.ng a batt of bonded fibres for use as insulation, said fibres comprising monoacrylic, acrylic or other synthetic or cellulose fibres with from 25 to 80~, wool fibres, said batt being formed by ragging, teasing and o-therwise doffering the fibres of was-te textile and other materials to form a randomly dispersed ~ibre sliver, passing said sliver through a lapper to ob-tain a mat of desired -thick-ness, spraying said mat to impregnate it wi-th resin or resins, which may comprise fireproofing resin or resins, and, op-tionally, smoke re-tardants, and pesticides, set-ting the resins by curing, preferably in an oven, and cut-ting -the batt to the desired lengths.
The bonded fibres have a plurality of air pockets which assi.sts in -the insulation effec-ts. If desired for a 'blow in' installation, the ba-tts may be broken down into small balls of bonded fibre in loose form.
Use of wool fibres in amoun-ts between 25%
and 80r~ of total fibres is preferred having regard to the known fire-retardant properties of wool. In addition, it is rot proof and vermin proof. As -the insulation is not visible in the finished ins-talla-tion, it i.s possible -to make use of wool 'seconds', especially black fleeces, cuttings from the shearing sheds and recycled woollen jumpers and other garments.
Other fibres which are combined with the wool fibres and which are particularly useful in -the invention inclu~e monoacrylic, acrylic, polyamide and polyester synthetic fibres as well as other natural a~

~ibres such as cotton. These types oE Eibres, when matted and bonded together in a bat-t, preferably wi-th additionally wool fibres, resul-ts in an insulation material which is extremely economical -to produce, which can be formed of waste clothing and other waste materials and which has excellent insula-ting proper-ties wi-thout the hazards of o-ther known insulating produc-ts.
Resins suitable for use in the present invention include flame depressants such as modified acrylic self-crosslinking polymers such as RHOPLEX
HA-20; trademark, available from Rohn & Haas. O-ther additives -to the spray include Aluminium Trihydra-te and -3a-23~L
Xem Gard (Trade Mark) (I.C.I~ smoke 4uppres~ant) and Perigen (Trade ~ark) ~ p~ticide~ s~pecially ~uitable against clothe~
moths and carp~t baetle and available rom Burrough~ Wellcome.
The insulation o formed may be used in any location i~e. in home, office, fac ory or ~ther building, for either heat or acoustic insulatiQn~
In ordar ~hat the invsntion may be more clearly understood, a preferred embodime~t the~eof will now be described.

DESC~IPTION OF PR~FERRED ~M~ODIMENT

A mi~ture of ragged acrylic and cotton garment~ and new wool is fed to a doffex or carding machine which separates the ~ibre~ a~d tease3 them to form a 31iver or web of randomly dispersed fibr~s, comprising 50~ acrylic and c~tto~ fibres and 50~ wool fibre~, which i~ ~ed out of the doffer or card onto a horizontal lapper where the ~liver or web is lapped Oll itself until a bat of desired thickne~s i8 ob~ained. The batt i~ then sprayed with a mixture compri~ing Rhoplex Re~in, Aluminium Trihydra~e and Perigen pesticide.
The batt i~ then;dried in an oven, at approximately 150~C. When the batt emerges frQm the oven, it is cut into suitable leng~h~, or rolled~in a long length, as required.
A bat ~ormad in ~he above manner, gav~ the followiny result~:-Sample Deacription: .
Insulatio~ batt~ compositions Wool - noMinal - 50~ W/W
Acryli~ a~d Cotton ~ Nominal 50~ WtW
Rhoplex Re~in ~ inal 25 - 42 g/m2 ~ex Rhom & Haa~ - ~hoplex HA/20) Fl~me retardant: Alu~inium Trihydrate lex Alcoa) Thickne~r Nominal 68mm Fira ~ating Te t - Standard Method Australian Btandard 1530.3.1976 TEST DESCRIPTION RESULT U~IT
EAR~Y FIRE ~ZARD PROPER~IES
, . _ OF ~TERI~LS
Ign~tabili~y Index 0 Rangs 0-20 Test De~cription Result Unit Spread of Fl~ne Index a Range 0-10 Heat Evolved Index 0 Ranye 0-10 Smoke Developed Index 6 ~ange 0-10 S Comments on T ts For the tes~ each specimen had a backing of 4.5mm thick Fire ~esl~ant board and wa~ res~rained by a layer of appro~.
O.~mm diameter square wire mesh having ~a spacing of approx.
12 mm in each direction.
Mea ureme~t of Thermal Re~stence Thickne~ (~m) 53.5 Density ~kg/m3) ~ 25 Moi3ture content (~) 9 Hot plate temperature ~C) 35.6 Cold plate temperature ~C) 15.7 Temperature differenGe (kl 19.9 Mean temperature (~C) 25.7 Thermal re~i~tance ~m2ktw) 1.34 Thermal conductivity (W/~ 0.0400 From the foregoing it will be Reen that wool, synthetic and other natural fibrPs are bonded together to form an insu1ation batt which may then be installed in a desired location.
Alternatively, thq b~tt may be broken down into small balls which are blown or otherwi~e spread over the de ired location, again to provide insulation. ~y rea~on of the inherent insulating propertios of the wool, synthetic a~d other natural fibres, particularly when matte~, the batt thickness is considerably le8~ than the thick~es~ of the ~ibreglas~ batt o~ comparable heat .in~ulation.
Thus the pres~nt inventlon provides a means of insulation ~hat avoid~ the health hazard~ of the existing insulation, which is able to UBe ~i~carded or second-grade wool fleeces, thereby improving the farmer~' economic retur~ on his flock, and yet the insulatlon so produced i8 squal to ~hat ~hich it is to replac~. In addition, discarded wool, ~ynthetic and other natural fibre~, or wool, ~ynthetic and other n~tural fibre garments may be ragged and used in the present invention, again reducing the co~$ of r~w m~terials.
Although use of an oven has been described for curing v~

the sprayed re~ins ~o the fibre bat~, other cwring methods may be u~ed, including elec~ron beam irradiation.
Similarly, although the preferred chemical reagents and resin~ have b~en de~cri~ed, other reagents and resins may be used, provided they are compatible with each other and wi~h the fibres~

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StJL':PL,E~ENTARY D:[SCL.OSIJRE
_ __ _. _ __ Applicant has described in the principal disclosure a method of producing a bondecl fibre insula-tion batt by ragging, -teasing and otherwise doffering fibres of wool and/or synthetic or o-ther natural fibres such as monoacrylic, acrylic, poly-amide, polyes-ter or cot-ton fibres, so as -to Eorm a sliver Witll the fibres randomly dispersed and passing -through a lapper which causes the sliver to lap on itself to form a mat of desired thickness. The mat is then impregnated wi-th a resin, such as a fireproofing resin, and preferably with a pesti.cide and a smoke retardant~ The impregnated mat is placed in an oven to cure the resin thus forming the insulating batt which can be cut to desired size.
It has now been found -that by spraying the sliver with a resin-emulsion prior to lapping ensures -that the resin completely penetrates the material so that the mat subsecluently formed is completely impregnated with resin.
Aceordingly, a feature of -the invention with whieh this supplementary disclosure is concerned resides in providing a method of forrning a batt of bonded fibres for use as thermal insulation, which eomprises the steps of:
(a) ragging, teasing and doffering fibres which include from an amoun-t from Q to 95% wool, -together with fibres selected from the group consist-ing of monoacrylic, acrylic, pol.yamide, polyester and natural fibres;
(b) forming a sliver of randomly dispersed fibres;

(c) Eeeding the sliver onto a lapper;
(cl) oscil].a-tiny the lapper at a rate which will deliver the sliver to a conveyor on which the sliver is lapped onto a multi-layered mat-t;
(e) oscill.ating a spray boom in sequence wi-th -the oscillatiny sliver to maintain -the spray boom at the same distance from -the sliver at all times as the sliver is delivered from the lapper;
(f) providing a second boom, which emits a cushion of air ayainst the sliver on the side of the sliver opposi-te the spray boom to maintain the sliver in correc-t alignment with the conveyor;
(y) supplyiny a resin-emulsion comprisiny a fireproofiny resin, a smoke retardant and pesticide to the spray boom;
(h) sprayiny -the osci:llatiny sliver with the resin emulsion so that the matt formed by -the lapped sliver is thorouyhly impreyna-ted with the resin-emulsion;
(i) conveyiny the impregnated matt to a dryiny means;
(j) evapora-ting or removiny up to 80% of -the water conten-t of the mat-t while main-taininy the tempera-ture of the rnatt below the minimum te~perature at which the fibre is substan-tially unimpaired by heat;
(k) curiny -the resin content of the matt to form a substantially rigid matt; and (1) cu-ttiny the matt to form batts of desired length.
As indicated above, by sprayiny the resins onto the relatively thin sliver of dispersed fibre immediately the sliver passes from the lapper but ~q~23~

before matting ensures that -the resins comple-tely penetrate the material so that the ma-t subsequently formed is completely impregnated.
According -to a preferred embodiment, -the sliver is suppor-ted on an air cushion against the force exer-ted on the sliver when spraying the resin-emulsion onto the sliver.
Wool and other fibres are affected by heat and become soft and less resilien-t. Because of the water con-tent of the resin-emulsion, up to 75% by weigh-t, and the heat required to cure the resins, the impregnated mat may collapse and shrink when subjected to the external hea-ting source required to cure the resins. The mat is therefore treated prior to the curing step to remove up to 80% preferably 50%, of the water in a manner which obvia-tes or reduces the heating effect on the fibres and resin.
Preferably the water removal treatment is carried ou-t by dielectric hea-ting; for example, -the mat can be passed between spaced plate elec-trodes of a dielec-tric dryer and applying an A.C. voltage to -the pla-tes at a high frequency. ~lowever, other subs-tantially non-heating -treatments may also be used. Where a resin-emulsion containing between 35% and 60~ water by weight is used, the water removal treatment is preferabLy carried out to remove approximately 50% of wa-ter from such an emulsion.
Use of wool fibres in amoun-ts be-tween 25%
and 60% of total fibres is preferred having regard -to the known fire-retardant properties of wool. In some forms of batt made with soft or light fibres or fibres which have no resiliency, if the resins used do not add sufficient stiffness to the ba-tt it is likely to collapse inwardly over time thus reducing the insulating properties. Accordingly, the resins i,r~, 9 used should preferably be selec-ted -to ensure -the hatt retains its bulk and structura] integrity. If desired, a stiffening agent, such as starch, resin stiffeners or similar agents, can be added to the batt ei-ther by incorpora-ting the stiffening agent in-to the resin-emulsion or by separately spraying the sliver or the mat.
The following non-limiting example further illustrates the invention.
EXAMPLE
A mixture of ragged acrylic and cot-ton garments and new wool is fed to a doffer, or carding machine, which separates the fibres and teases them to form a sliver or relatively thin web of randomly dispersed fibres, comprising 50% acrylic and co-tton fibres and 50% wool fibres. The sliver has a -thick-ness of about ~ inch. The sliver is fed from the doffer, or carding machine, onto a horizon-tal lapper which oscillates at a predetermined rate to deliver the sliver to a conveyor where the sliver is lapped onto itself to build up a mat of a predetermined thickness.
Before -the sliver leaving the lapper engages on -the conveyor, or on -to previously lapped material on the conveyor, it issprayed wi-th an emul-sion of resins comprising Rhoplex Resin, Aluminium Trihydrate and Perigen pesticide. The water content of the emulsion is approximately 54% by weight.
A spray boom having a plurality of spray nozzles for spraying the resin-emulsion is moun-ted adjacent the lapper and is connec-ted -there-to by a linkage system which maintains the boom a predeter-mined distance from the material sliver moving from the lapper towards the conveyor. The linkage system causes the boom to move with the lapper but through a ~i~' !-,;

distance related to the actual sliver movemen-t which, because of the oscilla-ting lapper movement and the distance between the lower end of -the lapper and -the conveyor, is different tha-t the ac-tual lapper move-ment.
A second boom positioned on the opposite side of the sliver to the spray boom is fed wi-th air to produce an air cushion to thereby balance -the forces produced by the resin-emulsion spray and main-tain the sliver in its correct alignment with the conveyor.
The mat formed of the lapped sliver, which is -thoroughly impregnated with the resin-emulsion sprayed onto the sliver, is conveyed to a dielectric drying station and passes be-tween spaced plate electrodes which are electrically charged by high frequency a.c. poten-tialO The frequency and vol-tage applied to the plate electrodes are chosen -to optimize drying of the ma-t with minimum hea-ting of -the fibres. Approximately 50~ of the water content is removed at -the drying s-ta-tion.
The mat is then conveyed -to a curing oven hea-ted to about 150C to complete -the drying and to cure the resins to form a relativeLy rigid but resilient insulating mat material. When the ba-t-t emerges from -the oven, it is cu-t in-to sui-table leng-ths, or rolled in a long length, as required.
A batt formed in the above manner, gave essentially -the same results as reported in -the principal disclosure.

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Claims (17)

The embodiments of the invention in which an exclusi-ve property or privilege is claimed are defined as follows:

1. A method of producing a thermal insulating batt for use as an insulating medium on its own or when broken down into loose insulating material, said fibres comprising monoacrylic, acrylic, polyamide, polyester or natural fibres with from 25 to 80% of the fibres being wool fibres, comprising the steps of ragging, teasing and otherwise doffering the fibres to form a randomly dispersed fibre sliver, passing said sliver through a lapper to obtain a mat of desired thickness, impregnating the mat with resin material and with one or more of the materials selected from the group of fireproofing resin, smoke retardant and pesticide, curing the resin and cutting the batt to desired length.

2. A method according to claim 1, wherein said resin is cured in an oven at a temperature of approximately 150°C.

3. A method according to claim 1, wherein said resin is a modified acrylic self-crosslinking polymer.

4. A method according to claim 1, wherein said smoke retardant is aluminium trihydrate.

5. A method according to claim 1, wherein the insulating batt is broken down into small balls of bonded fibres.

CLAIMS SUPPORTED BY THE
SUPPLEMENTARY DISCLOSURE

6. A method of forming a batt of bonded fibres for use as thermal insulation, which comprises the steps of:
(a) ragging, teasing and doffering fibres which include from an amount from 0 to 95% wool, together with fibres selected from the group consist-ing of monoacrylic, acrylic, polyamide, polyester and natural fibres;
(b) forming a sliver of randomly dispersed fibres;
(c) feeding the sliver onto a lapper;
(d) oscillating the lapper at a rate which will deliver the sliver to a conveyor on which the sliver is lapped into a multi-layered matt;
(e) oscillating a spray boom in sequence with the oscillating sliver to maintain the spray boom at the same distance from said sliver at all times as the sliver is delivered from the lapper;
(f) providing a second boom, which emits a cushion of air against said sliver on the side of said sliver opposite said spray boom to maintain the sliver in correct alignment with the conveyor;
(g) supplying a resin-emulsion comprising a fireproofing resin, a smoke retardant and pesticide to said spray boom;
(h) spraying said oscillating sliver with said resin-emulsion so that the matt formed by the lapped sliver is thoroughly impregnated with said resin-emulsion;
(i) conveying the impregnated matt to a drying means;

(j) evaporating or removing up to 80% of the water content of said matt while maintaining the temperature of the matt below the minimum temperature at which the fibre is substantially unimpaired by heat;
(k) curing the resin content of the matt to form a substantially rigid matt; and (l) cutting the matt to form batts of desired length.

7. A method according to claim 6, including the step of supporting said sliver on an air cushion against the force exerted on said sliver when spray-ing said resin-emulsion onto said sliver.

8. A method according to claim 6, wherein said evaporating step includes passing said mat between spaced plate electrodes of a dielectric dryer and applying an A.C. voltage to the plates at a high frequency.

9. A method according to claim 6, wherein said evaporating step removes approximately 50% of water from a resin-emulsion which contains between 35% and 60% water by weight.

10. A method according to claim 6, including the step of adding a stiffening agent to said sliver.

11. A method according to claim 10, wherein said stiffening agent is incorporated in said resin-emulsion.

12. A method according to claim 10, wherein said stiffening agent is sprayed onto said sliver after said sliver has lapped on itself to form a matt.

13. A method according to claim 6, wherein said forming step forms fibres comprising 25% to 50% wool fibres.

14. A method according to claim 6, wherein said curing stop is accomplished by heating the mat in an oven at a temperature of approximately 150°C.

15. A method according to claim 6, wherein said spraying step comprises spraying a modified acrylic self-crosslinking polymer onto said sliver.

16. A method according to claim 6, wherein said spraying step comprises spraying a resin-emulsion containing aluminium trihydrate as said smoke-retardant onto said sliver.

17. A method according to claim 6, including the step of breaking down said insulating batt into small balls of bonded fibres.