CA2095520A1

CA2095520A1 - Method and apparatus for producing insulation materials

Info

Publication number: CA2095520A1
Application number: CA 2095520
Authority: CA
Inventors: Derek W. Maude; Aaltje E. Maude
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-11-12
Filing date: 1991-11-11
Publication date: 1992-05-13
Also published as: EP0557394A4; EP0557394A1; NZ240561A; WO1992008588A1; JPH06504002A

Abstract

An insulation batt or material together with method and apparatus for production thereof is disclosed. The batt or insulation material comprises an open shredded cellulosic material having added defibrillated cellulosic material included therein. The batt or insulation material is bound with a suitable binder which may be fire retardant and fungicidal, bacteriocidal or rodenticidal.

Description

WO 92/08588 PCr/AU91/00515 2~9~2~

This invention relates to a method and apparatus for the manufacture of insulation materials and to an insulation material made by the process and relates particularly but not exclusively lo insulation materials and methods and apparatus for 5 Iheir manufacture manufactured from a combination of shredded and defibrillated fibrous cellulosic materials preferably in thc form of a batt.
The thermal insulation and sound attenuation properties of cellulosic materials are well known and it is known that such materials may be usad in insulation materials.
Advantages of using such materials in insulation materials are that waste materials such 10 as, newspaper, can be removed from the waste stream and recycled to form a useful product. Disadvanta~es of using cellulosic materials on insulation materiais are that the materials must be treatad to make them fire retardant and preferably insect, vermin and decay resistant. It is known to treat csllulosic materials such as wastepaper with fire retardant compounds such as, borax. Such compounds are hygroscopic and 1~ cellulosic materials treated with such compounds are non-resilient and subject to degradation.
A n~ed exists for the effcctive utilization of waste materials. Paper waste and other fibrous c~llulosic materials have been recognised as potential resource rnaterials for various products including insulation mat~rials due to their inherent insulating 2 0 properties. Until now there has been a lack of economical methods to convert such waste ~o acceptable and viable materials which ~are environmentally friendly, low in production energy consumption and resistant to hazards or degradation which would reduce their life ~xpectancy and, therefore, their usefulness.
Ceilulosic fibres from paper waste or other cellulosic materials have been used 25 praviously as insulation but in a very limited way. Production has besn restricted to loose fill products r~quiring special ~pplication melhods and devices. Such material is highly vulnarabl~ to moisturs in its untreated state and could be subjected lo long term degradation problems.
Mineral tibre insulation materials are brittle by nature and tend to degrade and3 0 break down if subj0cted to mechanical stresses releasing fine mineral particles into the environment which pose an unknown health risk. There is therefore a need ~o replace mineral fibre insulation materials with insulatiorl rnaterials which are less likely to be hazardous to h0alth.
Yarious proposals have been put forward to utilize waste cellulosic materials to35 produce insulating materials. Brilish patent 135~996 discloses an insulation material SiU13STlTl3TE SHIEET

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WO 92/08588 PCI-/AU91/0051$
2~9J~20 comprising a sandwich of shredded paper betwaen two outer facing sheets of papersuitably treatecl with fire retardant matdrials such as ammonium dihydrogan phosphate and ammonium sulphate. At least one of the facing sheets is perforated. The outer facing shaets may be bond~d to the shr~dded paper by spraying the shredded paper with a5 suitable bonding agant or adhesive prior to covaring with the facing sheets. Pressure may be applied to the sandwich configuration to assist with the l~nding of the shredded paper to the outer facing shaats. The material is specifically identified as an insulation material primarily designed as an acoustic inslJlation material with some thermal insulation properties. The product may ba stored in rolls or cut into insulation batts of 10 convenient size.
Australian patent Nos. 527843 and 540132 disclose a method of forming a batt of bonded synthetic and wool fibres in which th0 mixture of fibres is rag~ed, teased or otherwise defarrsd to form a sliver of randomly dispersed fibres. The sliver is then passed through a lapping machin~ to form a mat of desired thickness. Tha mat is then 15 sprayed with a rnixtur~ of fireproofing resins, smoke ratardants and pesticides cured and if desired cut into batts of appropriate configuration.
The prssant invention s0eks to overcome problems with prior art batts or insulation materials and to provide a saf~ and effactive insulation material and ~o provide methods and apparatus for producing such batts or insulation matarials. The 2 0 present invention aiso seeks to provide a mathod of manufacture of a fibrous c011ulosic insulating matcrial which by varying the density of the cellulosic material can be manufactured in Yarying degrees of rigidity and fire, weather and rot resistant. It is an object of the invention also to provide a fibrous cellulosic insulating material having She above properties.
2 S The pres~nt inventiun, therefore, provides in one form a method of manufaGturing an open fibrous cellulosic insulating material which comprises providing a shredded fibrous cellulosic material, coating said shredded mat~rial with a rigid or non-rigid binder to form a coat~d shredded material, introducing a d~fibrillated cellulosic material on and into said coated shredded material to provida a filled shredded material 3 0 and compressing and curing said fiiled shredded material to causa said binder to bind the maserial to form said fibrous cellulosic insulating material.
Preferably ~he binder comprises a tharmosettin~ resinous material which additicnally contains fungicidal, insecticidal and/or fire retardant chemicals.
~referably the binder is applied to the shredded material by means cf spraying.

Sl.1135TlTUTE SHEE~
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, ' ' ' WO 92/08588 PCr/AU91/00515 Preferably additionai binder is applied to the filled shredded material prior tocompression and curing. Preferably the shredd~d material is cardad or combed prior to the application of the binder to provide a loose evenly formeci bed of material to allow eas~ of introduction of the dafibrillated matarial.
Preferably the binder includes a cross linkad thermos~ning fl~xible polymeric material with elastic memory to provide the fibrous cellulosic insulating material with properties of resiliency and flexibility.
Suitable polymaric materials ~or inclusion in the binder are polymers, copolymers, modlfiad polymers, acrylics, modifi~d acrylics, P.V.A.'s, urea 10 forrnaldehyde resin, phenol formaldehyde, resorcinol formaldehyde, melamine formaldshyde and urethanes. The polymeric materials may be employed with thickeners, as is known in the art such as ceilulosic thicl~eners ~carboxy methyl cellulose, hydroxy ethyl cellulose, hydroxy methyl cellulose including any combinations thereof~ caseins. flour and cornflour.
The fire r~tardant chemicals may b~ chosen from any of the known fire retardant ch0micals and preferably ars sclected from highly hydrated inorganic chemicals such as borax, hydrated alumina and th~ like.
Examp!es of fira retardant materials which may be used alone or in combination are calcium carbonste, calcium sulphate, calcium silicatc, alurninium trihydrate, boric 20 acid, borax~ ammonilJm phosphates, poly ammonium phosphates, aluminium potassium sulphate, magnesium chlorid~, magnasium phosphat~,lsodium silicale, potassium silicat~, metaborates, chlorinated acryllcs; and chlorinated wax.
It wili be appreclated by those skllled In the flald that not all polymaric materials ar~ compatible with fira retardant materials as suggest~d and that appropriate 25 trials may be necsssary to d~termine the compatibillty or otherwise of polymeric materlal/fir~ retardant comblnations. For example, it Is known that sodium and potassium silicates and acldlc polymers and acrylics; poly ammonium phosphate and alkaline polymers; and celluloslc thlcken~rs and acidic fire retardant chemicals are not compatible. In addition to the above, considaration must be given to effective ins0cticide 30 and brocide as it is well known that cellulos~ fibre and most fire rqtardants contain nutrients. Thesa nutriants beoome accessible to mlcro organlsms. Cellulose flbre is also subjsct to anack by Insects and rodants. Thus whenever hlgh humidlty condltlons prevall or wh~n tha cellulose fibre becomes oth~rwlse wat, without a suitable blocide the cellulose flbre Insulation material would soon grow mould and c~mmanc2 to degrade 3 5 A sultable biocide, insecticida or rod~nticlde of low toxiclty and safe to the consumer an SUi~STlTUTE SHE~
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WO 92/OB588 PC~/AU91/00515 2~93:~a the ~nvironment is preferably incorporated into the formula. The biocide and theinsecticide must be compatible with the binder formuia. The following are examples of acceptable biocides: Busan 1009 (TM), Busan TCI~TB (TM), Kathon (TM), Densil (TM), Kocide (TM~ and insecticides: Peregin, Parmethrin, Biosmethrin, 13oron compounds, 5 Busan 11m1 (TM) Busan 11m2 (TM) or combinations theraof.
Preferred fungicidal, inssctioidal and bac~0ricidal material is Thiocyanomethyl benzathiazole, Kathon, Densil, Metaborates, Pyrethroids, Borax and other Boron compounds. The hJngicidal and bactericidal chemicals should of course be substantially stable at tha temperature of curing of the process which is of the order of 150C
10 depending on the particular binder material used.
The above binders musl also ba compatible with and/or preferably synergistic wilh the dry fire retardant incorporated during the manufacture of the defibrillated ~~
csllulosic material. The dry fire retardant is nacassary as in grinding or milling paper or other cellulosic matorial the rssuiling dust can create an axplosive mixture with air 15 therr~fore it is a safety requirement to incorporate a fire retardant during the manufactura of th~ defibrillated callulosic material. The dry fire retardant may be selected from the following matarials for axample:-Ammonium phosphates, polyammonium phosphates, barium metaborate, chlorinatedwax, aluminium trihydrate, borax, boric acid, calcium carbonate, magnesium chloride,2 0 magnesium phosphate, barium mataborate, barium sulphide, barilJm phosphate, antimony oxychloride, antimony trioxide, calcium sulphate, calcium silicate, sodium silicate, potassium silicate, aluminium potassium sulphate, or any oombinatlon of the above.
Particularly preferred fire retardants are:-2 5 Ammonium phosphates, aluminiulT trihydrate, ammonium phosphate, chlorinated wax,borax, barium metaborats, polyammonium phosphate and magn0sium chloride.
The matarial prior to compression and curing is pref0rably evenly distributed by way of spiked combing rollers and combs batween scrim materbl and passed to the compr0ssion step for compression to about 50% of its original height whilst curing.
3 0 Tha compr0ssed mat0rial may be cut into batts fcr roof or wall insulation or blanke~, or into strips for wrapping around air conditioning ducts for example. The batts may be formed having a thickness of 100 mm for example. Ths batts so prepared have equivalent or batt2r tharmal insulation properties to fibre glass batts of similar thickness, have batter lear strength and do not have the environmental and safety 3 5 problems of 7ibra glass bans.

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s The strips may be forrned with thicknssses of between 25mm to 100mm of varying densitias to provida tha requir~d tharmal resistance for any particular purpose for exampla 25mm strips with correspondin~ or better thermal insulation propeflies to fibre glass the flexibility and rasilience of the material permits the strips to be wound 5 around.
In a preferred ~mbodimsnt the shredded fibrous csllulosic material is shredciad waste paper. Other cellulosic or csllulosa-like materials which can be used are shredded straw from wh0at, rice, atc., shradd~i wood shavings.
In a prefatred embodiment ths defibrillated csllulosic material is defibrillated10 paper or cardboard waste which has been treated in, e.g. a hammer mill to reduce the material to a finely divided fluffy material. Similarly other cellulosic Of cellulose-like matarials as are indicated ai~ove may be utilized to form the defibrillated material. For example other cellulosic or cellulos~-like materials which could be utilized are waste natural fibre materials or textile materials.
There is no necessity for any de-inking or sirnilar treatment of the waste cellulosic mat~rials prior to incorporation into a product or prior to performing the method of lhe inventbn.
In a particularly preferrsd form of the invention th0 product contains shredded and defibrillated celllllosic mat~rial in a weight ratio of approximately 20:80. Binder 2 0 is preferably added to the matarial in the range of from 5 to 25 parts by weight (most preferably from 10 to 20 parts by weight) of the combined cellulosic materiais.
The present invention also provides in one form, apparatus for manufacturing an insulation material which comprises apparatus for the manufacture of sandwich callulosic insuiation material which includes means to form a rnat of evenly ciistributed 25 shredded cellulosic material, m0ans to introduce defibrillated c011ulosic material into ths shreddad c~llulosic material, maans to provide a cover sheat of cellulosic material to each face of the mat, means to introducc a bonding material to tha shredded cellulosic matarial and to the cov~r sheets to permit the shredd0d cellulosic materials and the cover sheals to be bonded together to forrn a bonded insulatbn matarial. Preferably the 30 shraddad cellulosic material is provided from a shradder. Preferably the means for forming the evanly distributed shredded rællulosic material Indudes a ~nveyor means whlch spreads and distributss the shredded material to form an ~venly di~tributed mat of shredded material. Praferably the conveyor m~ans oomprises a plurality of chain means which diverge from tha shredder and which include spike maans to spread and disperse 3 5 the shredded ma~eriai.

SUle3STlTUTE Sl 3E3ET

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W~ 92/08588 pcr/Au9l/oosls 209~'~2~

Preferably the apparalus additionally includes air injection means to assist in distributing the d~fibrillated matarial through the shredded material. Prefarably the apparatus includes ouring means to cure the bonded insulation material.
A prefsrred form of apparatus and method in acoordance with the invention will 5 now be d0scribed with r~f~rsnce to the accompanying drawings, in which:
Fig. 1 represents a schflmatic slevaUonal view of apparatus according to the invention;
Fig. 2 represents a plan view of spreader means of the apparatus;
Fig. 3 reprssents an end ssctional view of comminutad material introduction 1 0 means of the apparatus; and Fig. 4 shows a sch0matic representation of a preferred process of the present invention.
Raferring to Figs. 1 to 3 of the drawings, there is shown apparatus 1 O
comprising top sheet supply 20 and bottom sheet supply 21, shredder 11, spraader 12, 15 conveyor 13, defibrillated material feed 14, air injectors 15, bonding rnaterial sprays 16, 17 and 18 and curi/lg tunnel 19. Wastepaper is suppliad to shreddPr 11 via conveyor 22. Shredded sarni-compressed paper 23 which exits from the shredder 11 is spread and tsased on spreader 12 and fed into conveyor 13. , , A rotating drum (not shown) disposed above the chain bed spreader 12 with thin 2 0 spring steel tynes may be us~d to further distribu~e the shredded material more evenly over the chain bed.
As the shredded material leaves the chain bed a r~ouble row of air holes (not shown) beneath the end of the chain bed may bs included to blow low pressure air to help liSt the formad shredded cellulosic matsrial rnat off the chain bed and into convayor 13 to 2 5 help it to maintain its shape as it passes through lhe conveyor for subsaquent tteatment.
The rotating drum disposed over the chain bed may be any diameter eg. Srom 50mm to 1000mm, the preferrcd diameter is 150mm. The spring steel tynes may be between 50mrn and 200mm iong with a preferred length of 110mm. Thare may be 20 tynss or 2û0 tynes with a pr~ferred number of 90 tines ev0nly disposed around the 3 0 surface of the drum.
The spread and ~eased shradded,material 24 is sprayed with bondirlg material supplied via spray 16. The sprayed shredded material passes d~fibril~ated material feed 14 ( DM feedn) where defibrillated (e.g. finely dh/ided fluffy comminuted wastepaper or cardboard) matorial is fed Into the shredded materiai from the DM feed. Immediately 3 ~ foJlowing the DM feed the shredded material is subject to blasts or jets of compressed SIUE3STITI.ITE S~EET

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WO 92~08S88 PCr/AU91/00515 ;'t~ ~

air from air injectors 15 to disperse the defibrillated material substantially evenly through the shredded material.
Bottom sheQt 25 is sprayad on the inside thereof with bondin~ material supplied via spray 17 and similarly top shaet 26 is sprayed on the inside th~reof with bonding 5 material supplied via spray 18. The top and bottom sheets are brought into contact with the shredded matcrial and compressed betw0en hot platas 17 and cured in curing tunnel 19. The sandwich mat0rial may then be cut into batts or strip material as requirsd.
The spreader 12 comprises a series of chains 28 which spread out from the exit of the shreddar 11 to the widlh of the conveyor 13. As the ehains 28 spread apart they 10 are interspersed with additional chains 29, 30 to maintain adequate support for the spread t0ased shreddad material. Each of the chains is provided with spikes 34 which are, for a3sample between 75mm and 140mm high or could be all the sam0 hei~ht. The preferred height is 110mm.
Each link of the chains could be fittad with this spike or only one in every 20 15 links. The praferred number is one in svery five links.
As 1he shradded paper is forced out onto these spik0d chains, the spiked chains become further apart as the chain moves away frorn the shredder, this teased andspreads the shredded paper to Ih~ full width of the spreader.
The shredded, sprayad matsrial then passes past the two DM fe0ders 14 where 2 0 cellulose fluff is inj~ted into the sprayed shredded material. The fluff is pre-ground or rnilled and blown, via blowers into the troughs 29. These troughs hav~ a sefies of dado' biades 30 set at angles of approx. 60 degrsas in each directbn about axis 31, left of centre, sloping to the left and to the righ~ of csntre, sloping to the right (as shown in Fig. 2).
The DM feeder may additionally include baffles 33 to direct the defibrillated material, blown into the feader by means not shown, towards the dado blades 31.
The dado blades turning on a shalt located in the centra of the trough, ~istribute the fluff avenly along its length and assist to force the fluff lhrough the bottom ~2 of the trough. The fluff is extrudad in an ~ven density mass.
3 0 As this mass is extmded it is passad close to shredded paper and is blown into and around this shredded paper, by a series of air slugs, fired via a number of high pressure air injectors 15 (approx. 175), located each side of the shrQdded material. These nozzles fire the air slugs at diffarent intervals and pressures to obtain maximum penetration and densi~y of the fluff in ~he shredded material.

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WO 92/08588 Pcr/AU91/0osl5 ~ ~ 9 ~ 2 ~
The air slug may be of between 1/1o0 of a second to one second duration, but preferably between 1/1 0 of a se~nd and 1/2 Of a second duration.
Tha air slugs are controlled via a series of solenoid valv0s, whieh are designed to rover the hJII width and depth of the mat of shredded filled material.
this mat now passes through two vibrating plates 32 to further enhance the distribution of the fluff through the shreWed material.
Tha shradded material is preferably shredded rlewspapar or shredded stationary or computer paper but may be any suitable cellulosic material. The dafibrillatedmaterial is pr0ferably cardboard or other waste cflllulosic mat~rial whioh has been 10 ground or mill~d to Sorm a finely dividsd defibrillated fluffy matarial. The defibrillated material may be made from waste cellulosic materials such as, bagasse, straw, rice - - hulls, peanut shells,- coconut husks and the like.
The apparatus of the invention thus produces a sandwich of shr~dded filled cellulosic material beh~en two sheet materials bonded by a suitable bonding matPrial 15 which is flexible, resili~nt and able to be cut into insulation batts of approprlate si7e or into strips of flexible insulation material for lagging pipes, ducts and the like. The sheet materials may be any suitable sheet material suoh as paper, plastics film, aluminium film or tha like. It is pocsible to omit ths upper shset material provided that the upper surface of the shredd~d filled cellulosic material treated with binder is dried 20 sufficiently prior to the compression of the batt to the desirad thickness before the binder sets.
Referring to Fig. 4 there is shown a schQmatic representation of a preferred process according to the invention.
Shredded waste pap0r is conveyerJ from storage 41 and carded or oombed at 2 5 station 43 to ensura even distribution of the shradded waste. Binder from storage 44 is added to the shredd~d waste at station 45 and then conveyed to station 46 where defibrillated paper waste is added from storage 42. Furlher binder is adde~ at station 48 and the matarial conveyed be~ween scrim to compression station ~9, curing station 50 and is eventually cut to required batt or strip size at cutting station 51.
The following are examples of preferred binder formulatisns for use in the proce~s of the invention.

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, WO 92/08588 PCI/AU91/01)51S
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Phenol formaldehyde resin 5 Acrylic resin (ICI DP105)2 0 Para toluene sulphonic acid (PTSA) Magnesium chloride 30 Busan 1 009 Parmethrin 0.5 Water to100 E~a~P~ ~
Melamina formaldehyde resin 5 Polymer 2 0 PTSA , . 1 Boric acid 18 Borax 1 8 Cellulose 2 Water to 100 E~ .
Polymer Joncryl 554 25 Aluminium trihydrate 15 2 0 QR 703 (thickener) Chlorinated wax 6 Busan 11 m2 2 Busan 1 009 Water to100 2 ~ E~am~
Polymer Joncryl 53R 25 8Orax 1 8 Boric acid 18 3 0 Water to100 SU~STITUTE SHEE~

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- , WO 92/08588 PCI'/AU91/OOS1~
2~9~ui2~3 1 o Chlorinated wax/acrylic polymer 2 5 Arnmonium phosphate 3 0 Busan 11 m2 2 Busan 1009 Cellulosic thickener 2 Water to 100 Ex~ e 6 Chlorinated wax/acrylic polymer . 2 5 1 0 Polyammonium phosphate 3 0 Kathon 0-5 Borax 2 - -~
Cellulosic thickener 2 Water to 100 1 5 ~m~
Modified acrylic (Joncryi 1 42LP) 2 5 Aluminium trihydra1e 2 8 QR 708 (thickener) 2 Busan 11 m2 2 2 0 D~nsil 0.5 Water to 100 ~arrU21~ 8 Modified acrylic (Duramol 695) 2 5 Ammonium phosphate 2 5 2 5 (: R 708 (thickener) Glycol Busan 1 009 Chlorinated wax 6 Busan 11 m2 3 0 Water to 100 SUiE3STF~UTE ~HIE~E~ -.. , ' . '. " .
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WO 92/0~588 PCl/AU91/00515 2 ~

Haloflex polymer HF 202 (ICI) 25 Ammonium phosphate 3 0 Busan 1009 Busan 11 m2 2 Cellulosic thickener 2 Water to 100 R~ -Acrylic polym~r (Duramol 641 ) 2 5 1 0 Polyammonium phosphate 2 0 Chlorinated wax 2 Glycol . 2 Busan 11 m2 0 5 Kathon 2 Cellulosic thickener 2 Water to 100 ~m~ .

Calcium carbonate 3 0 Cellulosic thickener 2 Densil 0.5 TCMrB
Water to 100 Exar~pl~12 2 5 Poiymer Rhoplex HA16 2 5 Magnesium chloride 3 0 Permethrin 0.5 QP~ 708 (thickener) 2 Kocide 05 Water to 100 !SU8STITUTE~ Sll FEET

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Haloflex polymer HF202 (ICI) 25 Calcium carbonale 3 0 Busan 11 m2 2 Busan 1 009 Water to100 Examl21e 14 Polymer foncryl 530 25 1 0 Magnesium potassium sulphate 3 0 TT 615 (thick~ner) 2 TCMTB . . . 1.5- ~ ~~ ~
Biosmethrin 0.5 Water to100 1 5 ~me~
Hydroxy e~hyl cellulose 10 Calcium sulphate 30 Flour Busan 1009 1.5 2 0 Peregin 0.5 Water to100 ~ .
Car~oxy methyl cellulose 10 Flour 5 Calcium silicate 30 TCMrB
Busan 11 m2 2 Water to100 e~Q~
Modified acrylic HF 208 (ICI) 25 Magnesium phosphate 3 0 Borax 2 Busan 1 009 3 5 Water to 100 5T~ TI~

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WO 92/08S88 PCI'/AU9t/00515 2 ~ 9 i ~

Polymar Rhoplax Wl ~62 ~
Magnesium chloride 3 0 Busan 11 m2 Busan 1009 Water to100 .. ... ......

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Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A method of manufacturing an open fibrous cellulosic insulating material which comprises providing a shredded fibrous cellulosic material, coating said shredded material with a rigid or non-rigid binder to form a coated shredded material, introducing a defibrillated cellulosic material on and into said coated shredded material to provide a filled shredded material and compressing and curing said filled shredded material to cause said binder to bind the material to form said fibrous cellulosic insulating material.

2. A method as claimed in claim 1 in which the shredded material is carded or combed prior to the application of the binder to provide a loose evenly formed bed o material to allow ease of introduction of the defibrillated material.

3. A method as claimed in claim 1 or 2 in which further binder is applied to thefilled shredded material prior to compression and curing.

4. A method as claimed in claim 3 in which the filled shredded material is carded or combed prior to application of the further binder material to distribute the defibrillated material within the shredded material and to facilitate penetration of the additional binder into the filled shredded material.

5. A method as claimed in claim 1 in which the binder includes a thermosetting plastics material.

6. A method as claimed in claim 5 in which the binder additionally includes one or more fire retardant and/or biocidal materials.

7. A method as claimed in claim 6 in which the biocidal materials are selected from fungicidal, bacteriocidal, insecticidal and/or rodenticidal materials.

8. A method as claimed in claim 1 in which the binder is applied as a coating to the shredded cellulosic material by means of a spray or sprays.

9. A method as claimed in claim 3 in which the further binder is applied to the filled shredded material by means of a spray or sprays.

10. A method as claimed in claim 1 in which the fibrous cellulosic insulating material is cut into strips or batts.

11. A method as claimed in claim 5 in which the thermosetting plastics material is a flexible thermosetting plastics material.

12. Apparatus for the manufacture of a cellulosic insulation material which includes means to form a mat of evenly distributed shredded cellulosic material, means tointroduce defibrillated cellulosic material into the shredded cellulosic material, means to provide a cover sheet of cellulosic material to each face of the mat, means to introduce a binder to the shredded cellulosic material and to the cover sheets to permit the shredded cellulosic materials and the cover sheets to be bonded together to form a bonded insulation material.

13. Apparatus as claimed in claim 12 which includes a shredder to provide the shredded cellulosic material.

14. Apparatus as claimed in claim 12 in which the mat of evenly distributed cellulosic material is formed by means of a bed of chain conveyor means which diverge from the shredder to spread and evenly disperse the shredded cellulosic material.

15. Apparatus as claimed in claim 14 in which the chain conveyor means include upwardly directed spikes to spread and evenly dispense the shredded cellulosic material.

16. Apparatus as claimed in claim 15 in which the conveyor means serves also to transport the shredded cellulosic material.

17. Apparatus as claimed in claim 12 which includes one or more sprays to introduce the binder to the shredded cellulosic material.

18. Apparatus as claimed in claim 12 in which the means to introduce defibrillated cellulosic material includes means to evenly distribute the defibrillated cellulosic material across the width of the shredded material and compressed air means to force the defibrillated cellulosic material into and on the shredded cellulosic material.

19. Apparatus as claimed in claim 12 which additionally includes means to cure the bonded insulation material.

20. Apparatus as claimed in claim 12 which includes means to transport and constrain the shredded cellulosic material from the conveyor means to the curing means.

21. An open fibrous cellulosic insulation material which comprises shredded fibrous cellulosic material having defibrillated cellulosic material disposed therein and thereon and a binder to bind the insulation material in the form of a web, strip, roll, blanket or batt.

22. An insulation material as claimed in claim 21 in which the binder includes aflexible thermosetting plastics material.

23. An insulation material as claimed in claim 21 in which the binder additionally includes one or more fire retardant and/or brocidal materials such as fungicidal, bacteriocidal, insecticidal and/or rodenticidal materials.

24. An insulation material as claimed in claim 21 in which the binder additionally contains a filler or fillers.

25. An insulation material as claimed in claim 21 which includes a cover sheet of fire retardant treated paper on either side of the web, strip, roll, blanket or batt.

26. An insulation material as claimed in claim 21 in which the defibrillated cellulosic material is a fire retardant treated defibrillated cellulosic material.