CA1057183A

CA1057183A - Method and apparatus for producing multiple density fibrous product

Info

Publication number: CA1057183A
Application number: CA251,941A
Authority: CA
Inventors: Malcolm J. Stagg
Original assignee: Fiberglas Canada Inc
Current assignee: Owens Corning Canada Inc
Priority date: 1976-05-06
Filing date: 1976-05-06
Publication date: 1979-06-26

Abstract

ABSTRACT OF THE DISCLOSURE

A fibrous product of the general type of a predeter-mined or dual density mat or the like is produce by splitting a body of generally loose mat, conveyed in a longitudinal direc-tion, so as to obtain two strata both of which remain unitary with the mat portion located ahead of the point of splitting.
At least one of the strata is subjected to a treatment such as compression to compact fibers therein. The strata are then deposited back on each other and eventually cured to obtain a dual or multiple density final product. The invention results in a space saving arrangement. The apparatus of the invention can be used in existing glass fiber mat producing lines.

Description

3LOS~83 The present invention relates to a method andapparatus for continuous production of a fibrous pro-duct having at least two strata of dissimilar density.
It is known to produce mineral fiber bodies having dissimilar internal densities. Mineral flber bodies, for instance glass fiber bodies of the above type, are used in insulating conduits or the like, the basic advantage of the dual or multiple density bodies being in their capability of providing a relatively strong outer surface of the insulation which is less subject to mechanical damage than the internal layer of such an in-sulation, while the internal layer retains good insula-tion properties. Another application for multiple density fibrous body would be an insulation panel or the like which would have both its surfaces made of a higher density layer while the intermediate portion of same would have a rela-tively low density.
Multiple density fibrous bodies have thus far been produced either by laminating two different fibrous bodies together or, as disclosed in U.S. patent 3,652,377 issued to J.W. Helmick on March 28, 1972, by activating and cur-ing the binder contained in the fibrous body selectively within predetermined areas of dissimilar density to per-manently set the binder. The advantage of the latter method is in that it does not require two separate supply rolls of fibrous bodies and that it provides a product that is not susceptible to delamination. The latter method thus constitutes a significant advance in the art. Yet, it possesses several drawbacks. Firstly, it is to be appreciated that the inner portion of a "fiber pack" must also be cured by heat. Due to the inherent insulating pro-perties of the "pack", the use of Helmick invention is ~.

practically limited to lesser thicknesses of the product and to relatively low densities. Moreover, the heating means applicable in the latter method are of a rather special type and thus require a considerable modification of the produc-tion line. The relative proportion of higher and lower density areas of the latter method is relatively difficult to control. A still further disadvantage of the latter method resides in that the glass fiber product is being pulled between two heating plates which simultaneously com-press the mat. Inasmuch as the mat normally has a verylow tensile strength, it is desirable that the mat be sub-jected to as little pulling as possible.
It is an object of the present invention to over-come the drawbacks of both of the known methods and to provide a new and useful method and apparatus for produc-ing a dual or multiple density fibrous bodies of the above type.
According to the present invention, a method is provided of continuous production of a fibrous product or body having at least two strata, eac~ ~aY~ng ~ pre~
determined density. The method comprises the step of producing a continuous, unitary body of a generally loose mass of inter-meshed fibers containing uncured binder material. In sub-sequent step, the body is advanced in longitudinal direc-tion from a point at which the body is being produced. In a further step, the body is split along a line generally transverse to the direction of advancement of same to pro-duce at least two portions or strata thereof. Both of such portions are maintained unitary with the body. At the same time, the two portions are spaced apart from each other. The two separate portions are then advanced at generally the same speed, generally in said longitudinal ~057183 direction. In a subse~uent step, at least one of the separate portionsis subjected to a treatment to produce a predetermined density of fibers therein, the predeter-mined density of the one portion usually being different from that of the other of said portions. Eventually, the two separate portions are brought back together and bond-ed to each other to produce a unitary fibrous body having strata or layers of different density. The treatment of one of said separate portions to produce a predetermined density is preferably effected solely by a compressive force to increase the density of fibers. In other words, in the preferred embodiment, the treatment of one of the two separate portions does not involve the curing of thermo-setting binder which is normally used in production of fibrous bodies. The advantage of such treatment is in that the whole volume of the binder material becomes cured only after reuniting of the two portions which results in a considerably stronger bond between the two strata.
The apparatus according to the present invention is intended for use in a production line for producing fibrous body; the line itself is well known in the art and comprises fiber forming means, known per se, which includes a forming hood and comprises at least one fiber forming spinner and further includes coating means for coating the fiber with uncured binder agent. The apparatus further comprises con-veyor means for receiving the fiber from the fiber forming and coating means for advancing same in the form of a gener-ally loose mat in a longitudinal direction. A portion of the conveyor means may be arranged to pass the mat through binder curing means, also of a type known per se, arranged to cure the binder deposited on the fibers.

, -3-According to the present invention, mat splitting means is arranged to be disposed downstream of the fiber forming and coating means and upstream of the curing means.
The mat splitting means is arranged along a line extend-ing generally transversely across and above the conveyor means for splitting said mat to at least two portions.
The apparatus further comprises compacting means arrang-ed downstream of the mat splitting means but upstream of the curing means for compacting one of said portions of the mat to increase specific density thereof. De-flector means is disposed downstream of and adjacent to the splitting means in proximity of the compacting means. The deflector means extends from a location up-stream of and close to the compacting means to a loca-tion downstream of and adjacent to said splitting means.
It is to be appreciated, however, that the terms "upstream" and "downstream" in this context do not necessarily imply that the splitting means is a part of a single line. Indeed, the forming and/or the curing steps can be carried out in separate production lines entirely independent of and even relatively remote from the splitting and compactiny means. For instance, a fibrous mat can be produced in a known device and reeled in uncured state on a roll, the roll then being trans-ported to the splitting and compacting device provided at its end with another reel for reeling the uncured mat twhich now has the dual density featurel for subsequent transport of the roll to a known binder curing line for curing and finishing the product.
However, for the sake of clarity, the invention will now be described by way of an embodiment wherein the forming, splitting, compacting and curing steps are all carried out on a single production line, with reference to the accompanying drawings.
In the Drawings:
Figure 1 is a simplified, longitudinal, schematic section of an apparatus according to the present invention, showing typical features of the method of the present invention, the apparatus including, for the sake of clarity, both the forming and the curing section;
Figure 2 is a detailed perspective view of a band saw used as splitting means as referred to above;
Figure 3 is a perspective view in the direction from one side of the apparatus of Figure 1 and showing in detail the splitting and the deflector means as re-ferred to above;
Figure 4 is a perspective view from the opposite side to that of Figure 3, showing the bottom portion of com-pacting rollers used as compacting means for one of the layers of t~e fibrous body; ~the compacted layer being omitted) Figure 5 is a schematic sectional side view similar to that of Figure 1, but showing only the fiber forming portion of the apparatus as in Figure 1.
Turning now to the drawings, and in particular to Figure 1, an apparatus is shown for continuous pro-duction of a glass fiber mat which, eventually, has two strata of dissimilar density. The two strata are design-ated with reference numerals 1, 2, respectively. The apparatus comprises fiber forming means 3 which, in itself, is of a known type. In the embodiment shown in Figure 1, with reference to Figure 5, the fiber forming means includes a forming hood 4 comprising a plurality of fiber forming spinners 5, 5a normally disposed in a row parallel to the direction ~, also referred to as a longitudinal direction.

1057~83 The shown fiber forming means 3 is of a well known type and therefore only shown in a schematic way. In gen-eral, the forming means comprises spinners 5, 5a into which molten glass is fed from a supply (not shown) onto rota-ting surfaces 6, 6a to form on each surface a thin layer of the molten glass. As the surfaces 6, 6a rotate at a high speed, the molten glass is projected through openings in same and the result molten stream is attenuated to form veils 7, 7a of discontinuous flbers which pass through binder rings 8, 8a each having a plurality of inwardly turned spray nozzles 9, 9a for spraying the fibers with ~ heat curable binder composition. Steam jets 10 are located beneath t~Q ~inder ring 8 for distri~uting the fiber over the width of a conveyor lla, The conveyor lla of Figure 5 forms, in the embodiment of Figure 1, a part of the overall conveyor system. Tfi~ surface of conveyor lla is permeable and a suction box 12 is located beneath the forming section to assist in depositing the coated fiber veil onto the surface for further conveying.
As mentioned above, the forming and coating means described above have long been known and used in the art.
Similarly, it is known from the art that by selective control of different operational characteristics of the forming and coating parts it is possible to selectively produce a fibrous mat of desired characteristics. Thus, the supply of the binder agent to the rings 8, 8a can be controlled in accordance with the desired rate of coating, the holes in the surfaces 6, 6a can be of a larger or smaller diameter to produce coarser or finer fibers, re-3~ spectively, the coarser fibers generally tending to be somewhat shorter. Another known way of controlling the quality of the resulting product is selective temperature 1057~83 control of the incoming molten material, of the surfaces 6, 6a of spinners 5, 5a etc. Due to the fact that all these features are well known and used in the art, there is no need for further details of same.
Turning now back to Figure 1, the conveyors 11, lla form a part of conveying system generally referr-ed to as conveyor means for receiving the fiber from the fiber forming and coating means and to advance the same in the form of a generally loose mat 20 in longitudinal direc-tion A. The conveyor means includes, in addition to theconveyors 11, lla, a qecond conveyor 21 ~l~ch, as best seen from Figure 1, passes through binder curing means of the type of forced air convection curing oven ~ the oven 22 itself being of a well known type and therefore not being describ-ed in greater detai;l.
According to the present invention, the apparatus comprises mat splitting means 23 which is shown in greater detail in Figure 3. It will be appreciated from Figure 1 with reference to the direction A that the mat splitting means 23 is located downstream of the fiber producing means of the type of the forming means 3 (which includes the fiber coating means), but upstream of the oven 22.
The mat splitting means (Figure 3) is of the type of a band saw 24 the lower run 25 of which is arranged along a line extending generally transversely across and above the conveyor 11. Preferably, the band saw 24 is of the type having a scalloped edge 26 which has been found to minimize the build-up of glass wool on the blade.
With the conveyor 11 running indirection A, and while op-erating the band saw 24, the band saw 24 splits the mat 20 into two portions or strata 1, 2.

- The apparatus further comprises compacting means 27 which is shown in greater detail in Figure 4. As will be appreciated from Figure 1, the compacting means 27 is arrang~d downstream of the mat splitting means 23 and up-stream of said curing means or oven 22 and is of the type of two rolls 28, 2~ for compact~ng th~ port~on or stratum 1 of the mat 20, to increase specific density thereof.
With reference to Figure 4, it will be seen that the rolls, which are viewed from the opposlte side to that of Figure 1, are arranged so that the roll 28 ~s fl~xedly secured to the frame 30, whereas the opposite roll 2~ is mova~le in horizontal direction B (Figure 1) and yieldably pressed against roll 28 at a selectively adjustable pressure to thus predetermine the density to which the stratum 1 is compacted. The rolls 28, 29 are each provided with a Teflon (trademark) coating on the surfaces thereof to prevent the build-up of wool. Moreover, it will be seen from Figure 4 that the roll 2~ is-prov~ded ~ a blade or doctor 31 for removing any particles that might stick to the teflon surface of the roll 29. Similarly, the roll 28 has a teflon blade or doctor 32 at the "trailing" edge of which is arranged a curved shield 33 which (Figure 1) is used in bringing the compacted stratum 1 back on top of the stratum 2, before both strata enter the oven 22.
Disposed between the compacting means 27 and the mat splitting means 23 is deflector means 34, which is __ partly shown in both Figures 3, 4 and the operation of which can readily be understood from the arrangement of Fig-ure 1. The deflector means includes a Mylar (trademark) coated, upwardly curved shield 35 (not shown in Fig. 4) loca-ted adjacent to the rear edge of the band saw 2~. The trailing edge of the shield-35, in turn, is adjacent to the forward - lOS7183 e~d of tn~ upper run ~f a conveyor 36, whose rear end termi-nate~-ahe~e-t-he n-~p=b~tMeen_r~lle-rs 28, 29. ~_ Turning back to Figure 3, the assembly carrying the band saw 24 is unitary with a cross-beam 37 and is mounted for selective vertical movement on frame 38. By selectively moving the assembly up or down the frame 38, the distance between the lower run 25 (Figure 3) of bandsaw 24 and the conveyor can be adjusted. The posi-tion of t~e forward shield 35 of the deflector means 34 is adjusted simultaneously to maintain the for-ward edge of the shield 35 in a substantially co-planar relationship with the lower run 25 of the ~and saw 24.

. .
In operation, a veil of glass fibers coated with binder is produced in known way within the forming hood 4 and deposited on the upper run of conveyors 11, lla to form a continuous, unitary body of a generally loose mass of intermeshed fibers containing uncured binder material.
The said unitary body has been referred to as mat 20.
The mat 20 is advanced in the direction of the arrow A, i.e. in longitudinal direction away from the location of the forming hood 4. The lower run 25 of band saw 24 subsequently splits the body 20 along a horizontal line generally transverse to the direction A to produce two portions of the body 20, referred to as strata 1, 2. It will be appreciated that despite the splitting of the mat 20 into strata 1, 2, each of the strata 1, 2 remains un-severed from, the body 20, i.e. unitary with same. The strata 1, 2 are spaced apart from each other in the re-gion following the mat splitting means. The two separate portions or strata 1, 2 are then advanced generally in _g_ ~ 057183 the direction A, the term "generally" meaning that the upper stratum 1 is somewhat diverted from the direction of the stratum 2 which follows more or less exactly the original direction A.
The conveyor 36 runs at approximately the same speed as conveyor 11, to avoid undesired pull on the mat 20 in the region downstream of the splitting means 23. This, in effect, means that the particles of the upper stratum 1 descend back on the stratum 2, following the region of rollers 28, 29 in a slightly "retarded" fashion, due to the fact that the portion of stratum 2 beneath the deflect-ing means moves along a considerably shorter locus.
The upper stratum 1 is subjected to pressure between the rollers 28, 21 whereby the density of fibers contained in stratum 1 is increased to a predetermined degree depending on the compressive force between the two rollers 28, 29. The density of the compacted stratum 1 downstream of the rollers 28, 29,of course,is different from the density of the lower stratum

2. The shield 33 eventually brings the compacted stratum 1 back onto the surface of the lower stratum 2. It will be appreciated that at this stage the binder is still uncur-ed. The two strata 1, 2 then enter, as a unitary body, tfis forced a~x conyeat~pn curlng oven 2Z l~n wfii~ch the binding agent contained in the mat 20 is cured to firmly bond the strata 1, 2 and the fibers therein.
Referring back to Figure 5, it will be appreciated that if the type of fiber forming unit shown in that Figure is used, the body 20 of the loose mass of inter-meshed fibers may contain two strata in a cross-section perpendicular to the direction A differ~ng from each other in the volume of the binder and/or in the weight of the fibers or in the length of the fibers, or in other properties, depending on suitable adjustment of the individual spinners 5, 5a and the associated integers of the forming means

3. This arrangement makes it possible to vary the properties of the mat 20. On splitting of mat 20 between thus produced layers the properties of the eventually compacted or uncompacted layer of the final product can be modified in accordance with pre-determined requirements.
The apparatus and method of the present invention have been tested under pilot plant conditions, wherein the production parameters and the parameters of the final product were as follows:
Number of Spinners: 2 Approximate Diameter of Glass Fibers: 55 HT (.00055") Type of Binder Used: Phenol-Formaldehyde - urea Ratio of Volume of Binder to Glass Fiber: (weight basis): 10%
Speed of Conveyor: 6 FPM
Thickness of Fibrous Body Prior to Splitting: 5"
Thickness of Strata After Splitting: Upper: 1/2" to 1 - 1/2"
Lower: 3 - 1/2" to 4 - 1/2"
Curing Conditions: Temperature: 350-F
Time: two min.
Thickness of the Upper Strata After Compacting: 1/8"
Overall Thickness of the Product After Curing: 1"
In a modification of the above pilot plant conditions, the spinners are operated such that while the parameters for the first spinner 5 are generally the same as above, the approximate diameter of glass fibers produced by spinner 5a is reduced by 28HT, with the binder-to-fiber weight ratio changed to 4%, the remaining parameters remaining as in the above example.

Those skilled in the art will readily appreciate that various departures are possible from both the apparatus and the method as described above. For instance, it is possible to produce a "sandwiched" insulation product with two surface strata compacted, by utilizing two splitting and compacting units.
Another readily conceivable embodiment would have the compacting rolls arranged vertically one above the other to reduce the overall height of the deflection of the upper stratum 1 and to possibly eliminate the need of the rear shield 33. The curing apparatus, which in itself is well known, can be replaced by another known apparatus e.g. a platen press.
It will also be appreciated that an embodiment of the apparatus can also be provided, wherein the mat to be split is produced by unreeling from a roll stand with the mat forming stage being entirely separate from the splitting and compacting apparatus as shown. Similarly, the curing oven can be replaced with a reel stand for reeling the uncured mat after the process-ing as described above. The reeled mat can then be transported to a separate curing apparatus for unreeling and passing through a curing oven or the like.
These and many other departures from the embodiment of the invention as described above, however, do not depart from the scope of the present invention as defined in the accompanying claims.

Claims

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

1. Method of continuous production of a fibrous pro-duct having at least two strata each having a predetermined den-sity, said method comprising the steps of:
(a) producing a continuous, unitary body of a generally loose mass of intermeshed fibers containing uncured binder material;
(b) advancing said body in longitudinal direction from a point at which the body is being produced;
(c) splitting said body along a line generally trans-verse to the direction of advancement of said body to produce at least two separate portions thereof and maintaining each of said at least two portions unitary with said body but spaced apart from each other;
(d) advancing said two separate portions generally in said longitudinal direction;
(e) subjecting at least one said separate portion to a treatment to produce a predetermined density of fibers therein;
(f) bringing said two separate portions back together to produce a fibrous body; and (g) curing said fibrous body.

2. Method of continuous production of a fibrous product having at least two strata of dissimilar density, said method comprising the steps of:
(a) producing a continuous, unitary body of a genera-lly loose mass of intermeshed fibers containing uncured binder material;
(b) advancing said body in longitudinal direction from a point at which the body is being produced;
(c) splitting said body along a line generally trans-verse to the direction of advancement of said body to produce at least two separate portions thereof and maintaining each of said at least two portions unitary with said body but spaced apart from each other;
(d) advancing said two separate portions generally in said longitudinal direction;
(e) subjecting at least one said separate portion to a treatment to produce a predetermined density of fibers therein, said predetermined density of said one of said portions being different from that of the other of said portions;
(f) bringing said two separate portions back together to produce a fibrous body; and (g) curing said fibrous body.

3. Method of continuous production of a fibrous product having at least two strata of different density, said method comprising the steps of:
(a) producing a continuous unitary body of a generally loose mass of intermeshed fibers containing uncured binder material;
(b) advancing said body in longitudinal direction from a point at which the body is being produced;
(c) splitting said body along a line generally transverse to the direction of advancement of said body to produce at least two portions thereof and maintaining each of said at least two portions unitary with said body but spaced apart from each other;
(d) advancing said two separate portions at generally the same speed generally in said longitudinal direction;
(e) subjecting one of said separate portions to a compressive force to increase the density of same with respect to the density of the other of said separate portions;

(f) bringing said two separate portions back to-gether;
(g) subjecting said two separate portions as brought back together to curing of said thermosetting binder.

4. Method of continuous production of a fibrous product having at least two strata of dissimilar density, said method comprising the steps of:
(a) producing a continuous unitary body of a generally loose mass of intermeshed fibers containing uncured binder material;
(b) advancing said body in longitudinal direction from a point at which the body is being produced;
(c) splitting said body along a line generally transverse to the direction of advancement of said body to produce at least two portions thereof and main-taining each of said at least two portions unitary with said body but spaced apart from each other;
(d) advancing said two separate portions at generally the same speed generally in said longitudinal direction;
(e) subjecting one of said separate portions to a compressive force to increase the density of same with respect to the density of the other of said separate portions;
(f) bringing said two separate portions back to-gether to form a generally unitary fibrous body having at least two strata of dissimilar density, wherein said binder material is in uncured state;
(g) subjecting said generally unitary fibrous body to a treatment whereby said binder material becomes cured.

5. Method of continuous production of a fibrous product having at least two strata of dissimilar density, said method comprising the steps of:
(a) producing a continuous, unitary body of a generally loose mass of intermeshed glass fibers containing uncured thermosetting binder material;
(b) advancing said body in longitudinal direction from a point at which the body is being produced;
(c) splitting said body along a line generally transverse to the direction of advancement of said body to produce at least two portions thereof and maintaining each of said at least two portions unitary with said body but spaced apart from each other;
(d) advancing said two separate portions at generally the same speed generally in said longitudinal direction;
(e) subjecting one of said separate portions to a compressive force to increase the density of same with respect to the density of the other of said separate portions;
(f) bringing said two separate portions back together to form a generally unitary fibrous body having at least two strata of dissimilar density, wherein said binder material is in uncured state;
(g) passing said generally unitary fibrous body through a forced air convection curing oven to cure said thermosetting binder material.

6. Method of continuous production of a fibrous product having at least two strata of dissimilar density, said method comprising the steps of:
(a) producing a continuous, advancing, unitary body of a generally loose mass of intermeshed glass fibers containing uncured thermosetting binder material, said body having at least two strata in a cross-section perpendi-cular to the direction of advancement of said body, said two strata differing from each other in the ratio of the.
volume of said binder to the weight of said fibers;
(b) splitting said body along a line generally transverse to the direction of advancement of said body to produce at least two portions thereof and maintaining each of said at least two portions unitary with said body but spaced apart from each other;
(c) said splitting of said body being effected at a level generally coincident with a boundary between said two strata, to form two separate portions of said body;
(d) subjecting one of said two separate portions to a compressive force to increase density thereof with respect to the other of said portions, while advancing said two separate portions at generally the same speed in said direction of advancement;
(e) bringing said two separate portions back to each other whereby they become bonded to each other by the uncured binder thus forming a generally unitary glass-fiber body having at least two strata of dissimilar density, and (f) curing said glass-fiber body.

7. Method of continuous production of a fibrous pro-duct comprising glass fiber and having at least two strata of dissimilar density, said method comprising the steps of:
(a) producing a continuous, unitary body of a generally loose mass of intermeshed glass fibers contain-ing uncured thermosetting binder material, said body having at least two strata in a cross-section perpendicular to the direction of advancement of said body, said two strata differing from each other in length and/or diameter of said fibers;
(b) splitting said body along a line generally transverse to the direction of advancement of said body to produce at least two portions thereof and maintain-ing each of said at least two portions unitary with said body but spaced apart from each other;
(c) splitting said body at a level generally coincident with a boundary between said two strata, to form two separate portions of said body;
(d) subjecting one of said two separate portions to a compressive force to increase density thereof with respect to the other of said portions, while advancing said two separate portions at generally the same speed in said direction of advancement;
(e) bringing said two separate portions back to each other whereby they become bonded to each other by the uncured binder thus forming a generally unitary glass-fiber body having at least two strata of dissimilar density; and (f) subjecting said generally unitary glass-fiber body to a forced hot air stream to cure said binder.

8. Apparatus suitable for continuous production of a fibrous product of the type having at least two strata, each of a predetermined density, said apparatus comprising:
(a) conveyor means for advancing a fibrous body con-taining mineral fibers and a binding agent, in the form of a generally loose mat in a longitudinal direction;
(b) mat splitting means arranged along a line extend-ing generally transversely across and above said conveyor means for splitting said mat into at least two portions;

(c) compacting means arranged downstream of said mat splitting means for compacting at least one of said portions of the mat to increase specific density thereof;
(d) deflector means extending from a location upstream of said compacting means to a location downstream of and adjacent to said splitting means.

9. Apparatus as claimed in claim 8, wherein said mat splitting means is a bandsaw adapted to run generally trans-versely of said conveyor means and generally parallel with and spaced from the surface of said conveyor means.

10. Apparatus as claimed in claim 8, wherein said compacting means is a pair of rolls arranged to be yieldably pressed relative to each other, said rolls extending transversely of and above said conveyor means.

11. Apparatus as claimed in claim 10, wherein said deflector means includes a smooth, arcuately curved deflector shield extending substantially the entire width of said conveyor means, said deflector shield having a front edge located adjacent to and downstream of said splitting means, and a rear edge generally parallel with the front edge and spaced upstream of the surface of said rolls.

12. Apparatus as claimed in claim 8, wherein the distance between said splitting means and the level of the con-veyor means is selectively adjustable.

13. Apparatus as claimed in claims 8 or 10, wherein said compacting means is adjustable to selectively control the degree of compacting of one of said portions.

14. Apparatus as claimed in claims 8 or 19, wherein the distance between said deflector means and the level of said conveyor means is selectively adjustable.

15. Apparatus for continuous production of a fibrous product of the type having at least two strata, each of a pre-determined density, said apparatus comprising:
(a) fiber forming means including a forming hood and comprising at least one fiber forming spinner and further includ-ing coating means for coating said fiber with uncured binder agent;
(b) conveyor means for receiving the fiber from said fiber forming and coating means and for advancing same in the form of a generally loose mat in a longitudinal direction;
(c) a portion of said conveyor means being arranged to pass through binder curing means arranged to cure the binder deposited on said fibers;
(d) mat splitting means disposed downstream of said fiber forming and coating means and upstream of said curing means, said mat splitting means being arranged along a line extending generally transversely across and above said conveyor means for splitting said mat into at least two portion;
(e) compacting means arranged downstream of said mat splitting means and upstream of said curing means for compacting at least one of said portions of the mat to increase specific density thereof;
(f) deflector means extending from a location upstream of said compacting means to a location downstream of and adjacent to said splitting means.

16. Apparatus as claimed in claim 15, wherein said fiber forming means comprises at least two spinners spaced from each other in a direction generally parallel with said longitudinal direction, and means for selectively adjust-ing the operation of at least one of said spinners so as to produce by said spinners two types of said fibers differing from each other by their physical proper-ties.

17. Apparatus as claimed in claim 15, wherein said fiber forming means comprises a plurality of spinners spaced from each other in a direction generally parallel with said longitudinal direction, and means for selectively adjust-ing the operation of said spinners so as to produce by said plurality of spinners at least two types of fibers differing from each other by diameter of same.

18. Apparatus as claimed in claim 15, wherein said fiber forming means comprises a plurality of spinners each of said spinners being operatively associated with said coating means, said coating means comprising control means for controlling the volume of binder supplied to at least one of said coating means independent of the volume supplied to the rest of the coating means, whereby at least one of the fibers produced by the plurality of spinners has a bin-der coating different from that of the fibers produced by the other of said spinners.

19 . Apparatus for use in the production line for producing a mineral fibrous mat, said production line in-cluding mineral fiber forming means including a forming hood and comprising at least one fiber forming spinner and further including coating means for coating the fiber with uncured binder agent, conveyor means for receiving the fiber from said fiber forming coating means and for advancing same in the form of a generally loose mat in a longitudinal direction, a portion of said conveyor means being arranged to pass said mat through binder curing means arranged to cure the binder deposited on said fibers, said apparatus including:
(a) mat splitting means arranged to be disposed downstream of said fiber forming means and of said coat-ing means and upstream of said curing means, said mat splitting means being arranged to become disposed along a line extending generally transversely across and above said conveyor means for splitting said mat into at least two portions;
(b) compacting means arranged downstream of said mat splitting means for compacting at least one of said por-tions of the mat to increase specific density thereof;
(c) deflector means disposed downstream of and adjacent to said splitting means in proximity of the compacting means and extending from a location upstream of said compacting means to a location downstream of and adjacent to said splitting msans.

20. Apparatus as claimed in claim 19, wherein said mat splitting means is a bandsaw adapted to run generally trans-versely of the conveyor means, generally parallel with and spaced from the surface of the conveyor means.

21. Apparatus as claimed in claim l9, wherein said compacting means is a pair of rollers arranged to be yield-ably pressed against each other, said rollers being arrang-ed to extend transversely of said conveyor means.

22. Apparatus as claimed in claim 19, wherein said deflector means includes a smooth, arcuately curved de-flector shield arranged to extend substantially the entire width of the conveyor means, said deflector shield having a front edge located adjacent to and downstream of said splitting means, and a rear edge generally parallel with the front edge and spaced downstream of the surface of said rollers.

23. Apparatus as claimed in claim 19 or 20, wherein said splitting means is arranged to be secured to the con-veyor means so as to enable selective adjustment of the level at which said splitting means is located with respect to said conveyor means.

24. Apparatus as claimed in claims 19 or 20, wherein said compacting means is adjustable to selectively control the compacting pressure thereof.

25. Apparatus as claimed in claims 19 or 20 wherein the deflector means is arranged to be secured to the con-veyor means so as to enable a selective adjustment of the level at which the deflector means is located with respect to the surface means.