FR2670220A1 - FIBROUS MATTRESS FOR PRESSING. - Google Patents

Abstract

The invention relates to a composite product based on fibers of various origins and on a dry binder as well as its preparation process. The product of the invention is intended to be shaped subsequently by reactivation of the binder. It is made up of fibers from a continuous mat of mineral fibers and unbound fibers of various origins. The invention also relates to the method and the device for preparing the composite primitive mattress.

Description

FIBROUS MATTRESS FOR PRESSING

  The invention relates to a composite product based on fibers of various origins and a dry binder and its

  PROCESS OF PREPARATION The product of the invention is intended to be further shaped by reactivation of the binder.

  It is known to obtain parts, possibly in shape, of high or low density, by hot molding.

  of a primitive based on mineral fibers, in particular fi-20 bres of glass or rock, and containing a binder.

  These primitives can be constituted for example by mineral fiber mats useful for insulation.

  When it is desired to subsequently form by reactivation of the binder a fibrous mat, it is necessary during the manufacture of fibers by the traditional processes for the production of mineral fibers intended for insulation.

  as the glass or rock fibers replace the binder usually used to associate the fibers mattress or panel for insulation, a binder suitable for the process As soon as it is developed, the fiber mat is reduced to the desired thickness, he is then, immediately

  diastly used, still wet as primitive for the manufacture of molded parts. The mattresses or felts of mineral fibers for insulation can also be used later after polymerization and storage to form a primitive for the manufacture of molded parts In this case, the mattress is shredded by any suitable device to individualize the fibers in form To these individualized fibers is added a binder to form a composite product, which is therefore a reconstituted mat, and which is ready to be hot reactivated and shaped to obtain the desired shape of such a product. - 5 posite, obtained by reconstituting a mat of flakes of mineral fibers, is described for example in the French patent application FR 2,639,868. Previous techniques which exclusively use mineral fibers lead to final products which

  have given properties obtained for a given price, but it is often desired to be able to maintain satisfactory properties.

  For the lower cost, therefore, it would be advisable to add fibers of various inexpensive origins to the usual mineral fibers. On the other hand, the manufacture of the preceding primitive mattress leads to a ribbon of indeterminate length but

  With a defined and immutable width The operating conditions of this primitive mattress are such that it is often difficult to provide a plan for cutting the unit pieces, each intended to be pressed separately, which makes it possible to limit the falls. only processes envisaged

  In order to have variable widths, it is necessary to cut the edges of the primitives before their first heating to recycle them. But this operation destroys many fibers and forces the binder to be recycled, which increases the cost.

  For economic reasons, the method of the invention must make it possible to prepare primitive mattresses using

  fibers of the most diverse origins and also having the desired width, which allows the best geometrical operating yields.

  In the prior art, represented by the patent application FR 2,639,868, is used as raw material, systematically and exclusively continuous mattresses of mineral fibers associated with each other by a binder as they come out of the production lines of insulating mineral fibers The fibrous mat feeds a carding unit by means of two calender rollers which move it forward regularly The mattress is thus driven towards a cylindrical brush equipped with long metal bristles and of small diameter, the trajectory of the end of the hairs It is tangent to one of the two driving rolls. A comb is tangent to the carding roll in which it penetrates slightly to extract the fibers. After carding, the flakes of fibers are deposited in an enclosure where the powdery binder is introduced regularly. The bottom of the enclosure is a conveyor belt which entrains the fiber-binder mixture to a calender which defines the height of the mattress. It then goes into a medium temperature tunnel that allows a weak link

  between the fibers thanks to the binder with thermoplastic characteristic, a connection sufficient to allow the handling of the primitive-mattress and its cutting into uni-tary primitives The definitive setting of the binder being carried out -

  This technique, well known from the French patent application FR 2,639,848, allows the manufacture of very diverse parts intended, for example, for the production of internal coatings for the production of coatings. In the case where the final product is in the form of plates or panels intended to be cut or assembled together, it is necessary to work with a constant width. (that of the trowel and the enclosure evoked above as well as the calandreuse which follows it) is not a gene In revenge, if one wishes to produce during the final phase of the process, hot pressing, objects with a determined shape, more or less complex, such as, for example, the siding of an automobile door, the cutting of the product must take place before pressing and the In this case, it is desirable to have a primitive mattress whose width35 would be exactly adapted to cutting before pressing so as to be slightly greater than the size of the blank.

  unitary primitive or the sum of the dimensions of the unit primitives which must be cut off in such a way as to minimize falls.

  Similarly, the qualities of the products that can be obtained from mineral fiber, fiberglass or rock mattresses are very varied, however, for reasons of cost or because it is desired to expand the 5 field of performance, one may wish to introduce among the mineral fibers, other fibers, mineral or not, origins and various presentations Two reasons for this need: or we want to see lower the cost price of the product incorporating fibers whose cost per unit volume is lower than that of the usual mattresses because they are recovered products, for example various textile fibers or falls from the various phases of the production of mineral fiber products. The other reason lies in the search for new properties, the incorporation of silica-based refractory fibers, for example, will make it possible, with the use of a suitable binder, to widen the range of end-use temperatures upwards; Another example is the incorporation of relatively stiff but loopy textile fibers which will lighten and give flexibility to the finished product, or else long and strong fibers, for example polyamide added to conventional mineral fibers, will provide very thin sheets. The technique of the patent application FR 2 639 868 does not make it possible to achieve these two objectives freedom of choice of the width of the primitive mattress and addition of fibers in bulk. proposes a mattress-primitive formed of fiber flo- to which is added a reactivable binder

  subsequently, which include unbonded, mineral or organic fibers, the flakes may include fibers from a continuous mat of mineral fibers. In all, the proportion of fresh mineral fibers in the flakes may be less than 30%. , the mattress

  mitif is characterized in that its width is the operating width or the sum of dimensions of the unit primitives.

  The invention also relates to a process for preparing a mattress-primitive fiber flakes to which

  A subsequently reactivatable binder is added in which a carpet of bulk fiber flakes is formed in a receiving chamber by the action of gravity alone. In a variant, the width of the primary mattress is changed.

  This is achieved by rotating the carding unit about a substantially vertical axis. Furthermore, the thickness of the bulk fiber flake mat is adjusted at the edges by the displacement of the side plates of the receiving chamber. tion.

  Also part of the invention is a process for preparing a primitive mattress in which the fibers

  Unbound, before entering the carding unit, are successively processed by a bale-opener and a constant-load hopper.

  In order to carry out the process of the invention there is provided a device for varying the width of a fiberglass-primitive batt to which is added a later reactivatable binder and comprising a carding unit which is

  equipped with means of rotation about a substantially vertical axis. It is also intended that the receiving chamber

  In the preferred embodiment of the device of the invention, the receiving chamber is equipped with a vertical wall with means for adjusting them to move laterally.

  rear ticale which is an extension of the upstream wall and a contiguous wall Ue of the rectangular section channel Furthermore, the side plates are supported on the ar-30 outer edges of the rear vertical wall It is

  also provided that the receiving chamber is equipped with a calendering mat whose plan remains fixed.

  The main advantages of the technique of the invention are summed up in the possibility of obtaining

  las-primitives whose composition and width are controlled at the same time.

  The figures and the description which follow will make it possible to understand the operation of the invention and its

  advantages. FIG. 1 represents an overall view of a production line according to the invention, FIG. 2 is a representation of the flow control hopper, FIG. 3 shows the carding unit according to the invention, FIG. is a schematic view of the device of the invention, Figure 5 shows the fiber receiving chamber at the output of the carding unit, Figure 6 shows the detail of the downstream part of the receiving chamber,

  Figure 7 shows the upper part of this enclosure.

  FIG. 8 shows the mounting of the side plates of the reception enclosure,

  Figure 9 the preferred embodiment of this same enclosure.

  In Figure 1 is shown the entire line of

  The main element is the carding unit 4, which is powered by two machines.

  first, by continuous mattresses of inorganic fibers 1 and / or by non-bound fibers passing through the flow control hopper 21 (or) the solidifying binder (s) (s) s) brought by the worm 11 or 12 is (are) added (s) to the flakes of carded fibers in the enclosure 10 The assembly falls on the conveyor belt 14 and is driven to the calender 15 before enter the preheating oven 16 o premusion of the binder

  associates the fibers together to form the mattress-primitive 20 which is cut by the paper cutter 17 which delimits

  tapes intended to constitute rolls or panels. The other elements of FIG. 1 constitute the device allowing the preparation of bulk fibers, of the most diverse origins, to make a continuous web of unbound fibers which will be introduced into the hopper. One of the essential elements is the so-called machine 23. "bale-opener" for example, the marketed one

  7 by the company LAROCHE It includes a food apron

  The belt 26 is inclined and causes the bulk fibers to be lifted upwards. The roller 27, which is also equipped with spikes, makes it possible to return the excess of the fibers in a downward direction. Bulk This system allows to regulate the

  volume flow of the fibers that reach the top of the carpet 26 The function of the roller 28 is that it is able to extract all the fibers from the carpet

  bres are then evacuated to an outlet hopper 29 and then taken up by an unrepresented fan which transfers them

  pneumatically conveys through the pipe 22 to the flow control hopper 21. An important parameter of the process lies in the

  uniformity of distribution, the homogeneity of the flock of fibers which constitute the mattress-primitive 20, in particular their regular distribution in the width of this mattress. It is therefore important that the material inputs to the carding machine 4 are regular at all times and over its entire width. The continuous mat of mineral fibers 1 does not pose any particular problem: it is produced in the most homogeneous manner possible and its distribution A specific problem, on the other hand, is that of the constant flow rate and the repartition in width of the unbound fibers coming pneumatically through the pipe 22. The solution is provided by the hopper. Flow control 21 This, which is also referred to as a "regulating metering stack", is also marketed by the LAROCHE Company, it is shown in FIG. 2, it comprises three essential parts, a condenser 13, a constant load hopper 19 and

  A delivery system 41 All these elements are shown in a section perpendicular to their largest dimension which is always the same, equal to the width of the carding machine 35 4.

  The stream of unbonded fibers transported by the channel 22 arrives in the chamber of the condenser 13. The mechanical connection between the pipe 22 and the enclosure is designed to allow it to move about.

  8 in rotation around a vertical axis without the

  The rotary perforated cylinder 43, the central part of which is in communication with the atmosphere, draws the flakes on its wall while the air is discharged after passing through the perforations.

  vane 45 pulls the fibers which fall by gravity into the constant load hopper 19 while passing through the trench.

  Figure 52 which has the same width as all the other elements of Figure 2: The width of the carder 4 The constant load hopper 19 consists essentially of two rectangular plates, a semi-fixed plate 56 and an oscillating plate 58 These plates constitute the walls of a reservoir of unbonded fibers They have the horizontal dimension, the width of the carding machine 415 and for height about five times their maximum spacing. Constant flow is assured thanks to the level sensor

  59 The gap between the plates can be adjusted according to the flow rate The fibers are fed to the card-

  equipped with two delivery rollers 41 whose tan-ngential speed is that of the driving cylinders 2 and 3 of the carder To avoid clogging of the reservoir constituted by the plates 56, 58, the plate 58 is driven by a movement oscillating thanks to an eccentric 60 which makes it perform at the bottom part displacements of some 25 centimeters The level in the tank is kept constant by regulating the flow of the machine 23 opening bale machine through the indications of the detector 59. Figure 3 represents the Carding unit 4 according to the invention The two cylinders 2 and 3 rotating in opposite directions of rotation simultaneously drive the continuous mat of mineral fibers 1 and / or unbound fibers 18 from the flow control hopper 21. The function of these two cylinders 2 and 3 is only to regularly drive the materials to the carder 4.35 The materials entrained are various, they are const The respective proportions of mattresses 1 and unbound fibers 18 are highly variable, since they can have all the values of the range O 1, from a raw material consisting solely of unbound fibers 18 to a material first, which comprises only the continuous mat of mineral fibers 1 without the contribution of any allogeneic fiber. But obviously the most common proportions are intermediate between the two extreme values. The elements of the carding machine 4 are those described in FIG. French Patent Application FR 2 639 868 In summary, FIG. 3 shows the cylindrical brush equipped with fine, long and straight bristles 6 which causes the materials supplied by the rollers 2 and 3. The comb 7 with its adjustment system 9 , is made of spikes mounted on the plate 8 which penetrate between the bristles of the brush 5 and extract the flakes of fibers which fall naturally to the elements situated below. t essentially a hopper 54 attached to the carder This hopper ends with

  a rectangular section channel 55.

  At the exit of the channel 55, the fiber flakes fall freely under the effect of their own weight on the carpet

  14. The principle of the variation of the width of the mattress

  According to the invention, FIG. 4 shows that the channel 55 is perpendicular to the axis of the conveyor belt 14 and, therefore, of the primitive mattress 20. In this rotation, the right angle that existed between the axis of the channel and the axis of the conveyor belt 14 becomes an acute angle, and the hopper 54 which is mechanically connected thereto can rotate about a vertical axis. a, and the width of the carpet of loose fiber flakes 57 which was L becomes L 'These two sizes satisfactorily verify the relationship: LI = L Sin a However, it is necessary to provide additional devices which guarantee a density of flakes of

  fibers and / or a thickness of the fiber mat 57 which is the same over its entire width and in particular on the edges. An excellent result is obtained thanks to the combination of

  tion of a special receiving chamber 10 associated with a particular calender. At the outlet of the hopper 54, the fiber flakes after passing through the channel 55 fall naturally into the receiving chamber 10 whose lower horizontal wall is constituted by the conveyor belt 14 The device of the invention does not include any suction below the conveyor belt 14 nor any other means that would cause a crushing of the flakes.

  thus, avoiding any fiber breakage, any additional nesting, any preferential orientation, to keep the properties of the original products The enclosure 10 is shown schematically in FIG. 5 Among the other walls, only the rear vertical wall 53 is fixed , the

  king located forward is inclined and movable in its plane, it consists of a calendering mat 46 with a translation movement up and down in the plane 15 of the wall This wall is limited by two rollers: a upper fixed motor roller 47 and a lower roller

  This second roller can be moved along the wall that it tangents so as to produce primitive mattresses 20 of varying thickness. The third roller 4820, also free, can also be varied in its position so as to tension the carpet 46. design of the

  The first advantage of the invention is that the speed of the belt 46 and that of the conveyor belt 14 can be chosen exactly the same, which makes it possible to compress the fibers without slipping, thus limiting their deterioration. two carpets remain identical

  which allows the insertion of side walls between them. Laterally, the receiving enclosure 10 is thus limited by two plates 36, 37, which can move so as to materialize the width of the primitive-mattress 20.

  The sixth wall of the receiving chamber 10 is constituted by the bottom of the carding unit composed of the carding machine 4 surmounting the hopper 54 and its channel 55. This bottom serves as a cover for the receiving enclosure 10.35 FIGS. 7 and 8 show the details of the mechanical systems which constitute one embodiment of the invention. In FIG. 6, firstly, the front part of the receiving chamber is shown. movement of the roller 49 along the inclined wall, allows to vary the thickness of the primitive mat from hl, maximum thickness to h 2, minimum thickness To maintain the tension of the calendering mat 46, the third roller 48 by rotating the arms 51 which carry it around their common axis 50. FIG. 7 shows the upper part of the receiving enclosure, the calendering belt 46 driven by the fixed upper motor roller 47, the vertical wall rear re fixed 53 and one of side plates 36.10 The top wall 34 is shown isolated and structural ele- ments which support not on the

  This wall must be capable of supporting the hopper 54, the carder 4 as well as the feeder system of the carder. Only the hopper 54 is shown in the figure.

  The plate 34 is pierced with a circular hole 35. The carding assembly 4, hopper 54 and channel section rec-

  The plate 55 is based on a circular plate 31 of diameter greater than that of the hole 35. This plate can rotate around the vertical axis 30 by means of rotating rolling means schematized by the rollers 32. The channel 55 is provided at its end. The latter has the shape of a disc 33 which substantially closes the hole 35, such that the hopper 54 and its channel 55 are represented in the figure by the width of the primitive mat produced by the installation is at its maximum

  rotating the assembly, including the circular plate 31 about the axis 30, we obtain larger or smaller widths.

  As we have seen, after the rotation of the carding assembly about the axis 30, it is necessary to adjust the

  10 of the receiving enclosure 10 so that the thickness of the bulk fiber flock carpet 57 is constant up to the edges. To this end, the position of the two side plates 36 and 37 must be modified. For this purpose the parallelogram system represented in FIG. 8 The plate 36 is generally vertical, parallel to the wall 40 It rests on the ground by unrepresented rollers which are guided in

  12 grooves so that the plate 36 can be

  In a direction perpendicular to it, as well as at the wall 40, there are four rods 38 at two different levels connected in pairs by rods 5 such as 42. Cylinders 44 serve to deform the parallelogram formed by the stem 42, the wall which

  is parallel and the two rods 38 During this deformation, the ends of the rods 38 slide in housings 39 and the plate 36 moves towards or away from the wall 40 in the direction in which the jack 44 acts. previous example is provided, while any system

  The position of each of the plates 36, 37 with respect to the axis of the production line is determined empirically for each position. of the carding set, that is to say for

  Each of the values of the angle α (FIG. 4) In a variant of the invention, it has been provided that the plates 36, 37 can be inclined around a vertical axis and / or a horizontal axis.

  riceontal to also allow a concentration of fiber flakes on the edges.

  FIG. 9 shows the preferred form of an element of the device of the invention, namely the receiving enclosure 10 and the end of the rectangular section channel 55. FIG. 9 is a view The channel 55 instead of terminating at the plate 33 is extended on two of its adjacent sides 61 and 62. These sides extend to the vicinity of the conveyor belt 14 and form the rear wall 30. receiving chamber 10 in place of the fixed wall 53 of FIG. 5 When the upper assembly rotates about the axis 30, the wall 61 comes to 63 and the wall 62, in 64 In this variant, the walls 36, 37 are permanently supported on the free ends 65 and 66 of the walls 61 and 62. The density correction of the mattress on its edges is obtained here by tightening the downstream ends.

  plates 36, 37. The operation of the invention will become apparent from examples.

Example 1

  It is desired to manufacture a very inexpensive product, that is to say comprising a maximum of recycled fibers.

  Continuous mattresses of mineral fibers manufactured on an industrial line may contain a certain proportion of recycled fibers generally coming from falls or defective fabrications. In the case of the example, there was a fiberglass mattress with a fiberglass mat. density of 10 kg / m 3 and a proportion of recycled fibers of 10 17%,

  To this mattress were added unbound fibers also from mineral fiber drops which were

  The respective parts of the mattress and unbonded fibers at the entrance of the carder were 72.3% for the mattress 1 and 27.7% for the fibers 8.

  There was thus obtained a reconstituted product comprising

  % of recycled fibers, which makes it possible to keep production costs relatively low while keeping

  These are not very different from those of a product which is only made from new fibers.

Example 2

  In this example, it is desired to manufacture a product intended after final pressing to constitute the coating.

  Although the carding machine that is available has a useful width of 120 cm, it is desired to directly produce a primitive mattress 20 having a usable width of 120 cm. 90 cm is rotated the device of the invention around the axis 30 of an angle such that30 90 Sin a =

an angle α = 50 approximately.

  The spacing of the two side plates 36 and 37 is adapted to obtain a constant thickness in the enclosure 10.

  As regards the constitution of the mattress-primitive itself, it is here 70% of glass fibers of isola-

  30% of large, long-length textile glass yarns give the product a high elasticity. These yarns consist of scrap from the workshop of a plastics processor, a major user of fiber mats. Here the other fibers all come from the continuous mat of mineral fibers. As the proportion of bulk fiber flakes is relatively small, the plates 56, 58 of the regulating chimney 19 are bridged to obtain the desired flow rate (the speed the treadmill 26 of the bale opener 23 is adjusted accordingly to avoid too much fiber excess at the entrance of the chimney 19) With the settings

  Previously, we obtain a mattress-primitive which has a width (90 cm) which provides the maximum operating efficiency at the final transformer which presses the primitives15 units to produce the covering panels of the automobile casings. .

Example 3

  In order to produce a very inexpensive final composite product, a mineral fiber mattress was used as the raw material for the insulation, half of which was recycled fibers. This mattress accounts for 58% of the final product fibers. unbound fibers, which make up 42% of the total, come from

  This gives a primitive mattress composed of 71% of recycled mineral fibers. Such a product thus benefits from a high cost.

  particularly advantageous. The preceding examples show that the technique of the invention makes it possible to produce, under

  industrial, that is to say, in particular reproducible and cheap, products of various types and widths.

Claims (10)

  Primitive mattress (20) formed of fiber flakes to which a subsequently reactivatable binder is added, characterized in that the flakes include unbound, mineral or organic fibers (18).   Primitive mattress according to claim 1, characterized   in that the flakes include fibers from   a continuous mattress of mineral fibers (1).   Primitive mattress according to claim 2, characterized   characterized in that the proportion of new mineral fibers   in the flakes is less than 30%.   Mattress-primitive according to one of the claims   preceding, characterized in that its width is the width   even of exploitation or the sum of dimensions of unit primitives.   Process for the preparation of a fiber flakes-primitive mat with a subsequently reactivatable binder, characterized in that a carpet is formed   bulk fiber flakes (57) in an enclosure for   ception (10) by the action of gravity alone.   6 Process for the preparation of a primitive mattress according to   claim 5, characterized in that the variation   primitive-mattress pad (20) by rotation of a carding unit (4) about a substantially vertical axis ( 30).   Process for the preparation of a primitive mattress according to claim 6, characterized in that the thickness of the bulk fiber flake mat (57) is adjusted at the edges by the displacement of side plates (36, 37) of the receiving enclosure (10).   8 Process for preparing a primitive-mattress according to claim 1, characterized in that the unbound fibers before entering the carding unit (4) are treated successively by a bale-opener machine   (23) and a constant load hopper (19).   9 Apparatus for preparing a fiber flock-primitive mat, to which a later reactivatable binder is added, characterized in that the width of the primitive mattress (20) is varied by rotation of a unit of carding (4) equipped with rotation means (31,   32, 33) about a substantially vertical axis (30).   Device according to Claim 9, characterized in that the receiving chamber (10) has side plates (36, 37) with adjustment means (38, 39, 42,   44) allowing them to move laterally.   11 Device according to claim 10 characterized in that the receiving chamber (10) is equipped with a rear vertical wall which is an extension of the upstream wall (61,63) and a contig wall Ue (62,64 ) of the rectangular section channel (55) which follows the carding unit (4) and in that the side plates (36, 37) rest on the outer edges (65, 66) of the walls (61, 63, 62, 64).   12 Device according to claim 9, characterized in that the receiving chamber (10) is equipped with a   calendering mat (46) whose plan remains fixed.