CA1327875C - Method for discharging a foamed material mixture, more particularly a thermal insulating material, by means of a mixing head for at least two reactive compounding ingredients in the low pressure process, mixing head for performing the_method and thermal insulating material produced according to the method - Google Patents

Abstract

A B S T R A C T

Method for the discharge of a mixture of foamed material, more particularly for a thermal insulating material, by means of a mixing head for at least two reactive compoun-ding ingredients in the low pressure method, mixing head for performing the method and insulating material fabri-cated according to the method.
In order to provide a method for the discharge of a mixture of foamed material, more particularly for a thermal insula-ting material, by means of a mixing head for at least two reactive compounding ingredients in the low pressure process, consisting of a tube in which an agitator rotates at high speed, a mixing head for performing the method and an insula-ting material fabricated according to the method is proposed according to which the mixture ready for reaction is discharged by centrifugal force and distributed onto a substrate, in order to fully react and foam thereon, and a mixing head for perfor-ming the method. A thermal insulating material fabricated hereby is characterized in that the insulating materials are laminated onto a carrier web as a sealing layer and in that the strips of insulating material possess a cuneiform cross-section.

Description

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Method for discharging a foamed material mixture, more particularly a -thermal insulating material, by means of a mixing head for at least two reactive compounding in-gredients in the low pressure process, mixing head for -performing the method and thermal insulating material produced according to the method Scope of application The me-thod, the appropriate mixing head and also the thus fabricated insulating material can be employed wherever insu-lating material is produced and employed with which it is in-tended to provide larger roof areas in order to form an insu-lating and sealing layer.
The present invention relates to a method of discharging a mixture of foamed material, more particularly for a thermal , insulating material, by means of a mixing head for at least two reactive ~ n~ngredients in the low pressure pro-cess, consisting of a tube, inside which an agitator rotates at high speed, a mixing head for performing the method and an insulating material fabricated according to the method.
State of the art Mixing heads for polyurethane mixtures of foamed materials produced in the low pressure process are known. In order to distribute the material with the aid of a mixing head onto a substrate passed through underneath the mixing head, the most widely varying methods and means are employed which are subject to a great many shortcomings. Due to the high visco-sity of the Foamed material mixture, not even the reciprocal travel of the mixing head transversally to the direction of course suffices for achieving the desired run of the foamed material mixture. By way of example, fish tail-shaped dis-charge nozzles are used. Also employed are srrlall bore -tubes, in which case the mixture is discharged with the aid of .. . :

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compres~ed air. All these forms of dischargin~ the mixture of ~oamed materlals, subse~uent to the mixin~ operation, call for a substantial effort and do not result ln the desirad success or are, as the discharge ef~ected by compres~ed alr, a hazard to health.
The present invention seeks to provlde a method of the kind stated above and a device ~or thls, in which these disadvantages no longer exist and with the aid o~ which the dischar~e of foamed materials can be effected without fluctuations in quality, without interruptions due to arislng preparation ~ime and in a manner adaptable to all requirements.
For solving this technical problem, a method of the kind stated in the beginning i5 proposed, ln accordance wlth which the mixture ready for reaction is discharged by centrlfugal force and di~tributed onto a substrate~ so as to fully react and ioam ~hereon.
~ The tnventlon therefore provides a method for delivering a foamable mixture from a mixing head for mixing at least two reactive components in a low-pressure method, which ~ixin~ head comprises a tu~e in which an a~itator rotates at high ~peed and from which the mlxture ready ~or reaction is delivered by gravity and distributed onto a substrate to react completely thereupon and to foam ~hereupon, which method comprises discharglng ~he mixture by centrlfugal force as well a~ gravi~y ~rom the mixing head, and wherein only one (A) o~ ~he two reactive componen~s, whlch one reactive component (A~ comprises materials which do not react on their own, ls introduced in~o a space within said mixing head located in ~he viclnity of an outer bearing o~ a floatlny sha~

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327g75 2a 23589-124 upon which said agita~or i5 mounted and i~ then conveyed by centrifugal force to another location in thr mixing head at which other location reactive component (A) is intermixed with the other (B) of said two reactive component~ thereby preven~ing premature reaction of components (A) and (B) in the vicinity o~ the bearing and protecting said bearing against contamination, heat or damage by said lnterreacting components.
The method proposed renders a uniform distrlbution of the foamed materlals mixture on ~he substrate possible, even ~hen the mixture of foamed material is highly viscous and at the lowest throughput in the simplest manner whlle avoidlng the disadvantages ~tated.
The invention further provides a mixlng head comprising a casing-like mixing tube provided ~ith a dlscharge aperture at one end and a lid-like closing member at the other end, said closing member having a bearing disposed thereln, said bearin~ :
floatably supporting a drive shaft capable of being driven by driving means, sald drive shaft having mounted thereon an agitator body extending along the inside length of the mixing tube to the area of said discharge aperture, ~aid agitator body being formed so as to provide an interspace between the agitator body and the closing member and to provide a mixing chamber between sald mixing tube inner wall and said agitator body, a first feed channel terminating in said interspace and a ~econd feed channel terminating in said mixing chamber.
An appropriate device is ~haracterized in ~hat ~he mixlng head is axranged within a machine frame, in that the mlxing head consists of a casing-like mixing tube which, at its upper end , ~
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2b 23589-124 located oppo~ite its lower end in which the discharge aperture is constructed, is provided with a cover-like sealing body, in that a bearing is disposed within the sealiag body, "

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in which a shaft driveable by a drive means is floatingly supported, upon which an agitator body extending as far as into the area of the discharge aperture is mounted and which shaft is constructed so as to extend righ-t through the entire mixing tube, in which, underneath the bearing, while forming a gap-like interspace, the cylinder-like-configured agitator body is mounted on the shaft, in that the sealing body, a first feeder channel terminating in the interspace is construc-ted, and in that, in the mixing tube, a second feeder channel terminating in a mixing space constructed between the mixing tube inner wall and the agitator surface is constructed.
If, for instance, larger or smaller widths of the foamed mate-rial strand are to be fabricated on a laminating machine,then this can be achieved by the vertical adjustment o-f the mixing head, in which case the cone of the mixture to be applied, formed by the centrifugal force, accordingly covers a larger or a smaller area.
It is also possible to achieve a different thickness of the foamed material coating transversally to the direction of travel, as e.g. is necessary for the production of sloping panels, by inclination by a few degrees from the vertical and a slight displacement in the horizontal of the mixing head.
If larger widths of application become necessary ~e.g. in ex-cess of 1000 mm), -then it is possible to dispose two mixing heads side by side without allowing the mixing head to oscil-late transversally to the direction of travel of the subs-trate.
By conveying the one compounding ingredient of the foamed ma-terial with does not react with itself into the proximity of the outer bearing of the mixing head and the shaft by centri-fuging in the mixing space, so as to permit it only there to come into contact with the compounding ingredient wi-th which :, , , ~ , - :
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the reaction takes place, a contamination of the bearing is avoided and the entire mixing head is kept operable for a continuous operation.
The casing grooves of the agitator which interrupt the screw channels and bring about a subsequent mixing are expediently not to be constructed so as to reach the end of the agitator.
It is avoided thereby that, when the conveyor screw channels are not filled completely due to a high speed or a lower ma-terial throughput, mixed material about to come to reaction or air reachesthe lower portion of the agitator and a contami-nation is precluded here as well.
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D Preferred further development of the ~e are characterized in the Claims 4 to 13. With such a device it is possible to provide a thermal insulating material to be used as insula-ting and sealing layer for roof areas which makes it possible to simultaneously cover larger areas of several square meters, the material consisting of strips of insulating material bon-ded or laminated onto a substrate.
It is known in the case of flat roofs, especially in the case of so-called non-insulated roofs, to apply the roof sea-ling in several layers onto the insulation. The manufacturers of insulating material have tried to simplify this multiple-layer application in that insulating elements having the nor-mal dimension of 1 m x 0.5 m were provided with a single sea-ling layer with an overlap projecting on two sides to be bon-ded onto already laid material consisting of already applied insulating elements. It was intended to thereby simplify the entire roofing operation and to have the insulating material protected against atmospheric influences and exposure imme-diately following the laying. It was still necessary then to ,-. ;, . . . :
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apply the actual sealing layers (at least one) because, due to the application of the elements, overlaps were produced which were too short, which gave rise to the fear of a pene-tration of humidity from the outside.
For the sake of a further simplification and for the sake of a faster sequence of operations, web rolls were produced that consisted of a correspondingly wide sealing web having a length of up to 10 m, which were bonded onto the strips of foamed material, which made it possible to roll the same up so as to form webs of up to 10 m in length. These web rolls have a width of up to 1 m and, with a length of 5 m, cover a roof area of 5 m2 in one operation. 5 m was the required minimum length in order to avoid too shortoverlaps of the elements.
These web rolls made it possible for the strips of insulating material to be rolled up to form a larger unit for covering larger areas. Normal bituminous roofing webs are employed in this case as sealing webs. However, when unrolled, the same :: :
had buckling creases in the carrier web so that there was good cause to be afraid oF leaks in the finished flat roof.
That is why, additionally, several, but at leas-t one additi-onal roofing web has to be applied.
Even today, when flat roofs having a slope of 3% or more are invol;ved, the laying of at least two sealing layers on one thermal insulation layer is necessary. If the slope is less than 3% or even zero, three sealing webs or bituminous sheets on the thermal insulation layer are regarded as being in keeping with a workmanlike finish. Even the, today, very highly developed plastic sheets that are admitted in single layers even on roofs having a zero slope, require as a gua-rantee on a thermal insulation layer, one additional substrate web for the protection of the laid sheeting at the joints of ,: : . . ~. :............... ,. ~. . : : . . . .

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the thermal insulation against damage and against the migra-tion of e.g. plasticizers from the sheet sealing. However, the carrier web located on a web roll, irrespective of the type, is recognized as a protection of the sheet.
A further signiFicant disadvantage in the multple-layer roof sealing is the feared bubble formation on the flat roof. This is caused by non-bonded points between the sealing layers.
The slightest inclusion of moisture when superposing the sea-ling layers or placing them onto the thermal insulating ma-terial, results in non-bonded points and, thereby, in the formation of bubbles or hlisters.
The bubble formation is often put down to the apparently ari-sing steam pressure, e.g.due to solar irradiation. However, a steam pressure above atmospheric can only arise at 100C
and more. But the bubble formation in coating layers is only possible by the volume enlargement of the entrapped air at the non-bonded points according to the law of Gay-Lussac.
According to this law, the air volumes~behave like the abso-lute temperatures. That is why a distension of the air bet-ween the individual sealing layers is unavoidable when the connection between the individual sealing layers by relevant bonding or welding is not established in such a way that se-veral layers become one and a perfect connection comes about.
But this is quite impossible. Matters have improved due the employment of welding webs, in which case the two joined webs are fused together. The bubble formation can thus be avoided only when the layers or sealing layers laid on top of each other are joined so as to form one whole.
In addition, a further requlrement results today. In the case of flat roofs, an ever-increasing demand exists, be it in new buildings or in redevelopment of old ones, that no water : . . :~ ~- :

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be left standing on the roof after a rainfall. Consequently, more and more sloping roofs are produced.
This is done in a conventional manner, in new buildings in many cases by the application of a sloping coating, either in heavy concrete or by a light-weight concrete. ~ith this, the slope is provided and no further consideration is requi-red when applying the thermal insulating material and the sealing.
If this is not the case, then the thermal insulating material ~;
is mostly supplied in wedge shape and this very largely in polystyrene. Various demands are made on the slope, in par-ticular of from 1% to 3%. This is mostly done according to previously produced drawings in which the entire slope is then produced at the works in any form whatever, either by cutting or by the construction of individual pieces. It would therefore be desirable to provide a thermal insulating material which, due to a web-like construction, enables lar-ger surface elements of the material to be manufacture in one operation and to cover larger areas of several square meters all at once.
It is desirable to provide a thermal insulating material and sealing layer for roof areas which can be employed as the sole roofing element for the roof areas, that can be laid on larger areas in one operation and which can also be used for the construction of a roof slope without the previous application of a slope piece, in which the disadvantages of the known solution, such as the trimming waste or the ne-cessity of individual construction or the formation of buck-ling creases and the bubble formation are avoidable.

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Above all it is possible with the method and the device to provide a thermal insulating material as an insulating and sealing layer in that the strips of insulating material are laminated onto a suitable sheet web as a sealing layer in such a way that the thermal insulating material is construc-ted as a thermal insulating and sealing layer so that, when it is laid, no need exists for applying a further sealing layer and in that the strips of insulating material possess a rectangular or cuneiform cross-section.
By preference, provision is made in this case for the angle of inclination of the wedge shape transversally to the longi-tudinal direction of the web rollto correspond ,to a gradient of 1%,2% or 3%.
With such a thermal insulating material it is possible to provide a roof area with the requisite thermal insulation and sealing layer without it being necessary for an additio-nal sealing web having to be applied. It is possible to achieve quite a decisive saving in both labour and material thereby, while at the same time the quality of the roofing improves since, due to the reduction in the craftsmen's ac-tivities, a reduction in the possibility of errors is achie-ved. ~ ;
According to a preferred embodiment, provision is made in this case for the laminating material to consist of a plastic sheet while, according to another preferred embodiment, the laminating material consists of a metal foil. The essential thing is in this case that it is ensured by such laminating materials that the thermal insulating material is applied to the roof area in such a way that an appropriate thermal in-sulation is produced, on which, at the same time, a sealing layer is disposed which is connectable without difficulty 1~27875 within the overlap areas so that the insulating material is protected against atmospheric influences after laying. In this case the insulating material may, according to a prefer-red embodiment, consist of polyurethane strips, while accor-ding to another preferred embodiment, provision has been made for foamed polystyrene particles or extruded polystyrene to be used as insulating material. This construction of the strips of insulating material in the form of hard foamed ma-terial bodies results in an optimal thermal insulation> in which case provision is preferably made for the insulating material to be fabricated and/or applied in such a way that the strips of insulating material, in the laid state, are lo-cated side by side without any gaps therebetween.
In this case provision may be made for the insulating material to be provided with diffusion channels on its surface located opposite the lamination. These may be constructed in that, on the surface located opposite the lamination, projections are provided in regular arrangement which possess a spherical, a rib-like, a frusto-conical configuration or some other geo-metrical shape;
In order to increase the inherent stability of the thermal insulating material, especially -to satisfy the most exacting requirements, provision may preferably be made for the insu-lating material and/or the laminating material to be provided with a stabilizing or reinforcing fabric.
Advantageous and expedient embodiments of the invention are characterized in the subclaims.
Brief description of the drawings Embodiments of the invention are explained below with the aid of the drawings. Thus, "
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Figure 1 shows, in a vertical section, a diagrammatical re-presentation of a mixing head, Figure 2 shows, in a diagramrnatical representation, -the mixing head according to the Figure 1 wjth a drive means wi-thin an indicated machine frame with an indicated discharge of foamed material, Figure 3 shows the assembly according to Figure 2 with the laterally displaced mixing head swivelled out of the vertical, Figure 4 shows, in a view from below, a section of a thermal insulating material, Figure 5 shows, in a vertical section in the direction of Line V-V in Figure 4, the thermal insulating ma-terial, and Figure 6 shows the thermal insulating material in the side-by-side arrangement projected for a flat roof for forming a slope.

Detailed descrlption of the invention and the best way of .
performing the invention.
In the Figures 1 to 3, a mixing head is depicted for dischar-ging a mixture of foamed material consisting of compounding ingredients A and B not shown in the drawing. Such a mixing head is mounted within a machine frame 11 and is driven by a driving means 12, while the compounding ingredients ~ and B are supplied via feeder lines which are not shown.
The mixing head 10 consists of a mixing tube 13 which forms the discharge aperture 15 at its lower end 14, while the up-per end 16 is closed with the sealing body, to which the mi-xing tube 13 is secured.

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Within the area of the discharge aperture 15, the mixing tube 13 is provided with a chamfer 15a which imparts a spe-cific discharge cone K to the foamed material consisting of the mixed compounding ingredients A and B.
Within the sealing body 17 which is secured in a torsionally resistant manner to the drive means 12, a bearing 18 is dis-posed in which a floating shaft 19 is supported. Underneath the bearing 18, the shaft 19 carries the agitator body 20 while the shaft 19 and the agitator body 20 extend as far as into the area of the discharge aperture 15 of the mixing tube 13. In this case, the agitator body 20 is provided with a longitudinal drilled hole 120 with which it is mounted on the shaf-t 19. The shaft 19 is in this case provided with a shoulder 19a, while the longitudinal drilled hole 120 is provided with a step 20a in such a way that the agi-tator bo-dy 20 can be pushed onto the shaft 19 up to the limiting stop formed by the shoulder 19a and the step 20a.
The agitator body itseif which is constructed in the form of a cylinder has two sections 21,22, the upper section 21 being provided with mandrels 23 disposed on the surface 20b of the agitator body 20 and possesses e.g. a frusto-cylindri-cal shape, while the second section 22 is constructed as a conveyor screw 24 for conveying the material A,B through the screw channels 25 of the conveyor screw 24.
Between the disk-shaped upper terminal surface 121 of the agitating body 20 which is provided with a, in the longitudi-nal direction L of the shaf-t, projecting, rotating outer rim 12ia, and the oppositely arranged sealing body 17 supporting the bearing 18, a gap-like interspace 26 is constructed, in which, a first feeder channel terminating within the area of the gap-like interspace 26 and/or the rotating rim 121a ,, ~ ..

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~1 327875 delimiting the latter is constructed in the sealing body 17, -through which the compounding ingredient A `can be supplied to this area. Underneath the rotating rim 121a, on the surface 20b of the agitator body 20, before the beginning of the sec-tion 21 which bears the mandrels, a mandrel-free area 21a is constructed which has a distance from the inner wall 13a of the mixing tube 13 predetermined by the height of the mandrels 23 and which forms a first mixing space 27. Into the same, due to the centrifugal force, the compounding ingredient A
charged into the gap-like interspace 26 is transferred. At the same time, a second feeder channel 29 terminates within the area of the mixing space 27 on the inner wall 13a of the mi-xing tube 13 for supplying the compounding ingredient ~. That is why the compounding ingredients A and B are mixed within the mixing space 27, the actual mixing being brought about by the mandrels 23. Since the compounding ingredients A and B
are supplied in a pressurized state via the feeder channels 28,29, the compound ingredient mixture produced in mixing space 27 and mixed thoroughly by the mandrels 23 is conveyed within the area of the conveyor screw 24 and received by the screw channels 25.
In adaptation to the various factors and influence values as well as to the compounding ingredients A and B, the spatial size of the gap-like interspace can be adjusted or altered in that one or more disks 30 having the same or varying thicl<-ness can be pushed onto the shaft 19 and brought up -to the shoulder 19a before the agitating body 20 is mounted and screwed tight by means of the nut 31 of shaft 19. By the step 20a coming to abu-t against the disks 30, a longitudinal displacement of the agitator body is achieved, so that the size of the gap-like interspace 26 adjusts itself correspon-dingly enlarged.

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" ~27875 A number of the screw channels 25 of the conveyor screw 24 are connected by interruptions 132 in the screw 24 so that one or severalconnections extending in the longitudinal di-rection L of the shaft between the screw channels 25 of the conveyor screw 24 result. These may also be constructed in the form of casing grooves 32. In this case, provision is also made for the screw channels 25, within the area of the discharge aperture 15, not to be connected by interruptions 132 or by casing grooves 32.
On its outer wall 13b, the mixing tube 13 is, within the dis-charge aperture area 15, provided with a ring that embraces the mixing tube 13 as a wiper 33. The wiper 33 is displaceably mounted on the mixing tube 13 or on the outer wall 13b of the mixing tube 13 in the longitudinal direction L of the shaft, while in the drawing, at I., a working position of the wiper 33, and at II., a rest position of the wiper 33 is depicted.
As shown in the Figure 2, the mixed and reacting compounding ingredients A and B of the foamed material mixture are dis-charged by the interaction of the agitator 20, the centrifu-gal forces arising and the chamfer 15a into a discharge cone K. A discharge results hereby of the material located or moved underneath the mixing head 10, it being also possible for the chamfer 15a to be provided with a radius so that the issuing material forms a steeper dispersion cone K. The ap-proximately rectangular foam discharge is indicated wi-th 34, which resul-ts when the mixing head 10 assumes the position depicted in the Figure 2. when the mixing head, as is shown in the Figure 3, is swivelled out in the longitudinal direc-tion of the shaft through an angle with respect to the ver-tical and is laterally displaced, a rising foam 134 results that possesses a gradient St, as is also indicated in the ,, : :. . .
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Figure 3. It is hereby possible to construct the foamed mate-rials and particularly strips of insulating material which possess a cuneiform cross-section The mixing head described in the foregoing which, in principle, constitutes the device for carrying out the novel method, is not restricted to the embodiments described in the foregoing and depicted in the drawings. Changes in the type of the mi-xing members on the surface of the agitator as well as in the construction of the discharge aperture come under the scope of the invention just like another type of adjustment device when the fundamental teaching is realized, which consists in that the compounding ingredients A and B are first of all sup-plied separately to the mixing head and mixed within a space immune to contaminations.
In the Figures 4 -to 6, an accordingly fabricated thermal insu-lating material is identified with 100, which consists of the sheet web 150 as sealing layer and the strips of insulating material 140 placed thereupon as insulating material 40. In this case, the sheet web 150, in comparison with the strips of insulating material 140, are provided with projecting ed-ges which serve as overlap sections 51,52 and which are dis-posed on a longitudinal and a transversal edge, respectively.
In a side-by-side arrangement of the thermal insulating mate-rial web (depicted in Figure 6), relevant overlap sections 51, 52 can be placed upon the already laid insulation webs and be welded to each other so that a secure protection against at-mospheric influences is provided. The strips of insulating material 140 consist in this case of the insulating material 40, for which polyurethane or polystyrene can be selected.
The employment of glass fiber and rock wool strips is also possible. Provision may be made in this case for the insula-ting material 40 to be provided with a stabilizing fabric.

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In addition, on the side facing away from the sheet web 150 of the strips of insulating material 140, spherical projec-tions 41 in regular disposition are provided for the construc-tion of diffusion channels 42. These are cons-tructed in the form of flat prominences, while it is possible to also provide any other suitable configuration and disposition by means of which it is ensured that, between the roof to be covered and the insulating material 100, a dehumification zone is created, in which a partial pressure ratio then results which, on ac-count of its relationship to the partial pressure ratio of the ambient atmosphere, leads to an evacuation of the humidi-ty from the building surface.
By means of -the depicted assembly, particularly wide and regu-lar steam expansion paths are provided which ensure a certain dehumification. In this case, a metal foil 60 is bonded onto the insulating material 40 on the surface located opposite the single-layer sealing layer lamination 50, while the lamination ma-terial is constructed in the form of plastic sheet, metal foil, welding web or bituminous sealing web.
The insulating material 40 or the s-trips of insulating material 140 possess, in the longitudinal direction of the web, a uni-form cross-section which, in the transversal direction of the web, is rising in a cuneiform manner. In order to form a sui-table slope, a gradient of 1%,2% or 3% is provided, it also being possible to provide required intermediate values.
The sealing layer lamination 50 may consist of a material re-inforced by a fabric 53 or of a non-woven pressed into a plas-tic sheet, in which case provision may be made for the sealing layer lamination 50, for the sake of a better adhesion of -the insulating material strips 140, to be provided on its surface with a non-woven or a fabric of polyester or glass fibers or organic fibers, such as jute or the like.

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i~ ~3~7875 By preference, the strips of insulating ma-terial 140 are bon-ded on in the form of a strand in a laminating machine and are subsequently formed into cut insulating material 40, it being possible to provide in -this case for the insulating ma-terial 40 to be fabricated in panels and that, when the strips of insulating material are cut, the panels are not cut right through so that a connection of the strips of insulating ma-terlal still exists for bonding on in large areas.
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Claims (23)

1. A method for delivering a foamable mixture from a mixing head for mixing at least two reactive components in a low-pressure method, which mixing head comprises a tube in which an agitator rotates at high speed and from which the mixture ready for reaction is delivered by gravity and distributed onto a substrate to react completely thereupon and to foam thereupon, which method comprises discharging the mixture by centrifugal force as well as gravity from the mixing head, and wherein only one (A) of the two reactive components, which one reactive component (A) comprises materials which do not react on their own, is introduced into a space within said mixing head located in the vicinity of an outer bearing of a floating shaft upon which said agitator is mounted and is then conveyed by centrifugal force to another location in the mixing head at which other location reactive component (A) is intermixed with the other (B) of said two reactive components thereby preventing premature reaction of components (A) and (B) in the vicinity of the bearing and protecting said bearing against contamination, heat or damage by said interreacting components.

2. A mixing head comprising a casing-like mixing tube provided with a discharge aperture at one end and a lid-like closing member at the other end, said closing member having a bearing disposed therein, said bearing floatably supporting a drive shaft capable of being driven by driving means, said drive shaft having mounted thereon an agitator body extending along the inside length of the mixing tube to the area of said discharge aperture, said agitator body being formed so as to provide an interspace between the agitator body and the closing member and to provide a mixing chamber between said mixing tube inner wall and said agitator body, a first feed channel terminating in said interspace and a second feed channel terminating in said mixing chamber.

3. A mixing head according to claim 2 wherein said agitator body in a first section near to the closing member carries radially mounted pins and in a second section near to the discharge aperture carries a conveyor screw for discharge of mixed material.

4. A mixing head according to claim 2 or 3 wherein said interspace is capable of being varied in size by adjusting the location of the agitator body on the drive shaft.

5. A mixing head according to claim 4 wherein the size of the interspace is varied with interchangeable disks of different thicknesses, said disks adjusting the location of the agitator body on the drive shaft.

6. A mixing head according to any one of claims 2, 3 and 5 wherein said discharge aperture is provided with a chamfer which imparts a specific discharge cone to material discharged therefrom.

7. A mixing head according to any one of claims 2, 3 and 5 connected to a variable speed driving means.

8. A mixing head according to claim 7 wherein the frequency of the driving means is controllable.

9. A mixing head according to claim 3 wherein said conveyor screw is multiply channelled.

10. A mixing head according to claim 3 or claim 9 wherein screw courses of said conveyor screw intercommunicate by means of interruptions in the conveyor screw or by means of grooves in the casing-like mixing tube.

11. A mixing head according to claim 10 wherein said grooves are spaced apart from each other and extend in the longitudinal axis of the mixing tube.

12. A mixing head according to claim 10 wherein said interruptions or grooves do not extend to the discharge aperture end of the agitator or to the discharge aperture of the mixing tube.

13. A mixing head according to any one of claims 2, 3, 5, 7, 9, 11 and 12 mounted in a machine frame.

14. A mixing head mounted in a machine frame according to claim 13 wherein said mixing head is laterally and vertically adjustable.

15. A mixing head according to any one of claims 2, 3, 5, 7, 9, 11 and 12 additionally comprising a wiper mounted circumferentially on the outside of said mixing tube, said wiper being longitudinally displaceable along the outside of said mixing tube between a working position and a resting position.

16. A method for delivering a foamable mixture of at least two reactive components from a mixing head according to any one of claims 2, 3, 5, 7, 9, 11, 12 and 14 which method comprises discharging said mixture by centrifugal force as well as gravity from said mixing head wherein only one (A) of the two reactive components, which one reactive component (A) comprises materials which do not react on their own, is introduced into said interspace and is then conveyed by centrifugal force to said mixing chamber where said one reactive component (A) is mixed with the other (B) of the two reactive components and a mixture resulting therefrom is subsequently conveyed to said discharge aperture for delivery from said mixing head.

17. A temperature insulation material comprising strips of insulation of a foamable mixture delivered according to the method of claim 1 bonded to a sheet web sealing layer substrate in the form of an insulating and sealing layer capable of covering several square metres of a roof area wherein the sealing layer substrate comprises a plastic foil, a metal foil, a welding web or a bitumen sealing web, the strips of insulation having a rectangular or wedge-shaped cross-section and bearing, on an opposite surface to the sealing layer substrate, diffusion channels and a metal foil bonded to said opposite surface, said temperature insulation material, when laid, providing a temperature-insulating and sealing layer which requires no further sealing layer.

18. A temperature insulation material according to claim 17 wherein the wedge-shaped cross-section has an ascending gradient of 1%, 2% or 3%.

19. A temperature insulation material according to claim 17 wherein the insulation is provided with a stabilizing fabric.

20. A temperature insulation material according to claim 17 wherein the sealing layer substrate comprises material reinforced by a fabric or a non-woven fabric pressed into a plastic foil.

21. A temperature insulation material according to claim 17 wherein the insulation is manufactured in the form of a plate which is incompletely cut through into strips so that coherence of the plate is retained and the plate can be bonded to said sealing layer substrate.

22 22. A temperature insulation material according to claim 17 wherein the sealing layer substrate is provided with a non-woven or woven fabric of glass fibres or organic fibres.

23. A temperature insulation material according to claim 22 wherein said organic fibres are polyester or jute.