Plastic and nonmetallic article shaping or treating: processes – Direct application of fluid pressure differential to... – Producing multilayer work or article
Patent
1990-11-01
1991-12-10
Theisen, Mary Lynn
Plastic and nonmetallic article shaping or treating: processes
Direct application of fluid pressure differential to...
Producing multilayer work or article
264518, 264112, 264121, 425 811, 425 831, B27N 312, B27N 304
Patent
active
050716158
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a method of manufacturing a fiber slab, in which method a fiber/air suspension is blown through a nozzle into a forming chamber which is defined by two mutually opposing belt parts of two endless, air-permeable driven belts, said belt parts being moved in mutually the same direction, and further defined by two mutually facing, substantially impervious side walls, the mutually distal surfaces of said two band parts co-acting with a suction source. The invention also relates to apparatus for carrying out the method.
Slabs or mats, bats, produced in accordance with the aforedescribed technique have been found to have highly satisfactory heat and sound insulating properties, but lack the requisite stability for use, for instance, as building slabs, since it is then necessary to increase the density of the slab to a level higher than that required for sound absorption and heat insulation purposes, in order to prevent the fibrous material from collapsing and therewith loosing the open structure of the loosely knit fiber body formed when injecting the fibers into said forming chamber.
Accordingly, a prime object of the present invention is to provide with the aid of so-called dry forming processes on the basis of the known technique a fiber slab or fiber bat in which the fibers form an open structure or matrix where the fibers, to a substantial extent, are bound together and form a stable but non-compacted structure.
This object is realized by the novel method, mainly by creating a mist of highly liquid, or thin-bodied adhesive in the region between the nozzle exit orifice and the forming chamber, and by, imparting to the fibers kinetic energy of such high value that the fibers will pass substantially rectilinearly through the mist and into the forming chamber and collected in said chamber on a slab end surface previously formed in the forming chamber and facing said nozzle.
The main purpose of the aforesaid suction source is to remove the air injected and not to appreciably influence the fibers, which are thus able to move towards said slab end surface and collect thereon. The continued formation of the slab or bat can be regulated by controlling the kinetic energy imparted to the fibers and also by controlling the velocity of the belts, so that the slab will be built-up progressively from said end surface and such as to form an open, air-enclosing matrix or structure. The individual fibers in this matrix or structure will be bonded together in punctiform fashion, and because the adhesive or binder used is highly liquid, the adhesive will be sucked towards the points of contact between the individual fibers, through capillary forces, and therewith bind the fibers into a stable fiber matrix, in which those parts of the fibers located between the contact points will be essentially free from surplus adhesive. As opposed to the case when fibers are impregnated with adhesive, the free parts of the fibers will thus at most be coated with a highly superficial coating of adhesive and consequently the flexibility of the fibers will not be reduced to any appreciable extent, while retaining the ability of the fibers to dampen accustic energy will remain substantially unchanged.
The invention also enables a fireproof, or at least flame-proof, slab to be produced, even when the fibers used are cellulose fibers. In this instance the binder used is a known binder in this context, such as an alkali silicate adhesive.
A slab manufactured in accordance with the novel method can be given a relatively low density, e.g. a density of 30-50 kg/m.sup.3, without impairing the sound absorption properties of the slab. The slab can, at the same time, be made flame-proof.
The main characteristic features of the inventive apparatus are set forth in the following apparatus claims.
The invention will now be described in more detail with reference to the accompanying drawings, in which
FIG. 1 illustrates plant machinery chosen by way of example;
FIG. 2 illustrates in larger scale the forming chamber and the blow section
REFERENCES:
patent: 1931570 (1933-10-01), Brown et al.
patent: 2571334 (1951-10-01), Browne et al.
patent: 2715755 (1955-08-01), Jones
patent: 2975470 (1961-03-01), Snelson et al.
patent: 3147165 (1964-09-01), Slayter
patent: 3341890 (1967-09-01), Oja
patent: 3658626 (1972-04-01), Berger et al.
patent: 3882211 (1975-05-01), Kamp
patent: 4166090 (1979-08-01), Green et al.
patent: 4257754 (1981-03-01), Green et al.
patent: 4401610 (1983-08-01), Ohberg
Fredriksson Sven
Theisen Mary Lynn
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