A MACHINE FOR MANUFACTURING PRESSED LOOSE MATERIAL PRODUCTS

Abstract: A machine for manufacturing pieces made of a loose pressed material comprises a mould (2) in which a plurality of through-cavities (3) are afforded, an axially-mobile first pressor element which cooperates with a plurality of second pressor elements (5), each of which is mobile internally of a through-cavity of the plurality of through-cavities (3). In each second pressor element there is an infeed conduit (9) for a hot active fluid. The loose material, possibly mixed with an adhesive resin, is introduced into the plurality of cavities (3) and is pressed. The machine is for producting small compact blocks utilisable for various applications, for example as components in the manufacture of pallets. The machine is relatively highly productive in relation to a mass thereof.

Description: Description A Machine for Manufacturing Pressed oose Material Products- Technical Field Specifically though not exclusively the invention is usefully applied in making small blocks of wood chip, obtained by mixing chips with an agglomerating substance, followed by pressing. The products are applicable in many fields, for example in the manufacturing of pallets. Background Art A main aim of the present invention is to provide a higli-production machine for pressing loose materials, possibly made solid by the use of a glue, and manufacturing small compacted blocks. An advantage of the invention is that it provides a constructively simple and economical machine. A further advantage is that it makes available a machine which is able to manufacture relatively high-quality pressed products. Further advantages are that the invention reduces waste to a minimum and the finished pieces need no further work operations. These aims and advantages and others besides are all attained by the invention as it is characterised in the claims that follow. Disclosure of Invention Further characteristics and advantages of the present invention will better emerge from the detailed description that follows of a preferred but non-exclusive embodiment of the invention, illustrated purely by way of non-limiting exaniple in the accompanying figures of the drawings, in which: figure 1 is a view in vertical elevation of a machine made according to the present invention; figure 2 shows section II-II of figure 1; figures 3, 4 and 5 show the machine of figure 1 in three different operative configurations; figure 6 is a plan view from above the loading device of the mould; figure 7 is a side view from below of figure 6; figure 8 is a view from above of a second pressor element 5; figure 9 shows section IX-IX of figure 8; figure 10 shows a detail of figure 9; figure 11 shows section XI-XI of figure 9; figure 12 is section XLT-XII of figure 9. With reference to the figures of the drawings, 1 denotes in its entirety a machine for manufacturing pressed loose material products (possibly with the use of a glue). The loose material could comprise, for example, wood chips. The material to be pressed and/or the glue are heated by a hot fluid (for example water vapour) in order to activate in a short time the reactions winch contribute to fransforming the loose material into a compact block by effect of pressing. The pieces obtained in the illustrated example are small blocks, for example rectangular or cylindrical, destined for example to be used as components in manufacturing pallets: in this case the pieces obtained constitute spacer elements, located below the load plane of the pallet, the spacer elements going to create the spaces below the plane for the insertion of forklift truck forks. The machine 1 comprises a mould 2 in which a plurality of through-cavities 3 are afforded, one by the side of another, longitudinally extended and parallel to each other. In the illustrated case the mould comprises a single parallelepiped block of considerable width and provided with cavities 3 arranged in a special order. The cavity axis is vertical. A first pressor element 4 is axially mobile on command according to an axis which is parallel to the vertical axis of the cavity 3. The first pressor element 4 can assume an active position (figure 4 and figure 3 hi a broken line) in which it is lowered, and presents a flat lower side which is in contact with an upper face, also flat and horizontal, of the mould 2. The upper face of the mould 2 is perpendicular to the axis of the cavity 3. In the active position the first pressor element 4 closes the upper end of the cavity 3. The first pressor element 4 can also assume an inactive position (represented in figures 1, 5 and 3 in a continuous line), in which the lower side thereof is distanced from the upper face of the mould 2. The machine comprises a plurality of second pressor elements 5 which face the first pressor element 4 and collaborate there-with. The second pressor elements 5 extend in length in a parallel direction to the vertical cavities arranged one beside another. Each of the second pressor elements 5 is axially mobile on command internally of a respective cavity 3 of the mould and can assume a lower first position (figures 1 and 3) in which the cavities are filled with material to be pressed, and in which the lower end of the respective cavities 3 is closed, i.e. the end situated at the opposite end of the mould from the above-cited upper face. In the lower first position each of the second pressor elements 5 is relatively distant from the upper face of the mould and inferiorly delimits the cavity to be filled with the material to be pressed. The lower position of the second pressor elements 5 with respect to the upper face of the mould 2 determines the size of the filling cavity and can be chosen on the basis of the final density of the product to be obtained. Each filling cavity 3 extends in a vertical direction. The material to be pressed can be constituted by solid loose material (for example wood chips) or by an agglomerating substance (for example an adhesive resin), or by a mixture of the two. The second pressor elements 5 are supported by and are solidly constrained to a horizontal lower plate 6 which is perpendicular to the second pressor elements 5 and vertically mobile on command. Each of the second pressor elements 5 can assume an intermediate second position (figure 4) for the material pressing operation, chosen on the basis of the height or breadth of the final piece desired, in which intermediate second position the second pressor elements 5 exhibit their upper end internally of the respective cavities and closer to the upper face of the mould. Each second pressor element 5 can also assume an upper third position (figure 5) in which the pressed piece P is expelled from the mould; in this third position the upper end of the second pressor element 5 is coplanar or very nearly so to the flat upper face of the mould 2. The machine comprises means for injecting a hot activating fluid internally of the filling cavity 3; the activating function is generally the heat of the fluid. The hot fluid is injected internally of the mass of the material introduced into the filling cavity 3 before and during the pressing operation, so that it can act on the material (for example the resin or the material to be pressed) in order to obtain compact and resistant pieces rapidly. The hot fluid used is, for example, water vapour. The means for injecting the hot fluid comprise at least one feeding line 7 of hot fluid which sends the fluid towards a manifold 8 afforded internally of the lower plate 6 supporting the second pressor elements 5 (figure 1). The manifold 8 s connected to a plurality of hot fluid infeed conduits 9, each of which is afforded internally of a second pressor element 5. In the enlargement of figure 1, the second pressor elements 5 are only schematically represented: figures from 8 to 12 give more detailed illustrations of a second pressor element 5. Each infeed conduit 9 superiorly terminates in a horizontally-extended chamber 9a from wliich plurality of nozzles 9' depart, which nozzles 9' are also afforded internally of the second pressor element 5. Each nozzle 9' opens into the filling cavity 3 through one or more outlets for the fluid located at the upper end of the second pressor element 5. Thus each filling cavity comes into contact with a plurality of upwards-facing hot fluid outlets. In the illustrated embodiment these outlets are aligned one with another. The machine further comprises means for heating both the first pressor element 4, the mould 2 and the second pressor elements 5. The means for heating comprise a series of separate circuits, afforded internally of the above-cited elements, in which a second hot fluid (for example heat-radiating oil) circulates. The heating facilitates the hardening of the pressed material and the activation of a glue if present, hi the figures 11 and 12 denote the delivery and return conduits of the second hot fluid, which are afforded internally of a second pressor element 5 and are extended over almost the whole length thereof. In each of the second pressor elements 5 there is at least one further infeed conduit 13 for an active substance, for example paraffin, having one or more outlets 13' arranged on the lateral side of the second pressor element 5 in a low area 14 preferably close to the upper end of the second pressor element 5. The substance is injected from the inside of the second pressor elements 5 towards the outside during the return run of the second pressor elements 5, internally of the filling cavities 3 before filling them. The substance is distributed on the internal walls of the cavities 3, forming a thin layer so that after filling and pressing the external surfaces of the pieces exhibit special characteristics which depend on the substance used (for example by using paraffin water-repellent surfaces are obtained) and which also facilitate detacliment of the pieces from the mould walls. The various lower areas 14 form, together with the internal surface of the filling cavity 3, small chambers which spread over the whole of the transversal oftlie cavity 3. The machine can be equipped with means for aspirating, of known type and not illustrated, which are preferably connected to the circuits through which the activating fluid is injected into the filling cavity 3. These means for aspirating create a depression in the filling cavities and thus collect the vapours issued during the pressing operation. With reference to figures 6 and 7, the material loading device into the mould is now described. This device comprises a commandable axially mobile draw 15, mobile on horizontal guides 16 in the direction of arrows J. The drawer 15 can assume a first position (figure 7 and on the right in figure 6) in which it is in a material deposit station and receives the material destined for pressing; this station can be for example a hopper 17. The drawer can also assume a second position (on the left in figure 6) in which it is entirely above the mould 2. The drawer 15 is open both above and below. One or more rotating combs (set on rollers 18) are located at the lower opening of the drawer 15; the rollers 18 can be commanded to rotate about an axis which is transversal to the drawer movement axis. Each roller 18 bears a plurality of radial teeth thickly distributed over the external surface of the roller 18 and arranged in such a way as not to interfere with the teeth of an adjacent roller 18 during rotation. When the drawer 15 is in the first position, the lower opening is closed by a horizontal fixed plane 19, which in effect becomes the bottom of the drawer 15 and prevents exit of the material from the bottom of the drawer 15. The plane 19 is coplanar to the mould and extends up to the mould itself. To fill the mould 2, the drawer 15 displaces axially towards the mould 2, moving on the horizontal guides 16. Wliile the lower opening of the drawer 15 is thus closed by the fixed plane 19, up to the edge of the mould 2, the material will not fall down; then, as the drawer advances onto the mould 2, the material will fall, as the bottom constituted by the plane is no longer present. In the meantime the rotating combs distribute the material in the cavities 3, depositing the material uniformly up until the cavities 3 are filled. Once this point has been reached, the drawer 15 returns and its front terminal part, equipped with a scraper, removes the excess material, thus guaranteeing optimal conditions for a homogeneous pressing of the material. The pressing operation is now described, starting from the configuration of figure 1, in which the first pressor element 4 is raised and in the inactive position and the second pressor elements 5 are lowered and in the filling position. In this configuration the above-described loading device introduces the material to be pressed into the filling cavities 3 which are closed below by the second pressor elements 5 (figure 3). Subsequently the first pressor element 4 is made to lower, in the direction of arrow F, up until it comes into the active position in which it superiorly closes the various filling cavities. At this point the plate 6 supporting the second pressor elements 5 is raised, in the direction of arrow G into an end-pressing position (see figure 4), to press the material into the filling cavities 3. At the same time the means for injecting inject the hot fluid upwards into the mass of material. The injection stage can begin before the pressing phase. The hot activating fluid enters from the bottom into the mass of material contained in the cavity to activate the reactions contributing to transforming the loose material into a compact and coherent block after pressing. Once the compacting stage has been completed, comprising both the pressing and the activation of the glue if any, the first pressor element 4 is raised in the direction of arrow H, after which the plate is also raised (arrow K) to bring the second pressor elements 5 into the expelling position (figure 5). The pressed pieces P, after expulsion from the cavities in an upwards direction, can be easily removed from the mould. The hot fluid can be injected internally of the filling cavities 3 from above, through the first pressor element 4, either alternatively or in concert with the means for injecting which operate from the side of the second pressor elements 5. In this case second means for injecting the hot fluid are provided, which comprise a supply line 10 which conveys the fluid towards a manifold afforded internally of the first pressor element 4. The manifold is connected to a plurality of nozzles which terminate with downwards-facing outlets for the fluid, predisposed on the flat lower side of the first pressor element 4, for injecting the fluid internally of the filling cavities during the material compacting stage, activating the resin or glue.

Claims: Claims. 1). A machine for manufacturing pressed loose material products, comprising: a mould (2) in wliich a plurality of topless and bottomless filling cavities (3) are afforded, the cavities (3) being afforded one by a side of another, being elongate and being parallel one to another; a first pressor element (4) wliich is axially mobile along an axis which is parallel to the plurality of tlirough-cavities (3) and wliich can assume an active position, in which a side thereof contacts a face of the mould (2) and closes an end of each of the plurahty of through-cavities (3), and which can assume at least one inactive position, in which the side thereof is distanced from the face of the mould (2); a plurality of second pressor elements (5), extended in length in a direction which is parallel to the plurality of tlirough-cavities (3), each of wliich plurality of second pressor elements (5) is mobile internally of a respective plurality of cavities in the mould (2) and can assume a first position, in which material to be pressed can be introduced into the plurality of through-cavities (3), in which first position the plurality of second pressor elements (5) closes the plurality of through-cavities (3) at an end of the mould (2) which is opposite the face of the mould and which is distanced therefrom, and a second position, in wliich the material is pressed, in which second position the pluralit of second pressor elements (5) is internal of the plurality of through-cavities (3) and is closer to the face of the mould. 2). The machine of claim 1, comprising means (7, 8, 9) for injecting a hot fluid internally of the plurality of through-cavities (3). 3). The machine of claim 1 or 2, wherein the means for injecting (7, 8, 9) comprise one or more outlets for the fluid located at an end of each of the plurality of second pressor elements (5). 4). The machine of claim 2 or 3, wherein the means for injecting (7, 8, 9) comprise at least one infeed conduit (9) for the fluid, which at least one infeed conduit (9) is afforded internally of each of the second pressor elements (5). 5). The machine of any one of the preceding claims, wherein each of the plurality of second pressor elements (5) is mobile and can assume a third position, in wliich a pressed workpiece is expelled and in which each of the second pressor elements (5) exhibits an end which is very close to the face of the mould (2). 6). The machine of any one of the preceding claims, wherein the face of the mould (2) is flat, horizontal, upwards-facing and perpendicular to the througli- cavities (3). 7). The machine of any one of the preceding claims, comprising a loading device provided with at least one mobile drawer (15) having a lower opening for material to exit, which lower opening is occupied by one or more rotating elements (18) bearing a plurality of radial proj ections . 8). The machine of any one of the preceding claims, wherein each second pressor element (5) exhibits one or more lateral outlets (13') for distribution of a substance on internal walls of a tlirough-cavity of the plurality of through-cavities (3). 9). The machine of any one of the preceding claims, comprising means (11, 12) for heating one or more of: the mould (2); the first pressor element (4), the plurality of second pressor elements (5). 10). A process for manufacturing workpieces in loose pressed material wherein a punch runs inside a filling cavity containing the material, with a first run in which the second pressor element presses the material and a return run in which a hot active fluid exits from an external lateral surface of the second pressor element, which hot active fluid is distributed thinly over a internal surface of the filling cavity.

Inventors: BENEDETTI PAOLO, BENEDETTI, PAOLO
Applicants: BENEDETTI PAOLO, IMAL SRL, BENEDETTI, PAOLO, IMAL S.R.L.
Application year: 2001
Main classification: B27N3
IPC codes: B27N3, B27N5