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Title:
ELEMENT FOR TRANSFERRING DOSED BODIES OF POLYMERIC MATERIAL BY DROPPING FOR COMPRESSION MOLDING LINES
Document Type and Number:
WIPO Patent Application WO/2018/050740
Kind Code:
A1
Abstract:
An element for transferring dosed bodies of polymeric material in the melted state for compression molding lines, which comprises an internal guiding duct (41) which extends along a first axis (A) that connects an inlet (43) for a body of polymeric material (D) in the melted state to an outlet (44) of the same body; the transfer element is connected to means of feeding air or other fluid to the guiding duct, and an internal tubular surface of the guiding duct comprises a plurality of holes (45) that are connected to the feeder means through respective channels (46) that pass through the side wall of the duct (41); the channels extend from the respective hole in the side wall substantially along a second axis (B) which is oblique with respect to the first axis of the guiding duct (A).

Inventors:
MARASTONI DANIELE (IT)
CARATI MARCO (IT)
Application Number:
PCT/EP2017/073126
Publication Date:
March 22, 2018
Filing Date:
September 14, 2017
Export Citation:
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Assignee:
SACMI IMOLA SC (IT)
International Classes:
B29C31/04; B29C43/34
Domestic Patent References:
WO2001066327A22001-09-13
WO2009027777A12009-03-05
Foreign References:
EP2404732A12012-01-11
US3976414A1976-08-24
EP2404732A12012-01-11
Attorney, Agent or Firm:
MODIANO, Micaela (IT)
Download PDF:
Claims:
CLAIMS

1. An element (40) for transferring dosed bodies of polymeric material in the melted state for compression molding lines, which comprises an internal guiding duct (41, 141, 241, 341, 441) which extends along a first axis (A) that connects an inlet (43, 143, 243, 343, 443) for a body of polymeric material in the melted state (D) to an outlet (44, 144, 244, 344, 444) of the same body, said guiding duct (41 , 141 , 241, 341, 441) being adapted to guide said body (D) during descent from said inlet (43, 143, 243, 343, 443) to said outlet (44, 144, 244, 344, 444), said transfer element (40) being connected to means of feeding a fluid, preferably air, to said guiding duct, an internal tubular surface (47, 147, 247, 347, 447) of said guiding duct comprising a plurality of holes (45, 145, 245, 345a, 445a-445b) that are connected to said feeder means through respective channels (46, 146, 246, 346, 446) that pass through the side wall (48, 148, 248, 348, 448) of said duct (41, 141, 241 , 341, 441), characterized in that at least one plurality of said channels (46, 146, 246, 346, 446) extends from the respective hole (45, 145, 245, 345a, 445a) in the side wall (48, 148, 248, 348, 448) substantially along a second axis (B, C) which is oblique with respect to said first axis of the guiding duct (A), so as to form a vortex of said fluid introduced into said guiding duct through said plurality of channels by the fluid feeder means.

2. The transfer element according to one or more of the preceding claims, wherein said second axis (B, C) forms a first acute angle (a) with its projection on a first geometric plane (PI) perpendicular to said first axis

(A) .

3. The transfer element according to one or more of the preceding claims, wherein said second axis (B) forms a second acute angle (β) with its projection on a second geometric plane (P2) tangential to said internal tubular surface (47, 147, 247, 347, 447) at the point where said second axis

(B) intersects said internal tubular surface (47).

4. The transfer element according to one or more of the preceding claims, wherein said channels (46, 146, 246, 346, 446) are substantially cylindrical and have a diameter comprised between 0.01 and 100 mm.

5. The transfer element according to one or more of the preceding claims, wherein said holes (45, 145, 245, 345a, 445a) are arranged at levels, measured parallel to the first axis A, which are mutually spaced apart by from 0.01 to 100 mm, wherein the distance between the centers of the holes (45, 145, 245, 345a, 445a) at the same level is comprised between 0.01 mm and 100 mm and the angular offset between the holes at a given level and those at the level directly above or below along the first axis (A) is comprised between 0° and 180°.

6. The transfer element according to one or more of the preceding claims, wherein said internal tubular surface (47, 147, 247, 347, 447) of said guiding duct comprises a substantially cylindrical portion that includes said outlet (44, 144, 244, 344, 444) of the body of polymeric material, and a substantially conical portion that includes said inlet (43, 143, 243, 343, 443) of the body of polymeric material (D).

7. The transfer element according to one or more of the preceding claims, wherein said side wall (48, 148, 248, 348, 448) is a monolithic body (48, 148, 248) or comprises two coaxially superimposed monolithic bodies (348a, 348b) or comprises a monolithic body (448) and a stack (460) of flat rings, some of said flat rings (461) comprising a plurality of grooves (462) that are adapted to make said fluid of the fluid feeder means pass toward the inside of the stack (460).

8. The transfer element according to one or more of the preceding claims, wherein said internal tubular surface (347) further comprises a plurality of holes (345b) for the evacuation of the fluid which are optionally connected to means of aspirating said fluid through respective evacuation channels in order to avoid the accumulation of said fluid downstream of said outlet (344).

9. The transfer element according to one or more of the preceding claims, wherein there is, around said internal tubular surface (247, 347, 447), at least one annular slit (271, 371, 471) that is partially formed by a convex surface blended with said internal tubular surface (247, 347, 447) and connected to said fluid feeder means or to other fluid feeder means.

10. The transfer element according to one or more of the preceding claims, wherein said transfer element (40) is connected to an arm (21) of a carousel (20) that can rotate about a third axis (C) that is substantially parallel to said first axis (A).

11. A carousel (20) for transferring dosed bodies of polymeric material to the molds of a compression molding carousel (30), characterized in that it comprises a plurality of transfer elements (40) according to one or more of the preceding claims along the peripheral region of said transfer carousel (20).

12. A compression molding line (1) comprising a dispenser (11, 12) of dosed bodies of polymeric material, a molding carousel (30) that rotates continuously and is provided, along its peripheral region, with a plurality of molds (31), each mold (30) comprising a hollow female mold part (32) and a corresponding male plug (33), which can move toward and away from each other in order to form by compression objects inside said molds (31) starting from said dosed bodies of polymeric material (D), said line (1) being characterized in that it comprises the transfer carousel (20) according to the preceding claim, which rotates continuously so that the respective transfer elements (40) describe a trajectory that is partially superimposed on the trajectory described by said molds (31).

13. A method of continuous transfer of dosed bodies of polymeric material in the melted state into a hollow female mold part (32) of a movable mold (31) in a compression molding line, which comprises the steps of:

- dispensing a dosed body of polymeric material in the melted state (D); - transferring the dosed body (D) into a substantially rectilinear guiding duct (41) that can move continuously along a substantially circular trajectory;

- passing through the guiding duct (41, 141, 241, 341, 441) on the part of the dosed body (D), during the movement of the guiding duct (41,

141 , 241, 341, 441) along its substantially circular trajectory;

- releasing the dosed body (D) from the guiding duct into a hollow female mold part (32) of a compression mold (31) that can move continuously along another substantially circular trajectory on which the substantially circular trajectory of the guiding duct (41 , 141, 241 , 341 , 441) is superimposed, the release occurring in the region of overlap of the two substantially circular trajectories;

characterized in that said step of passing through comprises a step of generating a vortex of fluid within said guiding duct through channels (46, 146, 246, 346, 446) that lead into said guiding duct by way of respective holes (45, 145, 245, 345a, 445a-445b) and each extend along a respective axis (B, C) that is oblique with respect to the axis of the guiding duct (A).

Description:
ELEMENT FOR TRANSFERRING DOSED BODIES OF POLYMERIC MATERIAL BY DROPPING FOR COMPRESSION MOLDING LINES

The present invention relates to an element for transferring bodies of polymeric material in the melted state by dropping, for compression molding lines, in particular for transferring such bodies from a dispenser of polymeric bodies of discrete length to a respective mold cavity.

The invention also relates to a transfer carousel that comprises such element and a compression molding line that comprises such carousel.

It is known to form a polymeric object by way of compression molding, carried out by inserting a male plug, which constitutes the male mold element, into a hollow female mold part, which constitutes the female mold element and which contains a body of polymeric material in the melted state, in particular in a paste-like state, of equal mass to that of the object that it is desired to form. The material is typically a thermoplastic resin.

The male plug and the hollow female mold part are contoured so as to leave an interspace between them when the former is inserted into the latter. Such interspace is filled by the polymeric material that constitutes the body as a result of the insertion of the male plug into the female mold part, thus forming the final object. Such object can consist of a preform of a bottle, which after compression molding can be picked up in order to be fed to another processing station, for example a heat treatment station, an oven and/or a blower, or in order to be stored.

These lines can carry out the molding continuously, by having the molds mounted on a rotating compression molding carousel that carries a plurality of hollow female mold parts on its peripheral region and, above them, a plurality of corresponding male plugs that rotate integrally with the female mold parts about the central vertical axis of the carousel.

Such molding carousel is associated, upstream, with a device for emitting bodies of polymeric material in a dosed quantity, here also referred to as doses, which are obtained starting from an extruder that produces a continuous extruded mass of polymeric material in the melted state which exits from a dispensing nozzle. This extruded element made of polymeric material exiting from the dispenser is divided by way of a cutting device so as to obtain the doses of polymeric material.

The doses are then picked up by transfer elements arranged on a rotating transfer carousel, which are adapted as well to release each dose of plastic material taken from it into a respective hollow female mold part of the molds of the molding carousel. Such transfer elements comprise a transfer duct, in which the dose that the manipulation element has taken from the dispenser is guided in its descent, for example, through a concave wall that strikes the dose immediately after this has been released from the dispenser, pushes it with a horizontal component, and guides it toward the transfer duct.

Conventional compression molding lines are not devoid of drawbacks, among which is the fact that, while it is passing through such transfer duct, the dose of polymeric material can rub or bump against its inner surface, thus degrading the shape of the dose, altering its orientation and/or slowing its descent toward the respective hollow female mold part of the compression molds.

A solution to solve such drawback has been proposed in EP 2404732

Al, which teaches to have the transfer duct at a greater pressure than that of the compression mold, for example by closing the duct in an upper region and introducing compressed air through radial holes made in the side walls of the duct.

This solution also is not without drawbacks, which include the fact that the gaseous stream applied to the dose in the transfer duct is directed exclusively radially with respect to the dose, leading to a non-optimal use of the duct.

The aim of the present invention is to provide an element for transferring bodies of polymeric material in the melted state by dropping, for compression molding lines, and also a transfer carousel that comprises such element and a compression molding line that comprises such carousel, which are capable of improving the known art in one or more of the above mentioned aspects.

Within this aim, an object of the invention is to provide an element for transferring bodies of polymeric material by dropping, for compression molding lines, which is adapted to facilitate an accelerated or delayed transfer of the dose inside the duct of the transfer element.

Another object of the invention is to provide an element for transferring bodies of polymeric material by dropping, for compression molding lines, which is adapted to reduce the angle of transfer of the dose toward the molding carousel, thus increasing the number of active molds and therefore the speed of the machine itself.

Another object of the invention is to provide an element for transferring bodies of polymeric material by dropping, for compression molding lines, which is adapted optionally to create a cushion of air or of other fluid around the dose during the transfer.

A still further object of the present invention is to overcome the known drawbacks in a different manner to the existing solutions.

Another object of the invention is to provide an element for transferring bodies of polymeric material in the melted state by dropping, for compression molding lines, and also a transfer carousel that comprises such element and a compression molding line that comprises such carousel, which are highly reliable, easy to implement and maintain, and low cost.

This aim and these and other objects which will become better apparent hereinafter are achieved by an element for transferring bodies of polymeric material in the melted state for compression molding lines according to claim 1 , and also by a transfer carousel according to claim 11 , by a compression molding line according to claim 12 and by a method according to claim 13. Further characteristics and advantages of the invention will become better apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the element for transferring bodies of polymeric material in the melted state for compression molding lines, according to the invention, and also of a transfer carousel and a compression molding line which comprise such element, which are illustrated, by way of non-limiting example, in the accompanying drawings, wherein:

Figure 1 is a plan view from above of a compression molding line according to the invention;

Figure 2 is a side view of the line in the previous figure, at the region of intersection of the trajectories of the molding carousel and of the transfer carousel;

Figure 3 is a detailed side view of the dispenser of polymeric material and of the corresponding cutting device;

Figure 4 is a side view of a transfer element according to a first embodiment of the invention;

Figure 5 is a plan view from above of the transfer element in the previous figure;

Figure 5a is a detail view of Figure 5;

Figure 6 is a cross-sectional view taken along the line VI-VI of the transfer element in Figure 5;

Figure 7 is a side view of a transfer duct according to a second embodiment of the invention;

Figure 8 is an axial cross-sectional view of the transfer duct in the previous figure;

Figure 9 is a cross-sectional view taken along the line IX-IX of the transfer duct in Figure 7;

Figure 10 is an axial cross-sectional view of a transfer duct according to a third embodiment of the invention;

Figure 11 is a detail view of the previous figure; Figure 12 is an axial cross-sectional view of a transfer duct according to a fourth embodiment of the invention;

Figure 13 is an axial cross-sectional view of a transfer element according to a fifth embodiment of the invention;

Figure 14 is perspective view of one of the grooved rings of the transfer duct in the previous figure;

Figure 15 is a plan view from above of the grooved ring in the previous figure.

With reference to the figures, a continuous compression molding line according to the invention, generally designated by the reference numeral 1 for all the embodiments described, is particularly adapted to the forming of preforms in order to obtain containers made of polymeric material, such as bottles or phials.

In all the embodiments described, the line 1 comprises an extruder 11 , a dispenser 12, a cutting device 13, a transfer carousel 20 and a compression molding carousel 30.

The line 1 further comprises, angularly spaced apart from the transfer carousel 20 along the peripheral region of the molding carousel 30, a station (not shown) for extracting compression-molded objects from the molding carousel 30; these objects can subsequently be thermally conditioned, formed further by way of blow-molding, and/or stored.

The extruder 11 is conventional per se, and is adapted to heat the polymeric material to a temperature adapted to bring it to a melted state, more or less viscous, and to dispense it continuously through a nozzle 121 of the dispenser 12. The polymeric material can be a thermoplastic resin, preferably PET, and in this case the temperature to which such material is brought in the extruder in order to obtain the melted polymer can be comprised between 270°C and 300°C. Such temperature can be advantageously reduced by way of adapted heat exchangers to 230°C in output from the nozzle 121 so as to reduce the energy to be removed in the step of cooling the product and as a consequence speed up the machine, as described in WO 01/66327 A2 which is incorporated herein by reference.

By way of a cutting device 13 associated with the dispenser 12, the continuous extruded mass E of polymeric material in the melted state exiting from the nozzle 121 of the dispenser 12 is divided into a succession of dosed bodies D of polymeric material, here also referred to as doses, in a way that is known per se.

The cutting device 13, which is also known per se, can comprise one or more blades 131 which rotate with respect to a vertical axis and whose circular trajectory intercepts the axis of the dispensing nozzle 121 proximate to the latter, so as to cut the extruded mass E in a dose D at each pass of a respective cutter 131.

In all the embodiments described, the molding carousel 30 rotates continuously about a vertical central axis parallel to the axis G of the transfer carousel 20 and comprises a plurality of compression molds 31 that are angularly spaced apart along all the peripheral region of the carousel 30, and are made to rotate about the central axis of the carousel 30 along a circular path that extends on a horizontal plane. Each mold 31 comprises a lower hollow female mold part 32 and an upper male plug 33, which constitute respectively the female mold part and the male mold part of the mold 31 and can be moved mutually closer during the rotation of the carousel 30 in order to compress the dose D received by the hollow female mold part 32 by way of the penetration into such mold part of the male plug 33, and thus form the desired object made of polymeric material. Such object is preferably a preform, conventional per se, and is adapted to be used to provide bottles in thermoplastic resin by way of blow-molding. The preform obtained from the molds 31 is therefore a beaker-shaped object, provided with a neck with the final shape of the bottle to be obtained and with a hollow body that can be expanded by way of stretch-blow molding techniques that are conventional per se. In all the embodiments described, the transfer carousel 20, which rotates continuously about an axis G, comprises along its peripheral region a plurality of angularly equidistant transfer elements 40, which describe a substantially circular trajectory that is partially superimposed on the substantially circular trajectory described by the hollow female mold parts 32 of the molds of the molding carousel 30.

The transfer elements 40 are preferably connected to a central shaft by way of respective arms 21.

In all the embodiments described, each transfer element 40 of the dosed bodies D comprises an internal guiding duct 41, 141, 241, 341 or 441 that extends along a first axis A that connects an inlet 43, 143, 243, 343, 443 through the dosed body D to an outlet 44, 144, 244, 344, 444 of the same body D. The guiding duct 41 , 141 , 241 , 341, 441 is adapted to guide, during its drop from the dispenser, the dosed body D from the inlet 43, 143, 243, 343, 443 to the outlet 44, 144, 244, 344, 444 and it can be associated with means of conditioning temperature and/or humidity in order to improve efficiency.

The guiding duct 41 , 141, 241 , 341 , 441 is defined by a side wall 48, 148, 248, 348, 448 that surrounds the free internal volume of the duct 41 , 141 , 241, 341 , 441 and whose internal surface 47, 147, 247, 347, 447 is substantially tubular, for example cylindrical, frustum-shaped (as in the surface 147 of the second embodiment), flared (symmetrically or asymmetrically), and partially frustum-shaped/flared and partially cylindrical (as in the first, third, fourth and fifth embodiments).

Preferably, the flaring of the internal tubular surface 47, 147, 247,

347, 447 affects at least the upper part that leads to the inlet 43, 143, 243, 343, 443 so as to increase the extension of such inlet and thus facilitate the drop of the dosed body D into the guiding duct 41, 141, 241, 341, 441.

In a position adjacent to the inlet 43, 143, 243, 343, 443, externally to the guiding duct 41, 141, 241, 341 , 441, there can be a protruding concave wall 42 (shown only in the drawings of the first embodiment), which is adapted to bump against the dosed body D after this has been cut from the extruded mass released by the dispenser 12, pushing it with a horizontal component and thus guiding it toward the duct 41, 141 , 241, 341, 441. The concave wall 42 can optionally be provided with means of sliding using rollers, as described in WO 2009/027777 Al which is incorporated herein by reference.

Each transfer element 40 is connected to means of feeding a fluid, for example air, to the guiding duct 41, 141 , 241, 341 , 441, not shown, which can consist substantially of a generator of a flow of air or of another fluid, for example a fan or a compressor.

The internal tubular surface 47, 147, 247, 347, 447 of the guiding duct 41 , 141 , 241, 341, 441 comprises a plurality of holes 45, 145, 245, 345a, 445a-445b that are distributed substantially uniformly on at least part of the internal tubular surface 47, 147, 247, 347, 447. Such holes 45, 145, 245, 345a, 445a-445b communicate with the above mentioned fluid feeder means through respective through channels 46, 146, 246, 346, 446, 462 that pass through the side wall 48, 148, 248, 348, 448 of the duct 41 , 141 , 241 , 341 , 441. The peculiarity of these channels 46, 146, 246, 346, 446, 462 is that at least some of them extend starting from the hole and toward the inside of the side wall 48, 148, 248, 348, 448 substantially along a second axis B or C which is oblique with respect to the first axis A of the guiding duct 41 , 141, 241, 341 , 441, i.e. the directions of such second axes B do not intercept the axis A and, preferably, they are also not parallel to a geometric plane PI that is perpendicular to the axis A.

For example, in the first two embodiments in Figures 6-9, the holes 45, 145 are distributed uniformly and preferably offset along the entire internal tubular surface 47, 147 of the duct 41, 141, and all the corresponding channels 46, 146 lead into them with an axis B that is oblique with respect to the first axis A of the duct 41, 141. In the third embodiment in Figure 10, all the channels 246 lead into the holes 245 with an axis B that is oblique with respect to the first axis A of the duct 241, but the holes 245 are distributed uniformly and preferably offset only on a first tubular band of the internal tubular surface 247, in particular on the band 251 that leads to the inlet 243 of the dosed body D and which is substantially frustum-shaped. The second, remaining, tubular band 252 on the other hand has no holes up until the outlet 244 and is substantially cylindrical.

In the fourth embodiment in Figure 12, only some of the channels 346 lead into the holes 345a with an axis B that is oblique with respect to the first axis A of the duct 341. Such holes 345a are distributed uniformly and preferably offset only on a first tubular band of the internal tubular surface 347, in particular on the band 351 that leads to the inlet 343 for the dosed body D and which is substantially frustum-shaped.

The second, remaining, tubular band 352 of the surface 347, substantially cylindrical, on the other hand has a plurality of holes 345b for evacuating the air or other fluid, and optionally are connected to an intake pump and are adapted to direct the stream of air or other fluid away from the first axis A, differently from the holes 345a through which, on the other hand, the air or other fluid is injected toward the axis A. The purpose of such evacuation holes 345b is to prevent a falling dose D from rebounding or not completing the descent once it has entered the cavity of the mold, owing to too much thrust on the high part of the dose D or owing to the presence of the air or other fluid injected into the duct 341 which reaches the cavity of the mold before the dose and creates a cushion between the bottom of the cavity of the mold and such dose D, thus impeding its descent. Through holes 345b for evacuating the air or other fluid injected via the holes 345a, it is possible in this way to add further evacuation channels of the air or other fluid beyond the outlet 344.

The evacuation channels that connect the holes 345b to the outside of the duct 341, which are not shown, extend along substantially radial axes, but in other embodiments they can be inclined or partially radial and partially inclined, for example along a direction that converges toward the axis A away from the outlet 344.

In the example shown, the side wall 348 of the duct 341 is defined by two superimposed monolithic bodies 348a and 348b which comprise respectively the first tubular band 351 and the second tubular band 352 of the internal tubular surface 347 of the duct 341.

In the fifth embodiment shown in Figure 13, the duct 441 is at least partially constituted by a stack 460 of flat rings. Some of such rings 461 have, on at least one of the two flat faces, a plurality of grooves 462 that are adapted to make the air or the fluid fed from outside pass toward the inside of the ring 461. Such grooves 462 extend on a respective third axis C with the same inclination with respect to the tangent at the point of intersection of such third axis C with the inner circumference of the ring 461. In the case shown, the third axes C are parallel to a plane P 1 that is perpendicular to the first axis A of the duct and are skewed with respect to such axis A, so that, when the rings 461 are stacked in the stack 460, the grooved rings define skewed channels and through openings 445b that pass from the internal tubular surface to the stack 460 and on to the external surface of the stack 460.

Alternatively, the third axes C could all have a radial direction toward the first axis A, so as to define radial channels in the stack 460 at the grooved rings of the stack.

In the fifth embodiment, the portion of the duct 441 that is composed by the stack 460 affects the lower band 452 of the channel 441, while the upper band 451 which leads to the inlet 443 is formed by a monolithic body 448, in which the through channels 446 are provided and against which the stack 460 is clamped so as to define the internal tubular surface 447 with no points of internal surface discontinuity between the internal tubular surface of the monolithic body 448 and that of the stack 460.

The channels 446 lead into the holes 445a with a second axis B which is oblique with respect to the first axis A of the duct 441. Such holes 445a are distributed uniformly and preferably offset.

Advantageously, around the internal tubular surface of the guiding duct 247, 347, 447 there can be an annular slit 271, 371, 471, for example by way of an annular chamber 272, 372, 472 defined between a bushing 270, 370, 470 and a convex surface blended with the internal tubular surface 247, 347, 447. Such annular chamber 272, 372, 472 can be connected with the means of feeding the air, which also feed the channels 246, 346, 446, or with other means of feeding air, so as to generate a "blade" of air, substantially conical, that converges toward the axis A of the duct 241, 341, 441 in the direction of the outlet 244, 344, 444. The puffs can have different starts, ends, duration, and feed pressure.

A similar annular chamber 373 and a corresponding annular slit can also be defined in one or more intermediate positions of the guiding duct of the dosed body D, for example between the two monolithic bodies 348a, 348b that form the guiding duct 341.

Through the annular slits 271 , 371, 471 thus defined, it is possible to make the dosed body D slide better by way of a Coanda effect.

As can be seen from the embodiments described, during the passing of the dosed body D through the guiding duct 41, 141, 241, 341, 441 it is possible to generate a vortex of air or of another fluid introduced into the guiding duct 41, 141, 241, 341 , 441 through the channels 46, 146, 246, 346, 446 using the fluid feeder means. Such vortex, on the basis of the inclination of the channels defined during the manufacturing of the transfer element 40, can keep the dosed body D within the guiding duct 41, 141, 241 , 341, 441 or it can accelerate its expulsion from the guiding duct 41, 141 , 241, 341, 441.

In the first case, the gates at the outlet 44, 144, 244, 344, 444 of the guiding duct 41 , 141, 241, 341 , 441 which in the known art are used to stop the fall of the dosed body within the guiding duct or to release it into the hollow female mold part 32 of the compression mold can therefore actually be omitted.

In the second case, the production speed of the line 1 can be increased with respect to the known art.

The channels 46, 146, 246, 346, 446 are substantially cylindrical, with diameter comprised between 0.01 mm and 10 mm, but because they are skewed with respect to the axis A of the guiding duct 41 they make the holes 45, 145, 245, 345a, 445a oval, elongated and inclined with respect to the horizontal.

All of the above mentioned holes 45, 145, 245, 345a, 445a, or at least most of them, can be arranged substantially along a line describing a helix along at least part of the internal tubular surface 47, 147, 247, 347, 447 of the guiding duct 41 , 141, 241, 341 , 441. The helix preferably has a substantially constant pitch comprised between 0.01 mm and 250 mm, for example of at least 0.1 mm, and it optionally transitions from cylindrical to conical in the upper part in line with the upper flaring of the guiding duct 41, 141 , 241, 341, 441.

In general, the levels of the holes 45, 145, 245, 345a-345b, 445a-445b measured parallel to the first axis A are mutually spaced apart by between 0.01 mm and 100 mm, the distance between the centers of the holes 45, 145, 245, 345a-345b, 445a-445b at the same level is comprised between 0.01 mm and 100 mm, and the angular offset between the holes at one level and those at the subsequent or preceding level is comprised between 0° and 180°.

Each one of the channels 46, 146, 246, 346, 446 that are skewed with respect to the axis A, for example each one of the channels 46, 146, 246, 346, 446 of the flared or frustum- shaped band of the internal tubular surface 47, 147, 247, 347, 447 of the duct 41, 141, 241, 341, 441 , preferably defines a first acute angle a with its projection on a first geometric plane PI perpendicular to the axis A of the guiding duct 41, 141, 241 , 341, 441 and passing through the corresponding hole 45, 145, 245, 345a, 445a and, in the examples shown, lies in the half-space comprised between this plane PI and the inlet 43, 143, 243, 343, 443 of the guiding duct 41, 141, 241, 341, 441.

In alternative embodiments, which are not shown, the channels can instead lie in the half-space comprised between the above mentioned plane PI and the outlet of the guiding duct.

The axis B of the skewed channels 46, 146, 246, 346, 446 further define a second acute angle β with its projection on a second geometric plane P2, tangential to the internal tubular surface 47, 147, 247, 347, 447 of the guiding duct 41, 141, 241, 341, 441 at the point where the axis B of the channel 46, 146, 246, 346, 446 intersects such tubular surface 47, 147, 247, 347, 447.

The average speed of the air in output from the holes 45, 145, 245, 345a-345b, 445a-445b can be comprised between 5 m/sec and 400 m/sec, and the overall flow-rate by mass (considering all of the holes) can be comprised between 40 Nl/min and 2000 Nl/min. Optionally, an upper nozzle can be associated with the duct 41, 141, 241, 341, 441 for expelling the dosed body D from the duct when it is kept floating.

In practice it has been found that the device according to the invention fully achieves the set aim since it makes it possible to define a vortex in the ducts that guide the doses during the transfer thereof from the extruder to the compression molds, and a function of such vortex can be to slow the descent of the dose or to accelerate the fall thereof, based on the inclination and geometry of the channels for introducing the air or other fluid into the guiding duct.

The vortex further makes it possible to prevent the dose from adhering, or to reduce the adhesion, to the walls of the guiding duct during the transfer from the extruder to the compression mold.

The device, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In practice, the materials employed, as well as the dimensions, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. 102016000092917 (UA2016A006568) from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.