EP1591232A1

EP1591232A1 - Machine for the production of tubular bodies

Info

Publication number: EP1591232A1
Application number: EP03769512A
Authority: EP
Inventors: Jesus Sanchez Renasco; José Maria Sanchez Renasco
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-10-30
Filing date: 2003-10-30
Publication date: 2005-11-02

Abstract

Machine for the manufacture of tubular bodies consisting of an unwinder (1) in which are installed a number of spools (4) mounted on their respective independent shafts; a heating tunnel (9), aided by a hot air generator (12), is mounted after the said unwinder (1) in a lateral and oblique position; strips (5) accede to the front side of a fixed mandrel (10), both in an angular and an axial direction, and are mounted on projections of a support (15) to which the said strips accede tangentially and obliquely; said strips are drawn by a planar belt (14) which causes them to slide such that they partially overlap the mandrel (10) which is refrigerated to facilitate rapid plastic welding as well as aided by a lubricating liquid impregnator to facilitate the slip of the obtained tubular body over the mandrel; the said continuous tubular body being cut by a cutting device situated beyond the extreme end of the said mandrel (10).

Description

SUBJECT MATTER OF THE INVENTION

This invention relates to a machine which has been especially designed for the manufacture of tubular bodies, specifically cylindrical bodies which can be used as containers for various types of products in granular, powder or paste form, and which can also be used as formwork members in the context of construction for the production of cylindrical columns.
As a starting material the machine uses various continuous sheets or strips which combine raw materials or a base of plant and/or synthetic fibres combined with multiple polymers, grouping them into a single complex or strip which is helically round and heat welded to produce the intended cylindrical tubular body.
This invention also has the quality of incorporating means for heating the strips, which is required in order to bring about softening of the plastics material included in the strip and their consequent fusion or heat welding to form the intended tubular body.
The invention therefore relates Lo the quality of obtaining a drastic reduction in the size of the machine or plant, with the consequences deriving therefrom from the point of view of making use of the space in which the said machine is located.

BACKGROUND TO THE INVENTION

The Applicant is the proprietor of the patent of invention applied for in Spain under number P8803814, which describes a process for the manufacture of tubular containers and items of flat geometry.
In that patent of invention the existence of containers and items obtained from sheets or layers of fibres or non-fibrous materials, such as paper and board or kraft fibre, in a number which varies according to the thickness which it is desired to confer upon the walls of the container or item which is to be obtained, in which the said sheets are joined together by adhesion or adhesive products to form a body which in the specific case of tubular containers is subjected to rolling into a spiral, while in the case of an item having a flat geometry is finished by cutting and punching, is known.
In the said patent of invention, in order to eliminate the problems inherent in the use of adhesive it is provided that the sheets of paper or the like mentioned above are combined with plastics sheet in such a way that permanent attachment between the layers of the container or the flat item is achieved through heat welding of the plastics material.
Obviously the term "tubular containers" includes any type of container as such obtained using this kind of material, such as the cylindrical tubular bodies used as formwork for producing columns, which are also cylindrical, or any other practical support in which a body having these characteristics is required.

DESCRIPTION OF THE INVENTION

The machine for the manufacture of tubular bodies provided by the invention has been specially designed to produce cylindrical tubular bodies using the process according to the said patent of invention, specifically using raw materials based on plant and/or synthetic fibres combined with multiple polymers, configured into a strip or complex which may also incorporate a sheet of aluminium within it.
With the aim of achieving better use of space the invention also provides for a plurality of heating units located in the immediate vicinity of a mandrel within the said tunnel, specifically one for each strip which has to be heated, in such a way that by keeping the strips at a suitable distance from each other by means of an appropriate guide, despite the fact that they are moving together onto the mandrel, sufficient space is left for positioning the heating units between the same in the vicinity of the mandrel.
More specifically, the machine for the manufacture of tubular bodies to which the invention relates is constructed on the basis of a fixed cylindrical mandrel, that is one which is immobilised in both rotation and in the axial direction, of a diameter which is consistent with the diameter of the tubular body which has to be obtained, and which is hollow and provided with cooling means, the purpose of which will be described below.
The said mandrel is intended to receive a plurality of strips which partly overlap on the same, simultaneously in an oblique arrangement and longitudinally out of phase, these strips being delivered by corresponding spools independently mounted on an unwinder and which reach the mandrel after first passing through a heating tunnel assisted with a hot air generator which is orientated laterally and obliquely with respect to the said panel in the initial part thereof and which causes adequate heating of the strips so that the plastics material included in them softens and adopts a condition of thermal adhesion in the overlapping part between the sheets, producing permanent adhesion almost immediately thanks to the cooling system with which the mandrel is provided.
Tension in the strips is produced by a drawing device, based on a flat part which acts over the entire periphery of the mandrel, with the bundle of strips matching the shape of the latter placed in between, causing the strips to be drawn along with simultaneously sljppage of the same over the mandrel, which as a result of the inclination of the said strips gives rise to helical rolling of the same on the mandrel with simultaneous longitudinal displacement of the tube produced along the same.
The mandrel is projectingly mounted on a supporting structure at its end corresponding to the entry of the strips, in such a way that the tubular body obtained leaves freely from the other extremity of the mandrel, where a cutting device subdivides it into sections of predetermined length.
Lack of adhesion between the plastics material incorporated in the strips, generally a polymer, and the mandrel is ensured by cooling of the said mandrel, and to assist slipping of the strips over the mandrel it is provided that a lubricating liquid which acts as a lubricant between the surface of the strips and the surface of the mandrel is delivered to the same in the area where the strips are received.
Nevertheless the lack of adhesion between the material constituting the tubular body and the mandrel can be achieved by other means, specifically the following:

Cooling of the mandrel to frosting point.
Establishing an air cushion around the mandrel, by pipes inclined in the direction of rolling of the strips.
Treating the mandrel with Teflon-3.
Simultaneously providing an auxiliary strip of silicone constituting the medium for support and slipping on the mandrel simultaneously for the various strips forming the tubular body,

The strips are delivered independently from a feed unwinder, in which each spool is mounted on its own axis, rotating independently of the others, in order to maintain its linear movement substantially uniform, and they may have different angular velocities according to the different diameters of the spools used, each spool also being assisted by an auxiliary spool which enables the feed to the machine to be replaced substantially rapidly when the first spool is used up.
The physical independence between the axes of the various spools in turn makes it possible to absorb the differences in linear velocity between the respective strips brought about as a result of the different depths of the same wound on the mandrel.
Another object of the invention is to achieve better use of space in that a plurality of heating units, specifically one for each strip which has to be heated, in the immediate vicinity of the said mandrel, and in the form of a tunnel, in such a way that by keeping the strips at a proper distance from each other by means of a suitable guide for the same, despite the fact that they are moving together onto the mandrel, leave sufficient space in the vicinity of the same for the location of heating units between them with the result that there is a minimum, virtually negligible, occupation of space by the heating units and the mandrel can be located effectively adjacent to the unwinder.
Each of the aforesaid heating units may comprise a pipe for blowing high temperature pressurised air, in the form of a pipe which widens corresponding to the width of the strip and is located transversely with respect to the latter, in which case the pressurised air circuit may incorporate a coil housed within a heater in which heating of the air up to temperatures which can reach 300°C can be achieved in such a way that blowing the pressurised air onto the conLinuous strips causes instantaneous heating of the same to the working temperature considered appropriate.
Optionally the said pressurised hot air outlets may be replaced by burners located directly in the vicinity of the continuous strips, which may be gas-fired, or infrared.

DESCRIPTION OF THE DRAWINGS

To supplement the description provided and in order to assist better understanding of the features of the invention this description is accompanied as an integral part thereof by a set of drawings in which the following are represented by way of illustration and without restriction:
Figure number 1. Shows a diagrammatical view, in plan, of the machine for the manufacture of tubular bodies comprising the subject matter of this invention, as a whole, in relation to a machine for the manufacture of tubular bodies.
Figure number 2. Shows a detail of the unwinder in perspective.
Figure number 3. Shows, again in a perspective view, a partial detail of the heating tunnel, with a view of the entry of the strips into it.
Figure number 4. Shows another perspective view of the heating tunnel, on the side opposite that shown in Figure number 3.
Figure number 5. Shows a partial and top view of the extremity of the mandrel where the various strips gain access to it and on which the drawing device acts.
Figure number 6. Corresponds to a lateral perspective view of the same area of the mandrel in which the partial overlapping between the strips may be seen.
Figure number 7. Shows a detail of the said strip drawing device in perspective.
Figure number 8. Shows a diagrammatical view in plan of a machine for the manufacture of tubular bodies constructed in accordance with this embodiment.
Figure number 9. Shows a detail in perspective of the part of the machine shown in Figure number 8, incorporating the features of the second embodiment of the invention.
Figure number 10. Finally corresponds to a diagrammatical view of a lateral elevation of the whole shown in Figure number 9.

PREFERRED EMBODIMENT OF THE INVENTION

Having regard to Figures numbers 1 to 7, it will be seen that the machine for the manufacture of tubular bodies provided incorporates an unwinder (1), shown in detail in Figure number 2, in which a plurality of shafts (3), which are independent of each other, are mounted on a supporting frame (2) and are designed to receive the corresponding spools (4) delivering continuous strips (5) of plasticised paper, each main spool (4) having at least one auxiliary spool (6) designed to remain in reserve to eliminate the machine dead time when the main spool (4) runs out, at which time the initial extremity of the supplementary spool (6) is attached to the terminal end of the strip (5) by means of double-sided adhesive (7).
The various strips (5) are suitably guided by means of rollers (8) or by any other means to a heating tunnel (9) which opens out in the vicinity of the mandrel (10).
Said heating tunnel (9) is provided with internal separators (11) which keep strips (5) suitably apart, being assisted by a hot air generator (12) which engages the said tunnel (9) laterally and obliquely and which with the aid of a fan (13) provides air to the initial part of tunnel (9) at a temperature of between 160°C and 200°C, in such a way that a temperature of between 140°C and 190°C is maintained at the outlet from tunnel (9) and is sufficient for the plastics material, specifically polyethylene, incorporated in strips (5) to be in a thermal condition in which it adheres to both the other sheet of polyethylene and to any other sheet in the complex.
On leaving tunnel (9) strips (5) reach mandrel (10) obliquely, being offset in the axial direction of mandrel (10), as may be seen specifically in Figure number 6, but largely overlapping, with a drawing device comprising a planar belt (14) acting externally on strips (5) and comprising mandrel (10), located at this initial extremity of mandrel (10), the static member causing slip of the said strips (5) about mandrel (10) with parallel axial displacement of the same due to their inclinations, that is causing helical winding of the strips onto the mandrel with parallel axial displacement of the same along the said mandrel (10).
As previously mentioned, mandrel (10) is held static, in both rotation and in the axial direction, being secured to the structure of the machine at its initial extremity through a robust support (15) in such a way that its terminal extremity projects in order to permit free departure of cylindrical tube (16) already formed, and with a cutting mechanism, not shown, being located beyond the said free extremity of mandrel (10) for suitable subdivision of the continuous tube produced.
Mandrel (10) is coolcd, having for this purpose an inlet (17) and an outlet (18) for water in order to prevent the high temperature at which strips (5) reach said mandrel (10) from causing adhesion of the same to mandrel (10) and also a lubricating liquid facilitating surface slip of the strips (5) with respect to the repeatedly mentioned mandrel (10) is applied thereto in this initial part of the said mandrel (10), which lubricating liquid has an oily nature and can be applied dropwise or by any other type of impregnator.
The device for drawing strips (5) over mandrel (10) comprises, as already stated previously, a broad planar annular belt (14) surrounding the perimeter of mandrel (10) extending between two cylinders (19) having parallel axes mounted on both sides of mandrel (10).
These two parallel axis cylinders (19) may be driven independently and synchronously through corresponding motors housed in base (20) supporting the same, or the said drive may be applied to only one of the cylinders (19), moving the other cylinder synchronously with it through transmission provided by planar belt (14), and mechanical or hydraulic motors may be used in each case.
Because belt (14) exerts strong tension on cylinders (19) with a tendency for the latter to approach each other, it is provided that a stabiliser bar (21), which is preferably telescopic, that is of a length which can be adjusted by means of a screw/nut system, which also incorporates an activating wheel (22), is provided between the upper free extremities of the same, that is of cylinders (19), in such a way as not only to ensure stability of the axes of the cylinders (19) but also to adjust the tension in planar (14), that is the pressure of the same on mandrel (10).
With reference to the object illustrated in Figure numbers 8, 9 and 10 corresponding to a second embodiment of the invention, it will be seen in Figure number 8 that the machine incorporates an unwinder (31) on which a plurality of shafts (33) which are independent of each other are mounted on a support (32) and are intended to receive corresponding spools (34) delivering continuous strips (35) based on the plant and/or synthetic fibres combined with multiple polymers which were mentioned previously, each main spool (34) having at least one auxiliary spool (36) designed to remain in reserve in order to eliminate the machine dead time when the main spool (34) runs out, at which time the initial extremity of the supplementary spool (36) is attached to the terminal extremity of strip (35) by means for example of double-sided adhesive.
After being subjected to a stage of heating by a mechanism which in the diagrammatical illustration in Figure number 8 has reference (39), strips (35) reach mandrel (40) obliquely, and are therefore offset in an axial direction, as may be seen specifically in Figure number 9, but largely overlapping, there being a drawing device comprising a planar (41) located at this initial extremity of mandrel (40) which by acting on strips (35) and as the result of mandrel (40) being a static member causes slip of the said strips about mandrel (40) with parallel axial displacement of the same caused by their specific inclinations, that is bringing about helical winding of the strips on mandrel (40) with parallel axial displacement of the same along the latter, thus continuously forming the tube (42) which iL is desired to obtain.
Also, according to a preferred example of this second embodiment of the invention, a pipe (43) is located beneath each one of the continuous strips (35) to blow air under pressure at high temperature, a temperature which may reach 300°C, specifically at an appropriate temperature for the plastics material, specifically polystyrene, incorporated in strips (3b) to be in a thermal condition such as to adhere to another sheet of polystyrene or any other layer of the complex.
For feeding pipes (43) provision is made for the use of a heater (44) within which there is a coil (45) for circulation of the air reaching pipes (43), pressurised by fan (46), in such a way that heater (44) can be located at a convenient distance from heating member (39) as a whole, that is from outlets (43), thus having little effect on the occupation of space, which results in more rational utilisation of the same.
As mentioned previously, pipes (43) for blowing pressurised hot air may be replaced by burners located directly adjacent to strips (35), as gas-fired burners or infrared heaters.

Claims

A machine for the manufacture of tubular bodies which uses as a raw material a plurality of strips, each of these based on a plurality of layers obtained from plant and/or synthetic fibres, combined with multiple polymers, with the possibility of the incorporation of layers of aluminium, these strips being intended to be wound helically with partial overlap to form a tubular body in which the various strips are permanently attached together by heat welding of their plastics component, preferably a polymer, characterised in that it comprises a mandrel (10) which is fixed in both the angular direction and the axial direction, projectingly mounted through its initial extremity on a support (15) and designed to receive tangentially and obliquely a plurality of strips (5) acting together with the said fixed mandrel (10), a drawing device comprising a planar belt (14) surrounding the mandrel (10) with a group of strips (5) in between brings about surface slip of the latter over the mandrel, causing both rolling and axial displacement of the said strips (5).
A machine for the manufacture of tubular bodies according to the first claim, characterised in that immediately before the mandrel (10) it incorporates a tunnel (9) for heating the strips (5), through which the latter pass through, the tunnel (9) being assisted by a generator (12) of hot air provided by a fan (13), the generator (12) engaging the tunnel (9) laterally and obliquely in the vicinity of the extremity thereof in order that the strips (5) may enter.
A machine for the manufacture of tubular bodies according to the preceding claims characterised in that the strips (5) are delivered by an unwinder (1) provided with a plurality of independent shafts (3) for mounting the corresponding spools (4) delivering the corresponding strips (5), it being provided that each main spool (4) acts together with at least one auxiliary spool (6) mounted on an axis parallel to the first spool and which comes into operation when the latter runs out.
A machine for the manufacture of tubular bodies according to the preceding claims characterised in that the mandrel (10) is cooled, having for the purpose an inlet (17) and an outlet (18) for cold water in order to prevent the strips (5) from adhering to the said mandrel (10) when they come into contact with the latter.
A machine for the manufacture of tubular bodies according to the preceding claims, characterised in that an applicator for a lubricating liquid, of an oily nature, to facilitate slip of the strips (5) over the mandrel (10), is located in the initial part of the mandrel (10), specifically in the part where the strips (5) come into contact with the same.
A machine for the manufacture of tubular bodies according to the first, second and third claims, characterised in that optionally and in order to avoid adhesion of the strips (5) to the mandrel (10) when they come into contact with the latter, the said mandrel (10) is provided with means of cooling up to frosting, an air cushion surrounding the same and a treatment with Teflon-3, the possibility of using an auxiliary strip of silicone which is wound onto the mandrel (10) under the strips (5) comprising the tubular body being also envisaged.
A machine for the manufacture of tubular bodies according to the preceding claims, characterised in that the belt (14) surrounding the initial part of the mandrel (10) and which contributes to the drawing device for the group of belts (5) extends on both sides of the mandrel (10) and is connected to two cylinders (19) having parallel axes which act as drawing devices for the said belt (14), which are suitably motor-driven and synchronised and which also have means (21) for tensioning the said belt (14).
A machine for the manufacture of tubular bodies according to the preceding claims, characterised in that in a second embodiment, as a replacement for the heating tunnel for the continuous strips (35) which brings the said strips into a thermal condition such that they adhere to each other, provision is made for the use of a plurality of heating units (39), one for each continuous strip (35), located between them and in a position such that the unwinding of these strips (35) takes place in a position of maximum proximity to the mandrel (40), it being provided that the latter reach the mandrel (40) tangentially with a degree of angular displacement sufficient to permit positioning of the said heating units (39) between them.
A machine for the manufacture of tubular bodies according to the eighth claim, characterised in that the heaLing units (39) take the form of pipes (43) blowing under pressure which blow air transversely with respect to the said continuous strips (35), at high temperature, which can reach 300°C, the said pipes (43) being fed from a heating unit (44) through which there passes a coil (45) in which the air pressurised by a fan (46) circulates.
A machine for the manufacture of tubular bodies according to the eighth claim, characterised in that optionally the heating units (39) each comprise burners at a suitable distance from the continuous strips (35), burners which may be gas-fired, infrared or similar.