WO2002035915A1

WO2002035915A1 - Plastic film comprising protected water tubes

Info

Publication number: WO2002035915A1
Application number: PCT/GR2000/000031
Authority: WO
Inventors: Asterios D. Daios
Original assignee: Daios Asterios D
Priority date: 2000-11-03
Filing date: 2000-11-03
Publication date: 2002-05-10
Also published as: GR20000100385A

Abstract

The invention refers to a plastic film used in mulching applications which can be employed for covering vegetable and fruit plantations, cultivated in a linear fashion like asparagus, watermelons, strawberries etc. In such plantations is necessary that the plastic film used can be fixed on the cultivation line but it should also be easily withdrawn on a daily basis so that the cultivation line is revealed providing easy access to it so that the necessary work can be performed. The plastic film comprising protected water insertion tubes (1) carries along its sides protected water insertion tubes (9), each of which is entrapped into a protective tube (10) -both formed by the same plastic film (during the same production process by a combination of several weldings, cuts and foldings). During its use the two protected water insertion tubes (9) are filled with water distributing so the required weight to fix the plastic film. The plastic film comprising protected water tube (1) can additionally offer the alternative to use the protective tube (10) as a soil insertion pocket to provide the required weight for fixing the plastic film on top of the cultivation line.

Description

Plastic film comprising protected water tubes .

The invention refers to a plastic film used in mulching applications which can be employed for covering vegetable and fruit plantations, cultivated in a linear fashion like asparagus, watermelons, strawberries etc. In such plantations is necessary that the plastic film used can be fixed on the cultivation line but it should also be easily withdrawn on a daily basis so that the cultivation line is revealed providing easy access to it so that the necessary work can be performed.

The plastic film comprising protected water tubes (1) according to the present invention is produced from a plastic film of thickness up to 300μm and width (B) up to 4m. Two water tubes are produced during the manufacturing process using stripes of the film itself. Each of these tubes is entrapped in a protective tube (10) formed using the same plastic film (during an inline process by a combination of weldings, cuts and foldings) in such a manner that the end product has along its both sides protected water tubes (9). Effectively the water that is inserted into these tubes provides the required weight to fix the film on top of the cultivation line. The plastic comprising protected water tubes (1) additionally the option to put to put soil into the protective tubes for weight insertion purposes.

After the film comprising protected water tubes (1) has been laid on the field (or while it is being laid) the water tubes are filled with water being protected from any damage by the protective tubes (10). However in case the water tubes (9) are damaged the user has the option to fill the protective tube (10) with soil so that the film is not rendered useless.

Several solutions have been proposed and several innovations have been made towards the development of a plastic film, which has weight insertion structures along its both sides, so that the film is securely fixed qn top of the cultivation line. Most of them have been designed having soil as the weight insertion material in mind, since it is an abundant material on the field and it does not add any further cost.

Moreover several solutions have been proposed having water as the weight insertion material in mind, since it is a much easier to handle material compared to soil and it is also abundant on the fields.

The invention having the number 1002872 is such an invention, according to which by folding the ends of the film and by having complex welding patterns, small water insertion pockets are formed. There are also several proposals for the production of a film, which has small tubular chambers along both its sides either by folding the sides of the film or by welding a tube -of small diameter- along the sides of the film.

However several complications arise in all current solutions, that have water as the weight insertion material, both in the production of the film itself and the actual use, thus they have not been yet practically employed. The_. reason behind this fact is rather simple. Those films which have tubes along their sides that have been formed by folding and welding them, even if they have been flawlessly produced, they are vulnerable during transportation and use (there is not any means of protection for the tubes). In this case the tube walls have a maximum thickness of 200μm so the slightest external damage inflicted on the tube can have catastrophic consequences.

Other proposals include the production of films in which the tubes are welded on the film or they are inserted into it. These tubes are produced by a different process and usually with various materials (or combinations of them) clearly having thicker walls so that they are more durable compared to the actual film. This proposal solves the question of faults arising during production of the tubes as it appears in the previous solution but several other problems appear which pose serious restrictions to the production process, a) As known plastic films are wound in rolls of length from a few hundred to thousands of meters according to the user requirements and specifications.

When the tube is externally welded and due to the feet that it has a considerably bigger thickness compared to the actual film, local points of significantly bigger diameter develop. As a consequence it is rather difficult to wound such a film Moreover welding two components of different material composition can be a precarious process. Furthermore the transverse cut of the film during the roll change in the winding station of the production line could damage the tube and tear off the film parallel to the welding line. b) The insertion or welding of a tube has the disadvantage of requiring a separate production process adding a further cost to the total production cost. c) The tube produced in a separate production process has to be wound into jumbo rolls and that implies that specialised equipment must be used for the unwinding process and overall control as well as considerable quantities of scrap fijm are produced during the jumbo roll change.

The present invention heads towards employing water as the weight insertion material combining all the advantages of the above stated proposals eliminating their disadvantages and restrictions.

Thus its first -and important- characteristic is that the water insertion tube (9) is formed by the same film during the production of the film by a special arrangement which is going to be described later on. By an additional special arrangement of the plastic film, a protective tube (10) is formed entrapping the water insertion tube (9). The second characteristic of this film is that the protective tube (10) which is formed by the plastic film is designed in such a manner that in the seldom case that it is misused and destroyed it could be filled with soil so that the film is not rendered useless.

The advantages of this invention are rather obvious from the previous analysis and they could be summarised to the following points: a) The plastic film can be used securely for more than one cultivating seasons due to the presence of the protective tube (10) with which the water insertion tube (9) is protected. b) The production costs are low due to having a single step production process instead of a multiphase production process. c) The user has the option, in case the water insertion tube (9) is destroyed due to misuse, to fill the protective tube (9) with soil so that the film can still be used.

The invention is described below in relation to the schematics, which illustrate: Figures 1 - 4

Details of several shapes and forms of water insertion tubes (9).

Figure 5 The production process of the plastic film comprising protected water tubes (1) where the produced - from the plastic film - water insertion tube (9) is cut from the film before it is entrapped in the protective tube (10)

Figure 6 The production process of the plastic film comprising protected water tubes (1) where the produced - from the plastic film - water insertion tube (9) is entrapped into the protective tube (10) without being cut from the film.

Figure 7 Perspective of the plastic film comprising water insertion tubes (1) where the water insertion tube (9) is independent from the plastic film.

Figure 8

Perspective of the plastic film comprising water insertion tubes (1) where the weight insertion tube (9) is a continuity of the plastic film (dependent tube).

Figure 9

Perspective of the plastic film comprising water insertion tubes (1) where the water insertion tube comprises smaller tubes (9a, 9b) and is independent from the plastic film.

One of the possible ways of producing this film, referring to Figure 5 (where half the width of the film is shown) is described below in detail. One stripe of width (2d) is cut along each of the two sides of the plastic film (1) produced using a polyolefm or a combination of polyolefins having a thickness of up to 300μm and width (B) of up to 4 metres. Each one of the two produced stripes is folded so that it finally has a width of d and it is welded by a continuous welding (5) longitudinally along the two free ends (3, 4). By this way the water insertion tube is formed (9). This tube is led on top of the plastic film through a series of a guiding rolls (11). The end (2), which is formed after the original end has been cut, is folded at a distance (e) along its whole length entrapping the water insertion tube and it is welded to the surface of the film on which it is superimposed, preferably with a non - continuous welding (8) so that the water insertion tube is entrapped. The formed protective tube (10) which encloses the water insertion tube (9) being non-continuously welded can be filled with soil through the opening (12) which is formed between two parts (8) of the non-continuous welding. This is of paramount importance because in the seldom case that the water insertion tube (9) is destroyed the user could fill the protective tube (10) with soil as an alternative fixing the plastic film in place. A rather more complicated solution according to Figure 9 is when the protected water insertion tube comprises several tubes of smaller diameter and this can be achieved by cutting stripes of bigger width and using additional linear weldings so that the corresponding water tubes are formed (9a, 9b). This solution complicates the production process but offers the possibility of multiple use of the tube (in case one of the tubes is damaged one of the others can be used).

A third way of producing this film as shown in Figure 6 is when the protected water insertion tube (9) is not cut from the plastic film from which it originates. Namely both sides of the film (4) are folded longitudinally to a width of (dl) and they are welded using one (or more) linear weldings along the whole length (5). Thus the water insertion tubes (9) are formed. Each water insertion tube (9) is folded on to the plastic film to a length of d2 > dl . The resultant structure is folded once more to a width of d3 > d2 >dl. The end of the second in sequence fold (6b) is welded on the two parts of the plastic film on which it is superimposed, preferably with a non-continuous linear welding (5a). In this way the protected tube (10) is formed which in this case due to its design can be used as a pocket which can be filled with soil.

Apparently several other solutions that lead to the same result can be proposed. Namely the production from a single film of an independent or dependent water insertion tube (9) which is entrapped and protected by the protective tube (10), formed by the same plastic film (during the same production process by combinations of foldings, various weldings and cuts) so that the end film carries on both sides protected water insertion tubes (9). Also the production of a plastic film which additionally provides the protective tube (10) as a soil insertion pocket in order for the film to be fixed on the cultivation line could be another solution.

The user can securely use the proposed plastic film with protected water tubes (1) knowing that the protected by this method, water insertion tube (9) would be difficultly destroyed. Thus the user is assured that the film is protected against any damages during transportation, storage and use of the plastic film. Furthermore the two plastic films -i.e. the one which forms the water insertion tube (9) and the one forming the protective tube (10) can slide relative to each other so that in case a sharp object (branches, stones, animals' nails and beaks) impacts the structure the water insertion tube should remain intact.

Moreover in the case that both the protective tube and the water insertion tube are locally damaged the user can fill the protective tube (10) with soil through the non- welded parts of the non-continuous linear welding (12) so that the film could still be used. It is common practice to add several colorants and additives to such films to alter its properties and affect those of interest for the application (stabilisation against solar radiation, glossy surface and opaque optical properties or several other combinations)

Finally the foldings could be made on either of the two external surfaces of the film so that in case the film has a different colour on each surface one of the surfaces has one and only colour (i.e. if one surface is black and the other is white and the white surface is folded on the black surface then the film has a white surface and a black surface with white stripes on both its sides. Exactly the opposite occurs when the black surface is folded onto the white surface).

Claims

Claims1) Plastic film comprising protected water insertion tubes (1) produced from a plastic film of width (B) up to 4 metres and thickness up to 300μm which has weight insertion structures along its sides, so that it can be fixed on a linear vegetable or fruit plantation and it is characterised by the fact that:The weight insertion structures comprise a water insertion tube (9) and a protective tube (10) on each side the latter protecting the water insertion tube (9) both being formed by a combination of foldings, cuts and linear weldings using the sides of the original plastic film.2) Plastic film comprising water insertion tubes (1) according to claim 1 characterised by the fact that: a) Each protected water insertion tubes (9) is formed by cutting a stripe (4) of width dl along the length of the initial width of the plastic film, which is folded and its ends (3,4) are welded together longitudinally by a welding (5) and b) The protective tube (10) is formed by a second folding of the side (2) of the plastic film ( which arises after the film has been cut ) to a width (e) so that the stripe can be extracted and welded preferably by a non-continuous linear welding (8) to the par of the film on which it is superimposed.3) Plastic film comprising protected water insertion tubes (1) according to claiml characterised by the fact that: a) The protected water insertion tubes (9) are formed by folding the side (4) of the film to a width (dl) and welding along its length by a linear welding (5) and b) The protective tube (10) is formed by two consecutive foldings of the folded parts to widths d2 and d3 respectively so that d3 > d2 > dl and it is then welded preferably by a non-continuous linear welding (5a) to the part of the film onto which it is superimposed and along the folding (6b). 4) Plastic film comprising protected water insertion tubes (1) according to claims 1 and one of 2 or 3 which is characterised by the fact that the water insertion tube (9) comprises several smaller tubes (Figure 9) having two or more longitudinal tubes (9a,9b) which are formed by more than one linear welding (5) 5) Plastic film comprising protected water insertion tubes (1) according to claims 1 and one of 2, 3 or 4 which is characterised by the feet that the two surfaces of the film can have any coloration (the same or different) and the foldings of the film could be made on either of the two surfaces. AMENDED CLAIMS[received by the International Bureau on 13 September 2001 (13.09.01); original claims 1-5 replaced by new claims 1-5 (2 pages)]

1. Plastic film comprising protected water insertion tubes (1) produced from a plastic film of width (B) up to 4 metres and thickness up to 300μm which has weight insertion structures along its sides, so that it can be fixed on a linear vegetable or fruit plantation which has on both edges a protected water insertion tube (9) and a protecting tube (100) in order to be fixed above the linear vegetable plantation and it is characterized by the fact that the protected water insertion tube (9) is formed from the initial (original) plastic film by folding each of its sides and welding it linearly onto the art on which it is superimposed; the protecting tube (10) is formed by an additional folding of the same original film so that the protected tube (9) is finally enclosed into the protecting tube.

2. Plastic film comprising water insertion tubes (1) according to claim 1 characterized by the fact that a) each protected water insertion tubes (9) is formed by cutting a stripe (4) of width d1 along the length of the initial width of the plastic film, which is folded at its ends (3, 4) are welded together longitudinally by a welding (5), and b) the protective tube (10) is formed by a second folding of the side (2) of the plastic film (which arises after the film has been cut) to a width (e) so that the stripe can be extracted and welded preferably by a non-continuous linear welding (8) to the part of the film on which it is superimposed.

3. Plastic film comprising protected water insertion tubes (1) according to claim 1 characterized by the fact that a) the protected water insertion tubes (9) are formed by folding the side (4) of the film to a width (d1) and welding along its length by a linear welding (5) and b) the protective tube (10) is formed by two consecutive foldings of the folded parts to widths d2 and d3 respectively so that d3 > d2 > d1 and it is then welded preferably by a non-continuous linear welding (5a) to the part of the film onto which it is superimposed and along the folding (6b).

4. Plastic film comprising protected water insertion tubes (1) according to claims 1 and one of 2 or 3, which is characterized by the fact that the water insertion tube (9) comprises several smaller tubes having two or more longitudinal tubes (9a, 9b) which are formed by more than one linear welding (5).

5. Plastic film comprising protected water insertion tubes . (1) according to claims 1 and one of 2, 3 or 4, which is characterized by the fact that the two surfaces of the film can have any coloration (the same or different) and the foldings of the film could be made on either of the two surfaces.

STATEMENT UNDER ARTICLE 19 (1)

In reply to the International Search Report the following statement and amendments are submitted:

Ad D1 : The document (GB 2 311 923 A) discloses two manufacturing solutions for plastic sheets for soil coverage that have water insertion tubes at their sides as weights. According to one solution the plastic sheet has a water insertion tube on each side, said tubes being produced independently, i.e. the tube is formed separately and then inserted in the plastic sheet. In order to fasten and hold the independent tube in position the plastic sheet is folded and glued (figs. 5, 6). According to the second solution the foldable plastic sheet is itself after appropriate gluing the water insertion tube (fig. 4). There are also many other solutions with water insertion tubes in the state of the art. Most of them are referring to a non-protected water insertion tube formed by the plastic sheet itself through folding and gluing. The walls of these non-protected water insertion tubes touch when used various rough materials on the field (stones, wood etc.) and are in fact often easily damaged, which renders the plastic sheet useless. The plastic sheet of D1 is one of that kind. The procedure is rather expensive requiring two different production steps and therefore is not likely to be industrially applicable.

Ad D2: The same applies for D2 (our own former application WO 98 30082 A), which also involves independent water insertion tubes at the sides.

The present application differs from D1 and D2 in that a) the water insertion tubes are protected from outside influence, and b) they are made of the plastic sheet itself, so that production is easier and cheaper. To achieve this the ends of the plastic sheet must be folded over at least two times and, according to one embodiment, to be cut between first and second folding. Furthermore, at least two linear gluing sections must be created, one to hold and glue the first folding forming the protected water insertion tubes, and the second to glue the second folding forming the protective space.

Please find enclosed amended claims in triplicate according to Article 19 for above application.