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Title:
FLEXIBLE FILM, ASSEMBLY OF A STRUCTURE AND SUCH A FILM AND METHOD FOR PRODUCING SUCH A FILM
Document Type and Number:
WIPO Patent Application WO/2015/016713
Kind Code:
A1
Abstract:
A flexible film comprises a transparent support layer and a layer stack having one or more transparent layers, wherein at least one layer of the layer stack is divided into segments in the longitudinal direction. Adjacent segments of the at least one layer are separated from one another in the longitudinal direction by an intermediate space, which intermediate space is free of the at least one segmented layer. The invention further relates to an assembly of a support structure and the flexible film, wherein the support structure comprises a number of structural parts in the longitudinal direction substantially at right angles thereto; a support distance is provided between each pair of adjacent structural parts; the flexible film is stretched in the longitudinal direction in the vicinity of the structural parts in such a way that the longitudinal direction of the support layer coincides with the longitudinal direction of the support structure, and a position of a structural part substantially coincides with the position of an intermediate space on the support layer.

Inventors:
VAN DEURSEN ADRIANUS GERARDUS (NL)
BROOS JOHAN MARTIEN (NL)
PRINS VINCENT (NL)
Application Number:
PCT/NL2014/050535
Publication Date:
February 05, 2015
Filing Date:
July 31, 2014
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
VALK SYSTEMEN BVVD (NL)
International Classes:
A01G9/14
Domestic Patent References:
WO2012107701A12012-08-16
WO2009044066A22009-04-09
WO2012107701A12012-08-16
WO2009044066A22009-04-09
Foreign References:
US20080311392A12008-12-18
US4587159A1986-05-06
NL1017077C12002-07-15
NL1017077C12002-07-15
Attorney, Agent or Firm:
NEDERLANDSCH OCTROOIBUREAU (JS The Hague, NL)
Download PDF:
Claims:
Claims

1. Flexible film (F) comprising a transparent support layer (1) and a layer stack having one or more transparent layers (2, 3, 5), wherein at least one layer of the layer stack is divided into segments in the longitudinal direction, being the first direction (L), of the film, and

adjacent segments of the at least one layer are separated from one another in the longitudinal direction of the film by an intermediate space (4), which intermediate space is free of the at least one segmented layer.

Flexible film according to Claim 1, wherein one or more layers are in each case selected from a group of active layers comprising a photovoltaic layer, an electroluminescent layer, an electro chromic layer, a thermochromic layer, a fluorescent layer, a diffuser layer and a temperature-regulating layer.

Flexible film according to either of Claims 1 and 2, further comprising one or more passive layers chosen from a group comprising a transparent insulating layer and a transparent conducting layer.

Flexible film according to Claim 2, wherein the layer stack, apart from the first layer, further comprises at least a second layer, and the first layer is covered by the at least one second layer.

Flexible film according to Claim 3 or 4, wherein at least one of the at least first and second layers is divided in the longitudinal direction into segments having an intermediate space which is free of said at least one of the first and second layers.

Flexible film according to Claim 5, wherein the other of the first and second layers is continuous. 7. Flexible film according to Claim 5, wherein the other of the first or the second layer is divided into segments (25) having an intermediate space which is free of said other layer.

8. Flexible film according to Claim 7, wherein the segments (25) of the second layer coincide with the segments (20) of the first layer.

Flexible film according to one of Claims 3-8, wherein the first layer is conducting layer and the second layer is chosen from a photovoltaic electroluminescent or an electrochromic or temperature-regulating layer.

Flexible film according to Claims 3-9, wherein the second layer conductive.

11. Flexible film according to Claims 3-9, further comprising a third layer which consists of a conducting layer (5), with the second layer between the first layer and the third layer.

Flexible film according to Claim 11 , wherein the third layer is divided into segments (30).

13. Flexible film according to Claim 12 and one of Claims 5 and 7, wherein the segments (30) of the third layer coincide with the segments (20) of the first layer or with the segments (25) of the second layer.

14. Flexible film according to Claim 12 and Claim 8, wherein the segments (30) of the third layer coincide with the segments (25) of the second layer and the segments (20) of the first layer.

15. Flexible film according to Claim 9 to the extent that it is dependent on Claim 7, wherein the second layer is chosen from the group of active layers in each case for each separate segment.

16. Flexible film according to one of Claims 3-15, wherein the second layer is in each case interrupted at the location of the intermediate space (4).

17. Flexible film according to one of Claims 7-15, wherein the third layer is in each case interrupted at the location of the intermediate space (4).

18. Flexible film according to one of the preceding claims, wherein the support layer comprises a plastic film.

19. Flexible film according to one of the preceding claims, wherein the distance between the intermediate spaces (4) in the at least one layer of the layer stack is substantially constant in the longitudinal direction.

20. Flexible film according to one of the preceding Claims 1-19, wherein the segments of at least one of the layers from the layer stack on the support layer are ordered into two or more segment groups (G; Gl, G2) with, in the longitudinal direction (L), in each case an intermediate space of a first distance (4) between the segments within one segment group and with an intermediate space of a second distance (8) between the outer segments which face one another of adjacent segment groups.

21. Flexible film according to one of the preceding Claims 1 1-20, further comprising at least a fourth layer, wherein

the fourth layer is chosen from the active or passive layers; the fourth layer is optionally divided into segments and, if it is divided into segments, the segments of the fourth layer optionally coincide with segments of at least one of the first, second and third layers.

22. Flexible film according to one of the preceding claims, wherein the support layer is relatively thicker at the location of the intermediate space than in the segments.

23. Flexible film according to one of the preceding Claims 9-22, wherein a conductive layer of the layer stack is provided with one or more connecting parts (2a; 5a) for connecting an external conductor. Flexible film according to Claim 23, wherein the one or more connecting parts of the conductive layer extend on the support layer, outside the surface which is covered by the one or more other layers of the layer stack.

Assembly of a support structure and a flexible film (F), wherein the support structure comprises a number of structural parts (9) in its longitudinal direction (L) substantially at right angles thereto; a support distance (10) is provided between each pair of adjacent structural parts; the flexible film comprises a transparent support layer and a layer stack having one or more transparent layers, wherein at least one layer of the layer stack is divided into segments in the longitudinal direction (L) of the film, and

adjacent segments of the at least one layer are separated from each other in the longitudinal direction of the film by an intermediate space (4), which intermediate space is free of the at least one segmented layer;

the flexible film is stretched in the longitudinal direction of the support structure in the vicinity of the structural parts in such a way that the longitudinal direction of the film coincides with the longitudinal direction of the support structure, and a position of a structural part substantially coincides with the position of an intermediate space on the support layer.

Assembly according to Claim 25, wherein a distance between adjacent structural parts is equal either to an intermediate distance between positions of adjacent intermediate spaces or an integer multiple of said intermediate distance of adjacent intermediate spaces.

Assembly according to Claim 25 or Claim 26, wherein the film is connected to the structural part or supported by the structural part at the location of the intermediate space. 28. Assembly according to one of Claims 25-27, wherein the structural parts may be chosen from a group comprising transverse frames, wires and cables. Assembly according to one of Claims 25-28, wherein a width of the intermediate space (4; 8) is greater than a width of a bearing surface of the structural part (9) on the flexible film (F).

Assembly according to one of the preceding Claims 25-29, comprising the flexible film according to one of Claims 1 -24.

31. Flexible film according to one of Claims 1-24, applied to a structure of a horticultural greenhouse.

32. Cloth provided with a flexible film according to one of Claims 1-24, in order to be applied to a structure of a horticultural greenhouse.

Horticultural greenhouse provided with an assembly according to one of Claims 25-30 or with a flexible film according to Claim 31 or with a cloth according to Claim 32.

Method for producing a flexible film (F) comprising a transparent support layer (1) and a layer stack having one or more transparent layers (2, 3, 5), comprising: applying the at least one layer to the support layer;

wherein the method provides that

at least one layer of the one or more layers is divided into segments (20; 25; 30) in the longitudinal direction of the support layer;

segments of the at least one segmented layer which are adjacent to one another in the longitudinal direction are separated from one another by an intermediate space (4; 8), and in each case the intermediate space is kept free of the at least one segmented layer.

Description:
Flexible film, assembly of a structure and such a film and method for producing such a film

Technical field

The invention relates to a flexible film comprising a support layer and a layer stack having at least a first layer. The invention further relates to a method for producing such a flexible film. The invention also relates to an assembly of a support structure and a flexible film. Prior art

Globally, many horticultural crops are grown in greenhouses. These greenhouses consist of a space which is delimited by a covering of translucent material, as a result of which it is possible to maintain a climate in this space which is optimal for growing crops. Such greenhouses have a relatively large translucent surface in order to be able to provide the crops with sunlight.

It is known that influencing the light which passes through the covering can lead to a better interaction of the light with the crops. There are a wide variety of moveable cloths which are used in greenhouse structures in order to influence the climate in the greenhouse by means of shadow effect, insulation and moisture permeability. They can be controlled in terms of their surface area, but are not able to interact with transmitted light or to manipulate transmitted light.

On the one hand, there is a need to be able to control the transmission of sunlight through said surface. Due to the large surface area of a greenhouse, the use of the abovementioned conventional means, such as a plurality of suitable sunshade structures, is complex and makes it particularly difficult to construct and maintain the greenhouse. The use of, for example, sunshade cloth has the disadvantage that this significantly attenuates the sunlight but it is not possible to control the attenuation, which may have a negative effect on the desired growth of the crops.

On the other hand, there is also a demand for being able to combine various control measures in a relatively simple manner.

Support films are known from the prior art that are provided with at least one active layer, with the active layer being configured to react to incident light, wherein the transmitted light is manipulated under the influence of the active layer. International patent application WO 2012/107701 describes a material for modulating the wavelength of sunlight, comprising a polymer matrix and at least two luminescent organic compounds.

International patent application WO 2009/044066 describes a material comprising a substrate and a layer of photocatalytic titanium oxide and containing a compound which converts radiation in the visible or infrared range of the spectrum into radiation in the ultraviolet range of the spectrum.

Patent NL 1017077 describes an application of polymer film provided with inorganic phosphors for use in agriculture and horticulture.

Another application relates to the use of flexible solar cell films having an active layer for generating solar energy from incident light. However, one property of these films is that the light is largely absorbed, so that it is undesirable to use them in a translucent roof of, for example, a greenhouse. Recently, photovoltaic materials have been developed which absorb a relatively low amount of light (they allow approximately 70% of the light to pass through), but in many cases even this attenuation is enough to have a negative influence on the growth of some crops.

It is an object of the invention to provide a support layer comprising a layer stack having at least a first layer, which overcomes the disadvantage of the prior art. Summary of the invention

The object of the invention is achieved by a flexible transparent film comprising a support layer and a layer stack having one or more transparent layers, wherein at least one layer of the layer stack is divided into segments in the longitudinal direction, being the first direction, and

adjacent segments of the at least one layer are separated from one another in the longitudinal direction by an intermediate space, which intermediate space is free of the at least one segmented layer.

The layers are subdivided into active layers and passive layers. The transparent passive layers comprise conductive and insulating layers.

One property of the one or more transparent active layers is that they demonstrate an interaction, either with light or with an electrical voltage or current. The active layer either functions as a filter which influences how much of the transmitted light can pass through as a function of wavelength or intensity, and diffusion, or it functions as a light source for illuminating the underlying surface.

By means of the invention, it is ensured that the intermediate space allows part of the incident light to pass through without interaction with the at least one segmented layer. Said part of the incident light can therefore reach the underlying surface through the intermediate space in this segmented layer (layers) in an unobstructed manner.

Moreover, the segmentation has the advantage that the electrical power which may be required to control the active layer (layers) is limited for each segment.

In addition, the division provides segments having an intermediate space which is free of the at least one segmented layer, so that these intermediate spaces can be used as places where structural parts, such as frames, wires or cables of a support structure, can be arranged without damaging said layer or being able to make undesired electrical contact for discharge via the support structure.

One embodiment of the invention provides a flexible film as described above, wherein each of the one or more transparent layers is in each case selected from a group of layers comprising a photovoltaic layer, an electroluminescent layer, an electrochromic layer, a thermochromic layer, a diffuser layer, a fluorescent layer and a temperature-regulating layer.

Each of these active layers has an interaction with light or electrical voltage or current, as described above. The photovoltaic layer, electroluminescent layer, electrochromic layer and temperature-regulating layer are active layers which are also electrically connected in this case.

The thermochromic, fluorescent and diffuser layers are layers which are able to function independently without electrical contact.

With the aid of said group of layers, it is possible to construct a variety of configurations of layers on the support layer in order to obtain a desired function with respect to the incident sunlight.

With the aid of a thermochromic or diffuser layer or a fluorescent layer, it is possible to adapt the translucency, the light distribution or the transmitted spectrum range of the support layer, respectively.

In the case where the layer stack of the flexible film, apart from the first layer, further comprises at least a second layer, and the first layer is covered by the at least one second layer, a number of electrical functions are available:

An electrochromic layer in combination with one or more conducting layers makes it possible to adjust the translucency by controlling the electrical voltage and/or current on the conducting layers.

An electrolurninescent layer in combination with one or more conducting layers makes it possible to use the support layer as a light source by controlling the electrical voltage and/or current on the conducting layers.

A photovoltaic layer in combination with one or more conducting layers makes it possible to convert part of the incident light into electrical energy and thus to lower the net energy consumption within the greenhouse. This may have a very advantageous effect owing to the large surface area of greenhouse structures.

A temperature-regulating layer in combination with conducting layers makes it possible to achieve a cooling or heating effect.

In an embodiment, at least one of the at least first and second layers is divided in the longitudinal direction into segments having an intermediate space which is free of said at least one of the first and second layers.

In an embodiment, the invention provides that the other of the first and second layers is continuous.

In an alternative embodiment, the other of the first or the second layer is likewise divided into segments having an intermediate space which is free of said other layer.

In an embodiment, the invention provides a flexible film as described above, wherein the segments of the second layer coincide with the segments of the first layer.

In an embodiment, the invention provides a flexible film as described above, wherein the first layer is a conducting layer and the second layer is chosen from a photovoltaic or electroluminescent or an electrochromic layer.

In a further embodiment, the invention provides a flexible film as described above, wherein the second layer is also conductive. This ensures that the second layer also acts as an electrical conductor in addition to its active function, which dispenses with the need to apply an additional conducting layer.

In an embodiment, the invention provides a flexible film as described above, which further comprises a third layer which consists of a conducting layer, with the second layer between the first layer and the third layer.

In an embodiment, the invention provides a flexible film as described above, wherein the third layer is divided into segments.

In an embodiment, the invention provides a flexible film as described above, wherein the segments of the third layer coincide with the segments of the first layer and/or with the segments of the second layer.

In an embodiment, the invention provides a flexible film as described above, wherein the second layer is chosen from the first group in each case for each separate segment.

This advantageously ensures that segments having different functions can be available next to one another on the support layer.

In an embodiment, the invention provides a flexible film as described above, wherein the segments of at least one of the layers from the layer stack on the support layer are ordered into two or more segment groups with, in the longitudinal direction, in each case an intermediate space of a first distance between the segments within one segment group and with an intermediate space of a second distance between the outer segments which face one another of adjacent segment groups.

This ensures a variation in the intermediate distance between the segments, so that, for example, another intermediate space is available at a centre-to -centre distance between supports than in locations where only an insulating intermediate space is required.

In an embodiment, the invention provides a flexible film as described above, wherein the support layer further comprises at least a fourth layer, wherein the fourth layer is chosen from the first or second group of layers; the fourth layer is optionally divided into segments and, if it is divided into segments, the segments of the fourth layer optionally coincide with segments of at least one of the first, second and third layers.

It is thus possible to stack a plurality of layer stacks onto one another. This may be advantageous in order for layer stacks with different functions to be available in the same location.

In a further embodiment, the invention provides a flexible film as described above, wherein the support layer is relatively thicker at the location of the intermediate space than in the segments. This ensures that such an intermediate space can be reinforced against wear at that location, which can be caused for example by contract with a support or structural part.

In an embodiment, the invention provides a flexible film as described above, wherein a conductive layer of the layer stack is provided with one or more connecting parts for connecting an external conductor.

In an embodiment, the invention provides a flexible film as described above, wherein the one or more connecting parts of the conductive layer extend on the support layer, outside the surface which is covered by the one or more other layers of the layer stack.

In an embodiment, the invention provides a flexible film as described above, wherein the support layer comprises a plastic film.

In an embodiment, the invention provides a flexible film as described above, wherein the distance between the intermediate spaces in the at least one layer of the active layer stack on the support layer is substantially constant.

In an embodiment, the invention provides a flexible film as described above, wherein the segments of at least one of the first, second and third layers on the support layer are ordered into two or more groups with, in the longitudinal direction, in each case an intermediate space of a first distance between the segments within one group and with an intermediate space of a second distance between the outer segments of adjacent groups.

In an embodiment, the invention provides a flexible film as described above, further provided with at least a fourth layer, wherein the fourth layer is chosen from the group of layers; the fourth layer is optionally divided into segments and, if it is divided into segments, the segments of the fourth layer optionally coincide with segments of at least one of the first, second and third layers.

In an embodiment, the invention provides a flexible film as described above, wherein the support layer is relatively thicker at the location of the intermediate space than in the segments.

In an embodiment, the invention provides a flexible film as described above, wherein a conductive layer of the active layer stack is provided with one or more connecting parts for connecting an external electrical conductor.

In an embodiment, the invention provides a flexible film as described above, wherein the one or more connecting parts of the conductive layer extend on the support layer outside the surface of the one or more layers of the active layer stack which are chosen from the other layers in the group of layers.

In an embodiment, the invention provides an assembly of a support structure and a flexible film as described above, wherein the support structure comprises a number of structural parts in the longitudinal direction substantially at right angles thereto; a support distance is provided between each pair of adjacent structural parts; the flexible film is stretched over the structural parts in the longitudinal direction in such a way that the longitudinal direction of the support layer coincides with the longitudinal direction of the support structure, and the position of an intermediate space on the support layer in each case coincides with a position of a support or structural part.

In an embodiment, the invention provides an assembly as described above, wherein the support layer is connected to the structural part or supported by the structural part at the location of the intermediate space.

In an embodiment, the invention provides an assembly as described above, applied to a structure of a horticultural greenhouse.

The invention further relates to a horticultural greenhouse provided with an assembly as described above or provided with a flexible film as described above.

The invention further relates to a method for producing a flexible film provided with a support layer and a layer stack of at least a first layer, comprising: applying the at least one layer to the support layer, wherein the method provides that the at least one layer is divided into segments in the longitudinal direction, being the first direction; segments of the at least one layer which are adjacent to one another in the longitudinal direction are separated from one another by an intermediate space, and in each case the intermediate space is kept free of the at least one segmented layer.

In an embodiment, the invention provides a method as described above, wherein the application of the at least one layer involves conducting a printing process, and the printing process occurs on the basis of a pattern which segments the at least one layer. Brief description of the drawing

The invention will be explained below in more detail with reference to a number of drawings, in which some exemplary embodiments are shown. The drawings are only intended for illustrative purposes and not as a limitation of the inventive idea, which is defined in the attached claims.

In the drawings:

Figure 1 shows a top view of an assembly of a structure and a film according to the invention;

Figure 2 shows a cross section of a film according to an embodiment of the invention; Figure 3 shows a cross section of a film according to an embodiment of the invention; Figure 4 shows a cross section of a film according to an embodiment of the invention; Figure 5 shows a cross section of a film according to an embodiment of the invention; Figure 6 shows a cross section of a film according to an embodiment of the invention; Figure 7 shows a cross section of a film according to an embodiment of the invention; Figure 8 shows a cross section of a film according to an embodiment of the invention; Figure 9 shows a cross section of a film according to an embodiment of the invention; and

Figure 10 shows a top view of an embodiment of a film according to the invention.

Description of embodiments

In the following figures, identical reference numerals in each case refer to corresponding parts in these figures.

Figure 1 shows a top view of an assembly of a structure and a film according to the invention.

In the invention, a flexible film is provided with a lighting function in relation to the incidence of light on a surface (not shown) arranged behind or underneath the film, in particular a surface provided with crops, such as a greenhouse structure. Such a greenhouse structure generally covers a large surface area over which a covering layer is stretched, which covering layer is supported by at least a plurality of structural parts 9 arranged next to one another at a mutual support distance 10.

Such structural parts 9 comprise transverse frames, wires and cables.

According to the invention, the covering layer is formed in a first direction or longitudinal direction L of the greenhouse structure by a film web F which extends over a relatively large length, preferably substantially the entire length of the greenhouse in said first direction L.

The film web F is arranged on the structural parts 9 in order to thus form the covering layer.

In order to obtain a lighting function, the flexible film F comprises a support layer 1 and a layer stack of one or more layers arranged thereon.

The layer stack is constructed in such a way that at least one of the one or more layers in the layer stack is segmented in the first direction, with an intermediate space 4 between segments S, which intermediate space 4 is free of the material of the segmented layer.

According to the invention, provision is made for in each case a position of a structural part 9 to coincide with a position of an intermediate space 4 in the segmented layer.

In this case, the support distance 10 can be equal to a segment distance 1 1 between successive intermediate spaces 4 or to an integer multiple thereof.

Furthermore, provision is made for a width of the intermediate space 4 to be greater than a width of a bearing surface of the structural part 9 with the film F.

In this way, the at least one layer is prevented from being able to come into contact with the structural part. It prevents damage to the segmented layer, which could affect the function of the layer. It also prevents a conductive connection from arising in cases where the at least one layer is a conductive layer and the structural part is made of metal.

The segmentation also creates the possibility of spatially defining the function of the layer stack performed by the segmented layer.

A number of embodiments of a layer stack according to the invention are described below.

Figure 2 shows a cross section of a film according to an embodiment of the invention.

In this embodiment, the film comprises the support layer 1 and a first layer 2 which is segmented, with intermediate spaces 4 which are free of the layer. In an embodiment, the segmented layer 2 may be chosen from a thermochromic layer, a fluorescent layer, a diffuser layer or a conductive layer. A property of the thermochromic layer is that colour and translucency can be changed as a function of the temperature.

A property of the fluorescent layer is that a wavelength of incident light is converted into a different, longer wavelength.

A property of the diffuser layer is that incident light is diffused by transmission through the diffuser layer.

The conductive layer can be used to conduct a charge. For example, it is possible to discharge any static electricity which may occur from the support layer. Figure 3 shows a cross section of a film according to an embodiment of the invention. In this embodiment, the layer stack comprises two layers 2, 3 stacked on top of one another, wherein a bottom layer 2 is segmented, with in each case an intermediate space between adjacent segments. A top layer 3 is continuous.

In this way, there are insulated segments in the bottom layer 2 with respect to one another and with respect to a supporting structural part.

The bottom layer 2 and top layer 3 can in each case be selected from a first group of layers comprising a photovoltaic layer, an electroluminescent layer, an electrochromic layer, a thermochromic layer, a fluorescent layer, a diffuser layer or from a second group comprising an insulating layer and a conducting layer.

In one example, the bottom layer 2 could be a thermochromic layer while the top layer 3 could be a diffuser layer, but it is also possible to combine a conductive bottom layer 2 with a top layer 3 which exchanges charge with the conductive bottom layer. In the latter case, the top layer 3 can be one of a photovoltaic layer, an electroluminescent layer and an electrochromic layer. The top layer 3 could also be an insulating layer in order to insulate the conductive bottom layer 2.

In an embodiment, the bottom layer 2 is chosen from either the first or the second group and the top layer is chosen from the other of the first and the second group.

An example of a film according to this embodiment relates to a solar cell film having a support layer on which a segmented conducting layer is arranged and which is covered by a continuous photovoltaic layer, at least the top layer of which is conductive.

Figure 4 shows a cross section of a film according to an embodiment of the invention. In this embodiment, the layer stack comprises two layers 2, 3 stacked on top of one another, wherein the bottom layer 2 is continuous and the top layer 3 is segmented with intermediate spaces 4.

Figure 5 shows a cross section of a film according to an embodiment of the invention. The layer stack comprises two layers 2, 3 stacked on top of one another. The bottom layer 2 is segmented into segments 20, with in each case an intermediate space 4 between adjacent segments 20, and the top layer 3 is divided into segments 25, with in each case an intermediate space 4 between adjacent segments 25. In the embodiment shown, the bottom layer and the top layer have the same segment distance and the position of the bottom segment 20 in each case coincides with the position of the top segment 25.

It will be clear that it is possible to move the position of a bottom segment with respect to a top segment. It will also be clear that the segment distance of the bottom layer 2 may differ from (be larger or smaller than) the segment distance of the top layer 3.

Figure 6 shows a cross section of a film according to an embodiment of the invention.

The layer stack comprises three layers 2, 3, 5 stacked on top of one another on the support layer 1. The bottom layer 2 is divided into segments 20, with intermediate spaces 4 between adjacent segments 20. The bottom layer 2 is covered by a middle layer 3. The middle layer 3 is continuous. The middle layer 3 is covered by a top layer 5. The top layer 5 is also continuous.

The top layer 5 is also chosen from either the first or the second group of layers. In an embodiment, the bottom layer 2 and the top layer 5 are both chosen from either the first or the second group and the middle layer is chosen from the other of the first and the second group.

Figure 7 shows a cross section of a film according to an embodiment of the invention.

The layer stack comprises three layers 2, 3, 5 stacked on top of one another on the support layer 1. The bottom layer 2 is divided into segments 20, with intermediate spaces 4 between adjacent segments 20. The bottom layer 2 is covered by a middle layer 3. The middle layer 3 is divided into segments 25, with intermediate spaces 4 between adjacent segments 25. The middle layer 3 is covered by a top layer 5. The top layer 5 is also divided into segments 30, with intermediate spaces 4 between adjacent segments 30.

Figure 8 shows a cross section of a film according to an embodiment of the invention.

The layer stack comprises three layers 2, 3, 5 stacked on top of one another on the support layer 1. The bottom layer 2 is divided into segments 20, with intermediate spaces 4 between adjacent segments 20. The bottom layer 2 is covered by a middle layer 3. The middle layer 3 is continuous. The middle layer 3 is covered by a top layer 5. The top layer 5 is also divided into segments 30, with intermediate spaces 4 between adjacent segments 30.

It will be clear that the layer stack illustrated in one of Figures 2-8 may contain additional layers which may also be segmented. In this way, it is possible to stack layer stacks having different functions on top of one another in a film.

As an alternative, one side of a support layer may be provided with a first layer stack having a certain function and the other side may be provided with a second layer stack having the same function or a different function to the first layer stack.

Figure 9 shows a cross section of a film according to an embodiment of the invention.

The layer stack comprises at least two layers 2, 3 stacked on top of one another on the support layer 1.

In this case, both the bottom layer 2 and the top layer 3 are segmented, with the bottom layer being segmented in a different way to the top layer 3.

In this embodiment, the top layer segments S3 are arranged as bridging layers which in each case bridge the intermediate space between two adjacent segments S 1 , S2 of the bottom layer 2.

In this way, the two segments SI, S2 in the bottom layer may serve as electrical connections for the bridging top layer segment S3.

Figure 10 shows a top view of an embodiment of a film according to the invention.

This figure illustrates a film with the support layer 1 on which a layer stack is arranged. The layer stack contains two conducting layers. The configuration of the layer stack is, for example, as illustrated in the cross section of Figure 7 or Figure 8, where the bottom layer 2 and top layer 5 may be a conducting layer.

The bottom layer 2 and the top layer 5 may be provided with a connecting surface 2a; 5a which extends outside the surface occupied by the middle layer 3.

An external electrical conductor may be connected to each of the connecting surfaces.

It will be clear that a connecting surface 5 a may be unnecessary if the top layer 5 is free (i.e. is not covered by another layer).

This figure further shows a possible arrangement of the segments in groups Gl , G2. Within a group Gl ; G2, the segments are arranged with a first intermediate space 4. A second intermediate space 8 is provided between two segments of adjacent groups Gl, G2. In the first direction L, the second intermediate space 8 has a width which is different from a width of the first intermediate space 4.

In an embodiment, the width of the second intermediate space 8 is greater than that of the first intermediate space 4.

Furthermore, Figure 10 shows the positioning of the film F with respect to a structural part 9. In a greenhouse structure, it is possible for the position of each intermediate space to coincide with the position of a structural part, such as a transverse frame, a wire or a cable, by virtue of the fact that the distance between successive intermediate spaces on the film is equal to the support distance between successive structural parts.

The support distance may also be chosen to be an integer multiple of the distance between successive intermediate spaces, so that in each case the plurality of intermediate spaces on the support layer is kept free.

Provision is made for at least a width of said intermediate space 4; 8 which coincides with the position of a structural part 9 to be greater than a width of a bearing surface of the structural part 9 with the film F.

Provision is further made for the support layer to optionally have a greater thickness at the location of an intermediate space than under a segmented layer, so that if the intermediate space coincides with a structural part, the support layer is more resistant to wear caused by contact with the structural part.

At the location where the intermediate space coincides with the structural part, the support layer may be connected to the structural part or supported by the structural part.

In an embodiment, the flexible film is provided with at least one layer of the layer stack which is divided into segments in a width direction of the film, wherein adjacent segments of the at least one layer are separated from one another in the width direction of the film by a further intermediate space, which further intermediate space is free of the at least one segmented layer.

With respect to a structural part which runs in the longitudinal direction of the structure, it is ensured that the position of the further intermediate space can coincide with the position of said structural part in the longitudinal direction in a greenhouse structure. Alternative and equivalent embodiments of the present invention are conceivable without departing from the inventive idea, as will be clear to the person skilled in the art. The inventive idea is only limited by the attached claims.

List of reference numerals

1 Support layer

2 First layer

2a Connecting surface

3 Second layer

4 Intermediate space

5 Third layer

5a Connecting surface

8 Intermediate space

9 Structural part

10 Support distance

1 1 Segment distance

14 Intermediate space

20 Segment

25 Segment

30 Segment

F Film web

G1, G2 Group of segments

S Segment

SI, S2, S3 Segment

L First direction