IT201600078541A1 - METHOD TO OBTAIN A REUSABLE BAG FOR LIQUID CONTAINERS, MOSTLY GLASS BOTTLES, REUSABLE BAG AND ITS KIT - Google Patents

Description

"Method for obtaining a reusable bag for breakable containers of liquids, particularly glass bottles, a reusable bag and related equipment",

TEXT OF THE DESCRIPTION

Field of the invention

The present invention relates to packaging for the packaging and / or transport of breakable containers for liquids, and has been developed with particular reference to reusable bags for use in combination with glass bottles.

State of the art

For the purposes of packaging and / or transporting glass bottles and the like of breakable containers for liquids, it is known the use of special "protection" bags that can be transported manually and, if necessary, reusable. These bags - generally designed to contain a single bottle - are for example supplied by the operators of commercial establishments such as wine bars, wineries, airport duty free, etc., in order to ensure safe transport of the bottles purchased by their customers.

Some of these bags have an external envelope, configured in the manner of a bag and formed with a material impermeable to liquids, inside which there is an internal envelope, also configured in the manner of a bag. Between the two bags there is a padding, often formed with a material that is also susceptible to absorb liquids. This material therefore fulfills a double protection function, that is, it protects the bottle contained in the bag against accidental impacts and, on the other hand, in the event of the bottle breaking, it opposes the dispersion of the liquid, absorbing it at least partially. The fact that the outer casing is made of a waterproof material also avoids the dispersion of the liquid outside the bag; in this regard, the padding material also has the function of protecting the outer casing from lacerations that could be caused by sharp parts of the broken bottle.

A reusable bag of the type indicated is known, for example, from US 5372429 A, in which the inner envelope is formed with a fabric, with this inner envelope and the relative waterproof outer envelope which are attached to each other in correspondence of their upper extremities open.

Bags of the type indicated are generally of relatively complicated and expensive construction.

Summary and synthesis of the invention

In view of the foregoing, the main purpose of the present invention is to make a bag of the type indicated at the beginning of simple and economical construction, as well as of increased reliability.

These purposes are achieved, according to the present invention, by a method for obtaining a reusable bag for frangible containers of liquids, particularly glass bottles, a bag thus obtained and a related kit, having the characteristics indicated in the attached claims. The claims are an integral part of the technical teaching provided herein in relation to the invention.

Brief description of the drawings

Further purposes, features and advantages of the invention will become clear from the detailed description that follows, made with reference to the attached drawings, provided purely by way of non-limiting example, in which:

- Figure 1 is a schematic perspective view of a reusable bag made in accordance with possible embodiments of the invention;

- Figure 2 is a schematic perspective view of an external envelope of a reusable bag in accordance with possible embodiments of the invention;

- Figure 3 is a schematic perspective view of an internal envelope of a reusable bag in accordance with possible embodiments of the invention;

- Figure 4 is a perspective view of a sheet of absorbent material of a reusable bag according to possible embodiments of the invention;

- Figure 5 is a perspective view of two structural panels of a reusable bag in accordance with possible embodiments of the invention;

- Figures 6-10 are schematic views aimed at exemplifying a method of assembling a reusable bag in accordance with possible embodiments of the invention;

- Figure 11 is a schematic section of a reusable bag according to possible embodiments of the invention; And

- figure 12 is a schematic section of the bag of figure 9 with a generic bottle inside.

Description of preferred embodiments of the invention

The reference to "an embodiment" within this description indicates that a particular configuration, structure, or feature described in relation to the embodiment is included in at least one embodiment. Therefore, phrases such as "in an embodiment", "in one or more embodiments", "in at least one embodiment" and the like, possibly present in different places of this description, do not necessarily refer to the same form of implementation, but may instead refer to different forms of implementation. In addition, particular conformations, structures or characteristics defined within this description can be combined in any suitable way in one or more embodiments, even different from those depicted. The numerical and spatial references (such as "upper", "lower", etc.) used here are only for convenience and therefore do not define the scope of protection or the scope of the forms of implementation. In the figures the same reference numbers are used to indicate similar elements or technically equivalent elements.

Referring initially to Figure 1, 1 indicates as a whole a reusable bag for packaging and transporting breakable containers of liquids, for example glass bottles, particularly bottles of wine or spirits.

The bag 1 comprises an external envelope 2, also schematically represented in Figure 2, which essentially consists of a bag. The outer shell 2 is formed with a flexible sheet material impermeable to liquids. In various embodiments, the sheet material used to make the envelope 2 is polyethylene, particularly low density (LDPE), but the use of other liquid impermeable plastic materials suitable for making bags and pouches. The thickness of the sheet material is reduced, indicatively not more than 1 mm.

The outer casing 2 is extended in length (or height) and has two opposite major walls 3, a closed lower end and an open upper end, so as to delimit a relative internal space that is liquid-tight. In various embodiments, the casing essentially consists of two sheets of plastic material (for example the aforementioned polyethylene), which are welded at the relative lateral and lower edges, in order to define the aforementioned open space at the top (alternatively, a strip of the material can be folded back on itself to form the two main walls, then welded together at the relative side edges). Preferably, in a region of the upper end, respective openings 4 are defined in the major walls 3, in order to create a handle or grip for the external casing 2.

In various embodiments, in the aforementioned upper region, preferably lower than the openings 4, a closing arrangement is provided, schematically indicated by 5, which can be operated manually to openly seal the space inside the casing 2. Preferably, the aforementioned arrangement 5 is of the type known as "z / p- / oc &", although other types of closure are not excluded from the scope of the invention, preferably suitable for ensuring a releasable hermetic closure of the internal space of the envelope 2. In various embodiments, an upper end portion of the walls 3 is folded back on itself, or so as to form a double wall, within which the openings 4 can be defined and the respective parts 5a, 5b of the arrangement can be welded. closure 5: the presence of a double wall is advantageous, in order to give greater strength to this part of the bag 1.

Inside the envelope 2 there is a further envelope, preferably also substantially configured as a liquid-tight flexible bag, formed with a liquid-impermeable sheet material. This further envelope here defined as internal envelope is indicated as a whole with 6 in Figure 3.

In various preferential embodiments, the sheet material used to make the inner wrapping 6 is of the type known as "bubble wrap" or "airball" (or Bubble Wrap ™), i.e. a material typically used for packaging objects brittle, which includes at least one flexible sheet of plastic material (for example low density polyethylene) from one face of which protrudes an ordered series of bubbles or hemispheres filled with air. In various embodiments, the material includes a further layer of sheet material, similar to that bearing the bubbles, which covers the latter (ie substantially with a two-layer configuration between which the bubbles are located).

The internal envelope 6 is also extended in length (or height), but this dimension is preferably smaller than that of the external envelope 2, for example so that the first can be contained in the internal space of the second below the arrangement closing date 5, when this provision is envisaged. The width of the internal envelope 6 is preferably slightly less than that of the external envelope 2, in order to allow the insertion of the first in the second.

The internal envelope 6 also has two opposite major walls 7, a closed lower end and an open upper end, so as to delimit a relative liquid-tight internal space. Even the internal envelope 6 can be formed by two sheets of bubble wrap material welded at the relative lateral and lower edges, in order to define the relative open space at the top. In preferential embodiments, a strip of the material in question is folded back on itself to form the two main walls 7, then welded together at the relative lateral edges.

Inside the outer envelope 2 there is further contained an absorbent layer or sheet, which has a plurality of intermediate folds, formed with a third liquid absorbent flexible material. Such an absorbent sheet is shown in its unfolded condition in Figure 4, where it is indicated as a whole with 8.

In various embodiments, the absorbent sheet 8 is formed of a non-woven material, particularly a synthetic felt. In various embodiments, a technical felt or other non-woven fabric based on polyester and acrylic is used (for example 75% polyester and 25% acrylic), obtained by carding and thermo-cohesion processes. In addition to being economical, such a material has excellent hygroscopic and liquid absorption and retention properties. The absorbent capacity is preferably not less than 6L / m2.

In various embodiments, the felt or other non-woven fabric comprises at least one superabsorbent polymer, of a per se known type, in order to favor the liquid absorption characteristics of the sheet 7. According to various embodiments, such a superabsorbent polymer in powdery form can be integrated into the non-woven fabric in the production phase of the latter, according to techniques known per se.

The absorbent sheet has a development in length greater than the length (height) of the inner envelope 6. In various embodiments, the development in length of the absorbent sheet 8 is greater than twice the length of the inner envelope 6, preferably at least the length of the absorbent sheet. triple, very preferably about a quadruple or slightly less than the length of the internal envelope 6. As mentioned, and as will become clearer below, in the assembled condition of the bag 1 object of the invention the absorbent sheet 7 is folded in order to be able to be housed at least partly in the inner casing 6, and for this purpose it preferably has at least three intermediate folds. The width of the absorbent sheet 8 is preferably slightly less than that of the internal envelope 6, in order to allow the insertion of at least part of the first in the second. The thickness of the absorbent sheet 8 is relatively small, for example between 0.5 and 1.5 cm, but the same is preferably soft or compressible, thereby advantageously being an aid for protecting the contents of the bag 1.

Still in the external casing 2 (and in particular, as will be seen, in the internal casing 6) there are two structural panels, indicated with 9 in figure 5, having the double function of ensuring a minimum rigidity to the bag 1 as a whole. , as well as facilitate its assembly.

For this purpose, in various embodiments, the structural panels 9 are formed with a sheet material having less flexibility than the material or materials with which the outer 2 and inner 6 casings are formed, and preferably less flexibility even than that of the absorbent sheet 8. In preferential embodiments, the sheet material used to make the panels 9 - whose thickness is in any case reduced, indicatively not greater than 1-2 mm - is a paper-based or cellulosic material, most preferably a cardboard. The panels 8 can be obtained, for example, by means of elementary punching operations.

Preferably the panels 9 have a length not exceeding the length of the internal casing 6, in order to be received in the latter. Also the width of the panels 9 is preferably slightly less than that of the internal casing 6, in order to allow the insertion of the first in the second.

In the assembled condition of the bag 1, two respective first intermediate portions of the absorbent sheet 8 are housed in the internal space of the envelope 6, while two second end portions of the same sheet are folded on the outside of the major walls 7 of the envelope 6. structural panels 9 are also inserted in the internal envelope 6, each between a major wall 7 and a above-mentioned first portion of the absorbent sheet 8. The assembly formed by the internal envelope 7, the folded absorbent sheet 8 and the structural panels 9 is in turn contained in the internal space of the external envelope 2.

A preferred method for obtaining scholarship 1 will now be described with reference to figures 6-11. It should be noted that these figures are merely schematic, for example in terms of thicknesses, dimensions and proportions, as they are aimed at clearly highlighting the methodology followed.

The first stages of production concern the preparation of the outer shell 2, the inner shell 6, the absorbent sheet 8 and the structural panels 8.

The absorbent sheet 8 is then folded back on itself, or substantially in a V shape, as schematized in Figure 6, in correspondence with an intermediate or central transverse fold line, indicated by 10. In this way, two parts or halves are defined opposite of sheet 8a substantially opposite or parallel to each other. In order to facilitate the process, the folding line 10 can be defined in the production phase, for example by means of a series of small cuts.

The absorbent sheet 8 thus folded is then partially inserted into the internal envelope 6, through the relative open upper end, as shown schematically in figure 6. In this way, inside the envelope 6 there are two intermediate portions of the aforementioned opposite halves of sheet 8a, these intermediate portions being indicated with 8a <1> in Figure 12. As can be seen in Figure 12, each of the intermediate portions 8a <1> is substantially parallel to a relative major wall of the inner envelope 6. As can be seen in Figure 7, following the operation schematized in Figure 6, two extreme portions 8a <2> of the aforementioned opposite halves of sheet 8a protrude from the upper open end of the envelope 6.

In this condition, the two structural panels 9 are inserted inside the casing 6, through the relative open upper end, as shown schematically in figure 7. The panels 8 are inserted so that each of them is located between a relative intermediate portion of sheet 8a <1> and a corresponding major wall of the internal envelope 6, as seen in Figure 12.

In a possible variant, starting from the condition of figure 6, a respective structural panel 9 is superimposed on each of the opposite portions of sheet 8a, with the lower end of the panel itself substantially at or near the fold determined by the fold line 10, ie with the two structural panels 9 substantially parallel to each other with the respective intermediate portions 8a <1> of the opposite portions of sheet 8a interposed. Subsequently, the two panels 8 and the interposed intermediate portions of sheet 8a <1> are inserted into the internal envelope 6 through the relative open upper end. Such a variant of the methodology may be advantageous in order to facilitate the insertion of the absorbent sheet 8 partially folded into the internal envelope 6, exploiting for this purpose the greater rigidity of the panels 8.

In any case, after the sheet 8 folded in two and the panels 8 have been inserted into the outer casing, the extreme portions of the sheet 8a <2> which protrude from the outer casing 6 are folded on the outside of the major walls 7 of the The casing itself, as schematized in Figures 8 and 9 (these further folding areas are schematized in 10a in Figure 4).

At this point, the assembly formed by the inner envelope 6, the folded absorbent sheet 8 and the structural panels 9 is inserted into the outer envelope 2, through the relative open upper end, until the upper end of the envelope 6 is to be in correspondence with a region of the upper end of the casing 2, but below the relative open end, as shown in figure 11. This operation is particularly easy thanks to the presence of the structural panels 9, whose relative rigidity favors the insertion of the aforesaid assembly into the outer casing 2, which is by its nature extremely flexible.

In the condition thus assembled, as shown in Figures 11-12, the opposite major walls 7 of the inner envelope 6 are generally parallel to the opposite major walls 3 of the outer envelope 2, and each extreme portion of sheet 8a <2> is arranged between a major wall 3 of the outer envelope 2 and a corresponding major wall 7 of the inner envelope 6. As mentioned, the intermediate portions of sheet 8a <1> instead extend inside the envelope 6, substantially parallel to each other, with respect to to the walls 7 of the envelope 6 and to the panels 8, with the latter each arranged between an intermediate portion of sheet 8a <1> and a wall 7, as can be seen in figure 12.

It will be appreciated from what has been described that, thanks to the structure described, the various components of the bag 1 (i.e. the external envelope 2, the internal envelope 6, the absorbent sheet 8 and the structural panels 8) are free from mutual engagement, i.e. not made solidarity or fixed to each other. This simplifies, in addition to the assembly of the bag 1, also the differentiated disposal of the parts of different materials that make it up (it should be noted in this regard that also the parts of the closing arrangement 5, for example the parts 5a and 5b exemplified in figure 2 for a zip-lock closure, they are preferably made of plastic material welded to the inner side of the respective walls 3 of the casing 2).

In the bag 1 thus obtained, for example, a bottle 13 can be housed, as shown schematically in Figure 12. As previously mentioned, the outer casing 2 preferably has a length dimension less than the corresponding length dimension of the inner casing 2 and comprises , in a zone thereof comprised between the respective upper end and the upper end of the inner casing 6, a closure arrangement 5, for example of the zip-lock type.

In this way the bag 1 can be closed, as schematized in figure 12, with the inside of the envelope 2 which is sealed in an openable way. The bag can be comfortably carried by holding it with one hand at the handle made by the openings 4.

In the normal use of the bag 1, the internal envelope 8 fulfills the functions of protection against shocks, or acts as a shock-absorbing material, relative to the bottle 13 or other fragile container. This impact protection function is further enhanced by the presence of the absorbent sheet 8, which as mentioned is preferably soft or compressible. It will therefore be appreciated that the folded portions 8a <1>, 8a <2> of the sheet 8 form a plurality of layers on opposite sides of the bottle, suitable for cushioning the impacts (in this perspective, possibly, the internal envelope could not even be formed with a shock-absorbing material, such as the aforementioned bubble wrap). The presence of the structural panels 9 confers a relative rigidity to the structure of the bag which, although reduced, allows the effective manipulation or handling of the bag itself when empty, as well as its storage.

In the event of an excessive impact, the bottle 13 or other container can break and release its liquid content inside the bag 1. In this case, the internal envelope 6 creates a first barrier that opposes the dispersion of the liquid, with the respective intermediate portions 8a <1> of sheet 8 which allow to absorb a significant part of the liquid itself. The absorption capacity is improved by the presence of the aforementioned superabsorbent polymer, integrated in the sheet 8. The structural panels 9 can also contribute to the absorption of the liquid, when formed with an absorbent material, such as cardboard.

The liquid absorbed from the inside of the envelope 6 can transfer to some extent also to at least part of the extreme portions 8a <2> of the sheet 8, for example by capillarity, thereby contributing to the absorption of the liquid. In any case, given the impermeability of the outer casing 2, the liquid that impregnates the extreme portions 8a <2> is not transferred outside. In the event that the rupture of the bottle 13 is due to a fall of the bag, or occurs when the bag 1 is in a reclined position, the presence of the closure arrangement 5 and the impermeability of the outer casing 2 prevents the liquid from escaping from the bag itself. In such circumstances, the liquid can obviously escape from the inner container 6 and directly reach the extreme portions 8a <2> of the absorbent sheet 8, which together with the inner portions 8a <2> will in any case perform their absorption function.

Another advantage of the proposed solution, particularly important when the container received from the bag 1 is made of glass, is represented by the fact that the risk of tearing of the bag 1 is considerably reduced thanks to the presence of the folded portions 8a <1>, 8a <2> of the sheet 8: it will in fact be appreciated that even in the presence of sharp pieces of glass, caused by the breaking of the bottle 13, the likelihood of tearing of the internal envelope 6 and, even more so, of the external envelope 2, are minimal.

The bag according to the invention, in addition to being simple to make, therefore also proves to be remarkably reliable. Its further advantage is its compactness, i.e. its reduced thickness, when not in use (indicatively not exceeding 5 cm).

Obviously, in case of breakage of the bottle 13 or other breakable container housed in the bag 1, the latter will not be reusable. As mentioned, the fact that its parts are free from mutual commitment facilitates their differentiated disposal.

In view of the particularly simple assembly methodology, the bag object of the invention can also be assembled extemporaneously, when the need arises, for example directly in a commercial establishment, such as a winery or other type of shop.

From the above description the characteristics of the present invention are clear, as well as its advantages.

It is clear that numerous variants are possible for the person skilled in the art to the method and the reusable bag described as an example, without thereby departing from the scope of the invention as defined in the following claims.

It should be noted, for example, that the bag 1 could comprise a single structural panel 9, instead of two. Two structural panels of the type indicated with 9 could also be obtained from the same sheet of material folded back on itself.

As mentioned, the sheet material used to make the envelopes 2 and 6 could be of the same type (for example polyethylene), or of different types.

The bag object of the invention can of course be prepared in various formats, for the transport and / or packaging of containers of various sizes and types.

Claims (10)

CLAIMS 1. A method of obtaining a reusable bag (1) for breakable containers of liquids (13), particularly glass bottles, comprising the steps of: i) form an external envelope (2) with a flexible sheet material impermeable to liquids, the external envelope (2) defining a respective internal space and having two opposite major walls (3) and an open upper end, ii) form an internal envelope (6) with a flexible sheet material impermeable to liquids, the internal envelope (6) defining a respective internal space and having two opposite major walls (7) and an open upper end, iii) forming an absorbent sheet (8) with a flexible material capable of absorbing liquids, iv) forming at least one structural panel (9), preferably at least two structural panels, with a sheet material, the at least one structural panel (9), or each structural panel, having a length dimension less than a length dimension of 'outer casing (2), v) insert the inner shell (6), the absorbent sheet (8) and at least one structural panel (9) in the outer shell (2), in which step iii) comprises the operation of forming the absorbent sheet (8) with a greater length than a length dimension of the internal envelope (6), and in which step v) comprises the operations of fold the absorbent sheet (8) on itself, i.e. substantially in a V shape, in correspondence with its intermediate transverse folding line (10), in order to define two opposite parts of sheet (8a) substantially parallel to each other, insert into the internal envelope ( 6), through its open upper end: the absorbent sheet (8) folded, so that in the inner envelope (6) there are two intermediate portions (8a <1>) of said opposite parts of sheet (8a), each substantially parallel to a relative major wall ( 7) of the inner envelope (6), and from the upper open end of the inner envelope (6) protrude two extreme portions (8a <2>) of said opposite parts of sheet (8a), and Γ at least one structural panel (9), or each structural panel, between an intermediate portion (8a <1>) of a said sheet part (8a) and a corresponding major wall (7) of the inner envelope (6), fold the extreme portions (8a <2>) of said sheet parts (8a) on the outside of the major walls (7) of the inner envelope (6), and insert the assembly formed by the inner envelope (6), the structural panel or panels (9) and the folded absorbent sheet (8) into the outer envelope (2), through the relative open upper end, with the open upper end of the 'inner casing (6) at an upper end region of the outer casing (2) and with the opposite major walls (7) of the inner casing (6) which are generally parallel to the opposite major walls (3) of the outer envelope (2), in such a way that each extreme portion (8a <2>) of said sheet parts (8a) is arranged between a major wall (3) of the outer envelope (2) and a corresponding major wall ( 7) of the inner casing (6). The method according to claim 1, wherein step iii) comprises forming the absorbent sheet (8) with a non-woven fabric material, particularly a synthetic felt, which includes at least one superabsorbent polymer, particularly in powder form. 3. The method according to claim 1 or claim 2, wherein the flexible sheet material of the inner envelope (6) is a "pluribalF or" airball type material. The method according to any one of the preceding claims, wherein step i) comprises the operations of form the inner shell (6) with a length dimension less than the length dimension of the outer shell (2), and to provide, in the upper end region of the outer casing (2), in an area between the respective upper end and the upper end of the inner casing (6), a closure arrangement (5) to seal in an openable manner the relative internal space in which the internal envelope (6), the absorbent sheet (8) and the structural panel or panels (9) are arranged. The method according to any one of the preceding claims, wherein step iv) comprises forming the structural panel or panels (9) with a sheet material having less flexibility than at least the sheet material of the outer envelope (2) and the sheet material of the inner envelope (6), preferably a paper-based material capable of absorbing liquids, most preferably a cardboard. The method according to any one of the preceding claims, wherein the outer envelope (2), the inner envelope (6), the absorbent sheet (8) and the at least one structural panel (9) are free from mutual engagement . 7. A reusable bag for frangible containers for liquids, particularly for glass bottles, obtainable with the method according to one or more of claims 1-6, comprising: - an outer envelope (2), formed with a flexible sheet material impermeable to liquids, the outer envelope (2) defining a respective inner space and having two opposite major walls (3) and an open upper end, - a inner envelope (6), formed with a flexible sheet material impermeable to liquids, the inner envelope (6) defining a respective internal space and having two opposite major walls (7) and an open upper end, - an absorbent sheet (8), formed of a flexible material capable of absorbing liquids, - at least one structural panel (9), preferably at least two structural panels, formed with a sheet material, wherein the inner casing (6) is housed in the outer casing (2) with the respective upper end at an upper end region of the outer casing (2), the opposite major walls (7) of the inner casing (6) being generally parallel to the opposite major walls (3) of the outer envelope (2), in which the at least one structural panel (9), or each structural panel (9), is arranged in the inner shell (6) in a position generally parallel to the opposite major walls (7) of the inner shell (6), in which the absorbent sheet (8) has a development in length greater than a dimension of length of the internal envelope (6) and has at least three intermediate folds (10, 10a), so as to define at least two extreme portions of the sheet ( 8a <2>) and two intermediate portions of sheet (8a <1>) generally parallel to each other, in which each extreme portion of the sheet (8a <2>) is arranged between a major wall (3) of the external envelope (2) and a corresponding major wall (7) of the internal envelope (6), substantially parallel to them, wherein the at least one structural panel (9), or each structural panel, is arranged between an intermediate sheet portion (8a <1>) and a corresponding major wall (7) of the inner envelope (6), substantially parallel to they. The reusable bag according to claim 6, wherein - the absorbent sheet (8) is formed of a non-woven material, particularly a synthetic felt, which includes at least one superabsorbent polymer, and / or - the sheet material of the inner wrapper (6) is a pluribair type material or "Airball, and / or - the structural panel (9), or each structural panel, is / are formed of a sheet material having less flexibility than the sheet material of the inner envelope (6) and the sheet material of the outer envelope (2), preferably a paper-based material capable of absorbing liquids, most preferably a cardboard, and / or - the external envelope (2), the internal envelope (7), the absorbent sheet (8) and the at least one structural panel (9) are free from mutual engagement. The reusable bag according to claim 7 or 8, wherein the outer casing (2) has a dimension of length greater than the length dimension of the inner casing (6) and comprises, in an area thereof comprised between the respective end upper and upper end of the inner envelope (6), a closure arrangement (5) for opening in an openable manner the relative inner space in which the inner envelope (6), the absorbent sheet (8) and the panel or structural panels (9). 10. A kit for making a reusable bag for frangible containers for liquids, particularly for glass bottles, for implementation of the method according to one or more of claims 1-6, comprising a said outer casing (2), a said casing interior (6), a said absorbent sheet (8) and at least one said structural panel (9), preferably at least two said structural panels.