Producing a housing for a lighting device

Abstract

A housing for an elongated lighting device formed from a piece of cellulose fiber material windable about a mold. The piece comprises a first piece portion and a second piece portion. The piece has a plurality of primary aperture arrangements. When the piece is wound around the mold, the first and second piece portions are adhered to one another to form a physical bound of the housing for the lighting device, in which the plurality of primary aperture arrangements overlap one another so that the overlapped primary aperture arrangements defines at least one light exit window of the housing.

Description

[0001] Producing a housing for a lighting device

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the field of lighting devices, and in particular to lighting devices comprising recyclable material.

[0004] BACKGROUND OF THE INVENTION

[0005] There is an increasing reliance on artificial lighting in everyday life. Traditionally, lighting devices or luminaires for providing artificial light are formed of metallic or plastic components. In particular, it is extremely common for housings and structural supports for lighting devices to be formed of metallic or plastic components. Disadvantageously, components made of such materials add significant weight to the lighting and are difficult to assemble (e.g., requiring screws and / or adhesive).

[0006] One proposed approach to reduce the environmental impact of a lighting device is to replace metallic or plastic housings / supports with housings / supports made from paper- derived material, such as cardboard or paperboard.

[0007] To make such devices, conventional processes consist of twining several paper layers around a mold, followed by punching the paper layers to provide a paper housing with a light exit window.

[0008] There is an ongoing desire to improve the process of making lighting devices, particularly those comprising components formed from environmentally friendly material such as paper-derived material.

[0009] US 9989220B2 discloses a light device comprises a light source, a driver for providing an output to said light source, and a first housing. The first housing comprises a blister pack with at least one compartment suitable for locating said light source and driver.

[0010] US 2021213147A1 discloses light generating devices employing ultraviolet light emitting diodes and one or more UV active materials, such as UV reflective materials, UV scattering materials, and UV transparent materials. US 20150377422A1 discloses a tubular lighting device comprising a light engine and a flexible material sheet wrapped around said light engine such that a tubular housing enclosing said light engine is formed.

[0011] US 20110129625A1 discloses a method and apparatus for constructing a sheet of laminate material, which may be fibreboard.

[0012] SUMMARY OF THE INVENTION

[0013] The invention is defined by the claims.

[0014] According to examples in accordance with an aspect of the invention, there is provided a housing for an elongated lighting device that extends along a first axis, the housing being formed from a piece of cellulose fiber material windable about a mold. The piece comprises a first piece portion and a second piece portion. The piece has a plurality of primary aperture arrangements, each primary aperture arrangement extending along the first axis. When the piece is wound around the mold, the first and second piece portions are adhered to one another to form a physical bound of the housing for the lighting device, in which the plurality of primary aperture arrangements overlap one another so that the overlapped plurality of primary aperture arrangements defines at least one light exit window of the housing extending along the first axis.

[0015] The piece of cellulose fiber material is wound around the mold in loops. There is at least one first entire loop that goes entirely round the mold. However, after the first entire loop then subsequent loop(s) can be a partial one which only covers a part of the side of the housing. Of course, the subsequent loop(s) can also be another entire loop.

[0016] The present disclosure provides a housing, formed from a piece of cellulose fiber material, which can be manufactured without the need of punching the housing in order to provide a housing with a light exit window, once the shape of the housing is formed from the piece. In particular, the proposed approach provides a housing without undesirable deformations of the surface of the housing due to punching impact or stress release. By removing the punching step in the manufacturing of a housing for elongated lighting devices, the housing can have a more consistent size and thus can render the use of housing made of cellulose fiber material more reliable.

[0017] The first piece portion may comprise a first primary aperture arrangement and the second piece portion comprises a second primary aperture arrangement. A first distance may be equal to a loop length of the piece when wound around the mold, wherein the first distance is a distance along the piece between a center of the first primary aperture and a center of the second primary aperture. This allows to provide a housing with consistent dimensions.

[0018] Alternatively, in some examples, the piece comprises a plurality of piece portions, each piece portion comprising a respective primary aperture arrangement. When the piece is wound around the mold in loops, the piece portions are adhered together to form a stack of layers such that each primary aperture arrangement lies in a different layer. For each pair of neighboring primary aperture arrangements: a first one of the pair of neighboring primary aperture arrangements lies in a first layer; a second one of the of the pair of neighboring primary aperture arrangements lies in a second layer, more distant from a centroid of the housing; and the distance between centers of the pair of neighboring primary aperture arrangements along the piece is equal to the loop length, measured in a first plane, of the first layer, wherein the normal to the first plane is in the first axis.

[0019] In some examples, for each pair of neighboring primary apertures arrangements, a distance between the centers of the pair of neighboring primary aperture arrangements along the piece increases proportionally with the distance between the pair of neighboring primary aperture arrangements and the centroid of the housing (after wound) increases. In other words, the loop length of each loop increases proportionally with more loops wound. This further allows to manufacture housings with consistent dimensions, with each varying the mold dimensions, thickness of the piece and / or number of layers disposed on the mold.

[0020] In some examples, each of the plurality of primary aperture arrangements comprises at least a first secondary aperture and a second secondary aperture linearly arranged parallel to the first axis, configured so that a rib is formed between the first secondary aperture and the second secondary aperture. The presence of such ribs reinforces the structure of the housing by ensuring the strength of the housing.

[0021] In some examples, the housing is an elongated prism or cylinder. In more specific examples, the housing is an elongated prism having a rectangular cross-sectional shape.

[0022] The invention further relates to a process for producing a housing for an elongated lighting device that extends along a first axis, the process comprising providing a plurality of primary aperture arrangements in a piece of cellulose fiber material for forming the housing, the plurality of primary aperture arrangements extending along the first axis; and disposing the piece on a mold after providing the plurality of primary aperture arrangements in the piece, and thereby forming the housing. Disposing the piece on the mold comprises winding the piece around the mold in loops. There is at least one first entire loop that go entirely round the mold. However, after the first entire loop then subsequent loops can be a partial one which only covers a part of the side of the housing. Of course, the subsequent loop(s) can also be another entire loop. The piece comprises at least a first piece portion and a second piece portion. When the piece is wound around the mold, the first and second piece portions are adhered to one another to form a physical bound of the housing for the lighting device, in which the plurality of primary aperture arrangements overlap one another so that the overlapped plurality of primary aperture arrangements defines at least one light exit window of the housing extending along the first axis.

[0023] As described above, by avoiding punching, the process of producing a housing can provide a housing with consistent dimensions and a more reliable manufacture of a housing.

[0024] In some examples of the process, providing the plurality of primary aperture arrangements in the piece comprises flat cutting, roll-to-roll cutting or press molding. Other methods for providing a plurality of primary aperture arrangements will be apparent to the appropriated skilled person.

[0025] In some examples of the process, the first piece portion comprises a first primary aperture arrangement and the second piece portion comprises a second primary aperture arrangement. A first distance may be equal to a loop length of the piece when wound around the mold, and the first distance may be a distance along the piece between a center of the first primary aperture and a center of the second primary aperture. This allows to produce a housing with consistent dimensions.

[0026] Alternatively, in some examples of the process, the piece comprises a plurality of piece portions, each piece portion comprising a respective primary aperture arrangement. When the piece is wound around the mold in loops, the piece portions are adhered together to form a stack of layers such that each primary aperture arrangement lies in a different layer; and for each pair of neighboring primary aperture arrangements: a first one of the pair of neighboring primary aperture arrangements lies in a first layer; a second one of the of the pair of neighboring primary aperture arrangements lies in a second layer, more distant from a centroid of the housing; and the distance between centers of the pair of neighboring primary aperture arrangements along the piece is equal to the loop length, measured in a first plane, of the first layer, wherein the normal to the first plane is in the first axis.

[0027] In some examples of the process, for each pair of neighboring primary apertures arrangements, a distance between the centers of the pair of neighboring primary aperture arrangements along the piece increases proportionally with the distance between the pair of neighboring primary aperture arrangements and the centroid of the housing increases. In other words, the loop length of each loop increases proportionally with more loops wound, in the meantime, the primary apertures arrangements of each layer can overlap on the sidewall of the housing. This further allows to obtain consistent dimensions for the housing.

[0028] In some examples of the process, each of the plurality of primary aperture arrangements comprises at least a first secondary aperture and a second secondary aperture linearly arranged parallel to the first axis, configured so that a rib is formed between the first secondary aperture and the second secondary aperture. The presence of such ribs can reinforce the structure of the housing by ensuring the strength of the housing.

[0029] The process may further comprise removing the rib from the housing by cutting. This allows to remove the ribs in a simpler manner and with lower stress impact than punching, reducing the potential deformations on the housing due to stress release.

[0030] In some examples, the cellulose fiber material is derived from bark, wood, stems, leaves or any other part of a plant. This provides a housing made of sustainable material, helping to reduce the carbon footprint of the manufacture of housing for luminaires.

[0031] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0034] Figure 1 provides a view of a piece of material;

[0035] Figure 2 illustrates the piece of material following the forming of primary aperture arrangements in piece portions;

[0036] Figure 3 illustrates an alternative piece of material, in which each primary aperture arrangements takes the form of respective single aperture;

[0037] Figure 4 provides a perspective view of the piece of material as it is being wound around a mold;

[0038] Figure 5 provides a sectional view of the piece of material as it is being wound around a mold;

[0039] Figure 6 is a perspective view of the assembled housing; and Figure 7 illustrates a perspective view of an alternative example piece of material as it is being wound around a mold.

[0040] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] The invention will be described with reference to the Figures.

[0042] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

[0043] The invention provides a housing for an elongated lighting device that extends along a first axis, the housing being formed from a piece of cellulose fiber material windable about a mold. The piece comprises a first piece portion and a second piece portion. The piece has a plurality of primary aperture arrangements, each primary aperture arrangement extending along the first axis. When the piece is wound around the mold, the first and second piece portions are adhered to one another to form a physical bound of the housing for the lighting device, in which the plurality of primary aperture arrangements overlap one another so that the overlapped primary aperture arrangements defines at least one light exit window of the housing extending along the first axis.

[0044] A herein proposed approach is based on a housing, formed from a piece of cellulose fiber material, which can be manufactured without the need to punch the housing to form a light exit window, once the (desired) shape of the housing is formed from the piece. This provides a housing with a reduced risk of undesirable deformations of the surface of the housing that may otherwise result due to punching impact or stress release. By removing the punching step in the manufacturing of a housing for elongated lighting devices, the housing can have a more consistent size and thus can render the use of housing made of cellulose fiber material more reliable.

[0045] As described above, the housing is formed from a piece of cellulose fiber material. The cellulose fiber material (i.e., plant-derived fibers) is any material formed from cellulose fibers. It is well known how cellulose fibers can be derived from bark, wood, stems, leaves or any other part of a plant. This provides a housing made of sustainable material, helping to reduce the carbon footprint of the manufacture of housing for elongated lighting device, such as luminaires. To further reduce the carbon footprint of the manufacture of housing for elongated lighting device, the cellulose fiber material can be made of or partially made of recycled paper.

[0046] Figure 1 provides a view of a (portion of a) piece of material 100 before it is wound around a mold to define a housing and before any primary aperture arrangements are formed or created (e.g., cut) in the piece of material.

[0047] It is possible to define a plurality of piece portions 132, 135 in the piece of material 100. The plurality of piece portions are portions that will, when the piece 100 is wound around a mold to define the housing, come into contact with one another (e.g., be adhered to one another) so as to form a stack of piece portions. In the illustrated example, the piece 100 comprises at least a first piece portion 132 and a second piece portion 135.

[0048] The housing, formed by winding the piece of material 100, for an elongated lighting device is elongate along a length L. For ease of explanation, Figure 1 further illustrates a first axis Yi of the piece 100. The axis Yi is positioned parallel with the length L of the piece.

[0049] Figure 2 illustrates an example of the piece 100 following the forming (e.g., cutting) of primary aperture arrangements 112, 115 in the piece portion.

[0050] Each piece portion 130 comprises a respective primary aperture arrangement 110. After the piece 100 is wound around the mold, the piece portions 130 (each comprising a respective primary aperture arrangement) will be adhered together to form a stack of layers such that each primary aperture arrangement 110 lies in a different layer, but overlapping one another (e.g., to form a through hole throughout the stack of layers).

[0051] After winding of the piece 100, the primary aperture arrangements will thereby overlap one another to define one or more light exit windows for the housing.

[0052] Thus, each piece 100 may comprise a plurality of primary aperture arrangements 110, each primary aperture arrangement 110 extending along the first axis Yi. As previously mentioned, each primary aperture arrangement 110 is positioned or otherwise defined in a different piece portion 130.

[0053] A first distance D may be defined as the distance along the piece 100 between a center of the first primary aperture arrangement 112 and a center of the second primary aperture arrangement 115.

[0054] In the illustrated example, each primary aperture arrangement 112, 115 is formed of a plurality of (here: three) secondary apertures 117, 118, 119. The secondary apertures define one or more (here: two) reinforcing ribs 120 of the respective primary aperture arrangement 112, 115, each reinforcing rib 120 being disposed between two secondary apertures.

[0055] Thus, each of the plurality of primary aperture arrangements 110 may comprise at least a first secondary aperture 118 and a second secondary aperture 119 linearly arranged parallel to the first axis Yi. The secondary apertures are configured so that a rib 120 is formed between the first secondary aperture 118 and the second secondary aperture 119. The presence of such ribs 120 can reinforce the structure of the housing by ensuring the strength of the housing during manufacture.

[0056] Any one or more of the ribs 120 of the piece 100 can be removed after manufacture of the housing to provide a larger (e.g., single) light exit window. Alternatively, the ribs 120 can be kept to provide multiple light exit windows for the housing.

[0057] Figure 3 illustrates an alternative piece of material 100, in which each primary aperture arrangement 110 takes the form of a respective single aperture. This may, for instance, be produced by cutting any reinforcing ribs 120 (e.g., of the version illustrated in Figure 2) between secondary apertures for each primary aperture arrangement.

[0058] Of course, in some alternative examples, the primary aperture arrangements 110 are directly cut or formed as a single aperture (e.g., without producing the secondary apertures for each primary aperture arrangement).

[0059] As previously explained, a housing is produced by winding the piece of material about a mold such that the primary aperture arrangement(s) overlap one another. A proposed method for producing such a housing is hereafter described with reference to Figures 4 to 7.

[0060] The method for producing the housing comprises providing a plurality of primary aperture arrangements in a piece of cellulose fiber material for forming the housing. The plurality of primary aperture arrangements extends along the first axis. Appropriate examples of suitable pieces of material producing by performing this procedure have been previously described.

[0061] By way of example only, providing the plurality of primary aperture arrangements 110 in the piece 100 exemplified in Figures 2 and 3 may comprise flat cutting, roll-to-roll cutting or press molding. Flat cutting means the paper is cut when the paper is placed flat. Roll-to-roll means before and after the cutting, the paper is rolled on cores, e.g., steel rods. Press molding comprises using a press mold to create the primary aperture arrangements 110. A press mold is a commonly used tool to punch sheet material so as to create desired shapes with such sheets. A press mold may be in the form of a flat plate, may also be in the form of two rolls with pre-set knifes or blades on the surfaces. Other methods for providing a plurality of primary aperture arrangements will be apparent to the appropriately skilled person.

[0062] As previously explained, the piece comprises a plurality of piece portions, e.g., at least a first piece portion and a second piece portion. A respective primary aperture arrangement may be positioned, located or otherwise defined in each piece portion.

[0063] The method subsequently performs a step of disposing the piece on a mold, to thereby form the housing. The step of disposing the piece on the mold comprises winding the piece around the mold.

[0064] Figures 4 and 5 both illustrate the piece of material during this winding process, i.e., as it is being wound about a mold 150. Figure 4 provides a perspective view and Figure 5 provides a sectional view.

[0065] As previously explained, each of the plurality of primary aperture arrangements 110 may comprise at least a first secondary aperture 118 and a second secondary aperture 119 linearly arranged parallel to the first axis Yi. The secondary apertures are configured so that a rib 120 is formed between the first secondary aperture 118 and the second secondary aperture 119. Figure 4 illustrates an example piece of material with a plurality of secondary apertures (here: three 117, 118 and 119). A further example without the plurality of secondary apertures will be provided below.

[0066] For improved contextual understanding, Figure 4 also illustrates a first plane pi of the piece 100, when the piece 100 is wound on a mold 150. The first plane pi is configured to be perpendicular with the first axis Yi (along which the primary aperture arrangements extend).

[0067] For improved contextual understanding, Figure 5 illustrates the centroid C of the housing.

[0068] After winding the piece 100 about the mold 150, the first and second piece portions are adhered to one another to form a physical bound of the housing for the lighting device. This process is conceptually illustrated by the arrow of Figure 5, demonstrating how the first and second piece portions are adhered to one another.

[0069] The adhering of the first and second piece portions is configured such that the plurality of primary aperture arrangements 110 overlap one another. The overlapped plurality of primary aperture arrangements 110 thereby defines at least one light exit window of the housing, which will extend along the first axis Yi. It is recognized that if a (existing) tubular housing of cellulose fiber material is cut open, e g., to create a light exit window, then the tubular housing is likely to deform due to internal stress which is released after the opening. The most significant deformation will occur towards the middle of the light exit window, causing contraction or constriction (i.e., a reduction in size) of the light exit window. In some examples, the light exit window may also be distorted to such an extent that there is an enlarged opening at undesired position(s).

[0070] The present invention reduces or avoids this risk, by way of the step of providing the plurality of primary aperture arrangements 110 before winding the piece 100 on the mold 150. In particular, the cutting or forming of the primary aperture arrangements (before winding) and appropriate alignment of the primary aperture arrangement (during winding) avoids the need to perform cutting of a light exit window after forming the housing.

[0071] After adhering the first and second piece portions to one another to form a physical bound of the housing for the lighting device, the mold 150 can be removed from the assembly to thereby provide a housing.

[0072] As previously disclosed and illustrated in Figure 4, each of the plurality of primary aperture arrangements 110 may comprise at least a first secondary aperture 118 and a second secondary aperture 119 linearly arranged parallel to the first axis Yi. The first secondary aperture 118 and the second secondary aperture 119 may be configured so that a rib 120 is formed between the first secondary aperture 118 and the second secondary aperture 119.

[0073] When the piece 100 illustrated in Figure 2 is wound on the mold 150, the reinforcing ribs 120 of each layer will overlap and will thereby provide a housing with multiple light exit windows. The presence of such ribs 120 can reinforce the structure of the housing by ensuring the strength of the housing once the piece 100 is wound around the mold 150. Thus, by not cutting the ribs 120 of the housing after winding the piece 100, a stronger and reinforced housing with multiple light exit windows can be provided.

[0074] Alternatively, rather than keeping the ribs 120 to provide multiple light exit windows 140 for the housing, the production of a housing may further comprise removing any one or more of the ribs 120 from the housing by cutting. Other methods for removing a rib from the housing will be apparent to the appropriated skilled person. This allows to remove any one or more of the ribs 120 in a simpler manner and with lower stress impact than punching, reducing the potential deformations on the housing due to stress release.

[0075] Following the optional step of removing any one or more of the ribs 120 from the housing by cutting, the above method produces a housing as illustrated in Figure 6. Figure 6 is a perspective view of the assembled housing 160 on the mold 150. The assembled housing 160 has a single light exit window 140.

[0076] Fig 7 illustrates the winding of an alternative piece of material, in which each primary aperture arrangement comprises a single aperture extending along the first axis Yi. It will be clear that there is no need to perform the step of removing the ribs in order to produce the assembled housing 160 illustrated in Figure 6.

[0077] The housing 160 can be an elongated prism or a cylinder. In a preferred embodiment, the housing 160 is an elongated prism having a rectangular cross-sectional shape, e g., as shown in Figure 6. However, this is not essential, and other shapes and / or designs for the housing 160 will be apparent to the appropriately skilled person.

[0078] Referring back to Figure 2, the first piece portion 132 may comprise a first primary aperture arrangement 112 and the second piece portion 135 may comprise a second primary aperture arrangement 115. As previously mentioned, a first distance D may be defined as the distance along the piece 100 between a center of the first primary aperture arrangement 112 and a center of the second primary aperture arrangement 115. When the piece 100 is wound around the mold 150 as illustrated in Figures 4 to 7, the first distance D may be equal to (i.e. , effectively define) a loop length of the piece 100. This allows the provision of housing 160 with consistent dimensions.

[0079] In some examples, for each pair of neighboring primary aperture arrangements 110, a first one of the pair of neighboring primary aperture arrangements lies in a first layer; a second one of the of the pair of neighboring primary aperture arrangements lies in a second layer, more distant from the centroid C of the housing 160. The distance between centers of the pair of neighboring primary aperture arrangements 110 along the piece 100 is effectively equal to the loop length, measured in the first plane pi, of the first layer, wherein the normal to the first plane pi is in the first axis Yi.

[0080] In some further examples, for each pair of neighboring primary apertures arrangements, the distance D between the centers of the pair of neighboring primary aperture arrangements increases proportionally to the distance of the pair of neighboring primary aperture arrangements from the centroid C of the housing 160 because of the thickness of the piece 100 of cellulose fiber material. In other words, the distance between the centers of the pair of neighboring primary aperture arrangements will increase with an increasing number of layers disposed around the mold. This distance will also increase with increasing wall thickness of the housing 160 formed with the piece 100 of cellulose fiber material. This further facilitates the obtaining of consistent dimensions for the housing 160. As described herein, by avoiding punching, the process of producing a housing can provide a consistent size and a more reliable manufacture of a housing.

[0081] Although not explicitly illustrated for the sake of clarity, the housing for the elongated lighting device may comprise additional components, e.g., light emitting element, reflector, driving circuitry, one or more mounts, sensing circuitry, monitoring circuitry, control circuitry and so on.

[0082] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0083] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0084] If the term "adapted to" is used in the claims or description, it is noted the term "adapted to" is intended to be equivalent to the term "configured to". If the term "arrangement" is used in the claims or description, it is noted the term "arrangement" is intended to be equivalent to the term "system", and vice versa.

[0085] Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. A process for producing a housing (160) for an elongated lighting device that extends along a first axis (Yi), the process comprising: providing a plurality of primary aperture arrangements (110) in a piece (100) of cellulose fiber material for forming the housing, the plurality of primary aperture arrangements extending along the first axis; and disposing the piece (100) on a mold (150) after providing the plurality of primary aperture arrangements in the piece, and thereby forming the housing (160); wherein disposing the piece on the mold comprises winding the piece around the mold in loops; wherein the piece comprises at least a first piece portion (132) and a second piece portion (135); and wherein, when the piece is wound around the mold: the first and second piece portions are adhered to one another to form a physical bound of the housing for the lighting device, in which the plurality of primary aperture arrangements overlap one another so that the overlapped plurality of primary aperture arrangements (110) defines at least one light exit window (140) of the housing extending along the first axis.

2. The process of claim 1, wherein the loops comprise at least one first loop which is an entire loop that goes entirely around the mold.

3. The process of claim 2, wherein after the first loop there is a subsequent loop being a partial one which only covers a part of the entire loop.

4. The process of claim 2, wherein after the first loop there is at least one subsequent loop being an entire loop which covers the whole of the first loop.

5. The process of claim 1, wherein providing a plurality of primary aperture arrangements in the piece comprises flat cutting, roll-to-roll cutting or punching.

6. The process of any of claims 1 to 5, wherein the first piece portion (132) comprises a first primary aperture arrangement (112) and the second piece portion (135) comprises a second primary aperture arrangement (115); and wherein a first distance (D) is equal to a loop length of the piece when wound around the mold, wherein the first distance is a distance along the piece (100) between a center of the first primary aperture arrangement (112) and a center of the second primary aperture arrangement (115).

7. The process of any of claims 1 to 6, wherein the piece comprises a plurality of piece portions, each piece portion comprising a respective primary aperture arrangement, wherein, when the piece is wound around the mold: the piece portions are adhered together to form a stack of layers such that each primary aperture arrangement lies in a different layer; and for each pair of neighboring primary aperture arrangements: a first one of the pair of neighboring primary aperture arrangements lies in a first layer; a second one of the pair of neighboring primary aperture arrangements lies in a second layer, more distant from a centroid of the housing (C); and the distance between centers of the neighboring primary aperture arrangements along the piece is equal to the loop length, measured in a first plane (pi), of the first layer, wherein the normal to the first plane is in the first axis.

8. The process of claim 7, wherein, for each pair of neighboring primary apertures arrangements, a distance between the centers of the pair of neighboring primary aperture arrangements along the piece increases proportionally with the distance between the pair of neighboring primary aperture arrangements and the centroid of the housing increases.

9. The process of any of claims 1 to 8, wherein each of the plurality of primary aperture arrangements (110) comprises at least a first secondary aperture (118) and a second secondary aperture (119) linearly arranged parallel to the first axis, configured so that a rib (120) is formed between the first secondary aperture and the second secondary aperture.

10. The process of any of claim 9, further comprising removing the rib from the housing by cutting.

11. The process of any of claims 1 to 10, wherein the cellulose fiber material is derived from bark, wood, stems, leaves or any other part of a plant.

12. A housing for an elongated lighting device made with the process of any of claims 1-11.

13. The housing of claim 12, wherein the housing is an elongated prism or cylinder.

14. The housing of claim 13, wherein the housing is an elongated prism having a rectangular cross-sectional shape.

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