SPRING CORE WITH MOLDED FOAM EDGE

Abstract

 A pocket spring core assembly (10) includes an arrangement (20) of multiple pocketed springs (25). Each of the pocketed springs includes a pocket of fabric material and a spring enclosed in the pocket. Further, the pocket spring core assembly (10) includes a barrier layer (30) on a vertical peripheral edge of the arrangement (20) of pocketed springs (25). Further, the pocket spring core assembly (10) includes a molded foam edge (40) formed on only the vertical peripheral edge of the arrangement (20) of pocketed springs (25). The barrier layer (30) separates the molded foam edge (50) from the fabric material of the pockets on the vertical peripheral edge of the arrangement (20) of pocketed springs (25).

Description

FIELD OF THE INVENTION

[0001] The invention relates to a spring core with pocketed springs, a bedding or seating product comprising a spring core with pocketed springs, and method of manufacturing a spring core with pocketed springs.

BACKGROUND

[0002] Spring cores are widely used in seating or bedding products. Such spring cores may be made from a matrix of multiple springs joined together directly as by helical lacing wires, or indirectly as by fabric within which each individual spring is contained. Pocket spring cores in which springs are respectively contained in a pocket of fabric are popular, due to the comfort and luxury feel provided by pocket spring cores.

[0003] In order to produce a seating or bedding product, foam elements may be added to the spring core. For example, such foam elements may be added on the top surface of the spring core, on the bottom surface of the spring core, and on vertical edges of the spring core. For example, such foam elements may be attached by gluing. A further possibility, as described by US 7,644,461 B2, is to mold a foam layer around the periphery of a pocket spring core of a mattress. In TW 201600050 A, it is described to package a plurality of pocket springs into a bag, and to mold foam material around the entire bag and enclosed pocket spring arrangement.

[0004] When molding a foam layer around the around the periphery of a pocket spring core as described in US 7,644,461 B2, it is typically not desirable that liquid foam material enters into spaces between individual pockets of the pocket spring core. In US 7,644,461 B2, this issue is addressed by connecting the outermost pockets of the pocket spring core in such a way that the material of the pockets forms a contiguous surface is formed along the periphery of the pocket spring core. However, this renders the process of connecting the individual pockets more complex. Further, in some scenarios the penetration of liquid foam into the interior of the spring core might not be prevented in a satisfactory manner. For example, liquid foam material could penetrate at a bottom or top edge of a connection between two adjacent pocket springs. When molding foam material around the entire pocket spring core, like for example described in TW 201600050 A, it may be difficult to form top and/or bottom cover layers of the spring core, which are of high relevance to user comfort, with desirable uniformity and quality. In fact, the teachings of TW 201600050 A rather aim at forming a foam element of non-uniform outer shape.

[0005] Accordingly, there is a need for techniques which allow for efficiently forming a foam edge around a pocket spring core.

SUMMARY

[0006] According to an embodiment, a pocket spring core assembly is provided, the pocket spring core assembly comprises an arrangement of multiple pocketed springs. Each of the pocketed springs comprises a pocket of fabric material and a spring enclosed in the pocket. Further, the pocket spring core assembly comprises a barrier layer on a vertical peripheral edge of the arrangement of pocketed springs. Further, the pocket spring core assembly comprises a molded foam edge formed on only the vertical peripheral edge of the arrangement of pocketed springs, e.g., in the shape of a rectangular frame which encloses the arrangement of pocketed springs. The barrier layer separates the molded foam edge from the fabric material of the pockets on the vertical peripheral edge of the arrangement of pocketed springs. When molding the foam edge, the barrier layer efficiently prevents foam material from penetrating between the pocketed springs. The barrier layer may be formed of a fabric material, e.g., the same fabric material as the pockets of the pocketed springs.

[0007] According to an embodiment, the barrier layer is glued to the fabric material of the pockets on the vertical peripheral edge of the arrangement of pocketed springs. By gluing the barrier layer to the vertical peripheral edge, the pocket spring core assembly can be stabilized in an efficient manner.

[0008] According to an embodiment, the pocket spring core assembly further comprises a top layer attached on a top surface of the arrangement of pocketed springs and of the molded foam edge. In addition or as an alternative, the pocket spring core assembly may comprise a bottom layer attached on a bottom surface of the arrangement of pocketed springs and of the molded foam edge. The top layer or bottom layer may be formed of a different material than the molded foam edge, e.g., a different foam material or some other cushioning material. For example, the material of the top layer or bottom layer could have a softer or firmer characteristic than the foam material of the molded foam edge.

[0009] According to an embodiment, the barrier layer extends from the vertical peripheral edge over at least a part of a bottom surface of the arrangement of pocketed springs. This helps to avoid that during molding of the foam edge foam material penetrates from the bottom side between the between the pocketed springs.

[0010] According to an embodiment, the barrier layer extends from the vertical peripheral edge over the entire bottom surface of the arrangement of pocketed springs. In this case, the barrier layer can be efficiently formed from a fabric sheet which is used to cover the bottom surface of the arrangement of pocketed springs.

[0011] According to an embodiment, the barrier layer extends from the vertical peripheral edge over at least a part of a top surface of the arrangement of pocketed springs. This helps to avoid that during molding of the foam edge foam material penetrates from the top side between the between the pocketed springs.

[0012] According to an embodiment, the barrier layer extends from the vertical peripheral edge over the entire top surface of the arrangement of pocketed springs. In this case, the barrier layer can be efficiently formed from a fabric sheet which is used to cover the top surface of the arrangement of pocketed springs. According to an embodiment, the barrier layer comprises at least a first sheet of fabric material which covers the entire top surface of the arrangement of pocketed springs and a second sheet of fabric material which covers the entire bottom surface of the arrangement of pocketed springs. The barrier layer may then be efficiently formed by wrapping the first sheet and the second sheet onto the vertical peripheral edge of the arrangement of pocketed springs.

[0013] According to an embodiment, the barrier layer comprises at least a first sheet of fabric material and a second sheet of fabric material. The first sheet of fabric material covers a first part of the vertical peripheral edge, and at least a first part of a top surface of the arrangement of pocketed springs. The first part of the top surface is adjacent to the first part of the peripheral edge. Further, the first sheet of fabric material covers at least a first part of a bottom surface of the arrangement of pocketed springs. The first part of the bottom surface is adjacent to the first part of the peripheral edge. The second sheet of fabric material covers a second part of the vertical peripheral edge and at least a second part of the top surface of the arrangement of pocketed springs. The second part of the top surface is adjacent to the second part of the peripheral edge. Further, the second sheet of fabric material covers at least a second part of the bottom surface of the arrangement of pocketed springs. The second part of the bottom surface is adjacent to the second part of the peripheral edge. Accordingly, the barrier layer can be formed in an efficient manner, by wrapping multiple sheets of fabric material over different parts of the vertical peripheral edge, so that also adjacent parts of the top surface and bottom surface are covered. The length of the first sheet which extends over the top surface or bottom surface may be in the range of to one to three times of a diameter of the pocketed springs, thereby ensuring that the barrier layer covers at least the outermost pocketed springs from the top and bottom side. However, also a larger extent of coverage on the top surface and bottom surface is possible. For example, the first sheet could covers the entire top surface of the arrangement of pocketed springs and the second sheet could cover the entire bottom surface of the arrangement of pocketed springs. In the latter case, the barrier layer may be efficiently formed by fabric sheets provided as additional fabric cover on the top surface and bottom surface of the arrangement of pocketed springs.

[0014] According to a further embodiment, a bedding or seating product is provided. The bedding or seating product comprises a pocket spring core assembly according to any one of the above embodiments.

[0015] According to a further embodiment, a method of manufacturing a pocket spring core assembly is provided. The method may for example be used for manufacturing a pocket spring core assembly according to any one of the above embodiments. The method comprises providing of an arrangement of multiple pocketed springs. Each of the pocketed springs comprises a pocket of fabric material and a spring enclosed in the pocket. Further, the method comprises providing a barrier layer on a vertical peripheral edge of the arrangement of pocketed springs. Further, the method comprises molding a foam edge on only the vertical peripheral edge of the arrangement of pocketed springs. The barrier layer separates the molded foam edge from the fabric material of the pockets on the vertical peripheral edge of the arrangement of pocketed springs. During the molding of the foam edge, the barrier layer prevents foam material from penetrating between the pocketed coils.

[0016] According to an embodiment, the molding of the foam edge comprises placing the arrangement of pocketed springs with the barrier in a mold. In particular, a bottom surface of the arrangement of pocketed springs is placed adjacent to a bottom surface of the mold, a top surface of the arrangement of pocketed springs is placed adjacent to a top surface of the mold, and the vertical peripheral edge of the arrangement of pocketed springs is placed spaced apart from a vertical peripheral edge of the mold. Accordingly, the foam material of the foam edge may be injected into the space left between the vertical peripheral edge of the arrangement of pocketed springs and the vertical peripheral edge of the mold. The bottom surface of the mold and the top surface of the mold prevent the foam material from extending beyond the bottom surface or the top surface of the arrangement of pocketed springs.

[0017] According to an embodiment, the method further comprises attaching a top layer on a top surface of the arrangement of pocketed springs and of the molded foam edge. In addition or as an alternative, the method may comprise attaching a bottom layer on a bottom surface of the arrangement of pocketed springs and of the molded foam edge. The top layer and/or the bottom layer may for example be glued to the molded foam edge. This may be accomplished without fixation to the fabric material of the pocketed springs. The top layer or bottom layer may be formed of a different material than the molded foam edge, e.g., a different foam material or some other cushioning material. For example, the material of the top layer or bottom layer could have a softer characteristic than the foam material of the molded foam edge.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Embodiments of the invention will be described with reference to the accompanying drawings.

Fig. 1A is a perspective view of a mattress including a pocket spring core assembly according to an embodiment.

Fig. 1B is an exploded perspective view for illustrating a pocket spring core assembly according to an embodiment.

Fig. 2 shows a top view of an arrangement of pocketed springs enclosed by a barrier layer according to an embodiment.

Figs. 3A and 3B illustrate an example of forming a barrier layer according to an embodiment.

Figs. 4A and 4B illustrate a further example of forming a barrier layer according to an embodiment.

Figs. 5A and 5B illustrate a further example of forming a barrier layer according to an embodiment.

Fig. 6 illustrates molding of a foam edge according to an embodiment.

Fig. 7 shows a flowchart for illustrating a method of manufacturing a pocket spring core assembly according to an embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

[0019] Exemplary embodiments of the invention will be described with reference to the drawings. While some embodiments will be described in the context of specific fields of application, such as in the context mattresses, the embodiments are not limited to this field of application. The features of the various embodiments may be combined with each other unless specifically stated otherwise. Throughout the following description, same or like reference numerals refer to same or like components or mechanisms.

[0020] As an example of a bedding or seating product according to an embodiment, FIG. 1A shows a mattress 1 which includes a pocket spring core assembly according to an embodiment. As illustrated, the mattress 1 substantially has the shape of a rectangular box, having a width W, a length L, and a height H. The mattress 1 may for example be formed by covering a top surface and/or a bottom surface of the pocket spring core assembly with a foam pad layer and/or a fiber pad layer. Further, the mattress 1 may include an upholstered cover material encloses the pocket spring core assembly and, if provided, pad layer(s). In the following description, the designations "top" and "bottom" refer to orientations in normal usage of the mattress 1.

[0021] Fig. 1B further illustrates the structure of the pocket spring core assembly 10. In Fig. 1B a direction corresponding to the length of the mattress 1 is denoted by "x", a direction corresponding to the width of the mattress 1 is denoted by "y", and a direction corresponding to the height of the mattress 1 is denoted by "z". As illustrated, the pocket spring core assembly 10 includes an arrangement 20 of pocketed springs 25, in the following also referred to as pocket spring core 20. The pocketed springs 25 are compressible in the a vertical direction, i.e., in the z-direction. In the pocket spring core 20 described herein, the fabric from which the pockets are formed may be semi-impermeable. The fabric may be configured such that it has a greater resistance to air flow directed from an exterior to an interior of the pocket than to air flow directed from an interior to an exterior of the pocket. The seams which delimit the respective pockets may be sinusoidal welded seams, e.g., formed by ultrasonic welding.

[0022] In the embodiments described herein, a molded foam edge 40 is formed around a vertical peripheral edge of the spring core 20. A barrier layer 30, illustrated by a dotted line, separates the molded foam edge 40 from the spring core 20. During molding of the foam edge 40, the barrier layer 30 prevents foam material from entering into spaces between the individual pocketed springs 25 of the pocket spring core 20. The foam edge 40 defines the horizontal dimensions and shape, i.e., in the x- and y-direction, of the pocket spring core assembly 10. As further illustrated, the pocket spring core assembly 10 may include a top layer 50 on a top surface of the pocket spring core 20 and of the foam edge 40 and/or a bottom layer 60 on a bottom surface of the spring core 20 and of the foam edge 40. The top layer 50 and the bottom layer 60 may for example correspond to foam plates, however produced separately from the molded foam edge 40. For example, after molding the foam edge 40, the top layer 50 and/or the bottom layer 60 could be glued to the foam edge 40. This may be accomplished without fixing the top layer 50 or the bottom layer 60 to the fabric material of the pocket spring core 20, so that there is no adverse effect on the functionalities of the individual pocketed springs 25.

[0023] Fig. 2 shows a sectional view of the pocket spring core 20 and the barrier layer 30. As illustrated in Fig. 2, the pocket spring core 20 may be manufactured from multiple strings of pocketed springs 25. In Fig. 2, the strings extend along the x-direction. The strings may respectively be formed by providing a fabric layer, inserting a spring into the fabric layer, folding the fabric layer so as to cover the spring either before or after insertion of the spring, and applying longitudinal and transverse seams 26, e.g. by welding. Each string may extend across the full width of the pocket spring core 20. The strings may be connected in side-by-side relationship as, for example, by gluing the sides of the strings together in an assembly machine, so as to create an assembly or matrix of springs having multiple rows and columns of pocketed springs bound together, such as by gluing, welding or any other conventional assembly process commonly used to create pocket spring cores. As a result, the pocket spring core 20 forms a unitary structure. The pocket spring core 20 may be fabricated using various kinds of conventional pocket spring manufacturing machine and by any conventional spring pocketing process.

[0024] The barrier layer 30 is glued or otherwise attached to the vertical peripheral edge of the pocket spring core 20. The barrier layer 30 may for example be formed by wrapping one or more sheets of fabric material around the vertical peripheral edge of the pocket spring core 20. For example, along the vertical peripheral edge of the pocket spring core 20, a single sheet of fabric material could be wrapped around the pocket spring core 20. The barrier layer 30 seals open spaces formed between adjacent pockets at the peripheral edge of the pocket spring core 20 and, during molding of the foam edge 40, prevents foam material from entering into such spaces. Further, the barrier layer 30 also prevents the foam material from entering in parallel to the strings, i.e., along the x-direction, further into the interior of the pocket spring core 20. As a result, the molding of the foam edge can be performed in a precise and reproducible manner.

[0025] The barrier layer 30 may also extend over at least a part of the top surface and/or of the bottom surface of the pocket spring core 20. This overlap may help to prevent that during the molding of the foam edge 40 the foam material can penetrate from the top side or bottom side into spaces formed between adjacent pockets at the peripheral edge of the pocket spring core 20. A corresponding example, where the barrier layer 30 partially overlaps the top surface and the bottom surface of the pocket spring core 20 is illustrated in Figs. 3A and 3B. Fig. 3A shows a sectional view of the pocket spring core 20 and the barrier layer 30 along a x-z-plane, and Fig. 3B shows a sectional view of the pocket spring core 20 and the barrier layer 30 along a y-z-plane.

[0026] In the example of Figs. 3A and 3B, in the barrier layer 30 is formed of four sheets 31, 32, 33, 34 of fabric material, each being attached to one of the four sides of the pocket spring core 20. As can be seen, the sheets 31, 32, 33, 34 are wrapped around the edge of the pocket spring core 20, so as to extend over adjacent parts of the top surface and of the bottom surface of the pocket spring core 20. In the example of Figs. 3A and 3B the overlap over the top surface and bottom surface has a size corresponding to one diameter of the pocketed springs 25. However, it is noted that other sizes of the overlap could be used as well, e.g., larger sizes corresponding to two or three diameters of the pocketed springs 25. Further, different sizes of the overlap could be used on the top and bottom side.

[0027] In some embodiments, the barrier layer 30 may also extend over the entire top surface and/or bottom surface of the pocket spring core 20. Also in this case, the overlap may help to prevent that during the molding of the foam edge 40 the foam material can penetrate from the top side or bottom side into spaces formed between adjacent pockets at the peripheral edge of the pocket spring core 20. Moreover, in some designs the pocket spring core 20 could include a sheet of fabric material on its top surface or bottom surface. The barrier layer 30 may then be efficiently formed from such sheet of fabric material. A corresponding example, where the barrier layer 30 fully overlaps the top surface and the bottom surface of the pocket spring core 20 is illustrated in Figs. 4A and 4B. Fig. 4A shows a sectional view of the pocket spring core 20 and the barrier layer 30 along a x-z-plane, and Fig. 4B shows a sectional view of the pocket spring core 20 and the barrier layer 30 along a y-z-plane.

[0028] In the example of Figs. 4A and 4B, in the barrier layer 30 is formed of two sheets 35, 36 of fabric material. A first sheet 35 covers the top surface of the pocket spring core 20 and is wrapped around the vertical edge on two opposing sides of the pocket spring core 20, so as to also extend over an adjacent part of the bottom surface of the pocket spring core 20. A second sheet 36 covers the bottom surface of the pocket spring core 20 and is wrapped around the vertical edge on two other opposing sides of the pocket spring core 20, so as to also extend over an adjacent part of the top surface of the pocket spring core 20. In the example of Figs. 4A and 4B the overlap of the sheet 35 over the bottom surface and the overlap of the sheet 36 over the top surface have a size corresponding to one diameter of the pocketed springs 25. However, it is noted that other sizes of the overlap could be used as well, e.g., larger sizes corresponding to two or three diameters of the pocketed springs 25. Further, different sizes of the overlap could be used on the top and bottom side.

[0029] Figs. 5A and 5B illustrate a further example where the barrier layer 30 fully overlaps the top surface and the bottom surface of the pocket spring core 20. Fig. 5A shows a sectional view of the pocket spring core 20 and the barrier layer 30 along a x-z-plane, and Fig. 5B shows a sectional view of the pocket spring core 20 and the barrier layer 30 along a y-z-plane.

[0030] In the example of Figs. 5A and 5B, in the barrier layer 30 is formed of two sheets 37, 38 of fabric material. A first sheet 37 covers the top surface of the pocket spring core 20 and is wrapped onto the vertical edge on all sides of the pocket spring core 20, so as to also extend over at least a top part of the vertical peripheral edge of the pocket spring core 20. A second sheet 38 covers the bottom surface of the pocket spring core 20 and is wrapped onto the vertical edge on all sides of the pocket spring core 20, so as to also extend over at least a bottom part of the vertical peripheral edge of the pocket spring core 20. In the example of Figs. 5A and 5B the first sheet 37 and the second sheet 38 overlap on the vertical peripheral edge of the spring core 20. In this overlap region, the first sheet 37 and the second sheet 38 may be glued or otherwise attached to each other.

[0031] Fig. 6 illustrates molding of the foam edge 40. As illustrated, for molding the foam edge 40 the pocket spring core 20 with the barrier layer 30 on its vertical peripheral edge is placed in a mold 100. The mold has a bottom wall 110 defining a bottom surface of the mold 100, vertical side walls 120 defining vertical side surfaces of the mold 100, and a top plate 130 defining a top surface of the mold 100. The bottom surface, top surface, and vertical side surfaces of the mold 100 define the outer shape of the molded foam edge 40. The pocket spring core 20 is placed with its bottom surface on the bottom surface of the mold 100. The top plate 130 is placed on the pocket spring core 20, so that the top surface of the pocket spring core 20 is adjacent to the top surface of the mold 100. The vertical peripheral edge of the pocket spring core 20 is placed spaced apart from the vertical side surfaces of the mold 100. Accordingly, an space is formed between the vertical peripheral edge of the pocket spring core 20 and the vertical side surfaces of the mold 100. The molded foam edge 40 can thus be formed by injecting or pouring liquid foam material, e.g., a flowable mixture of Polyol and Isocyanate, into this space. At this stage, the barrier layer 30 prevents the foam material from penetrating between the pocketed springs 25. After curing or hardening of the foam material the pocket spring core 20 and the foam edge 40 molded to its vertical peripheral edge are removed from the mold 100. The barrier layer 30 remains as a separation between the pocket spring core 20 and the molded foam edge 40 and adds further stability to the pocket spring core assembly 10.

[0032] Fig. 7 shows a flowchart for illustrating a manufacturing process which may be used to manufacture a pocket spring core assembly as described above, e.g., the pocket spring core assembly 10. That is to say, the method may be used to manufacture a pocket spring core assembly including an arrangement of pocketed springs, each of the pocketed springs including a pocket of fabric material and a spring enclosed in the pocket, such as the above-mentioned pocket spring core 20, a barrier layer on a vertical peripheral edge of the arrangement of pocketed springs, and a molded foam edge formed on only the vertical peripheral edge of the arrangement of pocketed springs, the barrier layer separating the molded foam edge from the fabric material of the pockets on the vertical peripheral edge of the arrangement pocketed springs.

[0033] At step 710, the arrangement of pocketed springs is provided, such as the above-mentioned pocket spring core 20, which includes the pocketed springs 25. The pocketed springs each include a pocket of fabric material and a spring enclosed in the pocket. The springs may for example be formed of a metal wire. The pockets may be formed of one or more fabric layers, e.g., a non-woven fabric. The pockets may be formed by welding the fabric layer(s). The pocketed springs may be based on compression springs which are compressible in a vertical direction. In the arrangement of pocketed springs the individual pocketed springs may be aligned along the vertical direction.

[0034] At step 720, the barrier layer is attached to the vertical peripheral edge of the arrangement of pocketed springs. For example, this may involve gluing the barrier layer to the vertical peripheral edge. The barrier layer may be formed of a fabric material, e.g., the same or a similar fabric material as the pockets of the pocketed springs. In a plane which is perpendicular to the vertical direction, the arrangement of pocketed springs may have a rectangular outer shape. In this case, the vertical peripheral edge may include at least one vertical side edge corresponding to a side edge of the rectangular outer shape. In typical scenarios, e.g., as explained in connection with Figs. 1 to 5, the vertical peripheral edge may include all vertical side edges corresponding to the side edges of the rectangular outer shape.

[0035] The barrier layer may extend from the vertical peripheral edge over at least a part of a bottom surface of the arrangement of pocketed springs. The barrier layer may cover the bottom surface only partially, such as explained in connection with the example of Figs. 3A and 3B. However, the barrier layer could also extend from the vertical peripheral edge over the entire bottom surface of the arrangement of pocketed springs, such as explained in connection with the example of Figs. 4A and 4B. In addition or as an alternative, the barrier layer may extend from the vertical peripheral edge over at least a part of a top surface of the arrangement of pocketed springs. The barrier layer may cover the top surface only partially, such as explained in connection with the example of Figs. 4A and 4B. However, the barrier layer could also extend from the vertical peripheral edge over the entire top surface of the arrangement of pocketed springs, such as explained in connection with the example of Figs. 4A, 4B, 5A, and 5B.

[0036] The barrier layer may include at least a first sheet of fabric material and a second sheet of fabric material, such as shown in the example of Figs. 3A and 3B, where the barrier layer includes the sheets 31, 32, 33, 34, or as shown in the example of Figs. 4A and 4B, where the barrier layer includes the sheets 35, 36, or as shown in the example of Figs. 5A and 5B, where the barrier layer includes the sheets 37, 38. The first sheet of fabric material may then cover a first part of the vertical peripheral edge, at least a first part of a top surface of the arrangement of pocketed springs, the first part of the top surface being adjacent to the first part of the peripheral edge, and at least a first part of a bottom surface of the arrangement of pocketed springs, the first part of the bottom surface being adjacent to the first part of the peripheral edge. The second sheet of fabric material may then cover a second part of the vertical peripheral edge, at least a second part of the top surface of the arrangement of pocketed springs, the second part of the top surface being adjacent to the second part of the peripheral edge, and at least a second part of the bottom surface of the arrangement of pocketed springs, the second part of the bottom surface being adjacent to the second part of the peripheral edge.

[0037] Like explained in connection with the example of Figs. 4A, 4B, 5A, and 5B, the first sheet could also cover the entire top surface of the arrangement of pocketed springs and/or the second sheet could cover the entire bottom surface of the arrangement of pocketed springs.

[0038] The barrier layer may be attached to the arrangement of pocketed springs during assembly of the arrangement of pocketed springs at step 710, i.e., in a single process integrates steps 710 and 720. Alternatively, the barrier layer may be attached to the arrangement of pocketed springs in a separate process which is performed when assembly of the arrangement of pocketed springs at step 710 is finished.

[0039] At step 730, the arrangement of pocketed springs with the attached barrier layer is placed in a mold, such as the above-mentioned mold. Like explained in connection with Fig. 5, this may involve placing a bottom surface of the arrangement of pocketed springs adjacent to a bottom surface of the mold, placing a top surface of the arrangement of pocketed springs adjacent to a bottom surface of the mold, and placing the vertical peripheral edge of the arrangement of pocketed springs spaced apart from a vertical peripheral edge of the mold.

[0040] At step 740, raw foam material, such as a flowable mixture of Polyol and Isocyanate or similar liquid foam material, is introduced into the mold. The raw foam material will then fill a space left between the vertical peripheral edge of the arrangement of pocketed springs spaced and the vertical peripheral edge of the mold. The barrier layer prevents the foam material from penetrating into spaces between the pocketed springs of the arrangement. By hardening and/or curing of the raw foam material, the molded foam edge is formed around the perimeter of the arrangement of pocketed springs. If in a plane perpendicular to the vertical direction the arrangement has a rectangular shape, the resulting molded foam edge may have the shape of a rectangular frame, with a central opening of the frame conforming to the outer contour of the arrangement of pocketed springs. However, it is noted that in some scenarios also other geometries, which do not involve a rectangular outer shape of the foam edge or a rectangular outer shape of the arrangement of pocketed springs, could be used.

[0041] At step 750, the pocket spring core assembly with molded foam edge is removed from the mold. After that, a top layer, such as the above-mentioned top layer 50, may be attached on a top surface of the arrangement of pocketed springs and of the molded foam edge, and/or a bottom layer, such as the above-mentioned bottom layer 60, may be attached on a bottom surface of the arrangement of pocketed springs and of the molded foam edge. The top layer or bottom layer may for example be glued to the molded foam edge, without being fixed to the fabric material of the pocketed springs. The top layer or bottom layer may for example correspond to foam plates which are prepared from a different foam material than the molded foam edge.

[0042] In some scenarios, the top layer and/or bottom layer may also be attached during molding of the foam edge. For example, before introducing the raw foam material into the mold, the bottom layer may be placed between the bottom surface of the arrangement of pocketed springs and the bottom surface of the mold. During curing or hardening of the foam material, the molded foam edge may then also form a connection to the bottom layer. In addition or as an alternative, before curing or hardening of the foam material, the top layer may be placed between the top surface of the arrangement of pocketed springs and the top surface of the mold. This may be accomplished after introducing the raw foam material into the mold. For example, the raw foam material could be introduced into the mold, then the top layer placed on the arrangement of pocketed springs and raw foam material, and then a top plate of the mold be placed on the top layer. During curing or hardening of the foam material, the molded foam edge may then also form a connection to the top layer. By integrating the attachment of the top layer and/or bottom layer into the molding process, production efficiency can be improved.

[0043] Due to the molded foam edge and barrier layer, the resulting pocket spring assembly has a good stability and well defined outer shape. At the same time, the pocket spring assembly can be light-weight and offer sufficient flexibility for roll packaging or the like.

[0044] It is noted that the embodiments and examples described above are susceptible to various modifications. For example, characteristics of the barrier layer like explained in connection with Figs. 3A, 3B, 4A, 4B, 5A, and 5B could be combined in the same pocket spring core assembly, e.g., by having complete overlap of the barrier layer on only one of the top surface or the bottom surface of the pocket spring core 20. Further, a wide variety of springs may be used, without limitation to coil springs. The springs of the pocket spring core may be formed of various materials and may have various shapes. Further, while in the above examples the pocket spring core assembly is part of a mattress, it is noted that the same or similar pocket spring core assembly could also be used in various other kinds of bedding or seating products, such as in sofas or seats, e.g., as part of a sofa cushion or seat cushion.

Claims

1. A pocket spring core assembly (10), the pocket spring core assembly (10) comprising:

- an arrangement (20) of multiple pocketed springs (25), each of the pocketed springs comprising a pocket of fabric material and a spring enclosed in the pocket;

- a barrier layer (30) on a vertical peripheral edge of the arrangement (20) of pocketed springs; and

- a molded foam edge (40) formed on only the vertical peripheral edge of the arrangement (20) of pocketed springs (25),

wherein the barrier layer separates the molded foam edge (40) from the fabric material of the pockets on the vertical peripheral edge of the arrangement (20) of pocketed springs (25).

2. The pocket spring core assembly (10) of claim 1,
wherein the barrier layer (30) is glued to the fabric material of the pockets on the vertical peripheral edge of the arrangement (20) of pocketed springs (25).

3. The pocket spring core assembly (10) of claim 1 or 2,
wherein the barrier layer (30) is formed of the same fabric material as the pockets of the pocketed springs (25).

4. The pocket spring core assembly (10) according to any one of the preceding claims, comprising:

- a top layer (50) attached on a top surface of the arrangement (20) of pocketed springs (25) and of the molded foam edge (40); and/or

- a bottom layer (60) attached on a bottom surface of the arrangement (20) of pocketed springs (25) and of the molded foam edge (40).

5. The pocket spring core assembly (10) of any one of the preceding claims,
wherein the barrier layer (30) extends from the vertical peripheral edge over at least a part of a bottom surface of the arrangement (20) of pocketed springs (25).

6. The pocket spring core assembly (10) of claim 5,
wherein the barrier layer (30) extends from the vertical peripheral edge over the entire bottom surface of the arrangement (20) of pocketed springs (25).

7. The pocket spring core assembly (10) of any one of the preceding claims,
wherein the barrier layer (30) extends from the vertical peripheral edge over at least a part of a top surface of the arrangement (20) of pocketed springs (25).

8. The pocket spring core assembly (10) of claim 7,
wherein the barrier layer (30) extends from the vertical peripheral edge over the entire top surface of the arrangement (20) of pocketed springs (25).

9. The pocket spring core assembly (10) of any one of the preceding claims,
wherein the barrier layer (30) comprises at least:

- a first sheet (31, 32, 33, 34; 35, 36) of fabric material which covers a first part of the vertical peripheral edge, at least a first part of a top surface of the arrangement (20) of pocketed springs (25), the first part of the top surface being adjacent to the first part of the peripheral edge, and at least a first part of a bottom surface of the arrangement (20) of pocketed springs (25), the first part of the bottom surface being adjacent to the first part of the peripheral edge; and

- a second sheet (31, 32, 33, 34; 35, 36) of fabric material which covers a second part of the vertical peripheral edge, at least a second part of the top surface of the arrangement (20) of pocketed springs (25), the second part of the top surface being adjacent to the second part of the peripheral edge, and at least a second part of the bottom surface of the arrangement (20) of pocketed springs (25), the second part of the bottom surface being adjacent to the second part of the peripheral edge.

10. The pocket spring core assembly (10) of any one of the preceding claims,
wherein the barrier layer (30) comprises at least:

- a first sheet (35, 37) of fabric material which covers the entire top surface of the arrangement of pocketed springs and

- a second sheet (36, 38) of fabric material which covers the entire bottom surface of the arrangement of pocketed springs.

11. The pocket spring core assembly (10) of any one of the preceding claims,
wherein the molded foam edge has a shape of rectangular frame which encloses the arrangement of pocketed springs.

12. A bedding or seating product (1),
wherein the bedding or seating product (1) comprises a pocket spring core assembly (10) according to any one of the preceding claims.

13. A method of manufacturing a pocket spring core assembly (10), the method comprising:

- providing an arrangement (20) of multiple pocketed springs (25), , each of the pocketed springs comprising a pocket of fabric material and a spring enclosed in the pocket;

- providing a barrier layer (30) on a vertical peripheral edge of the arrangement (20) of pocketed springs (25); and

- molding a foam edge (40) on only the vertical peripheral edge of the arrangement (20) of pocketed springs (25),

wherein the barrier layer (30) separates the molded foam edge (30) from the fabric material of the pockets on the vertical peripheral edge of the arrangement (20) of pocketed springs (25).

14. The method according to claim 13,
wherein said molding of the foam edge (40) comprises:

- placing the arrangement (20) of pocketed springs (25) with the barrier (30) in a mold (100);

- placing a bottom surface of the arrangement (20) of pocketed springs adjacent to a bottom surface of the mold (100);

- placing a top surface of the arrangement (20) of pocketed springs (25) adjacent to a bottom surface of the mold (100); and

- placing the vertical peripheral edge of the arrangement (20) of pocketed springs spaced apart from a vertical peripheral edge of the mold (100).

15. The method according to claim 13 or 14, comprising:

- attaching a top layer (50) on a top surface of the arrangement (20) of pocketed springs (25) and of the molded foam edge (40); and/or

- attaching a bottom layer (60) on a bottom surface of the arrangement (20) of pocketed springs (25) and of the molded foam edge (40).

Drawing