GB2534930A - Filled article and method - Google Patents

Abstract

A filled article 10 such as a pillow, duvet, or cushion with two fabric layers 12a, (12b, figure 2) enclosing a filling (14, figure 2). The edges of the fabric are joined by discontinuous ultrasonically-formed seams 16a-d. There may also be a continuous ultrasonically-formed seam 15, which may be positioned outward of the discontinuous seam. There may be many discontinuous ultrasonically-formed seams alongside one or more edges. The discontinuous seam may be a stitch pattern such as running, zigzag or tent stitch. The fabric layers may be heat-sealable. The fabric may be a polymer and the filling microfibre. The invention also relates to a method for forming a filled article 10 of two fabric layers 12a, (12b, figure 2) enclosing a filling (14, figure 2) with the steps of; welding one or more edges with a discontinuous ultrasonically-formed seam 16a-d, inserting the filling between the fabric layers and then closing the article with a further discontinuous ultrasonically-formed seam or seams 16a-d.

Description

DESCRIPTION

FILLED ARTICLE AND METHOD

The present application relates generally to a filled article and method of forming the same and in particular, but not exclusively, to a filled article comprising a pillow, duvet, cushion or the like.

Pillows, duvets, cushions and the like are traditionally formed by stitching together upper and lower rectangular fabric sheets along three edges, Inserting a filling into the volume between the sheets through the gap between the unstitched edges and then stitching together the edges through which the filling has been inserted. Whilst this traditional production method produces an aesthetically pieasing result. the formation of the seams, whether by a sewing machine or by hand. is a skilled process and one which does not readily lend itself to continuous production processes, and as a consequence the production cost per item is relatively high.

As an alternative to traditional fabric joining methods, pillows, duvets, cushions and the like can be formed from sheets of heat-sealable fabrics, typically containing a significant proportion of polymer fibres such as polyester, which are joined together by means of ultrasonic welding instead of by stitching. Ultrasonic welding typically involves applying ultrasonic energy, i.e. at acoustic frequencies above the range of the human ear, or above approximately 20,000 Hertz, and pressure, to an area of fabric to be bonded. The ultrasonic energy causes the temperature of the fibres within the fabric to increase to such an extent that polymeric fibres within the fabric met Subsequent cooling causes the melted fibres to re-solidify and thereby bond with each other at the interface of the fabric surfaces that are to be bonded. Appropriate application of ultrasonic energy enables continuous seams to be formed, which secure tooether the two layers of fabric.

The formation of seams by ultrasound lends itself to continuous, high,. volume production processes, whereby the two layers of fabric can be paid out from rolls of fabric to lie one over the other, and continuous ultrasonically-formed seams can be continuously formed at or adjacent to the lateral edges of the aligned fabric layers.

However, ultrasonically-formed seams can be quite stiff as compared to traditionally stitched seams, which can make them unsuitable for use in some applications. Furthermore, ultrasonically-formed seams can tend to look more functional rather than decorative, particularly when compared with traditional stitched seams, and may therefore be undesirable for articles requiring at least some aesthetic qualities.

The present invention is intended to overcome or at least alleviate the problems with the prior art.

In accordance with a first aspect of the present invention, a filled article comprises at least two ayers of fabric enclosing a filling, wherein the at least two layers of fabric are overlaid and comprise one or more edges joined by a discontinuous ultrasonically-formed seam.

The use of a discontinuous ultrasonically-formed seam retains the advantages of continuous production processes afforded by ultrasonic seam formation, while at the same time producing a more visually appealing seam which can resemble a traditional stitched seam.

The filled article may further comprise at least one continuous ultrasonically-formed seam.

The at least one continuous seam may be located outwardly with respect to the discontinuous seam.

The filled article may comprise a plurality of discontinuous seams located adjacent to one or more edges of the fabric layers.

The discontinuous seam may comprise a simulated stitch pattern, i.e. the seam may be arranged to resemble a sewing stitch pattern, such as running stitch, zigzag stitch or tent stitch. In particular, a running stitch is preferably used to provide the filled article, such as a duvet or pillow, with a hand stitched appearance.

Preferably at least one, and more preferably a plurality, of said at least two layers of fabric are heat-sealable.

The fabric comprising the filled article may comprise a polymer.

The two layers of fabric may be formed by folding a length of fabric substantially in half, to form an upper layer and a lower layer from a single piece of fabric. In another embodiment, the two layers of fabric may be formed using two separate pieces of fabric.

The filling of the filled article may comprise polyester microfibre or hollowfibre.

The filled article may be a pillow, duvet, cushion or the like.

In accordance with a second aspect of the present invention, there is provided a method for forming a filled article comprising at least two layers of heat-sealablo fabric enclosing a filling, the method comprising: overlaying the at least two layers of fabric; ultrasonically welding at least two edges of the layers of fabric with a discontinuous seam; inserting the filling between the layers of fabric: and ultrasonically welding any unwelded edges of the layers of fabric with a discontinuous seam.

The method may comprise ultrasonically welding a continuous seam outwardly of the discontinuous seam.

The method may comprise ultrasonically welding a plurality of discontinuous seams towards one or more edges of the fabric.

The discontinuous seam may comprise a stitch pattern, i.e. the seam may be arranged to resemble a sewing stitch pattern, such as running stitch, zigzag stitch or tent stitch. In particular, a running stitch is preferably used io provide the filled article, such as a duvet or pillow, with a hand stitched appearance.

The two layers of fabric may be formed by folding a length of fabric substantially in half, to form an upper layer and a lower layer from a single piece of fabric. In another embodiment, the two layers of fabric may be formed using two separate pieces of fabric.

The fabric of the filled article may comprise at least 65% polymeric content. The filling of the filed article may comprise polyester microfibre or insertion of the filling between the layers of fabric may occur simultaneously with respect to the ultrasonically welding, Specific embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which: Fig. .1 is a plan view of an embodiment of pillow in accordance with a first aspect of the invention; Fig. 2 is an exploded view of the pillow of Fig. 1.

Fig. 3 shows, schernaticaily, an embodiment of apparatus for performing a method in accordance with a second aspect of the invention; Fig. 4 shows, schematically, an embodiment of horn and anvil for ultrasonically welding a discontinuous seam in accordance with the invention; and Fig. 5 shows, schematically, a further embodiment of apparatus for performing a method in accordance with the second aspect of the invention.

The pillow 10 shown in Figs 1 and 2 comprises two identical upper and lower elongate rectangular pieces of fabric 12a. 12b which are overlaid one on the other such that their edges abut. The fabric is a heat-sealable fabric and in the particular embodiment described is a blend of 65% polyester and 35% cotton. A layer of polyester microfibre. filling 14 is positioned between the two fabric layers 12a, 12b and extends substantially the length and width of the fabric layers 12a, 12b and is retained between the layers 12a, 12b by a continuous ultrasonically-formed seal 15 extending around the periphery of the upper and lower fabric pieces 12a, 12b, thereby sealing the edges of the fabric pieces 12a; 12b together, and four discontinuous straight, ultrascnically-formed seams 16a. 166, 16c, 16d running adjacent, and parallel to, each edge of the fabric layers 12a, 12b, to form the filled pillow 10.

The continuous peripheral seam 15 and the discontinuous seams 16a to 16d are formed by pressing together the edges of the two layers of fabric 12a, 12b and applying localised ultrasonic energy, via ultrasonic heads in a continuous manner for the peripheral seam 15 and a discontinuous manner for the discontinuous seams 16a to 16d, as will be described. The application of ultrasonic energy to the fabric causes the heat-sealable fibres in each piece of fabric 12a, 12b which are local to the ultrasonic head to melt. The melted fibres combine and solidify, creating a bond between the two pieces of fabric 12a, 125. in addition, the ultrasonic energy also causes localised polyester microfibre filling fibres 14 to melt, which also bond to the two fabric pieces 12a, 12b, creating a stronger bond, or seam, between the fabric pieces 12a, 126.

Polyester microfibre filling fibres 14 melted between the sealed portions of the discontinuous seams 16a to led and extending into the gaps 18 between the sealed portions also act to reinforce the discontinuous seams 16a to 16d by at least partially obstructing the gaps 18 of the seam 16. The discontinuous simulated stitch pattern 16 increases the amount of welded material near the edge of the pillow 10, which allows the seam strength to be tailored to specific requirements.

This acts to further retain the filling 14 within the seam boundary 16 without altering the external visual appearance of the discontinuous seam 16, This is an important feature, as by using discontinuous linear ultrasonic seams 16a to 15d inwardly of the peripheral edge seal 15, the pillow le is provided with the appearance of a 'hand stitched' running stitch finish. This adds value to the pillow as the overall finish of the product is significantly improved by the "machine stitched" appearance.

Furthermore, the discontinuous pattern of the seams 18a to 16d enables greater flexibility in the region of those seams, making the pillow 10 more comfortable during use.

The dimensions of the discontinuous "stitch" pattern 16 are approximately equivalent to those of a conventional stitch and the inventors have found that subtle variations in the scale and relative sizes of the stitch elements give similar weld strengths.

The invention improves on conventionally stitched pillows by providing a pillow which has the aesthetic qualities of a traditionally-stitched seam, but wnich can be formed usinc the more economical continuous production processes afforded by ultrasonically-formed seams. Furthermore, it is also possible to alter the ultrasonic welding pattern to produce different seaming patterns, for further aesthetic merit.

The pillow 10 can be formed using apparatus as shown in Fig 3. Corresponding features of the pillow 10 are numbered using the same reference numerals as in Figs 1 and 2, but increased by 100.

First and second rolls 112a, 112b of identical fabric comprising 05% polyester are each mounted on a respective dispenser (not shown) and upper and lower continuous webs of fabric 113a, 113b are dispensed from the first and second rolls 112a, 112b respectively, with the lateral edges of the two webs aligned with each other.

The two webs of overlaid fabric 112a, 112b are then fed into a first ultrasonic welding station 120, having two opposing sets of ultrasonic welding heads (not visible) for creating seams along the two lateral edges of the overlaid webs. In a first step, the side edges 113 of the two webs of fabric 112a, 112b are compressed as the fabric 112a, 112b is fed through the welding station 120. In a second step, ultrasonic welding heads deliver ultrasonic energy to the compressed side edges 113 of the two layers of fabric 112a, 112b, which causes the localised fibres within the two webs of fabric 112a. 112b to melt, to form a continuous seam between the two webs of fabric at their lateral edges and discontinuous seams 16e, 16b, in the form of a running stitch pattern. inwardly of, and parallel to, the lateral edges.

Upon application of ultrasound, the temperature of the rolymerie fibres in the fabric increases to such an extent that they melt. As the melted fibres subsequently cool, the fibres sohdify to form a secure, continuous bond at the lateral edges of the webs and discontinuous bonds, or seams 116a, 1161, between the two webs of fabric 112a, 1121, towards the side edges 113, The continuous bonds at the lateral edges will ultimately form the longer lengths of the continuous peripheral seam 115 of the final product and the discontinuous seams will form the seams 116a, 1160 extending parallel to, and adjacent to, those portions of the peripheral seam 115 (see Fig. 1).

The weld parameters are adjusted depending on the characteristics of the fabric to be welded, such as material composition and thickness. For any given material, there will be a minimum amount of ultrasonic energy required at the welding sate (melt zone), to produce sufficient melting and thus welding, as Ari he readily understood by a person skilled in the art.

The first and second steps have been described separately for clarity purposes, However, these steps occur simultaneously.

The weld power used is typically between 200W and 400W. This is the electrical power required to drive the ultrasonic generator. The ultrasound is then applied to a piezo-electric stack, which converts the electrical signal into high frequency vibrations in the welding horn or sonotrode.

The welding horn used to create the discontinuous seam of the present invention is shown, schematically, in Fig. 4 Only one horn 700 is shown, but one horn 700 is located at each /elec.& edge of the webs 112. The horn 700 in the present embodiment is static with a rotating anvil 701 comprising a rotatable disc 702 bearing a working surface about its circumference, mounted directly above the horn 700. The working surface comprises a series of teeth 703, which when applied to the fabric 112, produce the series of discontinuous lines which form the discontinuous seams 116a, 116b. Laterally outwardly of the teeth 703, the rotating anvil is also provided with a continuous knife edge 704 which, when applied to the fabric, forms the continuous seams along the lateral edges of the web (which will ultimateiy form the portions of the continuous peripheral seam 115 along the longer edges of the finished product -see Fig. 1) and simultaneously trims excess fabric 705 from the edges of the webs, to form a neat edge.

The design of the horn 700 is such that ultrasonic vibrations are arnplified at the teeth 703 sections, which creates both the continuous seams at the edges of the web and the discontinuous seams 116a, 116b located laterally inwardly of the edges, when webs 112a, 112b is fed across a sewing table 706, located between the horn 700 and the anvil 701. Specifically, energy from the horn vibrations is directed into the fibres of the fabric layers 112a, 112b. The heat thereby generated, in conjunction with pressure applied to to fabric 112 around the weld sites, melts the polymeric fibres within the fabric 112. When the melt solidifies, it binds adjacent fibres, creating the seams. The frequency of the system Is defined by the geometry of the horn 700, as will be understood by the skilled person.

When the ultrasound is initiated, the surface temperature of the horn increases by approximately 50 degrees Celsius. The bulk temperature of the horn then increases further, depending on welding conditions. It will be appreciated that it is necessary for the bulk temperature to remain well below the temperature at which the fabric 112 would be visually affected. This critical temperature will be dependent on the fabric used. However, by way of example, the critical temperature for polyester is typically 150 degrees Celsius.

The fabric webs 112a, 112b, which have been secured together along their lateral edges, are fed out of the first ultrasonic welding station 120 and pass through a speed compensating unit 122 comprising a series of alternating he:ght rollers 122a. 122b, 122c, 122d which act to slow the feed of the 'joined webs 112a, 112b emerging from the first ultresonc welding station 120 so that the fabric can be presented to a cutting unit 124 at an appropriate speed.

The cutting unit 124 comprises a fabric inlet 126 for receiving the two webs of fabric 112a, 112b which are joined along their lateral edges, and a cutting blade (not visible). The cutting blade extends substantially the width of the fabric inlet 126. The joined webs of fabric 112a, 112b are fed into the fabric inlet 126 of the cutting unit 124 so that the cutting blade is perpendicularly located with respect to the side edges 113 of the layers of fabric 112a, 112b; which are cut at predetermined intervals by the cutting blade, to form individual rectangular shaped pillow ticks 212, having upper and lower sheets which are joined at their side edges 213 only.

One end 215 of each pillow tick 212 is then passed through a second ultrasonic welding station 128, having a single set of ultrasonic welding heads {not visible), identical to that of Fig. 4 for creating end seams. The end 215 of each pillow tick 212 is fed into the second ultrasonic welding station 128. which compresses the end edge 215 and subsequently welds an outer end seam and a discontinuous seam 1160 parallel to, and adjacent to, the continuous end seam (and simultaneously' trimming the end of the tick) into each pillow tick 212, in a manner substantially identical to the welding process of the first ultrasonic welding machine 120.

The pillow tick 212, whose upper and lower sheets 12a, 12b (see Fig. 1) are now joined along three edges, is transferred to a filling station 130, which inserts a predetermined amount of polyester microfibre filling 14 into the open end of the pillow tick 212, The open end of the pillow tick 212 is then led into a third ultrasonic welding statical 132, which is substantially identical in operation and configuration to the second ultrasonic welding station 130. The third ultrasonic welding station 132 ultrasonically seams the open end of the pillow tick 212 with an outer continuous seam portion and an inner discontinuous seam 16d (and also trims the end of the pillow), to form a completed pillow 210 whose upper and lower sheets 12a, 12b are joined together along each edge to retain the polyester microfibre filling 14 with a continuous peripheral seam 15 and four discontinuous seams 16a and led adjacent to, and parallel to, the edges of the pillow 10 (see Fig. 1) Flo. 5 shows an embodiment of apparatus for creating a duvet 410 in accordance with the present invention. Corresponding features are numbered using the same reference numerals as for Figure 3, increased by 200. The nature of the apparatus and seaming process for creating the duvet 410 is substantially identical to that described above with reference to creating the pillow 10, and so will not be described again. The significant difference in forming the duvet 410 is that the filling 314 and fabric layers 312a, 312b are brought together at the start of the welding process. This allows both the trailing edge of one duvet and the leading edge of the next duvet to be formed ultrasonically and simultaneously.

A further difference in the welded edge of each of the duvet and pillow line is that, in the duvet line, the filling 314 is entirely caught in the ultrasonic seam. When a thermoplastic filling is used, it adds to the mass of material available for melting during ultrasonic seaming. This can improve the weld. as described above with reference to the pillow formation. However, the skilled person will understand that the weld parameters will require adjustment to compensate for the added bulk of the fibres and the spring-back of the fibres after welding.

The invention is not restricted to the details of the foregoing embodiments.

For example, although the embodiments have been described with reference to fabrics comprising 65% polyester and 35% cotton, any fabric can be used, as long as it is capable of being heat-sealed.

Moreover, differently-patterned discontinuous seams, for example a herringbone pattern, running stitch pattern, zigzag stitch pattern or tent stitch, may be used instead of, or in addition to, the straight interrupted seam described above.

Furthermore, a rotary horn can be used to produce the same discontinuous seam as created by the welding horn described above.

Claims (2)

1. CLAIMS1. A filled article comprising at least two layers of fabric enclosing a filling, wherein the at least two layers of fabric are overlaid and comprises one or more edges joined by a discontinuous ultrasonically-formed seam.
2. 2. A filled article as claimed in daim 1, further comprising at least one continuous ultrasonically-formed seam, 1 A filled article as claimed in claim 2. wherein the at /east one continuous seam is located outwardly with respect to the discontinuous seam.4. A filled article as claimed in any preceding claim, comprising a plurality of discontinuous seams located adjacent to one or more edges of the fabric layers.5. A filled article as claimed in any preceding claim, wherein the discontinuous seam comprises a stitch pattern.6. A filled article as claimed in claim 5, wherein the stitch pattern comprises running stitch, zigzag stitch, tent stitch.7. A filled article as claimed in any preceding claim, wherein at least one of said at least two layers of fabric is heat-sealable.5. A filled article as claimed in claim 7, wherein a plurality of said at least two layers of fabric is heat-sealable.9. A filled article as claimed in any preceding claim, wherein the fabric comprises a polymer, 10.A filled article as claimed in any preceding claim, wherein the filling comprises microfibre.11. A filled article as claimed in any preceding claim, wherein the filled article is a pillow, duvet or a cushion.12. A filled article substantially as herein described with reference to, and as illustrated in, the accompanying drawings.13. A method for forming a tilled article comprising at least two layers of fabric enclosing a filling: the method comprising: overlaying the at least two layers of fabric; ultrasonically welding at least one edge of the layers of fabric with a discontinuous seam; inserting the filling between the layers of fabric; and ultrasonically welding at least one unwelded edge of the layers of fabric with a discontinuous seam.14. A method as claimed in claim 13, comprising ultrasonically welding a continuous seam outwardly of the discontinuous seam.15. A method as claimed in claim 13 or claim 14, comprising ultrasonically welding a plurality of discontinuous seams adjacent to one or more edges of the fabric.15, A method as claimed in any of claims 13 to 15, wherein the discontinuous seam comprises a stitch pattern.17. A method as claimed in claim 15, wherein the stitch pattern comprises running stitch, zigzag stitch, tent stitch.18. A method as claimed in any of Sims 13 to 17, wherein the fabric comprises a polymer.19. A method as claimed in any of claims 13 to 18, wherein the Ming comprises rnicrofibre.20. A method substantially as herein described with reference to, and as illustrated in, Figures 3 and 4 of the accompanying drawings.21. A tilled article obtained by the method of any of claims 13 to 20.G.I.cliermvio-ii4ssur44366skss'appik.mtion 3 Feb 209 5.dcm