MANUFACTURING OF A WEB OF PACKAGING MATERIAL

Abstract

Disclosed is an arrangement and a method for manufacturing of a web of packaging material for an oral pouched snuff product. The web is a saliva-permeable nonwoven web includes fibres, whereof 0%-95% of said fibres are of a first type and 5%-100% of a second type, the fibres of the first type being cellulose-based staple fibres, and the fibres of the second type being thermoplastic fibres, which are meltable and/or softenable at least at the surface. The arrangement includes a carding unit for carding the fibres to form a pre-web, an air-through bonding unit for bonding the pre-web by means of at least partial melting and/or softening of the fibres of the second type to form the web, and a calendering unit for surface treatment of the web.

Claims

1. An arrangement for manufacturing of a web of packaging material for an oral pouched snuff product, said web being a saliva-permeable nonwoven web comprising fibres, whereof 0%-95% of said fibres are of a first type and 5%-100% of said fibres are of a second type, said arrangement comprising a first fibre supply unit for supplying said fibres of said first type, said fibres of said first type being cellulose-based staple fibres, and a second fibre supply unit for supplying said fibres of said second type, said fibres of said second type being thermoplastic fibres, which are meltable and/or softenable at least at the surface, a carding unit for carding said fibres to form a pre-web, an air-through bonding unit for bonding said pre-web by means of at least partial melting and/or softening of said fibres of said second type to form said web, said air-through bonding unit comprising or being constituted by a flat air-through dryer and/or a cylinder air-through dryer, a calendering unit for surface treatment of said web by smooth calendering, said calendering unit being configured to operate at a surface treatment temperature being within the range of 45° C.-120° C.

2. The arrangement according to claim 1, said flat air-through dryer being configured to blow air through said pre-web at a temperature being within the range of 100° C.-160° C.

3. The arrangement according to claim 1, said cylinder air-through dryer being configured to blow air through said pre-web at a temperature being within the range of 100° C.-160° C.

4. The arrangement according to claim 1, further comprising a pre-bonding unit being located before said air-through bonding unit.

5. The arrangement according to claim 1, wherein said calendering unit is configured to operate at a surface treatment temperature being within the range of 50° C.-110° C.

6. The arrangement according to claim 1, wherein said calendering unit is configured to operate at a pressure being within the range of 5-70 kg/cm.sup.2.

7. The arrangement according to claim 1, wherein said calendering unit comprises or is constituted by a pair of rollers having smooth surfaces.

8. The arrangement according to claim 1, further comprising a supplying unit for supplying a smokeless tobacco composition or non-tobacco composition to said web, e.g. as portions, and a tube-forming unit for forming said web into a tubular structure, said tube-forming unit being located before or after said supplying unit.

9. The arrangement according to claim 1, further comprising a longitudinal sealing unit for fixing said web of packaging material into a tubular shape by making at least one longitudinal seal.

10. The arrangement according to claim 1, further comprising a transverse sealing unit for forming said web of packaging material into individual products by making at least one transverse seal between two of said individual products.

11. A method for manufacturing of a web of packaging material for an oral pouched snuff product, said web being a saliva-permeable nonwoven web comprising fibres in the arrangement according to any one of the preceding claims, whereof 0-95% of said fibres are of a first type and 5%-100% of said fibres are of a second type, said method comprising a1) supplying said fibres of said first type by a first fibre supply unit, said fibres of said first type being cellulose-based staple fibres, a2) supplying said fibres of said second type by a second fibre supply unit, said fibres of said second type being thermoplastic fibres, which are meltable and/or softenable at least at the surface, a) carding said fibres to form a pre-web, b) bonding said pre-web by blowing air through said pre-web to at least partially melt and/or soften said fibres of said second type to form said web of packaging material, and c) smooth calendering of said web for surface treatment of said web in a calendering unit operating at a surface treatment temperature being within the range of 45° C.-120° C.

12. The method according to claim 11, wherein said fibres of said second type are thermoplastic fibres comprising a first component and a second component, said second component having a lower melting temperature than said first component, wherein step b) of said method comprises bonding said web by at least partially melting and/or softening of said second component of said fibres of said second type.

13. The method according to claim 11, wherein step c) is performed at a lower temperature than step b).

14. The method according to claim 11, wherein said calendering in step c) is performed to obtain a preselectable thickness and/or surface finish and/or air permeability of said web.

15. The method according to claim 11, further comprising sealing said web with at least one seal by at least partially melting said fibres of said second type in said seal.

16. The method according to claim 11, further comprising forming said web of packaging material into individual products by making at least one transverse seal between two of said individual product.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0089] The present invention will hereinafter be further explained by means of non-limiting examples with reference to the appended drawings wherein:

[0090] FIG. 1 schematically illustrates an arrangement for manufacturing of a web of packaging material for an oral pouched snuff product according to the invention,

[0091] FIG. 2 illustrates a flat air-through dryer,

[0092] FIG. 3 illustrates a cylinder air-through dryer, and

[0093] FIG. 4 illustrates a method according to the invention.

[0094] It should be noted that the appended drawings are not necessarily drawn to scale and that the dimensions of some features of the present invention may have been exaggerated for the sake of clarity.

DETAILED DESCRIPTION

[0095] The invention will, in the following, be exemplified by embodiments. It should however be realized that the embodiments are included in order to explain principles of the invention and not to limit the scope of the invention, defined by the appended claims. Details from two or more of the embodiments may be combined with each other.

[0096] FIG. 1 schematically illustrates an arrangement 100 for manufacturing of a web of packaging material for an oral pouched snuff product according to the invention. The arrangement 100 will be described below following a running direction through it. Dashed lines in FIG. 1 indicate optional units.

[0097] The web is a saliva-permeable nonwoven web comprising fibres, whereof 0%-95% are of a first type and 5%-100% of a second type.

[0098] The fibres of the first type, which may be dispensed with, are cellulose-based staple fibres, typically man-made fibres, e.g. regenerated cellulose fibres, such as rayon, lyocell or viscose.

[0099] The fibres of the second type are thermoplastic fibres, which are meltable and/or softenable at least at the surface at the temperatures used in the arrangement 100. The fibres of the second type may comprise a first component and a second component, wherein second component has a lower melting temperature than said first component. The fibres of the second type may also be mono-component fibres, for which the whole fibre is meltable and/or softenable.

[0100] The arrangement 100 comprises a carding unit 110 for carding the fibres of the first type and second type to form a pre-web. Normally the fibres are detached from each other before reaching the carding unit. If utilizing fibres of both the first type and the second type, they are advantageously mixed with each other before being supplied to the carding unit, such that they are carded together.

[0101] Downstream of the carding unit 110, the arrangement may comprise a pre-bonding unit 120. Preferably, the pre-bonding unit 120 is configured to blow air through the pre-web at a temperature being within the range of 80° C.-155° C., preferably 90° C.-140° C., more preferably 100° C.-135° C., most preferably 110° C.-130° C. The temperature is selected depending on the melting temperatures of the fibres of the first and second types, such that the temperature in the pre-bonding unit 120 is less than the melting temperatures of the fibres of both the first and second type. The pre-bonding unit 120 is an optional unit which may be dispensed with.

[0102] The arrangement 100 further comprises an air-through bonding unit 130 for bonding the pre-web by means of at least partial melting and/or softening of the fibres of the second type to form a web. Thereby the at least partially melted or softened fibres of the second type bind the fibres together to form a cohesive web, such that the bonded web is formed. Hence, there is no need to add an additional binder. If the fibres of the second type are the above-mentioned thermoplastic fibres comprising a first and a second component, the second component partially melts or softens in the air-through bonding unit 130 to bind the fibres together to form a cohesive web.

[0103] The air-through bonding unit 130 may comprise or be constituted by a flat air-through dryer 200, e.g. like the one illustrated in FIG. 2. The exemplary flat air-through dryer 200 comprises five zones 202a-e, but it would also be feasible with another number of zones, such as a single zone or in the range of from 2 to 10 zones, such as from 3 to 8 zones. The flat air-through dryer 200 is configured to operate at a temperature within the range of 100° C.-160° C., preferably 115° C.-155° C., more preferably 120° C.-150° C., most preferably 130° C.-150° C. If utilizing a flat air-through dryer 200, the pre-bonding unit 120 may be dispensed with. Instead, one or more of the first zones of the flat air-through dryer 200 may be utilized for pre-bonding. There may also be a sliding scale from pre-bonding to air-through bonding.

[0104] As an alternative or a complement, the air-through bonding unit 130 may comprise or be constituted by a cylinder air-through dryer 300, as illustrated in FIG. 3. The cylinder air-through dryer 300 is configured to operate at a temperature being within the range of 100° C.-160° C., preferably 115° C.-155° C., more preferably 120° C.-150° C., most preferably 130° C.-150° C. The cylinder air-through dryer 300 may advantageously be combined with a pre-bonding unit 120, which is located before, i.e. upstream of, the cylinder air-through dryer 300.

[0105] It is also feasible to combine a flat air-through dryer 200 with a cylinder air-through dryer 300, e.g. by utilizing a flat air-through dryer with one zone or a few zones, such as 2-3 zones, followed by the cylinder air-through dryer 300. In that case, one or more of the zones of the flat air-through dryer 200 may be utilized for pre-bonding. There may also be a sliding scale from pre-bonding to air-through bonding.

[0106] In order for the cylinder air-through dryer 300 to operate in an appropriate way, the intermediate web 302 should preferably be self-supporting when reaching the cylinder air-through dryer 300, see FIG. 3. In the flat air-through dryer 200 on the other hand, the intermediate web is supported by a machine element, such as a fabric or belt 204, such that also a non-self-supporting web can be handled, see FIG. 2.

[0107] After, i.e. downstream of, the air-through bonding unit 130, there is a calendering unit 140 for surface treatment of the web. The calendering is performed to obtain a pre-selectable thickness and/or surface finish and/or air permeability of the web. Hence, in this arrangement, the calendering unit 140 is not utilized to obtain bonding of the web. Instead the web is already sufficiently bonded when reaching the calendering unit 140. The calendering unit 140 may comprise or be constituted by a pair of rollers having smooth surfaces, preferably the rollers having smooth steel surfaces.

[0108] The arrangement 100 may further comprise additional units of the types known by the skilled person within the field of nonwoven, not illustrated in FIG. 1. There may e.g. be a fine opener, i.e. a unit for breaking up fibre chunks, before the carding unit 110. The calendering unit 140 may be followed by a winding unit and/or a slitting unit.

[0109] The arrangement 100 further comprises a tube-forming unit 150 for forming the web into a tubular structure suitable to enclose a smokeless tobacco composition or non-tobacco composition. The tubular structure has a width suitable for the oral pouched snuff product. The tube-forming unit 150 may e.g. comprise a folding unit folding the web to the tubular structure.

[0110] The arrangement 100 of FIG. 1 may further comprise a longitudinal sealing unit 160 for fixing the tubular structure of the web of packaging material into the tubular shape by making at least one longitudinal seal, thus fixing the tubular structure. The longitudinal sealing unit 160 is thus used to make a seal in the above-mentioned tubular structure formed in the tube-forming unit 150. The longitudinal sealing unit 160 may e.g. be a heat-sealing unit or an ultrasonic sealing unit. Thereby the smokeless tobacco composition or non-tobacco composition may be fed into an already formed and sealed tubular structure by a supplying unit 170. Typically, the smokeless tobacco composition or non-tobacco composition is fed as portions of smokeless tobacco composition or non-tobacco composition.

[0111] In the longitudinal sealing unit 160, energy is applied to create a seal in the nonwoven web by at least partial melting of the fibres of the second type. If the fibres of the second type are fibres as mentioned above comprising a first and a second component, at least the second component melts, and preferably both the first and the second component melts. The seal is preferably located outside the smokeless tobacco composition or non-tobacco composition, such that the seal is formed between two nonwoven surfaces being placed surface to surface in relation to each other.

[0112] In the illustrated embodiment, the tube-forming unit 150 and the longitudinal sealing unit 160 are located before, i.e. upstream of the supplying unit 170, such that the smokeless tobacco composition or non-tobacco composition is fed into an already formed tubular structure by the supplying unit 170.

[0113] In an alternative arrangement, the supplying unit 170 may be located before the tube-forming unit 150 and the longitudinal sealing unit 160, such that the smokeless tobacco composition or non-tobacco composition, e.g. as portions, first is placed on the web and thereafter the tubular structure is formed around the smokeless tobacco composition or non-tobacco composition. The web may e.g. be longitudinally folded around the smokeless tobacco composition or non-tobacco composition.

[0114] The arrangement 100 may further comprise a transverse sealing unit 180 for forming the web of packaging material into individual products by making at least one transverse seal between two consecutive individual products formed by the web.

[0115] The individual products may also be separated or made separable from each other along a separation line, e.g. by cutting or perforation in a separation unit 190. The transverse sealing unit 180 may be a heat-sealing unit or an ultrasonic sealing unit, like the type of sealing units described above for the longitudinal sealing unit 160. The separation unit 190 may be combined with the transverse sealing unit 180, e.g. if using the same ultrasonic unit both for sealing and separating as is disclosed in WO 2017/093486 A1.

[0116] FIG. 4 schematically illustrates a method 400 for manufacturing of a web of packaging material for an oral pouched snuff product according to the invention. The method 400 is suitable to be performed in an arrangement 100 as described herein. In that case the steps of the method correspond to the various units of the arrangement 100. Dashed lines in FIG. 4 indicate optional steps.

[0117] The web to be manufactured by the method is a saliva-permeable nonwoven web comprising fibres, whereof 0%-95% are of a first type and 5%-100% of a second type. The fibres of the first type, which may be dispensed with are cellulose-based staple fibres. The fibres of the second type are thermoplastic fibres, which are meltable and/or softenable at least at the surface, e.g. thermoplastic fibres comprising a first component and a second component, wherein second component has a lower melting temperature than said first component.

[0118] The method comprises the steps of:

[0119] 410: Carding the fibres to form a pre-web.

[0120] 430: Bonding the pre-web by blowing air through the pre-web to at least partially melt and/or soften the fibres of the second type to form the web of packaging material.

[0121] 440: Smooth calendering of the web.

[0122] In case the fibres of the second type are thermoplastic fibres comprising a first component and a second component as described above, wherein the second component has a lower melting temperature than the first component, step 430 preferably comprises bonding the web by at least partially melting and/or softening of the second component of the fibres of the second type.

[0123] The method 400 may comprise an optional step:

[0124] 420: Pre-bonding the pre-web formed by carding in step 410.

[0125] The pre-bonding of step 420 is performed before the step 430 of air-through bonding. The step 420 of pre-bonding may be performed in a pre-bonding unit 120 configured to blow air through the pre-web, please see the description of FIG. 1. The pre-bonding of step 420 may be performed at a temperature being within the range of 80° C.-155° C., preferably 90° C.-140° C., more preferably 100° C.-135° C., most preferably 110° C.-130° C. The temperature interval is selected dependent on the melting temperatures of the fibres of the first and second types, such that the temperature in the pre-bonding step 420 is less than their respective melting temperatures. Moreover, the pre-bonding step 420 is an optional step which may be dispensed with.

[0126] The calendering of step 440 is preferably performed at a lower temperature than the air-through bonding of step 430. More preferably, the temperatures of steps 430 and 440 are selected such that all bonding or substantially all bonding of the web occurs already during step 430. The calendering in step 440 may then be performed to obtain a pre-selectable thickness and/or surface finish and/or air permeability of the web.

[0127] In the air-through bonding of step 430, the fibres of the second type melt or soften and bind the fibres together to form a cohesive web, such that the web is formed. If the fibres of the second type are the above-mentioned thermoplastic fibres comprising a first and a second component, the second component partially melts or softens to bind the fibres together to form a cohesive web.

[0128] The air-through bonding of step 430 may be performed in a flat air-through dryer 200, e.g. as illustrated in FIG. 2. In that case the air-through bonding of step 430 may be performed at a temperature within the ranges mentioned above. If utilizing a flat air-through dryer 200, the pre-bonding step 420 may be dispensed with, cf. above.

[0129] As an alternative or a complement, the air-through bonding of step 430 may be performed in a cylinder air-through dryer 300, e.g. as illustrated in FIG. 3. In that case the air-through bonding of step 430 may be performed at a temperature within the ranges mentioned above.

[0130] There may also be a combination of pre-bonding and air-through bonding or there may be a sliding scale from pre-bonding to air-through bonding, which is also described above, e.g. in conjunction with FIG. 1.

[0131] The method 400 may further comprise one or more of the following optional steps:

[0132] 450: Forming the web into a tubular structure.

[0133] 460: Longitudinal sealing

[0134] 470: Supplying smokeless tobacco composition or non-tobacco composition

[0135] 480: Transverse sealing

[0136] 490: Separation

[0137] Step 450 may be performed by means of a tube-forming unit 150, which forms at least one tubular structure of the web, e.g. by folding, which tubular structure has a width suitable for the oral pouched snuff product.

[0138] The tube-forming unit 150 may be located before the supplying unit 170, as is in the method illustrated to the left in FIG. 4, such that the smokeless tobacco composition or non-tobacco composition later on, e.g. as portions, is fed into an already formed tubular structure by the supplying unit 170, see step 470 below.

[0139] The method 400 of FIG. 1 further comprises an optional step of sealing the web with at least one seal by at least partially melting the fibres of the second type in the web at the location where the seal is formed. The sealing may be a longitudinal sealing, as in step 460 or a transverse sealing, as in step 480, but typically sealing is first performed in the longitudinal direction and thereafter in the transverse direction, i.e. by performing steps 460 and 480.

[0140] The step 460 of longitudinal sealing results in fixing the web of packaging material into a tubular shape by making at least one longitudinal seal. The longitudinal sealing 460 is thus performed to make a seal and thereby fix the above-mentioned tubular structure. The longitudinal sealing 460 may be performed by heat-sealing or ultrasonic sealing as described above. During sealing, energy is applied to create a seal in the nonwoven. The seal is preferably located outside the smokeless tobacco composition or non-tobacco composition, such that the seal is formed between two nonwoven surfaces being placed surface to surface in relation to each other. In the method depicted to the left in FIG. 4, the step 460 of longitudinal sealing is performed before the step 470, such that the smokeless tobacco composition or non-tobacco composition is fed into an already formed and sealed tubular structure.

[0141] As an alternative, the tube-forming unit 150 may be located after the supplying unit, such that step 450′ of supplying smokeless tobacco composition or non-tobacco composition is performed before step 460′ of forming the web into a tubular structure, see method depicted to the right in FIG. 4. The smokeless tobacco composition or non-tobacco composition is then first placed on the web, typically as portions, and thereafter the tubular structure is formed around the smokeless tobacco composition or non-tobacco composition. The web may e.g. be longitudinally folded around the smokeless tobacco composition or non-tobacco composition. Step 460′ is thereafter followed by the step 470′ of longitudinal sealing.

[0142] As an alternative or a complementary way to the folding the web into a tubular structure, a second saliva-permeable nonwoven web may be positioned on top of a first saliva-permeable nonwoven web such that one or more tubular structures are formed between the two webs as described above. In that case, the step of supplying the smokeless tobacco composition or non-tobacco composition may be made either before or after forming the tubular structure, i.e. it would be feasible to follow either steps 450 to 470 depicted to the left or steps 450′ to 470′ depicted to the right. There would then be a longitudinal seal at either longitudinal side of the smokeless tobacco composition or non-tobacco composition.

[0143] The method 400 may further comprises a step 480 of transverse sealing for forming the web of packaging material into individual products by making at least one transverse seal between two of the individual products. The transverse sealing may be performed by a heat-sealing or an ultrasonic sealing, e.g. in the transverse sealing unit 180 described above.

[0144] The individual products may also be separated or made separable from each other along a separation line, by a step 490 of separation, e.g. by cutting or perforation, as described above when describing the arrangement 100. Transverse sealing 480 and separation 490 may be performed as a common step.

[0145] Further modifications of the invention within the scope of the appended claims are feasible. As such, the present invention should not be considered as limited by the embodiments and figures described herein. Rather, the full scope of the invention should be determined by the appended claims, with reference to the description and drawings.