Method for producing a packed filter tow bale

Abstract

The present invention relates to a method for producing a packed bale of highly compacted filter tow material. A compressed filter tow bale is first provided in cuboid shape in a baler. Then the compressed filter tow bale is packaged, having an air-tight packaging sleeve fully enclosing the compressed filter tow bale. According to the invention, the packaging sleeve is applied to the compressed filter tow bales such that at least 80%, preferably at least 90% and more preferably at least 95%, of the packaging sleeve is directly adjacent to the highly compacted filter tow material and touches, or is at least spaced less than 15 mm from, the highly compacted filter tow material.

Claims

1. A method for producing a packaged filter tow bale, wherein the method comprises the following steps: i) producing a compressed filter tow bale in a baling press; and ii) wrapping the compressed filter tow bale with an airtight packaging sleeve, which completely encloses the compressed filter tow bale, wherein step ii) further includes applying the airtight packaging sleeve to the compressed filter tow bale in such a way that at least 80% of the airtight packaging sleeve does at least one of: (1) directly adjoins and therefore contacts the compressed filter tow bale; and (2) is spaced apart from the compressed filter tow bale by less than 15 mm, wherein step ii) further includes wrapping the compressed filter tow bale with the airtight packaging sleeve in such a way that a volume enclosed by the airtight packaging sleeve can increase by at least 32 liters after the packaged filter tow bale is released from the baling press without thereby extending or stretching the airtight packaging sleeve.

2. The method according to claim 1, wherein step ii) further includes applying the airtight packaging sleeve around the compressed filter tow bale in such a way that no more than 50 liters of air are enclosed between the airtight packaging sleeve and the compressed filter tow bale at a temperature of 20 C.

3. The method according to claim 1, wherein step i) further includes producing the compressed filter tow bale with a base adapted to the dimensions of a transport pallet and measuring at least 6,500 cm.sup.2; and producing the compressed filter tow bale with a height of at least 75 cm and a bale density of at least 300 kg/m.sup.3; and step ii) further includes applying the airtight packaging sleeve to the compressed filter tow bale in such a way that no more than 650 liters of air are contained in a volume enclosed by the airtight packaging sleeve at a temperature of 20 C.

4. The method according to claim 1, wherein step i) further includes producing the compressed filter tow bale between at least one cover film section and one bottom film section, and wherein step ii) further includes producing the airtight packaging sleeve by at least one of: (1) bonding together the at least one cover film section and the one bottom film section; and (2) welding together the at least one cover film section and one bottom film section.

5. The method according to claim 1, wherein step i) further includes the following steps: i.a) preparing a filling can by placing a bottom film section at a bottom of the filling can; i.b) preparing a press ram of the baling press by placing a cover film section on the press ram; i.c) placing a filter tow material into the prepared filling can; and i.d) compressing the filter tow material in the baling press.

6. The method according to claim 5, wherein at least one of (1) the cover film section and (2) the bottom film section is in the form of a flat film.

7. The method according to claim 6, wherein the cover film section and the bottom fil section are flat films with edge lengths, wherein each edge length of each of the cover film section and the bottom film section is longer than each corresponding peripheral horizontal edge length of the compressed filter tow bale by at least 10 cm.

8. The method according to claim 1, wherein the airtight packaging sleeve features at least one film section of a plastic material.

9. The method according to claim 1, wherein the packaged filter tow bale includes a packing density of at least 250 kg/m.sup.3.

10. The method according to claim 1, wherein step ii) further includes applying the airtight packaging sleeve around the compressed filter tow bale in such a way that no more than 10 liters of air are enclosed between the airtight packaging sleeve and the compressed filter tow bale at a temperature of 20 C.

11. The method according to claim 1, wherein step ii) further includes applying the airtight packaging sleeve to the compressed filter tow bale in such a way that at least 95% of the airtight packaging sleeve does at least one of: (1) directly adjoins and therefore contacts the compressed filter tow bale; and (2) is spaced apart from the compressed filter tow bale by less than 15 mm.

12. The method according to claim 1, wherein step i) further includes the following steps: i.e) preparing a stationary press yoke by placing a cover film section on the stationary press yoke; i.f) preparing a press ram of the baling press by placing a bottom film section on the press ram; i.g) arranging a filter tow material between the stationary press yoke and the stationary press ram; and i.h) compressing the filter tow material by displacing the press ram in the direction of the stationary press yoke.

13. A method for producing a packaged filter tow bale, wherein the method comprises the following steps: i) producing a compressed filter tow bale in a baling press, the compressed filter tow bale having lateral surfaces; and ii) wrapping the compressed filter tow bale with an airtight packaging sleeve, which completely encloses the compressed filter tow bale, wherein step ii) further includes applying the airtight packaging sleeve to the compressed filter tow bale in such a way that at least 80% of the airtight packaging sleeve does at least one of: (1) directly adjoins and therefore contacts the compressed filter tow bale; and (2) is spaced apart from the compressed filter tow bale by less than 15 mm, wherein step i) further includes producing the compressed filter tow bale between a cover film section and a bottom film section, and wherein step ii) further includes the following steps: ii.a) applying a sleeve film section to the lateral surfaces of the compressed filter tow bale, wherein the sleeve film section has a surface area and two opposite end regions; ii.b) bringing together the opposite end regions of the sleeve film section; and ii.c) connecting the opposite end regions of the sleeve film section to one another and connecting the surface area of the sleeve film section to the bottom film section and the cover film section to produce the airtight packaging sleeve completely enclosing the compressed filter tow bale, wherein step ii.a) further includes applying the sleeve film section around the lateral surfaces of the compressed filter tow bale in such a way that at least 80% of the surface area of the sleeve film section does at least one of (1) directly adjoins and therefore contacts the compressed filter tow bale; and (2) is spaced apart from the compressed filter tow bale by less than 15 mm; and wherein the sleeve film section is in the form of a flat film; wherein step ii.a) further includes applying the sleeve film section around the lateral surfaces of the compressed filter tow bale with an average application prestressing force of at least 50 N.

14. The method according to claim 13, wherein step i) further includes producing the compressed filter tow bale with a base adapted to the dimensions of a transport pallet and measuring at least 6,500 cm.sup.2; and producing the compressed filter tow bale with a height of at least 75 cm and a bale density of at least 300 kg/m.sup.3; and wherein step ii) further includes applying the airtight packaging sleeve to the lateral surfaces of the compressed filter tow bale in such a way that no more than 650 liters of air are contained in a volume enclosed by the sleeve film section, the cover film section and the bottom film section at a temperature of 20 C.

15. The method according to claim 14, wherein step ii.a) further includes applying the sleeve film section to the lateral surfaces of the compressed filter tow bale in such a way that no more than 50 liters of air are enclosed between the surface area of the sleeve film section and the compressed filter tow bale at a temperature of 20 C.

16. The method according to claim 13, wherein step ii.a) further includes applying the sleeve film section to the lateral surfaces of the compressed filter tow bale with the prestressing force in a horizontal direction.

17. A method for producing a packaged filter tow bale, wherein the method comprises the following steps: i) producing a compressed filter tow bale in a baling press, the compressed filter tow bale having lateral surfaces; and ii) wrapping the compressed filter tow bale with an airtight packaging sleeve, which completely encloses the compressed filter tow bale, wherein step ii) further includes applying the airtight packaging sleeve to the compressed filter tow bale in such a way that at least 80% of the airtight packaging sleeve does at least one of: (1) directly adjoins and therefore contacts the compressed filter tow bale; and (2) is spaced apart from the compressed filter tow bale by less than 15 mm; wherein step i) further includes producing the compressed filter tow bale between a cover film section and a bottom film section, and wherein step ii) further includes the following steps: ii.a) applying a sleeve film section to the lateral surfaces of the compressed filter tow bale, wherein the sleeve film section has a surface area and two opposite end regions; ii.b) bringing together the opposite end regions of the sleeve film section; and ii.c) connecting the opposite end regions of the sleeve film section to one another and connecting the surface area of the sleeve film section to the bottom film section and the cover film section to produce the airtight packaging sleeve completely enclosing the compressed filter tow bale, wherein step ii.a) further includes applying the sleeve film section around the lateral surfaces of the compressed filter tow bale in such a way that at least 80% of the surface area of the sleeve film section does at least one of (1) directly adjoins and therefore contacts the compressed filter tow bale; and (2) is spaced apart from the compressed filter tow bale by less than 15 mm; and wherein the sleeve film section is in the form of a flat film wherein step ii) further includes the following steps: ii.d) producing a vertically extending weld seam in a vertical overlapping region formed when the opposite end regions of the sleeve film section are brought together; ii.e) prestressing the sleeve film section in a direction of the vertically extending weld seam and fixing the sleeve film section in its prestressed state; ii.f) producing a first peripheral horizontal overlapping region between an upper end region of the sleeve film section and a peripheral edge region of the cover film section and producing a second peripheral horizontal overlapping region between a lower end region of the sleeve film section and the peripheral edge region of the bottom film section; and ii.g) producing a peripheral weld seam in each of the peripheral horizontal overlapping regions, wherein the vertically extending weld seam and the peripheral weld seams in the peripheral horizontal overlapping regions are produced in such a way that the bottom film section, the cover film section and the sleeve film section form the airtight packaging sleeve, which completely encloses the compressed filter tow bale, and wherein step ii.e) further includes prestressing the sleeve film section with an average prestressing force of at least 50 N.

18. The method according to claim 17, wherein step ii.g) further includes producing the peripheral weld seam in the peripheral horizontal overlapping regions at a predefined-minimum distance from the compressed filter tow bale, wherein the predefined minimum distance lies in the range between 2 and 20 cm and wherein the predefined minimum distance between the peripheral weld seam and the compressed filter tow bale is dependent on at least one elastic restoration property of the compressed filter tow bale after the compressed filter tow bale is released from the baling press.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In these drawings:

(2) FIG. 1a schematically shows the filter tow material to be packaged in the baling press or filling can prior to the compression process in an exemplary embodiment of the inventive method for producing a packaged bale of highly compacted filter tow material;

(3) FIG. 1b schematically shows the filter tow material to be packaged after the compression in the baling press or filling can, namely in the exemplary embodiment of the inventive method according to FIG. 1a;

(4) FIG. 1c schematically shows the application of a sleeve film section to the lateral surfaces of the compressed filter tow bale according to FIG. 1b; and

(5) FIG. 1d schematically shows the connection of the surface area of the sleeve film section to the bottom film section and the cover film section in the exemplary packaging method illustrated in the drawings.

DETAILED DESCRIPTION

(6) In the exemplary embodiment of the inventive method, filter tow material 1 is placed into a baling press as schematically indicated in FIG. 1a. The filter tow material 1 is compressed to the desired packing dimension (see FIG. 1b) in the baling press, which has a compressive force, for example, of 300 to 400 t.

(7) The compression process is preferably carried out in such a way that the filter tow bale being compressed in the baling press has a packing density of at least 250 kg/m.sup.2, particularly a packing density of at least 300 kg/m.sup.2. It is furthermore preferred to carry out the compression process in such a way that the filter tow bale being compressed in the baling press has a packing density of no more than 700 kg/m.sup.2, particularly a packing density of no more than 600 kg/m.sup.2.

(8) The packing dimension, i.e. the height of the filter tow bale being compressed in the baling press, preferably amounts to at least 700 mm. As initially mentioned, the production of the compressed filter tow bale in the baling press causes the filter tow material 1 to be compressed in such a way that the elastic restoration properties of the filter tow material are reduced.

(9) In the embodiment schematically illustrated in FIG. 1a and FIG. 1b, the press ram 10, 10 of the baling press is prepared accordingly prior to placing the filter tow material into the baling press or prior to placing the filter tow material into the filling can of the baling press. In the embodiment schematically illustrated in the drawings, it is specifically proposed that the compression of the filter tow material in the baling press takes place between a cover film section 11 and a bottom film section 12.

(10) In the embodiment schematically illustrated in the drawings, it is proposed that the bottom of the filling can is for this purpose garnished with a bottom film section 12 prior to compressing the filter tow material and prior to placing the filter tow material into the filling can. The filter tow material 1 to be compressed is subsequently placed into the thusly prepared filling can.

(11) Prior to pushing the content of the full filling can including the filling can bottom on the baling press into the press chamber, the upper press ram 10 of the baling press is likewise garnished with a film section (cover film section 11).

(12) Due to the inclusion of the cover and bottom film sections 11, 12, the subsequent bottom and cover films already are correctly positioned (above and underneath the bale) prior to the compression of the filter tow material.

(13) The thusly prepared filter tow material 1 is then compressed into a filter tow bale in the baling press (see FIG. 1b). The actual compression process corresponds to conventional compression processes known from the prior art and is not part of the invention disclosed herein.

(14) As a matter of principle, it is advantageous if the compression of the filter tow material in the baling press takes place in accordance with a predefined program sequence such that the relaxing restoration component in the compressed filter tow bale is likewise reduced in accordance with a predefined or predefinable event sequence. In this context, it is advantageous if the compression process continues for at least 4 minutes, preferably at least 5 minutes, in order to sufficiently reduce the relaxing restoration component in the filter tow material.

(15) Consequently, a compressed filter tow bale of cuboid shape is produced in the baling press between the cover film section 11 and the bottom film section 12 as schematically illustrated in FIG. 1b. In the subsequent step, the compressed filter tow bale is wrapped with an airtight packaging sleeve, which completely encloses the compressed filter tow bale.

(16) According to the schematic illustration in FIG. 1c, a sleeve film section 13 is for this purpose applied to the lateral surfaces of the compressed filter tow bale in the exemplary embodiment of the inventive method, wherein the sleeve film section 13 has a surface area with two opposite end regions. Subsequently, the opposite end regions of the sleeve film section 13 are brought together on the face and connected to one another.

(17) Furthermore, the surface area of the sleeve film section 13 is connected to the bottom film section 12 and the cover film section 11as schematically illustrated in FIG. 1d. The connection of the end regions of the sleeve film section 13 to one another and the connection of the surface area of the sleeve film section 13 to the bottom film section 12 and the cover film section 11 are produced in such a way that an altogether airtight packaging sleeve, which completely encloses the compressed filter tow bale, is ultimately formed.

(18) In the inventive method schematically illustrated in the drawings, the sleeve film section 13 is applied to the lateral surfaces of the compressed filter tow bale in such a way that at least 80%, preferably at least 90%, particularly at least 95%, of the surface area of the sleeve film section 13 directly adjoins and therefore contacts the highly compacted filter tow material or is at least spaced apart from the highly compacted filter tow material by less than 15 mm.

(19) In order to reduce the risk of a bale burst, it is particularly advantageous if the compressed filter tow bale being produced in the baling press has a cuboid shape with a preferably rectangular base, which is adapted to the dimensions of a transport pallet, particularly a Europool pallet, and measures at least 6,500 cm.sup.2, preferably at least 8,500 cm.sup.2, and a height (packing dimension) of at least 75 cm, preferably at least 85 cm. In the exemplary embodiment, a compressed filter tow bale with these dimensions produced in the baling press has a bale density of at least 300 kg/m.sup.3.

(20) The term dimensions of a transport pallet used herein particularly refers to the dimensions of a commonly used transport pallet. This particularly concerns a transport pallet that is adapted to standard container dimensions such as a Europool pallet.

(21) Europool pallets are based on a basic module with a size of 400 mm600 mm. Pallets of this size are also referred to as Europool pallets and correspond to the size of a so-called VDA box. The wooden Europool pallets EUR, which have been commonly used for many years, measure 8001200144 mm. These half Europool pallets with a size of 800 mm600 mm are also referred to as display pellets. At EPAL, they are called EUR 6-pallets; they are also referred to as Dusseldorf pallets.

(22) So-called industrial pallets (10001200144 mm) are slightly larger and also widely used, wherein these industrial pallets are respectively standardized as EUR 3-pallets or in reinforced form as EUR 2-pallets by EPAL.

(23) Large non-standardized pallets frequently have twice the industrial size, i.e. they measure 20001200 mm or 20001250 mm.

(24) The pallets commonly used on the American continent and partially also in China have a size of 4840 inches, i.e. they measure 1219.2 mm1016 mm and therefore approximately correspond to industrial pallets (1,200 mm1,000 mm), whereas pallets with a size of 1,100 mm1,100 mm or 1,140 mm1,140 mm are generally used in Asia.

(25) In this exemplary embodiment, the sleeve film section 13 is applied to the lateral surfaces of the compressed filter tow bale in such a way that no more than 650 liters of air, preferably no more than 450 liters of air, particularly no more than 400 liters of air, are altogether contained in the volume enclosed by the sleeve film section 13, the cover film section 11 and the bottom film section 12 at a temperature of 20 C.

(26) As already mentioned in the general portion of the description, the risk of a bale burst after the release of the hermetically enclosed bale from the baling press is thereby effectively reduced to considerably less than 1%.

(27) In the exemplary embodiment schematically illustrated in the drawings, in which the baling press is garnished with a bottom film section 12 and a cover film section 11 prior to the compression of the filter tow material and a sleeve film section 13 is subsequently applied to the lateral surfaces of the compressed bale, it is advantageous if the sleeve film section is applied to the lateral surfaces of the compressed filter tow bale in such a way that no more than 50 liters of air, preferably no more than 30 liters of air, particularly no more than 10 liters of air, are enclosed between the surface area of the sleeve film section and the highly compacted filter tow material at a temperature of 20 C.

(28) This can be achieved, for example, in that the sleeve film section 13 is applied to the lateral surfaces of the compressed filter tow bale with an average application prestressing force of at least 50 N, preferably at least 75 N. This application prestressing force can be easily controlled and monitored with strain gauges or similar sensors.

(29) In order to form an airtight packaging sleeve in the embodiment schematically illustrated in the drawings, it is proposed to produce a vertically extending weld seam, particularly a finned seam, in a vertical overlapping region formed when the opposite end regions of the sleeve film section 13 are brought together on the face.

(30) Subsequently, the sleeve film section is prestressed in the direction of the vertically extending weld seam and fixed, temporarily, with the aid of clamps or similar fixing means. In an exemplary embodiment, it is proposed to subsequently produce a peripheral horizontal overlapping region between the upper end region of the sleeve film section 13 and a peripheral edge region of the cover film section 11. A peripheral horizontal overlapping region between the lower end region of the sleeve film section 13 and a peripheral edge region of the bottom film section 12 is produced analogously. A peripheral weld seam, particularly a finned seam, is then respectively produced in the peripheral horizontal overlapping regions.

(31) In this case, the vertically extending weld seam and the peripheral weld seams in the peripheral horizontal overlapping regions are produced in such a way that the bottom film section 12, the cover film section 11 and the sleeve film section 13 altogether form an airtight packaging sleeve, which completely encloses the compressed filter tow bale.

(32) In order to produce the peripheral horizontal overlapping regions, it is advantageous if the respective edge regions of the cover film section 11 and the bottom film section 12 are drawn outward and away from the bale.

(33) According to an exemplary embodiment, the sleeve film section 13 is applied to the lateral surfaces of the filter tow bale in such a way that the vertical overlapping region preferably is arranged centrally between two vertically extending corner edges of the filter tow bale. In order to prestress the sleeve film section 13 in the direction of the vertical weld seam, the film material of the sleeve film section 13 can then preferably be displaced manually in the direction of the vertical weld seam such that the overlapping region is enlarged in the horizontal direction. In this context, it is advantageous if the sleeve film section 13 is prestressed with an average prestressing force of at least 50 N, particularly at least 75 N. This prestressing force can be easily monitored, for example, with correspondingly arranged strain gauges.

(34) When producing the peripheral weld seam in the peripheral horizontal overlapping regions in accordance with the inventive method, it is advantageous to produce the peripheral weld seam in the respective peripheral horizontal overlapping region at a predefined or predefinable minimum distance from the bale. This predefined or predefinable minimum distance lies in the range between 2 and 20 cm, preferably in the range between 5 and 10 cm. This distance between the bale and the weld seam ultimately represents the dimension, by which the finished bale can expand without exerting stress upon the packaging sections when the bale is released from the baling press.

(35) In general terms, the predefined or predefinable minimum distance between the peripheral weld seam and the bale should therefore be chosen in dependence on the elastic restoration properties of the compressed filter tow material after its release from the baling press.

(36) The compressed filter tow bale is released from the baling press after it has been hermetically packaged. This can be realized by incrementally increasing the distance between the upper and lower press plates of the baling press in order to allow an incremental expansion of the filter tow material. Stress peaks can be thereby prevented.

(37) In this context, it is advantageous if the distance between the upper and lower press plates is in a first step increased by 10 to 35 mm, preferably by 15 to 30 mm, particularly by 20 to 25 mm. The distance between the upper and the lower press plate is then increased to at least 1,200 mm in a second step, which is carried out with a certain time delay after the first step.

(38) The characteristics of the packaging method schematically illustrated in the drawings can be briefly summarized as follows: Step i): producing a compressed filter tow bale of cuboid shape in a baling press. Step ii): wrapping the compressed filter tow bale with an airtight packaging sleeve, which completely encloses the compressed filter tow bale. Step iii): releasing the filter tow bale, which is completely enclosed by the airtight packaging sleeve, from the baling press.

(39) According to the invention, it is proposed that the packaging sleeve is in step ii) applied to the compressed filter tow bale in such a way that at least 80%, preferably at least 90%, particularly at least 95%, of the packaging sleeve directly adjoins and therefore contacts the highly compacted filter tow material or is at least spaced apart from the highly compacted filter tow material by less than 15 mm.

(40) In this context, it is particularly advantageous if the packaging sleeve is in step ii) applied around the compressed filter tow bale in such a way that no more than 50 liters of air, preferably no more than 30 liters of air, particularly no more than 10 liters of air, are enclosed between the surface area of the sleeve film section 13 and the highly compacted filter tow material at a temperature of 20 C.

(41) In preferred realizations of the inventive packaging method, the filter tow bale being compressed in the baling press has in step i) a cuboid shape with a preferably rectangular base, which measures at least 6,500 cm.sup.2, preferably at least 8,500 cm.sup.2, and a height of at least 75 cm, preferably at least 85 cm, wherein the filter tow bale particularly is produced in step i) in such a way that the filter tow bale being compressed in the baling press has a bale density of at least 300 kg/m.sup.3.

(42) In this context, it is advantageous if the packaging sleeve is then in step ii) applied to the compressed filter tow bale in such a way that no more than 650 liters of air, preferably no more than 450 liters of air, particularly no more than 400 liters of air, are altogether contained in the volume enclosed by the packaging sleeve at a temperature of 20 C.

(43) It would alternatively or additionally also be conceivable that the filter tow bale of cuboid shape being compressed in the baling press is in step i) produced between a cover film section 11 and a bottom film section 12, wherein the airtight packaging sleeve, which completely encloses the compressed filter tow bale, is subsequently produced in step ii) by bonding or welding together the two film sections.

(44) According to an aspect of the invention, which is also incorporated into the packaging method schematically illustrated in the drawings, it is proposed that the filter tow bale of cuboid shape being compressed in the baling press is in step i) produced between a cover film section 11 and a bottom film section 12. With respect to the following step ii), it is proposed that this step comprises the following procedures:

(45) a) applying a sleeve film section 13 to the lateral surfaces of the compressed filter tow bale, wherein the sleeve film section 13 has a surface area with two opposite end regions;

(46) b) bringing together the opposite end regions of the sleeve film section 13 on the face; and

(47) c) connecting the opposite end regions of the sleeve film section 13 to one another and connecting the surface area of the sleeve film section 13 to the bottom film section 12 and the cover film section 11 in such a way that an altogether airtight packaging sleeve, which completely encloses the compressed filter tow bale, is ultimately produced.

(48) According to an enhancement of this exemplary embodiment of the inventive packaging method, it is proposed that the filter tow bale being compressed in the baling press has in step i) a cuboid shape with a preferably rectangular base, which measures at least 6,500 cm.sup.2, preferably at least 8,500 cm.sup.2, and a height of at least 75 cm, preferably at least 85 cm, wherein the filter tow bale is in step i) produced in such a way that the filter tow bale being compressed in the baling press has a bale density of at least 300 kg/m.sup.3.

(49) In this context, it is proposed that the sleeve film section 13 is in step a) applied to the lateral surfaces of the compressed filter tow bale in such a way that no more than 650 liters of air, preferably no more than 450 liters of air, particularly no more than 400 liters of air, are altogether contained in the volume enclosed by the sleeve film section 13, the cover film section 11 and the bottom film section 12 at a temperature of 20 C.

(50) It would alternatively or additionally also be conceivable that the sleeve film section 13 is in step a) applied to the lateral surfaces of the compressed filter tow bale in such a way that no more than 50 liters of air, preferably no more than 30 liters of air, particularly no more than 10 liters of air, are enclosed between the surface area of the sleeve film section 13 and the highly compacted filter tow material at a temperature of 20 C.

(51) For this purpose, it is particularly proposed that the sleeve film section 13 is in step a) applied around the lateral surfaces of the compressed filter tow bale with an average application prestress of at least 50 N, particularly at least 75 N.

(52) According to an enhancement of the latter embodiments, it is proposed that step ii) furthermore comprises the following procedures: d) producing a vertically extending weld seam, particularly a finned seam, in a vertical overlapping region formed when the opposite end regions of the sleeve film section 13 are brought together on the face; e) prestressing the sleeve film section 13 in the direction of the vertically extending weld seam and fixing, in particular temporarily, the sleeve film section 13 in its prestressed state; f) producing a peripheral horizontal overlapping region between the upper end region of the sleeve film section 13 and a peripheral edge region of the cover film section 11 and producing a peripheral horizontal overlapping region between the lower end region of the sleeve film section 13 and a peripheral edge region of the bottom film section 12; and g) respectively producing a peripheral weld seam, particularly a finned seam, in the peripheral horizontal overlapping regions.

(53) In this context, it is particularly proposed that the vertically extending weld seam and the peripheral weld seams in the peripheral horizontal overlapping regions are produced in such a way that the bottom film section 12, the cover film section 11 and the sleeve film section 13 form an airtight packaging sleeve, which completely encloses the compressed filter tow bale.

(54) The respective edge regions of the cover film section 11 and the bottom film section 12 are preferably drawn outward and away from the bale in order to produce the peripheral horizontal overlapping regions in step f). On the other hand, it is also advantageous if the sleeve film section 13 is in step e) prestressed with an average prestressing force of at least 50 N, particularly at least 75 N.

(55) In a preferred realization of the latter embodiments, it is proposed that the sleeve film section 13 is in step a) applied to the lateral surfaces of the filter tow bale in such a way that the vertical overlapping region preferably is arranged centrally between two vertically extending corner edges of the filter tow bale, wherein the film material of the sleeve film section 13 is then preferably displaced manually in the direction of the vertical weld seam such that the overlapping region is enlarged in the horizontal direction in order to prestress the sleeve film section 13 in the direction of the vertical weld seam.

(56) As a matter of principle, it is advantageous if the peripheral weld seam is in step g) produced in the peripheral horizontal overlapping regions at a predefined or predefinable minimum distance from the bale. The predefined or predefinable minimum distance should lie in the range between 2 and 20 cm, preferably in the range between 5 and 10 cm. This predefined or predefinable minimum distance between the peripheral weld seam and the bale should particularly be chosen in dependence on the elastic restoration properties of the compressed filter tow material after its release from the baling press.

(57) According to a preferred realization of the latter embodiments, it is proposed that the sleeve film section 13 is in step e) fixed, in particular temporarily, in its prestressed state, namely by laterally folding over the vertical overlapping region and fixing the folded overlapping region on the bale, preferably with an adhesive tape or a similar detachable fixing means.

(58) It is alternatively or additionally also advantageous if the sleeve film section 13 is in step a) applied to the lateral surfaces of the filter tow bale with a certain prestress in the horizontal direction. In this context, it would particularly be conceivable that the sleeve film section 13 is in step a) positioned relative to the cover film section 11 and the bottom film section 12 and temporarily fixed in the positioned state. The upper and/or lower edge region of the sleeve film section 13 is preferably held on the baling press by a restraint in order to position and temporarily fix the sleeve film section 13.

(59) In this context, it is particularly advantageous if the baling press features an upper and a lower press plate, between which the compressed filter tow bale is produced in step i), wherein the upper edge region of the sleeve film section 13 is held, particularly clamped, by a restraint arranged on the upper press plate of the baling press in order to position and temporarily fix the sleeve film section 13. In this case, the temporarily fixed sleeve film section 13 should be released, in particular, directly before the peripheral horizontal overlapping regions are produced in step f).

(60) According to an aspect of the present invention, step i) comprises the following procedures: preparing a filling can by garnishing the bottom of the filling can with the bottom film section 12; preparing a press ram 10 of the baling press by a garnishing the press ram 10 with the cover film section 11; placing the filter tow material to be packaged into the prepared filling can; and compressing the filter tow material placed into the prepared filling can by moving the prepared press ram 10 into the filling can from above.

(61) It would alternatively be conceivable that step i) comprises the following procedures: preparing a stationary press yoke by garnishing the press yoke with the cover film section 11; preparing a press ram 10 of the baling press by garnishing the press ram 10 with the bottom film section 12; arranging the filter tow material to be packaged between the prepared press yoke and the press ram 10; and compressing the filter tow material by displacing the prepared press ram 10 in the direction of the press yoke from below.

(62) With respect to step iii), it is particularly proposed that the baling press features an upper and a lower press plate, wherein the filter tow bale is released from the baling press by incrementally increasing the distance between the upper and the lower press plate. In this context, it is particularly proposed that the distance between the upper and the lower press plate is in a first step increased by 10 to 35 mm, preferably by 15 to 30 mm, particularly by 20 to 25 mm. The distance between the upper and the lower press plate is then increased to at least 1.200 mm in a second step, which is carried out with a certain time delay after the first step.

(63) It is particularly advantageous to compress the filter tow bale in the baling press for at least 180 s, particularly for at least 250 s, such that a bale density of at least 300 kg/m.sup.3 is achieved prior to releasing the filter tow bale, which is completely enclosed by the airtight packaging sleeve in step ii). This ensures that the elastic restoration properties of the filter tow material are sufficiently reduced. The invention is not limited to the exemplary embodiment of the inventive packaging method illustrated in the drawings, but rather results from a synopsis of all characteristics disclosed herein.

(64) The invention particularly also pertains to a filter tow bale of cuboid shape, which is produced in accordance with the inventive method and has a packing density of at least 250 kg/m.sup.3.

(65) The present application has priority in case the content of any patents, patent applications and publications, to which this application refers, conflicts with the content of the present application to the effect that the conflict obscures a definition of the present application.