DE2319735A1 - FILTER MATERIAL - Google Patents

Description

The present invention relates to filter material and more particularly, but not exclusively tobacco smoke filter material.

It is known to produce fibrous material by dividing a longitudinal polyolefin film into a plurality of to produce interconnected fibers. The production of such material is called fiber formation ' known, and the material is hereinafter referred to as "frayed Material as previously mentioned ".

The present invention is based on the finding that aufgefasertes material, as mentioned before, surprisingly proved to be effective for tobacco smoke filter material, provided that certain specific structure ₅

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features. Compared with conventional fibrous Tobacco smoke filter materials are due to the new frayed material tobacco smoke filters with better filtering ever Unit pressure drop or pressure drop created, and better filtering and lower pressure drop are with one lower material weight achievable. It is surprisingly easy to make tobacco smoke filters from this material, as it can be processed on any conventional machine. The same properties that make the material one Making an extremely effective tobacco smoke filter also makes it extremely effective for various other filtering purposes.

According to the invention, the filter material contains frayed material, as mentioned above, with generally longitudinal main fibers which are connected to one another by connecting fibers and have a considerable number of free ends, which were created by splitting off main fibers and / or those fibers which would otherwise have formed connecting fibers are. The fibers have a strength in the range from 5 μ to 25 p. » and at least 40 % (preferably 70 %) of the fibers have a width no greater than their thickness.

The term "strength" as used herein in relation to fibers means the extent in the same direction as the strength of the Film from which the material was made.

The thickness of the fibers is preferably 1h μ (ie 1h ' micromillimeter).

The multitude of split ends in the frayed material, as mentioned earlier, can best serve to increase filter effectiveness to increase the filter material considerably, while having enough strength for the usual continuous Movement to follow-up treatment remains. The arbitrary arrangement of the split ends throughout the network effectively leads to the largest possible surface, which in turn creates better filter effectiveness.

Preferably, the connecting fibers substantially meet evenly spaced on the main fibers. If the material is laterally expanded, this creates a substantially uniform network in contrast to one Network with clearly arbitrary connection distances and arbitrarily varying openings.

The polyolefin from which the polyolefin film is made, can be made from polypropylene or polyethylene or a mixture of both or from a copolymer of propylene and Ethylene exist (see examples).

A bleach in the form of a finely divided solid, preferably titanium dioxide, can be incorporated into the polyolefin be, surprisingly, it turned out that such Means enable the manufacture of very narrow fibers, as previously mentioned.

The object of the present invention is also to provide a tobacco smoke filter and a cigarette with a tobacco

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smoke filter, the filter being a body of filter material held in a tubular outer shell, as mentioned above, contains / preferably the main fibers extend axially in the longitudinal direction of the filter. According to experience a binder is preferably incorporated into the material, for example by spraying. '

The object of the present invention is also to create a method for producing filter material, as before mentioned, whereby the material is moved over a roller with protruding pins. The arrangement of the pins, the touch between the film and the roll on a certain arc and the relative speed of the film and the Rolls are chosen so that a frayed material with the characteristics described above is created.

A plurality of films one on top of the other are advantageously used moved over the roll at the same time, so that all films frayed will.

The requirements can be determined from calculations and / or routine experimentation by a worker skilled in fiber formation. In order to obtain a significant number of free ends, as previously mentioned, the Fa-. The formation ratio (ie, the ratio of the surface speed of the roller to the speed of the film) desirably be between 1.05 'x 1 and 3 * 1, preferably between 2: 1 and 2.5: 1.

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In order to obtain the best structure in which the connecting fibers are spaced at essentially constant intervals where the main fibers hit, the pins are on the reel preferably arranged in parallel rows and offset from one another, for example as described in British Patent No. 1,073,711. Therefore, when the roller rotates, the trajectory of the pins in each row is different from that in the side Distance to the trajectory of the pins in immediately adjacent rows.

In order to facilitate the manufacture of narrow fibers, each row of pins preferably extends on one to a parallel line of the roller axis inclined line over the roller. Each row can lie on a sinusoidal line, which extends parallel to the roller axis. Or the pins can be arranged in parallel rows of two, the extend over the roller on lines inclined to parallel lines of the roller axis, with immediately adjacent rows of two are inclined towards each other.

Below is an * example of how to make tobacco smoke filter media described according to the invention.

EXAMPLE 1

A copolymer of propylene and ethylene having a melt index of 0.8 and about 20 weight percent copolymer - siertem ethylene was extruded using a known explosion process to form a film of nominally 25 μ thickness. The film produced in this way was

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te cut (ζ.B, 11 inches = approx. 28 cm), and the cut film was passed through a conventional heating and stretching (straightening) device in which it was formed with a stretching ratio of 7: 1 to a film of 14 µm Strength was aligned lengthways. The oriented film was fed around part of the circumference of a fiberizing roller with pins. The physical data of the role and the working conditions were as follows:

Fiber forming roll diameter .8 inches (20.3 cm) Pins offset to one another at a distance. ·

the roller axis running on parallel sinusoidal lines parallel cur

Number of rows of pins 90 density of pins in each row of MO pins per inch

(16 pins per cm)

Angle of inclination of the pins (angle of the
Pins to the tangent to the roller, opposite to the direction of rotation of the roller) 60 °

The pins protrude 1 mm

Pin diameter 0.0145 inch (0.368 mm)

Contact between film and role

on an arc of 60 ^G

Film input speed 150 ft / min (45.7 m / min) Fibrous roll surface speed 300 ft / min (91.4 m / min)

i.e. fiber formation ratio 2: 1

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The frayed film, the filter material according to the invention was collected by conventional means directly after defibration. Finally, a number (e.g. three) frayed films bonded together to make the required Get length su (i.e. length per unit of weight).

The frayed film produced in this way was then pebbled, e.g. by passing the film through a tamping machine in a known manner. Other conventional crimping devices ", e.g., "gear", false twist crimping machines, etc., can also be used to crimp the raised film.

In the following the invention is illustrated by means of schematic drawings explained in more detail using exemplary embodiments. Show it:

1 shows a piece of the frayed film according to the invention, which was stretched sideways to clarify the network before the curling process was carried out.

Fig. 2 shows a cigarette with a filter

As can be seen from the figures, the reference number 1 in Fig. 1 designates main fibers, 2 connecting fibers and 3 free ends. In Fig. 2, a cigarette is denoted by 4, which has a filter 5 made of filter material 6 according to the invention in a tubular outer shell 7 includes.

TEST 1

Tobacco smoke filters were made from a fiberized one according to the invention Film produced according to the process described above,

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The frayed film was 182 ft (55 »5 m) each Pound (453 g) (8175 tex) was measured on a conventional filter rod machine processed into filter rods, which were cut into filter rods of 15 mm in length. Each filter contained 103 mg of fiberized film, the pressure vessel of the filter was 5> 6 cm water column with an air flow of 1050 ml / min.

The filters were attached to cigarettes and smoked using a smoking machine which took a puff of 35 ml volume and two seconds each minute. A comparison of the weight of the total residues from cigarettes with filters with those from cigarettes without filters showed that the filter removed HO% of the residues.

TEST 2

15 mm of a commonly used cigarette filter made of acetate-cellulose fibers (denier specification 3 / 46,000) contained 101 mg of acetate-cellulose. When tested under the same conditions as in Example 1, the pressure drop was 5 * 5 cm water column and the filter removed 35 % of the residues.

TEST 3

Filters were made and tested as in Example 1, but in this case the frayed film did not contain severed ends. The filter contained 103 mg of frayed film and the pressure drop was 4.8 cm water column with an air flow of 1050 ml / min. The filter efficiency for residues was 35 %

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Another example of a method for producing filter material according to the invention is described below.

EXAMPLE 2

A copolymer of propylene and ethylene with a melt index of 0.8 ( containing 20% copolymerized ethylene) was made into a film by a known explosion method using an oscillating mold. 28 μ thickness molded. The double layer of film so produced was cut to the desired width (eg 6.4 inches = about 16.3 cm). Three such pieces of bilayer film were laid one on top of the other and passed through conventional heating and stretching (layering) equipment in which they were straightened at an expansion ratio of 7: 1 to form films of I ¹ J µ thickness. The oriented films were fed around part of the circumference of a fiberizing roller with pins. The physical data of the role and the working conditions were as follows:

Fiber forming roll diameter 8 inch (20.3 cm) Pins offset from one another in parallel rows of two, inclined to the parallel line / i of the roller axis Lines extending across the roll, with immediately adjacent rows of two being inclined towards one another.

Number of rows with pins l80

- 10 -

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Density of pins in each row "25 pins per inch

(10 pens per cm)

Angle of inclination of the pins (angle of the pins to the tangent to the roller, ent- ■ opposite to the direction of rotation of the roller) 60 °

The pins protrude 1 mm

Pin diameter 0.0145 inch (0.368 mm)

Contact between film and role
on an arc of 45 °

Pilm entry speed 210 ft / min (64-m / min)

Surface speed of the fiber forming roll 525 ft / min (l60 m / min)

Fiber formation ratio 2.5: 1

The frayed product, filter material according to the invention, was collected by conventional means directly after defibration.

The product was 4444 tex (i.e., a linear yarn density (length per unit weight) of 40,000 denier).

The frayed material obtained in the example described above was then structured as previously described (i.e. curled by a darning machine).

TEST 4

The structuring process was followed by a de-curling process, resulting in a fluffy, flaky mass, whose

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Crimping feature l6 crimps / inch (* to crimps / cm) was. When this material was processed into a filter rod as described in Test 1, each filter (15 mm long) 72 mg of frayed film. The pressure drop of the filter was 4.2 cm water column with an air flow of 1050 ml / min.

All information contained in the documents and! "Will be explained - as far as they are one or in combination new compared to the state of the art - claimed as essential to the invention. .

Expectations:

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Claims (24)

EXPECTATIONS 1. Filter material with fiberized material, as mentioned above, characterized in that it generally contains longitudinally riveted main fibers (1) which are connected to one another by connecting fibers (2) and have a considerable number of free ends (3) which by splitting off Main fibers and / or those fibers that would otherwise have formed connecting fibers, the fibers having a strength in the range from 5 to 25 μm and at least 40 % of the fibers having a width that is not greater than their strength. 2. Filter material according to claim 1, characterized in that at least 70 % of the fibers have a width which is not greater than their strength. 3. Filter material according to claim 1 or 2, characterized in that the strength of the fibers is approximately 14 micromillimeters. 4. Filter material according to one or more of the claims 1 to 3j characterized in that the material contains the greatest possible number of split ends (3) that are still with sufficient strength for the usual Continuous movement for follow-up treatment can be agreed is. p - 13 309843/0969 5. Filter material according to one or more of claims 1 to 4, characterized in that the Connecting fibers (2) impinge on the main fibers (1) at essentially constant intervals. 6. Filter material according to one or more of claims 1 to 5, characterized in that the Polyolefin from which the material is made, from polypropylene or polyethylene or from a mixture of polypropylene and polyethylene or a copolymer of propylene and .äthylen. 7. Filter material according to one or more of claims 1 to 6, characterized in that a Bleaching agent in the form of a finely divided solid is introduced into the polyolefin, from which the filter material was produced., 8. Filter material according to claim 7, characterized in that the bleaching agent is titanium dioxide. 9. Filter material according to one or more of claims 1 to 8, characterized in that the Filter material made from several stacked polyolefin films is made, which were frayed while lying on top of each other. - IH 309843/0969 10. Tobacco smoke filter, characterized in that it has a filter body (6) made of filter material after a which contains claims 1 to 9. 11. tobacco smoke filter according to claim 10, characterized shows that the main fibers (1) axially in Extend the longitudinal direction of the filter. 12. Method for the production of a filter material according to one of claims 1 to 11, characterized net that the filter material was made by the Film was passed over a roll with protruding pins. 13. The method of claim 12, characterized in that the fiber formation ratio (i.e. the ratio of the surface speed of the roller to the speed of the film) within the range 1.05: up to 3: 1. 14. The method according to claim 13, characterized in that the fiber formation ratio in the range 2: 1 to 2.5: 1. 15. Method according to one of Claims 12 to Ik _3, characterized in that the pins are arranged on the roller in parallel rows and offset from one another. - 15 309843/0969 16. The method according to claim 15, characterized in that each row on one to one Impact line of the roller axis extends inclined line. 17. The method according to claim 15, characterized in that each row is on a sinusoidal Line extends parallel to the roller axis over the roller. 18. The method according to claim 1β, characterized in that g e k e η η -, draws, ■ that the pins are arranged in parallel rows of two, which extend to parallel lines of the roller axis inclined lines extend over the roller, with immediately adjacent rows of two being inclined towards each other. 19. A method for the production of filter material according to one or more of claims 1 to 9, characterized in that a copolymer of propylene and ethylene with a melt index of 0.8 and about 20 percent by weight of copolymerized ethylene using a known explosion process to form a film of nominal 25 μ thickness is extruded, the film produced in this way is cut to the desired width, the cut film is passed through a conventional heating and stretching (straightening) device in which it is vrird with an expansion ratio of 7: to a film of 14 μ Strength is longitudinally oriented, the oriented film around part of the periphery of a fiber forming roll - 16 309843/0989 with pins that the diameter of the fiber forming roll is 20.3 cm, that the pins run offset from one another on parallel sinusoidal lines parallel to the roll axis, that there are 90 rows of pins, that the density of the pins in each row is 16 / cm, the angle of inclination of the pins (angle of the pins to the tangent to the roller, opposite to the direction of rotation of the roller) is 6C °, that the pins protrude 1 mm and have a diameter of 0.368 mm, that the film and roller are on one Circular arcs of 60 ° touch that the film input speed is 45.7 m / min and the surface speed of the fiber formation roller 91 »4 m / min and that the fiber formation ratio is thus 2: 1 . 20. A method for producing filter material according to one or more of claims 1 to S _3, characterized in that a copolymer of propylene and ethylene with a melt index of 0.8 ( containing 20% copolymerized ethylene) by a known explosion process using an oscillating mold is formed into a film of 28 μ thickness, the thus produced double layer of the film is cut to the desired width, three such pieces of double-layer film are placed on top of one another and passed through a conventional heating and stretching (straightening) device in which they are with a Expansion ratio of 7: 1 to films of 14 ρ thickness are longitudinally oriented, the oriented films - 17 309843/0969 ■ be guided around part of the circumference of a paser formation roller with pins so that the diameter of the paser formation roller is 20.3 cm, that the pins are arranged offset from one another in parallel rows of two and extend over the roller on lines inclined to parallel lines of the roller axis, wherein immediately adjacent rows of two are inclined to each other, that there are 180 rows with pins, that the density of the pins in each row is 10 / cm, that the angle of inclination of the pins (angle of the pins to the tangent to the roller, opposite to the direction of rotation of the roller) 60 °, that the pins protrude 1 mm and have a diameter of 0.368 mm, that the film and roll touch on an arc of 45 °, that the film input speed is 64 m / min and the surface speed of the paser formation roller is 160 m / min and that the paser formation ratio is thus 2.5 ' 1, 21. Filter material, characterized in that that it is produced by the method according to claim 19. 22. Filter material, characterized in that it is produced by the method according to claim 20. 23. Tobacco smoke filter, thereby marked. Chnet that its filter body (6) filter material according to claim 21 contains. - 18 309843/0969 24. Tobacco smoke filter, characterized in that that its pilter body (6) contains filter material according to claim 22. 25 · Cigarette, characterized in that it has a tobacco smoke filter according to claims 10, 11, 23 or 24 contains. 309843/0 9 69