GB2124264A

GB2124264A - Method and apparatus for disintegrating fibrous sheet material

Info

Publication number: GB2124264A
Application number: GB08320127A
Authority: GB
Inventors: Fred Robert Radwanski
Original assignee: Kimberly Clark Corp
Current assignee: Kimberly Clark Corp
Priority date: 1982-07-26
Filing date: 1983-07-26
Publication date: 1984-02-15
Also published as: FR2531981A1; KR840005500A; DE3326753A1; ZA835073B; IT8348745A0; GB2124264B; NL8302639A; AU1641483A; JPS5943159A; FR2531981B1; BR8303952A; IT1184254B; GB8320127D0

Abstract

An apparatus and method is disclosed for disintegrating a plurality of sheets 20, 28 of fibrous material within a casing 4 by means of impacting means 7 carried by a rotor 6 mounted within the casing 4. The disintegrated fiber 21, 29 from each sheet is separately exhausted from the casing though discharge openings 14, 16 in the casing wall 5 and thereafter is passed through a separate forming chamber 42, 44 and is deposited onto a foraminous member 34. Each of the fibrous sheets 20, 28 may be of a different type of fiber and the separate fibers may be consecutively deposited onto the foraminous member 34 whilst it is moving to form a layered batt structure 36. <IMAGE>

Description

SPECIFICATION Method and apparatus for disintegrating fibrous sheet material This invention relates to an apparatus and method for impacting and disintegrating a plurality of sheets of fibrous material.

Due to the variety of properties which batts for fluid absorbent purposes are required to have, different types of fiber are often used in each batt to assist in providing these properties. For example, in the case of an absorbent batt for use in a disposable diaper, it may be desirable that the fiber closest adjacent to the skin of the wearer be of a hydrophobic character so that it will not retain fluid contacting the skin and, at the same time, it may be desirable that the fiber more remote from the skin of the wearer have a hydrophilic characteristic such that it will retain and hold fluid passing to it through the hydrophobic fiber.Probably the most common approach to obtaining layered fibers is to fiberize sheet material comprising one of the desired types of fibers in a first fiber disintegrating apparatus and fiberize sheet material comprising the second type of fiber in a separate fiber disintegrating apparatus. The two types of fibers are passed through separate forming chambers and consecutively deposited in a superimposed layered relationship onto a moving screen. This method requires an entirely separate fiberizing apparatus for each layer of fiber deposited onto the screen. One approach to minimizing the amount of apparatus needed to fiberize several different fibrous sheets as disclosed in U.S. Patent 3,984,898.This patent illustrates the use of several different fiberizing devices, each disintegrating a separate fiber material, with each fiber disintegrator device sharing a single forming duct immediately over the moving screen onto which the fiber from each fiberizing device is consecutively deposited. This is not a particularly effective solution due to the considerable amount of apparatus required since separate fiberizing devices for each type of fiber sheet are employed.

It is a principle object of this invention to provide a simple, efficient method and apparatus for disintegrating a plurality of fibrous sheets which may be of different types of fiber and maintaining the disintegrated fibers separate while they are being transported to one or more product forming stations.

According to the invention there is provided a method of disintegrating a plurality of sheets of fibrous material including the steps of: feeding said plurality of sheets of fibrous material into a casing at spaced apart locations; impacting the sheets of fibrous material at said locations to disintegrate them and move the disintegrated material along separate paths within the casing; and discharging the disintegrated material from each of said sheets out of said casing at separate spaced apart locations along the periphery of the casing.

According to the invention there is further provided apparatus for disintegrating fibrous sheet material including a casing and impacting means moving along a path within the casing, the combination including: first and second spaced apart support means each supporting fibrous sheet material at a position in the path of movement of the impacting means whereby the material is impacted and disintegrated and also moved by the impacting means; and first and second discharge openings in said casing, the disintegrated material impacted at the first support means moving through the first discharge opening to exit from the casing and the disintegrated material impacted at the second support means moving through the second discharge opening to exit from the casing.

As separate discharge openings are provided in the casing for disintegrated fibrous material from each different sheet, different types of fiber can be kept separate during their discharge from the casing. The relative arrangement of discharge openings and support means enables substantially all (at least 95%) of the disintegrated material impacted at one support means to exit from its associated discharge opening. After they are discharged from the casing, disintegrated fibers preferably pass through separate forming chambers and onto a moving foraminous member such as a screen where they may be consecutively deposited to form a batt having layers of each different types of fiber.The impacting means preferably strikes the fibrous sheet material such that the disintegrated fiber follows a substantially arcuate path within the casing and the discharge opening for each of the different types of disintegrated fiber is positioned in alignment with a tangent to the arcuate path and at a point between the location of the impacting of the disintegrated fiber passing through the particular discharge opening and the next location of impacting of another fibrous sheet.

The invention enables fibrous sheets to be disintegrated at a high throughput volume using a relatively low current of expanded energy.

The invention will be further described by way of example only with reference to the accompanying drawings in which: Fig. 1 is a side elevation schematic view of the apparatus according to the invention; and Fig. 2 is an enlarged side elevation view of a portion of the layered batt as shown in Fig. 1.

Referring now to the drawings, a preferred embodiment of the apparatus and method will be described with particular reference to the disintegration of fibrous sheet material. As used herein, the term "fibrous sheet material" describes any type of fibrous sheet material capable of disintegration by use of the invention.

The most common type of fibrous sheet material disintegrated by the process and apparatus of this invention is a dried cellulosic fibrous sheet material, however, the invention may also be utilized to disintegrate sheet material comprised of other types of fibers such as rayon. It should also be noted that the fibrous sheet material may be supplied in flat or in rolled sheet form.

With reference to Fig. 1, a disintegrator apparatus 2 is shown as having a casing 4 including a wall 5, a rotor 6 including hammer or impacting means 7 rotating about a shaft 8 in a counterclockwise direction relative to the view of Fig. 1, a first infeed opening 10 in the casing wall 5, and a second infeed opening 12 in the casing wall 5 spaced from the first infeed opening 10 along the periphery ofsthe wall 5.The casing wall 5 also contains a first fiber discharge opening 14 positioned in the portion 9 of the wall 5 most adjacent to and counterclockwise of the infeed opening 10 and a second fiber discharge opening 1 6 positioned in the portion 11 of the wall 5 most adjacent to and counterclockwise of the infeed opening 1 2. At the first infeed opening 10, extending into the casing 4, an anvil or support means 13 and a support plate 1 5 are affixed to the casing wall 5 to support the sheet material 20 as it is being fed into the casing 4 and impacted by the impacting means 7. A similar anvil or support means 1 7 and support plate 19 are affixed to the casing wall 5 at the second infeed opening 12.

A roll 18 of a fibrous sheet material 20 is rotatably mounted on a shaft 22 and is fed to the disintegrator apparatus 2 through the first infeed opening 10 by a pair of drive rolls 24 and 24'. A second roll (not shown) of sheet material 28 is also rotatably mounted on a shaft (not shown) and fed to the disintegrator apparatus 2 through the second infeed opening 1 2 by a pair of drive rolls 32 and 32'. The sheet material 28 is guided toward the infeed opening 12 by a turning roll 54 and an idler roll (not shown).As will be discussed in gerater detail hereinafter, the impacting means 7 of the rotor 6 strike the fibrous sheet 20 at the first infeed opening 10 to disintegrate the fibrous sheet 20 and provide impelling motion to the disintegrated fibers 21 from the sheet 20 which then pass out of the casing 4 through the first fiber discharge opening 14 and into a forming duct 42. As the impacting means 7 continute to rotate in a counterclockwise direction after passing the first infeed opening 10, they also impact the fibrous sheet material 28 at the second infeed opening 12 and impel the disintegrated fibers 29 from the sheet 28 out of the casing 4 through the second fiber discharge opening 1 6 and into a forming duct 44.

Movement of the disintegrated fibers 21 and 29 by the impacting means 7 around the inside periphery of the casing 4 and out of the discharge openings 14 and 1 6 is assisted by air flowing into the casing 4 through air inlet 50 and inlet duct 52.

Continuing with reference to Fig. 1, a moving foraminous support member 34 such as a screen is supported on rotating rolls 38 and 40 and moves continuously past the forming ducts 42 and 44 at a position such that the disintegrated fibers 2 1 from sheet 20 are deposited onto the foraminous member 34 and the disintegrated fibers 29 from sheet material 28 are deposited onto the fibers 21 from sheet 20 to form a batt 36 having super-imposed layers of fiber from the two different sheets 20 and 28. The movement of the fibers 21 and 29 out of the casing 4, through the forming ducts 42 and 44 and onto the foraminous member 34 is assisted by a vacuum provided by a vacuum means 48 disposed immediately beneath the foraminous member 34, as shown in Fig. 1, and connected by duct 48 to a suitable vacuum source (not shown).

The foraminous member 34, via at least one of the rolls 38 and 40, the rotor 6, the drive rolls 24, 24' and 32, 32' are all driven by suitable motive means which are well known in the art and will not be described herein.

As briefly referred to above, the plurality of impacting means 7 rotate on the rotor 6 about the shaft 8 and each of the impacting means 7 consecutively impact the fibrous sheet 20 supported by the support means 13 and plate 1 5 and the fibrous sheet 28 supported by the support means 17 and plate 19. The impacting of the sheets 20 and 28 causes their disintegration to produce fibers 21 and 29, respectively, which move in the direction of the force applied by the impacting means 7 which is tangential to the radial direction of the imapcting means 7 as they rotate about the shaft 8. However, since the fibers 21 and 29 are contained within the casing 5, their movement along such tangential path will be modified to an arcuate path which somewhat follows the periphery of the casing wall 5 due to the centrifugal force acting on the fibers.The discharge opening 14 is positioned in the counterclockwise direction of travel of the fibers 21 so that the fibers 21 approach the opening 14 prior to the time the fibers 21 reach the infeed opening 12 at which the fibers 29 are being produced from the sheet 28. The tendency of the fibers 21 to move, due to the centrifugal force acting on them, in a tangential direction from their arcuate path causes the fibers 21 to move through the dishcarge opening 14 and into the forming duct 42 toward the foraminous member 34. Inasmuch as the discharge opening 14 is located, along the path of movement of the fibers 21, prior to the location of the infeed opening 12, there will be minimum intermingling of the fibers 21 with the fibers 29 being produced at the infeed opening 12. Similarly, the discharge opening 1 6 is located prior to the location of the infeed opening 10 along the path of movement of the fibers 29 so that the fibers 29 move through the discharge opening 16 into the forming duct 44 toward the foraminous member 34 and there is a minimum intermingling of the fibers 29 with the fibers 21 adjacent the infeed opening 10. As previously mentioned, a vacuum applied by vacuum means 46 to the underside of the foraminous member 34 assists in the movement of the fibers 21 and 29 towards the foraminous member 34.

Thus, if different types of fibrous sheets 20 and 28 are disintegrated within the disintegrator apparatus 2, the corresponding fibers 21 and 29, when deposited in a layered fashion on the foraminous member 34, will produce a batt 36 having the advantages of the individual properites of the fibers, of the interactions between the fibers and of the combination of properties that may occur at the interface of the two fibers.

It will be understood that the foregoing description of the present invention is for purposes of illustration only and that the invention is susceptible of a number of modifications or changes, none of which entail any departure from the scope of the present invention as defined in the hereto appended claims. For example, additional fiber sheet infeed locations and fiber discharge openings may be provided, depending on the casing space available which permits discharge of the fibers disintegrated at each infeed location with only such intermingling of the different types of fibers as may be tolerated.

Claims

1. Apparatus for disintegrating fibrous sheet material including a casing and impacting means moving along a path within the casing, the combination including: first and second spaced apart support means each supporting fibrous sheet material at a position in the path of movement of the impacting means whereby the material is impacted and disintegrated and also moved by the impacting means; and first and second discharge openings in said casing, the disintegrated material impacted at the first support means moving through the first discharge opening to exit from the casing and the disintegrated material impacted at the second support means moving through the second discharge opening to exit from the casing.

2. Apparatus as claimed in claim 1 wherein the first and second discharge openings in said casing are respectively positioned in the path of movement of the disintegrated material impacted at the first support means and in the path of movement of the disintegrated material impacted at the second support means.

3. Apparatus as claimed in claim 2 wherein the disintegrated fibrous material has an arcuate path of movement and each of said discharge openings is positioned in alignment with a tangent to said arcuate path.

4. Apparatus as claimed in claim 1, 2 or 3 wherein each of the first and second discharge openings is respectively positioned at a distance from the first and second support means such that substantially all (at least 95%) of the disintegrated material impacted at the first support means exits from the casing through the first discharge opening and substantially all (at least 95%) of the disintegrated material impacted at the second support means exits from the casing through the second discharge opening.

5. Apparatus as claimed in any of the preceding claims including a pair of forming ducts each having an outlet end and an inlet end, the inlet end of each end of the forming ducts being connected to a different one of the discharge openings whereby the disintegrated material passes through the forming duct; and a foraminous member movable past the outlet ends of the forming ducts whereby disintegrated material from each duct can be consecutively deposited on the foraminous member.

6. Apparatus as claimed in claim 5 wherein the fibrous sheet material supported at the first support means comprises a first type of fiber and the fibrous sheet material supported at the second support means comprises a second type of fiber; and the first type of fiber and the second type of fiber have a layered structure on the foraminous member.

7. Apparatus as claimed in any preceding claim wherein the impacting means is provided on a rotor and the first and second support means each include an anvil.

8. A method of disintegrating a plurality of sheets of fibrous material embodying the steps of: feeding said plurality of sheets of fibrous material into a casing at spaced apart locations; impacting the sheets of fibrous material at said locations to disintegrate them and move the disintegrated material along separate paths within the casing; and discharging the disintegrated material from each of said sheets out of said casing at separate spaced apart locations along the periphery of the casing.

9. The method of claim 8 wherein the discharge step is accomplished by discharged the disintegrated material from one of the sheets reaches the location at which the material from the other of the sheets is impacted.

10. The method of claim 9 wherein: the disintegrated material from the plurality of sheets is moved along paths within the casing and the disintegrated material from each of the sheets is discharged through a separate opening in the casing in its path into a forming duct.

11. A method of forming a multilayered batt of fibrous material comprising the steps of: feeding a plurality of sheets of fibrous material into a casing at spaced apart locations; impacting the sheets of fibrous material at said locations to disintegrate them and move the disintegrated material along separate paths within the casing; discharging the disintegrated material from each of said sheets out of said casing at separate spaced apart locations along the periphery of the casing into a forming duct connected to the casing at each of the locations; and moving the same area of a foraminous support member, sequentially past the exhaust opening of each forming duct to deposit disintegrated material from each duct on the member in a layered structure.

12. Apparatus for disintegrating fibrous sheet material substantially as herein described with reference to the accompanying drawings.

13. Apparatus for forming a multilayered batt of fibrous material substantially as herein described with reference to the accompanying drawings.

14. A method of disintegrating a plurality of sheets of fibrous sheet material substantially as herein described with reference to the accompanying drawings.

15. A method of forming a multilayered batt of fibrous material substantially as herein described with reference to the accompanying drawings.