IL98229A - Process for recycling disposable diapers and the machine components therefor - Google Patents

Description

98229/3 A process of recycling of disposable diapers and the machine components thereof ing Technologies Ltd. n"ys *mn>a ni >i¾t>iJ3tt po A PROCESS OF RECYCLING OF DISPOSABLE DIAPERS AND THE MACHINE COMPONENTS THEREOF.

This invention relates to processes of garbage recycling and to machines for that purpose; more particularly, to a process and machines for processing and producing products from disposable diapers and other non woven cellulose articles to be used as basic raw materials, such as compacted cellulose, and plastics.

Background of the invention The eccological impact of disposable diapers and other similar cellulose articles such as sanitary towels, panties, sick-bed undersheets and other hygiene products requires efficient processes to decompose the contents of these articles and to separate the components to be recycled in an economical way. This invention is particularly aimed at recycling of disposable diapers and separating the cellulose contents into a dry and compact product , and the plastic component into a reusable raw material.

A child from his birth till the age of 30 month uses approximately 6 disposable diapers a day. Each of the diapers has an average volume of 500 cc. Thus one child results on average 3000 cc of garbage a day, i.e. 21 liters a week thus 1.092 cubic meters per year. There are about 50,000 diaper users per million population, so that during one day it is necessary to remove from a city of one million inhabitants 150. cubic m of that kind of gar adge.

Different attempts were made to solve the problem of recycling of disposable diapers, napkins, hospital bed sheets, sanitary towels and other similar products. All these cellulose containing articles have the same structure: an envelope of a non woven tissue, a plastic or rubber cover material, a cellulose-flock filling mixed in most cases with superabso bent polymers which can absorb liquid till 400 times their own volume.

The main idea is to recover the cellulose, being the most valuable raw material, and to recover the plastic cover material which is an eccological hazard.

Most of the patents, existing in the prior art, suggest one common process of separating of the cellulose from the other materials of the rejected hygiene articles.

The following patents: DE 2704035, EP 92982, SE 8303765, DE 3214294, DE 2703063 describe processes including the following basic operations: disintegrating (shredding, cutting) of the disposed articles, and then separating the cellulose fibres from the covering elements by sieving.

DE 2704035 stipulates , that the cellulose fibres can be separated from the non-cellulose materials by dry sieving in one or more stages.

Other patents describe the mode of separation of the cellulose from the non-cellulose cover components by using a machine (such as a perforated drum), creating suction on the drum surface and separating the cellulose mass. These patents describe the suction means using ambient air.

US 4592115 describes a perforated cylindrical separator for separation of cellulose fibres. The separator is provided with perforations large enough to permit the cellulose fluff fibres to pass through, but small enough to screen out larger non-fluff materials from the waste fibrous material. The balance between the air flow rate and the differential pressure across the separator is sufficient to prevent blockage of the apertures in the separator by the waste fibrous material and to achieve the purpose of separation between the cellulose and non-cellulose materials.

Several specific units for recycling of disposable diapers are described in the above mentioned references.

SE 8303765 suggests a pneumotransporter for transporting the diapers on to a cylindrical perforated separator having an upper inlet and two lower outlets for releasing the waste products.

DE 3214294 describes the shredding of the diapers by rotating entrainers, which are arranged in an enclosed housing.The cellulose flock thus separated is removed from the housing under suction through a sieve.The shredded cover material is then removed separately.

EP 0180696 describes an apparatus in which a disintegrated material suspension is introduced tangentially into a separator, comprising a cylindrical housing having one inlet and two outlets.The cellulose separation is achieved by a perforated separation drum and air suction means, provided by a fan.

However, the main problem of the cellulose recycling from disposable diapers is not the separation from the elastic or tissue covers, but the separation of the cellulose media from the superabsorbent polymers incorporated in the diaper flock.

All the above described processes are relatively complicated, because they require installations having compressed and heated air, and therefore can be utilized only for large quantities of diaper garbage.

The second disadvantage of these processes is that the separation process of the cellulose fibres from the superabsorbent polymers is not resolved effectively.

The third disadvantage is that the processes described above provide disintegrated cellulose and plastic, which cannot be used as such for further processing.

The machine components used in the above mentioned processes have the corresponding disadvantages: complexity, high cost, not usable in conventional dwellings. No safety means are provided for introduction of the diapers into the processing machine to guard the user when introducing the disposed item.

Moreover, no means are suggested for transformation of the disintegrated diaper parts into raw materials for further use.

It is the purpose of the present invention to provide a process for recycling cellulose and plastic components of different disposable hygienic cellulose articles which can be utilized for conventional dwellings and machine components thereof.

The process and the machine components, herein provided, is intended to be used for recycling cellulose and plastic components of disposable diapers and other non woven cellulose articles to be utilized as basic raw materials, said diapers and cellulose articles; separating said mass into a plastic stream and a cellulose stream; and disposing said plastic stream; and disintegrating said cellulose stream into water, and separating said cellulose flock from the superabsorbent polymers and other waste effluent included in said cellulose streamjand disposing off said superabsorbent polymers and waste in said water effluent; and compacting said separated cellulose flock prior discharge.

In the preferred embodiment said process provides moistening of said pliced diapers and cellulose articles before separation of said spliced mass into said plastic stream and said cellulose stream.

In the preferred embodiment said process provides separation of said cellulose flock from said superabsorbent polymers and other waste included in said cellulose stream by collecting said cellulose fibers onto a rough surface.

In the preferred embodiment said separation process of said cellulose from said waste materials is provided in a solution of a disinfectant in water .

In the preferred embodiment said process provides compacting of said separated cellulose flock by compressing and simultaneous drying and disinfection of said wet flock.

In the preferred embodiment said plastic stream is compacted prior disposal.

In the preferred embodiment said compacting process of said plastic stream is performed by melting , and then cooling.

In the preferred embodiment said machine components comprise a lid for introducing safely said diapers and said disposed cellulose articles into said machine; and splicing means for splicing said diapers and cellulose articles; and a separation and compacting, melting and cooling unit of said plastic stream; and a water basin into which said cellulose stream is introduced; and a collecting unit of said cellulose flock from said water basin; and a unit for compacting of said cellulose flock; and disposal means for removal of the liquid effluent in said water basin.

In the preferred embodiment said safety lid for introducing said diapers and said disposable cellulose articles into said machine, comprises a cylindrical body having an orifice through which said diapers and cellulose articles are introduced; and said cylindrical body is attached to a pedal by connecting means , also providing raising,and turning means, thus enabling said lid to rise over said machine housing when said diaper or cellulose article is introduced into said orifice, and then return into said machine housing and turn around simultaneously in order to protect the user's hand from any movable parts.

In the preferred embodiment said splicing means are placed under said lid and comprise a circulating continuous saw.

In the preferred embodiment said separating,compacting and melting unit of said plastic stream comprises movable clips for holding the plastic cover parts of said diaper and said cellulose articles; and said clips tear said plastic covers away from the cellulose stream,and transfer said plastic stream into a conical hollowed heated element where said plastic melts and is then cooled, compacted and discharged.

In the preferred embodiment said movable clips are provided with means for opening, closing, and moving up and down over said water surface in said basin so that during the separation process of said plastic stream from said cellulose stream moisture is provided to said oellulose stream.

In the preferred embodiment said movable clips comprise a support tube, having two grips, one of them being movable; and said support tube is provided inside with a spring,connected to said movable grip; and provided with a movable cylindrical body, having at the outer end a rotatable ball, and said means comprise an inclined wall having three sections of different thicknesses, and driving means for the vertical movement of said clips, so that when said clips are driven downwards,said ball roles along said wall sections,and presses said cylindrical body; and said cylindrical body causes compression of said spring,thus closing said grips, and grabbing a part of said diaper or said other cellulose article; and when said driving means drive said closed clips up and down along one of said surfaces, while moisture is provided from said basin on to said cellulose.

In the preferred embodiment said collecting unit of said cellulose flock from said water basin comprises a rotatable element provided with rotatable pins having rough surfaces; and having a corresponding rotatable doffer, provided with slots for unloading said cellulose flock from said pins, so that when said rotatable pins are loaded with said cellulose flock, said rotating pins interact with said slots of said doffer to release said cellulose flock from said pins,and said cellulose flock is discharged towards said compacting unit.

In the preferred embodiment said pins are covered with small hair-like filaments, such as, Velcror-hair cover.

In an alternative collecting unit of said cellulose flock from said water basin an abrasive non oven fabric such as Scotch Bright*1" is provided; and said abrasive fabric is moved in said water basin and cellulose flock builds up on said moving rough surface and is then unloaded and discharged.

In the preferred embodiment said compacting unit of said cellulose flock oomprises a rotatable screw feeder; and when said cellulose flock is compacted by said screw means, elevated temperature is created thus providing disinfection and drying of said cellulose flock, prior discharge.

In the preferred embodiment said separated superabso bent polymer and waste effluent remaining in said water basin after said cellulose flock has been separated is pumped away into the sewage system by pumping means;and consequently fresh water is introduced into said water basin.

In the preferred embodiment a blower is provided, creating suction for pneumatically transferring of said cellulose articles and their components from one of said units to another.

Two designs of the machine are considered, one for treating mass cellulose articles to be installed in hospitals, nurseries, or in community centers; the other will be a compacted cheaper unit to be installed in private homes for a family use. The second smaller unit may not be required to have a plastic processing unit as elaborated as the one described.

The invention can be best understood by aid of the drawings attached.

Fig.l illustrates a block-diagram of the process described.

Fig.2 illustrates a general isometrical view of a family-use machine accomplishing the process described.

Fig.3 illustrates a safe lid unit and its components.

Fig. illustrates splicing means in form of a circulating continuous saw.

Fig.5A,B,C illustrate movable clips for holding and moistening of the parts of the cellulose articles after splicing.

Fig.6 A,B,C illustrate the cellulose flock collecting unit.

Fig.7 illustrates the cellulose flock compacting element.

Fig.8 illustrates a hollowed conical heated element for the processing of the plastic covers of the cellulose articles.

Detailed description of the invention In Fig.l one can see the main sequence of operations of the process; these operations are performed by the major machine components.

The disposable diaper D or any non woven cellulose article is introduced into the machine through a safe lid unit 11. Then the diaper is spliced by a saw illustrated in unit 12. The two parts of the diaper are held by clips 13, which move up and down over the surface of water or a solution containing a disinfectant in a water basin 14, the diaper parts are moistened and separated into two streams: a cellulose and plastic stream. The plasic stream is then removed to a melting element 15 from where the melted plastic is transferred to a cooling unit 16 and then to a discharging and compacting unit 17, which includes a shredding device.

The oellulose stream, separated from the diaper, disintegrates in the water basin 14, where the superabsorbent polymers and waste effluents are carried away by the water ; the oellulose flock is collected by a collecting unit 18, which comprises rotating pins and a doffer;and the liquid effluent is pumped away from the water basin 14 to the sewage system 20, while fresh water is consequently added into the water basin 14. The moistened oellulose flock, separated in unit 18, is compacted by a compacting unit 19, which comprises a screw and provides compression, disinfection and drying of the cellulose flock before discharging.

A blower 21 is provided to create suction into all the operational units (the blower connections are shown by light cut double lines).

An electric motor 22 is provided to drive all the moving parts of all the operational units ( the motor connections are shown by thick double lines) Conventional sources of electricity 23 and water 24 are indicated by their schematic connections.

Dark cut lines show the sequence of the process operations, performed by the specific units. In other embodiments of the process some units could be ommited or differently designed.

In Fig.2 one can see a general view of the family-use machine, accomplishing the process described above. A safety lid 111, a motor 122, a pedal 133, discharging reservoirs 125 for cellulose and plastic obtained in the separation process, cover housing panels 126 and the main core body 127 including the splicing unit, the plastic and cellulose separating units, the water basin, and the cellulose and plastic compacting units of the machine (not indicated in detail) .

In Fig.3 the safe lid unit comprises a cylindrical lid 31, having an orifice 32, and the lid 31 is attached to a pedal 33 by a connecting mechanism, which includes raising means 34 and turning means 35 . The diaper or any other cellulose article may be introduced into the orifice 32, when the lid 31 is raised by the movable connecting levers of the means 34, applied by the pedal 33. After loading the diaper, the lid 31 turns towards the entry of the splicing unit (not seen) of the machine to unload the diaper and simultaneously the entry orifice 32 is turned by means of the screw 35 to protect the user's hand from any movable parts of the machine.

Fig.4 illustrates a top view and a side view of the splicing unit , having a circulating continuous saw 41, rotating around two wheels 42, one of which is driven by a gear wheel 43. The saw 41 is located at the outlet position 44 of the lid unit described in figure 3 above, the diaper is sliced by the saw 41 and is transfered to the movable clips described below in figures 5 A,B,C.

Fig.5A,8,C illustrate the movable clips 51 . Fig.5A and 58 demonstrate two views of the clip 51, having a support tube 52 with blocking ring 53 and two diaper grips 54 A and 548, one of them is movable;a spring 55 and a second movable tube 56 are provided inside the support tube 52 and the tube 56 having a smaller diameter than the support tube 52. The second movable tube 56 has at its outer end a ball 57. The movable grip 54A is installed between the first fixed grip 54B and the ring 53 by means of a connecting shaft 58, moving in a groove 59 of the tube 52; and the spring 55 is located between the grips 54A and 548 inside the tube 52. When pressure is applied to the ball 57, the smaller tube 56 will move into the support tube 52 and press the spring 55 by means of the shaft 58 so, that the grips 54A and 548 will close.

Fig.5C illustrates the clips unit. The unit includes two opposite groups of elements, located above a water basin(not seen), and each group comprises: the movable clips 51; an inclined wall 61, having three sections A,B and C; a partition 62, having a vertical groove 63, where a shaft 64 moves, activated by a motor (not seen). The shaft 64 is connected to the ring 53 of the clips 51.

During the diaper splicing process a sensor (not shown) activates the motor, the shaft 64 moves downwards with the clips 51. The ball 57 roles from the section A to the section B of the wall 61. In the position A the grips 54A and 548 are open, in the position B the grips 54A and 54B close and grab any part of the diaper. From this moment the shaft 64 (activated by a signal of the sensor, not shown) begins to move up and down along the g-oove 63; and clips 51 with the diaper parts begin to move up and down along the section C of the wall 61 near the water surface in the basin (not seen) till the cellulose flock becomes moist and separates from the plastic cover of the diaper.

Fig.6A,8,C illustrate the cellulose flock gathering and unloading processes.

Fig.6A( is a side view) . For the cellulose flock collection from the water basin 71 two major rotating elements are provided above the water surface; one of them is a gathering unit 72, having a plurality of rotating gathering pins 73, and the second element is a doffer 74 for unloading the cellulose fibres from the gathering pins 73. Said two units 72 and 74 rotate in opposite directions to each other. These two major units 72 and 74 are similar to the devices, which are widely used in automatic cotton gathering machines.The gathering unit 72 is provided with a fixed main gear weel 75 and a fixed 8-shaped element 76.

Fig.6B is a top view and Fig.6C is an isometric view of an element of the cellulose gathering unit 72. Combs 77 rotate around a central axis 81 and move along the inner surface of the main gear wheel 75 by means of the engaged gear wheels 82. . The combs 77 are provided with rotatable gathering pins 73, covered with small hail—like filaments 78, such as the Velcror, ( see Fig.6C). The pins 73 gather all the cellulose fibres from the water basin 71 in fig. 6A and simultaneously the pins 73 stir the contents of the water basin 71.

The doffer 74 rotates around an axis 83 and is provided with slots 80 for interacting with the pins 73. The combs 77 are movably attached to the 8-shaped detail 76 by rigid levers 79, in order to obtain the right angle of the pins 73, as they penetrate into . the doffer 74 for unloading the cellulose fibers. As a result of the mode of attachement the pins 73 pass the slots 80 of the doffer 74 in the appropriate direction, so that the rubber surfaces of the slots 80 remove the cellulose flock from the pins hair-like cover 78. The cellulose flock is then removed from the slots 80 to the cellulose compacting unit by suction, provided by the blower ( not seen). The water, containing supe absorbent polymers and waste effluent is disposed from the water basin 71 by pumping means 84 in form of a diaphragm, which is activated by a sensor (not seen). Fresh water is introduced consequently into the water basin 71 through a valve 85. C^.6A).

In Fig.7 the cellulose compacting unit comprises an endless screw 90, moving in a groove 91 of a housing 92. The housing 92 has a cellulose inlet 93, and a narrow outlet 94, provided by a liquid passage 95 . When the cellulose flock is drawn into the inlet 93 by suction, the rotating screw 90 compresses the cellulose flock, thus dries it simultaneously.

Fig.8 illustrates the construction of a conical hollowed heated element 101 for processing the plastic stream as it comes off the moving clips (not seen), described in fig. 5A,B,C.

The element 101 consists of a conical hollowed receiving part 102, attached to a hollowed cylindrical part 103, coiled by a heating electrical element 104. According to the process described in this invention, the plastic cover parts of the disposable diaper or other cellulose articles are accumulated in the conical part 102 and then melted in the cylindrical part 103 as a result of the heating, caused by the heating element 104. The melted plastic mass is transferred to a cooling unit prior discharge. hile the invention has been described in reference to the attached illustrations, it should be appreciated that other machine components could be utilized for the diaper recycling process described above.

Claims (2)

1. - 23 - 98229/2 WHAT IS CLAIMED : 1. A process for recycling cellulose and plastic components of disposable diapers and other non woven cellulose articles to be utilized as basic raw materials, using slicing of said diapers and cellulose articles; separating said sliced mass into a plastic stream and a cellulose stream; and disposing said plastic stream; disintegrating said cellulose stream into water, and separating said cellulose flock from the superabsorbent polymers and other waste effluent included in said cellulose stream; disposing of said superabsorbent polymers and waste in said water effluent; and compacting said separated cellulose flock prior discharge.

2. The process as in claim 1, wherein said process provides moistening of said sliced diapers and cellulose articles before separation of said sliced mass into said plastic stream and said cellulose stream. he process as in claims 1-2, wherein said process provides separation of said cellulose flock from said superabsorbent polymers and other waste included in said cellulose stream by collecting said cellulose fibers onto a rough surface. he process as in claims 1-3, wherein said separation process of said cellulose from said waste materials is provided in a solution of a disinfectant in water. he process as in claims 1-4, wherein said process provides compacting of said separated cellulose flock by compressing and simultaneous drying and disinfection of said wet flock. he process as in claims 1-5, wherein said plastic stream is compacted prior disposal. he process as in claims 1-6, wherein said compacting process of said plastic stream is performed by melting , and then cooling. Machine components for accomplishing of the process as in claims 1-7, comprising a safety lid for introducing safely said diapers and said disposed cellulose articles into said machine; and splicing means for splicing said diapers and cellulose articles; and a separation and compacting, melting and cooling unit of said plastic stream; and a water basin into which said cellulose stream is introduced; and a collecting unit of said cellulose flock from said water basin; and a unit for compacting of said cellulose flock; and disposal means for removal of the liquid effluent in said water basin. he machine components as in claim 8, wherein said safety lid for introducing said diapers and said disposable cellulose articles into said machine comprises a cylindrical body having an orifice through which said diapers and cellulose articles are introduced; and said cylindrical body is attached to a pedal by connecting means , also providing raising,and turning means, thus enabling said lid to rise over said machine housing when said diaper or cellulose article is introduced into said orifice, and then return into said machine housing and turn around simultaneously in order to protect the user's hand from any movable parts. ~ - The machine components as in claims 8-9, wherein said splicing means are placed under said lid and comprise a circulating continuous saw. The machine components as in claims 8-10, wherein said said separating,compacting and melting unit of said plastic stream comprises movable clips for holding the plastic cover parts of said diaper and said oellulose articles; and said clips tear said plastic covers away from the cellulose stream,and transfer said plastic stream into a conical hollowed heated element where said plastic melts and is then cooled, compacted and discharged. The machine components as in claims 8-11, wherein said movable clips are provided with means for opening, closing, and moving up and down over said water surface in said basin so that during the separation process of said plastic stream from said cellulose stream moisture is provided to said cellulose stream. The machine components as in claims 8-12, wherein said movable clips comprise a support tube, having two grips, one of them being movable; and said support tube is provided inside with a spring,connected to said movable grip; and provided with a movable cylindrical body, having at the outer end a rotatable ball, and said means comprise an inclined wall having three sections of different thicknesses, and driving means for the vertical movement of said clips, so that when said clips are driven downwards,said ball roles along said wall sections,and presses said cylindrical body; and said cylindrical body causes compression of said spring,thus closing said grips, and grabbing a part of said diaper or said other cellulose article; and when said driving means drive said closed clips up and down along one of said surfaces, while moisture is provided from said basin on to said cellulose. -ζβ- The machine components as in claims 8-13, wherein said collecting unit of said cellulose flock from said water basin comprises a rotatable element provided with rotatable pins having rough surfaces; and having a corresponding rotatable doffer, provided with slots for unloading said cellulose flock from said pins, so that when said rotatable pins are loaded with said cellulose flock, said rotating pins interact with said slots of said doffer to release said cellulose flock from said pins,and said cellulose flock is discharged towards said compacting unit. The machine components as in claims 8-14, wherein said pins are covered with small hair-like filaments, such as, Velcrov-hair cover. The machine components as in claims 8-14, wherein said collecting unit of said cellulose flock from said water basin is provided with an abrasive nonwoven fabric such as Scotch Bright*1"; and said abrasive fabric is moved in said water basin and cellulose flock builds up on said moving rough surface and is then unloaded and discharged. 17.The machine components as in claims 8-16, wherein said compacting unit of said cellulose flock comprises a rotatable screw feeder; and when said cellulose flock is compacted by said screw means, elevated temperature is created thus providing disinfection and drying of said cellulose flock, prior discharge. 18. The machine components as in claims 8-17, wherein said separated superabsorbent polymer and waste effluent remaining in said water basin after said cellulose flock has been separated is pumped away into the sewage system by pumping means; and consequently fresh water is introduced into said water basin. 19. The- machine componei its as in claims 8- 15, wl'ver em a blower is provided, creating suction for pneumatically transferring of said cellulose articles and their components from one of said units to another. P 08 39448 Tel-Aviv 61393