Method of producing granular excreta treating material using an extrusion type compressive granulating apparatus

Abstract

A method of producing granular excreta treating material utilizes an extrusion type compressive granulating apparatus configured to produce granular excreta treating material that has an absorbing property and is formed by extruding and granulating a raw material via a granulating hole of the apparatus. The granulating hole includes a small diameter hole and a large diameter hole which are continuous to each other in the axial direction of the hole, in which the small diameter hole forms a compression zone, and the large diameter hole forms a non-compression zone, and in which the raw material is compressed at the compression zone, swells at the non-compression zone, and is cut into granules by a cutting blade rotating along an outlet surface of the non-compression zone.

Claims

1. A method of producing a granular excreta treating material, comprising: providing a disc-shaped die table having a plurality of round compressive granulating holes passing therethrough from an upper surface of the disc-shaped die table to a lower surface of the disc-shaped die table, each of the round compressive granulating holes consisting of a double-stage hole structure consisting of an axially elongated small diameter hole and an axially elongated large diameter hole which are continuous in an axial direction of the corresponding round compressive granulating hole, the axially elongated small diameter hole having a first constant diameter and the axially elongated large diameter hole having a second constant diameter, with the first constant diameter being smaller than the second constant diameter; supplying a raw material containing organic fiber onto the upper surface of the disc-shaped die table; providing a plurality of pressurizing rotation wheels arranged to rotate so as to travel along the upper surface of the disc-shaped die table in a circumferential direction thereof; causing the pressurizing rotation wheels to rotate so as to travel along the upper surface of the disc-shaped die table in the circumferential direction thereof, so as to press the raw material into and through the round compressive granulating holes of the disc-shaped die table, such that, for each of the round compressive granulating holes, the raw material is initially compressed at the axially elongated small diameter hole, and then the raw material extruded from the axially elongated small diameter hole swells at the axially elongated large diameter hole and an extrusion posture of the raw material extruded from the axially elongated small diameter hole is regulated by a hole wall of the axially elongated large diameter hole; and arranging at least one cutting blade at the lower surface of the disc-shaped die table so as to move along the lower surface of the disc-shaped die table at an outlet surface of the axially elongated large diameter hole of each of the round compressive granulating holes, to thereby cut into granules the raw material extruded from the round compressive granulating holes, to thereby form absorbent granules of the excreta treating material, wherein, for each of the round compressive granulating holes, a height of the axially elongated small diameter hole is set to 1 to 10 mm, and a height of the axially elongated large diameter hole is set to 30 to 39 mm.

2. The method of producing a granular excreta treating material, according to claim 1, wherein the at least one cutting blade is arranged such that a gap is formed between the at least one cutting blade and the outlet surfaces of the axially elongated large diameter holes of the round compressive granulating holes.

3. The method of producing a granular excreta treating material, according to claim 1, wherein the at least one cutting blade comprises a plurality of cutting blades arranged to travel along the lower surface of the disc-shaped die table in a circumferential direction thereof.

4. The method of producing a granular excreta treating material, according to claim 1, wherein the first constant diameter is set to 2 to 6 mm, and the second constant diameter is set to 3 to 8 mm.

5. The method of producing a granular excreta treating material, according to claim 1, wherein the first constant diameter is set to 2 mm, and the second constant diameter is set to 3 mm.

6. The method of producing a granular excreta treating material, according to claim 1, wherein the first constant diameter is set to 6 mm, and the second constant diameter is set to 8 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a main enlarged cross-sectional view illustrating a shape of a granulating hole according to a first embodiment of the invention;

(2) FIG. 2 is a main enlarged cross-sectional view illustrating a state where a raw material passes through a compression zone and a non-compression zone to be granulated in the first embodiment;

(3) FIGS. 3A and 3B are tables illustrating a result of a breaking load test for a granular excreta treating material having 3 mm, where FIG. 3A illustrates the first embodiment, and FIG. 3B illustrates the related art;

(4) FIGS. 4A and 4B are tables illustrating a result of a breaking load test for a granular excreta treating material having 6 mm, where FIG. 4A illustrates the first embodiment, and FIG. 4B illustrates the related art;

(5) FIG. 5 is a plan view illustrating a die table installed in an extrusion type compressive granulating apparatus according to a second embodiment;

(6) FIG. 6 is a main enlarged cross-sectional view taken along the line A-A of FIG. 5 that shows the extrusion type compressive granulating apparatus according to the second embodiment;

(7) FIG. 7 is a main enlarged cross-sectional view illustrating a state where a raw material passes through a compression zone and a non-compression zone to be granulated in the second embodiment;

(8) FIG. 8A is a perspective view illustrating absorbent granules;

(9) FIG. 8B is a plan view illustrating an aggregated state of the granules;

(10) FIG. 9A is a main cross-sectional view illustrating an extrusion type compressive granulating apparatus according to the related art;

(11) FIG. 9B is a plan view illustrating the extrusion type compressive granulating apparatus; and

(12) FIG. 10 is a main enlarged cross-sectional view illustrating a shape of a granulating hole according to the related art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(13) The invention provides a granular excreta treating material having satisfactory absorbing property, whereby disintegrability and aggregativeness of the granular excreta treating material are expected. The granular excreta treating material has absorbing property and is formed by extruding and granulating a raw material via a granulating hole, wherein the granulating hole includes a small diameter hole and a large diameter hole which are continuous to each other in the axial direction of the hole, in which the small diameter hole forms a compression zone, and the large diameter hole forms a non-compression zone, and in which the raw material is compressed at the compression zone, swells at the non-compression zone, and is cut into granules by a cutting blade rotating along an outlet surface of the non-compression zone.

First Embodiment

(14) Hereinafter, the invention will be described in detail by referring to a first preferred embodiment shown in the accompanying drawings. However, for convenience of description, an extrusion type compressive granulating apparatus for a granular excreta treating material according to the invention will be described first together with a production method thereof.

(15) As shown in FIG. 9, a general extrusion type compressive granulating apparatus includes: a disc-like die table 1 which has a plurality of round compressive granulating holes 2 passing through the die table; a plurality of pressurizing rotation wheels 3 which presses a raw material mainly containing organic fiber into compressive granulating holes 2 of the die table 1; and a cutting blade 4 which cuts the raw material extruded from the outlet of each compressive granulating hole 2 of the die table 1 into granules. A granular excreta treating material having absorbent granules is obtained in a manner such that the raw material is supplied onto the upper surface of the die table 1, the raw material is pressed into each compressive granulating hole 2 while each rotating rotation wheel 3 revolves about the axis of the die table 1, and the raw material extruded into a rod shape from the outlet of each compressive granulating hole 2 is cut into a predetermined length. Further, the die table 1 does not rotate.

(16) In this case, as shown in FIG. 10, all of the compressive granulating holes 2 passing through the die table 1 are formed to have the same diameter in the axial direction of the hole. Accordingly, the raw material passing the compressive granulating hole 2 out is pressed by a pressure obtained from the inner peripheral surface of the hole as well as a pressure of the pressurizing rotation wheel 3, so that the raw material is continuously compressed inside the compressive granulating hole 2 while it runs from the inlet to the outlet thereof, and then finally extruded.

(17) For this reason, the granule is hardened with high density in the granular excreta treating material of the related art, whereby a urine absorbing property is degraded, and disintegrability and aggregativeness are not expected. In order to make up for this problem, as described in the related art, a method of forming a coating layer on the outer peripheral surface of the granule was adopted.

(18) Therefore, in the first embodiment, as shown in FIG. 1, each compressive granulating hole 2 passing through the die table 1 is formed as a double-stage hole structure; the front stage forms a compression zone Z1 having a small diameter hole 2a having the same diameter as the compressive granulating hole 2 of the related art; and the rear stage forms a non-compression zone Z2 having a large diameter hole 2b which is continuous, in the axial direction, from the small diameter hole 2a forming the compression zone Z1 and which has the same axis as the small diameter hole 2a. Right after the raw material passes the compression zone Z1 and the non-compression zone Z2, in other words, the small diameter hole 2a and the large diameter hole 2b, the cutting blade 4 is rotated along the outlet surface of the non-compression zone Z2 to cut the raw material into granules. In this case, the height of the compressive granulating hole 2 composed of the small diameter hole 2a and the large diameter hole 2b is set to be substantially equal to the height of the compressive granulating hole 2 of the related art. When the total thickness of the compressive granulating hole 2 of the related art is 40 mm, the invention has a configuration in which a thickness T1 of the compressive zone Z1, that is, the height of the small diameter hole 2a is set to be in the range from 1 to 10 mm, a thickness T2 of the non-compression zone Z2, that is, the height of the large diameter hole 2b is set to be in the range from 30 to 39 mm, a diameter R1 of the compression zone Z1 is set to be in the range from 2 to 6 mm, and the diameter R2 of the non-compression zone Z2 is set to be in the range from 3 to 8 mm. In addition, as shown in FIG. 6, the cutting blade 4 is attached to a shaft 11 of the compressive granulating apparatus while the cutting blade 4 is disposed to face the outlet surface of the non-compression zone Z2 with a slight gap therebetween or to slide thereon, and the cutting blade is configured to rotate along the outlet surface of the non-compression zone Z2. Further, the blade edge is obliquely inclined with respect to the rotation direction.

(19) Accordingly, the granular excreta treating material produced by the extrusion type compressive granulating apparatus according to the first embodiment continuously passes through the compression zone Z1 that is applied with a pressure and the non-compression zone Z2 that is not applied with a pressure in each compressive granulating hole 2 as shown in FIG. 2, and is cut into granules by the cutting blade 4. The density of the entire raw material becomes comparatively high due to the high pressure applied to the raw material for a short time when the raw material passes through the compression zone Z1, but the pressure applied to the raw material is completely released when the raw material passes through the compression zone Z1 and arrives at the non-compression zone Z2, so that the raw material swells. That is, the raw material is appropriately fastened at the compression zone Z1, and is extruded into a rod shape to go into the non-compression zone Z2. The rod-shaped material 7 extruded into the non-compression zone Z2 is not fastened inside the large diameter hole 2b, but swells for a time when the rod-shaped material passes through the large diameter hole 2b, so that a low-density portion 5 is formed at the free end of the rod-shaped material 7. Granules 9 having a coarse density produced in this manner are restored to be slightly rough as shown in FIG. 8A, so that it comes to have a low-density, that is, a coarse void structure. Accordingly, the absorbing property improves, and the disintegrability and the aggregativeness are promoted. Further, the reference numeral R3 shown in FIG. 8A indicates 3 mm or 6 mm of diameter.

(20) Since each compressive granulating hole 2 is formed as a double-stage hole structure in the axial direction of the hole, as shown in FIG. 2, the raw material 5 passing through the non-compression zone Z2 is supplied to the cutting blade 4 while its extrusion posture from the compression zone Z1 is regulated by a hole wall defining the non-compression zone Z2, whereby the raw material is appropriately cut by the cutting blade 4 without causing excessive bentness. Further, in the first embodiment, the double-stage hole structure is continuously perforated in one die table 1, but the invention is not limited thereto. For example, a configuration may be adopted in which the die table 1 is formed by two plates, the compression zone Z1 (small diameter hole 2a) is perforated in one plate by drilling, the non-compression zone Z2 (large diameter hole 2b) is perforated in the other plate by drilling, and the plates are laminated. Particularly, in this case, there are advantages in that the hole edge of each plate may be formed at a right angle and one or the other plate may be replaced with a plate having a hole with a different diameter.

(21) In other words, when it is assumed that the granular excreta treating material according to the first embodiment has the same granular shape as that of the related art, the entire granular excreta treating material of the related art is compressed over the entire length of the elongated small diameter hole 2 shown in FIG. 10 to be fastened, but the granular excreta treating material of the first embodiment is compressed at the short small diameter hole 2a in the compression zone Z1 to have necessary hardness, and naturally swells while passing through the non-compression zone Z2 to have a low-density structure (coarse void structure). As a result, the disintegrability of the granules 9 is promoted when absorbing urine and as shown in FIG. 8b, the joining or aggregation 10 of the granules are more expected in accordance with the disintegration.

(22) Further, when the coarse void structure of the granular excreta treating material is represented with a numerical value of a breaking load test, the test results shown in FIGS. 3A, 3B, 4A, and 4B are obtained. That is, in the tables shown in FIGS. 3A and 3B, the absorbent granule 9 is 3 mm in diameter. Regarding 1 and 2 of FIG. 3A, the raw materials having the mixing ratios A and B below are granulated by the compressive granulating apparatus and the production method thereof according to the first embodiment. Regarding 3 and 4 of FIG. 3B, the raw materials having the mixing ratios A and B are granulated by the compressive granulating apparatus and the production method thereof according to the related art. AN 1 has a condition that the moisture is 8.6% and the die thickness (the height of the compression zone Z1) is 7 mm. 2 has a condition that the moisture is 10.6% and the die thickness is 7 mm. 3 has a condition that the moisture is 9.6% and the die thickness is 40 mm. 4 has a condition that the moisture is 8.9% and the die thickness is 40 mm.

(23) In the tables shown in FIGS. 4A and 4B, the absorbent granule 9 is 6 mm in diameter. Regarding 1 and 2 of FIG. 4A, the raw materials having the mixing ratios A and B are granulated by the compressive granulating apparatus and the production method thereof according to the first embodiment. Regarding 3 and 4 of FIG. 4B, the raw materials having the mixing ratios A and B are granulated by the compressive granulating apparatus and the production method thereof according to the related art. 1 has a condition that the moisture is 10.5% and the die thickness (the height of the compression zone Z1) is 5 mm. 2 has a condition that the moisture is 10.8% and the die thickness is 5 mm. 3 has a condition that the moisture is 7.2% and the die thickness is 40 mm. 4 has a condition that the moisture is 9.3% and the die thickness is 40 mm. Further, the above-described test was conducted by a strength tester (trade name: auto graph manufactured by Shimadsu Corporation.) under the condition that the temperature is about 20 C. and the humidity is about 60%.

(24) According to the test result, in the breaking test of the granular excreta treating material according to the first embodiment, the numerical value of the breaking load N was 95 N or less. The same test was repeatedly conducted, changing the mixing ratio or the diameter of the granule. As a result, it was turned out that satisfactory disintegrability and aggregativeness were obtained with the breaking load of from 13 N to 95 N. On the contrary, in the granular excreta treating material granulated by the method of the related art, all the numerical values of the breaking load were 160 N or more. Therefore, there was found an obvious difference between the invention and the related art.

(25) <Mixing Ratio A> (Ratio by Weight)

(26) Recycled Paper from 40% to 55%

(27) Inorganic Filling Material from 30% to 44%

(28) Adhesive from 1% to 30%

(29) <Mixing Ratio B> (Ratio by Weight)

(30) Recycled Paper from 40% to 54%

(31) Inorganic Filling Material from 30% to 44%

(32) Adhesive from 1% to 15%

(33) Absorbent Polymer from 1% to 15%

(34) Here, the inorganic filling material indicates a material formed by selectively mixing one or more of bentonite, calcium carbonate, talc, acid clay, zeolite, and the like. The adhesive indicates a material formed by selectively mixing starch, CMC, guar gum, and the like.

(35) In the granular excreta treating material according to the invention, a cheap granular excreta treating material having high absorbing property and satisfactory disintegrability and aggregativeness may be provided without using a method of applying a paper powder to the outer peripheral surface of the absorbent granule 9 to form a coating layer thereon or a method of adding oil, wax, or silicon into a mixed material as in the related art. Further, in the first embodiment, the longitudinal compressive granulating apparatus has been described, but the invention is not limited thereto. For example, a transverse compressive granulating apparatus may be arbitrarily adopted.

Second Embodiment

(36) Next, a second embodiment of the invention will be described. The second embodiment is basically similar to the first embodiment except for the configuration below. In the configuration of the first embodiment, the compressive granulating hole 2 is formed as a double-stage hole structure, the front stage forms the compression zone Z1 having the small diameter hole 2a, and the rear stage forms the compression zone Z2 having the large diameter hole 2b. On the contrary, in the configuration of the second embodiment, as shown in FIG. 5, space ribs 6 are disposed on the lower surface of the die table 1 in a radial shape, a circular shape, a square shape, or a protrusion shape, and the non-compression zone Z2 is formed between the space ribs 6.

(37) That is, as shown in FIGS. 6 and 7, when the raw material is extruded and compressed via the compressive granulating hole 2 to be granulated, the cutting blade 4 is provided with a gap (a gap corresponding to the plate thickness of the space rib 6) 8 at the outlet surface side of the compressive granulating hole 2.

(38) Then, the compression zone Z1 is formed by the compressive granulating hole 2 having the small diameter hole 2a, and the non-compression zone Z2 is formed between the gaps 8. Here, the raw material is compressed by the small diameter hole 2a forming the compression zone Z1, swells at the non-compression zone Z2, and is cut into granules by the cutting blade 4 rotating along the outlet surface of the non-compression zone Z2. Further, the gap 8 is formed in an area defined between the space ribs 6, and the plurality of compressive granulating holes 2 is formed in each area.

(39) In other words, the compressive granulating hole 2 forms the compression zone Z1 having the small diameter hole 2a with the same diameter over the entire height thereof. On the other hand, the cutting blade 4 is provided with a gap corresponding to the plate thickness of the space rib 6 at the outlet surface side of the compressive granulating hole 2, and the non-compression zone Z2 that is open and continuous to the compression zone Z1 having the small diameter hole 2a is formed between the cutting blade 4 and the compressive granulating hole 2.

(40) In this manner, the raw material 5 of the granules 9 passes through both the small-diameter compression zone Z1 and the opened non-compression zone Z2, and is cut by the cutting blade 4 rotating along the outlet surface of the non-compression zone Z2 right after passing out both zones Z1 and Z2. However, the non-compression zone Z2 mentioned in the second embodiment is not provided to correspond to each compression zone Z1 unlike the first embodiment, and the non-compression zone Z2 is formed to be common to and extending through below all compression zones Z1.

(41) Therefore, even in the second embodiment, the compressive granulating hole (small diameter hole 2a) 2 and the compression zone Z1 are formed, the gap 8 and the non-compression zone Z2 are formed, and the cutting blade 4 is rotated along the outlet surface of the non-compression zone Z2 to cut the raw material into granules right after the raw material passes out both the compression zone Z1 and the non-compression zone Z2.

(42) Accordingly, the granular excreta treating material produced by the extrusion type compressive granulating apparatus according to the second embodiment also continuously passes through the compression zone Z1 that is applied with a pressure and the non-compression zone Z2 that is not applied with a pressure, and is cut into granules by the cutting blade 4. The density of the entire raw material becomes comparatively high due to the high pressure applied to the raw material for a short time while the raw material is passing through the compression zone Z1, but the pressure applied to the raw material is completely released when the raw material passes through the compression zone Z1 and thereby arrives at the non-compression zone Z2, so that the raw material swells. That is, the raw material is appropriately fastened at the compression zone Z1, and is extruded into a rod shape to go into the non-compression zone Z2. The rod-shaped material 7 extruded into the non-compression zone Z2 is not fastened, but naturally swells in the non-compression zone Z2. The granules 9 having a coarse density produced in this manner are restored to be slightly rough, so that it comes to have a low-density structure, that is, a coarse void structure. Accordingly, the absorbing property improves, and the disintegrability and the aggregativeness are promoted.

(43) Further, the production method or the extrusion type compressive granulating apparatus according to the second embodiment are the same as those of the first embodiment except for a method of forming the non-compression zone Z2. Accordingly, the examples of the mixing ratios and the results of the breaking load test shown in FIGS. 3A, 3B, 4A, and 4B based on the examples of the mixing ratios are incorporated herein for reference.

(44) The invention may provide the granular excreta treating material for pets such as a cat or a dog, which has sufficient absorbing property and satisfactory disintegrability and aggregativeness without a coating layer or adding oil or the like. Further, since the granular excreta treating material may be produced at lower cost and fewer process steps compared to the case where a coating is applied onto the surface of the granule, or the case where oil or the like is added, the problem of the related art may be reliably eliminated.