JPH11286015A - Method and apparatus for collecting comminuted plastic pieces according to source separated material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize a running cost by enhancing a quality level and a real yield according to collection of comminuted plastic pieces of source separated material and relatively miniaturing an apparatus constitution. SOLUTION: A surface tension relaxation liquid and a plurality of types of comminuted plastic pieces having different material specific gravities are supplied from one side of a container into the container. Introduced comminuted plastic pieces are divided pieces precipitated in the liquid and pieces floated in the liquid while flowing from one side to the other side of the container together with the liquid regulated at specific gravities necessary to separate the introduced pieces to collect source separated materials. The floated pieces are flowed out of the container together with the liquid, while the precipitated pieces are scraped up from a bottom of the container, and discharged out of the container via another flow-out passage from a flow-out passage of the floated pieces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for separating a plurality of types of plastic fragments having different specific gravities.

[0002]

2. Description of the Related Art From the viewpoint of avoiding environmental pollution and effectively utilizing resources,
Plastic products tend to reuse materials rather than being incinerated or landfilled. The plastic material to be reused is usually supplied as plastic fragments. Various materials such as PET (polyethylene terephthalate) and PE
Plastic crushed pieces of different materials such as (polyethylene) or PP (polypropylene) are mixed.
For this reason, it is necessary to sort materials when reusing.

[0003] In the conventional sorting or sorting method, the difference in specific gravity of each material (for example, PET is 1.35, PE is 0.95, PP is 0.
89) is the most common technology. The crushed plastic pieces are put into a container filled with water, and separated into those that settle in the water and those that float on the surface of the water, and are collected separately. FIG. 8 shows a schematic configuration diagram of the apparatus.

In the figure, reference numeral A denotes a container, and B denotes a feed blade disposed at the bottom of the container A.
D is transferred along the length direction of the container A, and is discharged from the container side end (the right end in the figure). E denotes a rotating shaft extending in the longitudinal direction at the upper part of the container A, and a stirring blade e is mounted around the shaft. The stirring blade e stirs while hitting the plastic crushed pieces C and D in the water. Since the plastic crushed pieces C and D have hydrophobicity, even if they are, for example, PET having a specific gravity of 1 or more, they are hardly settled due to the surface tension of water if they are simply introduced. By hitting the plastic crushed pieces C and D with stirring by the stirring blade e, the wettability of the plastic crushed piece surface is improved, and only the crushed piece D having a high specific gravity is forcibly settled.

[0005]

In the case of the prior art, in practice, heavy plastic crushed pieces D remain on the surface of the water, or lightly crushed plastic crushed pieces C are contained in the settled plastic crushed pieces D. And the quality and actual yield of the fractionation are not sufficiently satisfactory. Also,
The devices themselves tend to be relatively large, and
Running costs tend to increase because the two shaft members B and E are rotated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus for separating plastic crushed pieces, which are excellent in the ability to separate and can improve the quality and the actual yield by separating the plastic crushed pieces. Another object of the present invention is to provide a method and an apparatus for separating plastic crushed pieces, which can make the apparatus configuration relatively small and can reduce the running cost as much as possible.

[0007]

The present invention has the following configuration to achieve the above object. A plurality of types of plastic crushed pieces having different material specific gravities are put into a container containing a surface tension relaxing liquid. The injected plastic crushed pieces are separated into those that settle and those that float in the above-mentioned surface tension relaxation liquid adjusted to the required specific gravity. Materials are separated by separately removing both settling and floating material from the container. Specifically, a surface tension relaxation liquid and a plurality of types of plastic crushed pieces having different material specific gravities are supplied into the container from one side of the container. The poured plastic crushed pieces are settled and floated in the surface tension relaxation liquid while flowing from one side to the other side of the container together with the surface tension relaxation liquid adjusted to the required specific gravity. Separate. The floating plastic crushed pieces are caused to flow out of the container together with the surface tension-reducing liquid, while the settled plastic crushed pieces are scraped up from the bottom of the container, and are separated from the floating plastic crushed pieces through a flow path different from the flow path of the floating plastic crushed pieces. Let it drain out.

Further, the apparatus of the present invention is a horizontal cylindrical container for accommodating a plurality of types of plastic crushed pieces having different material specific gravities and a surface tension relieving liquid adjusted to a specific gravity necessary for separating these plastic crushed pieces. Having. At one end of the container, there are provided means for supplying plastic crushed pieces and a surface tension relaxing liquid. In addition, of the plastic crushed pieces supplied into the container, the plastic crushed pieces floating in the upper layer of the surface tension relaxation liquid while the plastic crushed pieces flow from one side end of the container to the other end together with the surface tension relaxation liquid. First discharging means for discharging the container from the other end of the container together with the surface tension relaxing liquid, and second discharging means for discharging the plastic crushed pieces settled in the lower part of the surface tension relaxing liquid to the outside of the container. Prepare.

As means for supplying the plastic crushed pieces and the surface tension relaxing liquid, for example, an inlet for the plastic crushed pieces and an inlet for the surface tension relaxing liquid are provided at one end of the container. The inlet and the inlet may be the same. In addition, a fixed quantity supply device can be assembled. By providing a discharge port for discharging the separated plastic crushed pieces at the other end of the container, it can be used as a first discharge means. As the second discharge means, an upper surface open type discharge path that extends along the axial direction of the container in the upper part of the container inner space and whose tip projects forward from above the discharge port, and rotates in the container inner peripheral direction, It is preferable that a scraping means for scraping the settled plastic crushed pieces at the bottom of the container at the lower position and dropping the plastic crushed pieces scraped and held at the upper position to the discharge path is preferable. In order to make the surface tension relaxation liquid and the crushed plastic pieces flow from one side to the other side in the container, for example, it is desirable that the accommodation space in the container is inclined downward to the discharge port (the other side end). The inclination may be such that the upper surface of the gantry supporting the container has an inclination. A storage tank for the surface tension relaxation liquid is provided in the gantry together with the submersible pump. The discharge path is supplied with a fluid that causes the plastic crushed pieces on the discharge path to flow toward the tip. As the fluid, a surface tension relaxing liquid can be used.

As the surface tension relaxing liquid, for example, an aqueous solution of a surfactant is used. The specific gravity of the surface tension relaxing liquid is adjusted to an appropriate value of 1 or more or 1 or less by adding a solute such as a salt. The surface tension relaxation liquid flowing out from the discharge port and the end of the discharge path may be returned to the storage tank for circulating use. In addition, if air is blown into the surface tension relaxation liquid near the injection location of the plastic crushed pieces, the wettability of the plastic crushed pieces increases. By continuously supplying the plurality of types of plastic crushed pieces from one side end of the container,
From the other end of the container, plastic crushed pieces having been subjected to material separation are continuously discharged.

The scraping means is fixed, for example, to the inner wall of the container, and is integrally rotated by rotating the container by an appropriate rotating means. The discharge passage extends from one side of the container to the other side, and is fixed without being affected by rotation of the container. Partition plates extending downward without reaching the container bottom are provided on both sides in the width direction of the discharge path. Then, plastic crushed pieces are put between the two partition plates. The scraping means is constituted by, for example, a large number of scraping blades spaced in the inner circumferential direction of the container and extending in the axial direction of the container.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on illustrated embodiments. FIG. 1 is an external front view of a state in which an apparatus according to an embodiment of the present invention is fixed to a gantry, FIG. 2 is a cross-sectional view of the apparatus viewed from the front, FIG. 3 is a right side view of the apparatus, and FIG. 2 is a longitudinal sectional view in which a part of the device is omitted, and FIG. 5 is a perspective view showing a main part of the device in a partial cross section.

In FIG. 1, reference numeral 1 denotes a substrate made of punched metal (see FIGS. 2 and 4), and reference numeral 2 denotes a drum-shaped container rotatably supported on the substrate 1. The crushed plastic pieces are separated while passing in the container 1 in the axial direction. Container 1
Is a circular opening 3 in the center of one side (the right side in the figure).
And a circular outlet 4 on the other side (left side in the figure). An outflow tube 5 is attached to the outlet 4. Two rotating shafts 6 are provided horizontally on the substrate 1 in parallel at a required interval (see FIGS. 4 and 5). Both rotating shafts 6
Rolls 6a are attached to the shaft ends of the shafts, respectively, and the shaft end of one rotating shaft 6 is connected to the shaft of the motor via a gear (not shown). The lower part of both ends of the peripheral surface of the container 1 is supported in contact with these four rolls 6a, and rotates slowly by receiving the rotating force of the rotating shaft accompanying the driving of the motor.

A support frame 7 stands on the substrate so as to face one side surface of the container 1. The support frame 7 supports a discharge chute 8 for sorted plastic crushed pieces, a material supply chute 9 and a quantitative supply device 10 for sorted plastic crushed pieces before sorting. As shown in FIGS. 4 and 5, the discharge chute 8 has side pieces that expand upward on both sides in the width direction, and has a wide open upper surface. The discharge chute 8 has a rear end (right end in the figure) at a vertical plate 7a of the support frame 7 (FIG. 5).
) And extends axially through the inside of the container from the opening 3 of the container 1.
Projecting outward through the other side. Vertical plate 7a
The plate surface is provided with a flow liquid inlet 7b for facilitating the movement of the plastic crushed pieces on the chute toward the tip of the chute. In the figure, reference numeral 11 denotes a conduit connecting the inflow port 7a and the liquid source. In this embodiment, a surface tension relaxation liquid is also used as the fluid.

The material supply chute 9 is a chute for supplying the plastic crushed pieces and the surface tension relieving liquid before separation into the container. The intermediate portion near the front is fixed to the support frame 7 below the vertical plate. I have. The rear portion 9a of the material supply chute projecting rearward of the support frame 7 has an open upper surface, and has an inlet 9b for the surface tension relaxation liquid at the rear end surface. A front portion 9c protruding from the support frame 7 toward the container 1 passes through the above-described opening 3 of the container 1 and enters the space inside the container. A material inlet 9d is formed in the bottom plate located near the tip of the material supply chute front part 9c (see FIG. 5). A guide plate 12 that extends obliquely below the inlet 9d toward the bottom of the space in the container is attached to the lower surface of the bottom plate behind the inlet 9d.

On the inner peripheral surface of the container 1, a number of raising blades 13 extending along the axial direction are fixed at intervals in the circumferential direction. The scraping blade 13 includes a standing piece 13a extending from the base end toward the center of the container 1, and an inclined piece 13b bent from the tip of the rising piece toward the rotation direction of the container 1. With the rotation of the container 1, the scraping blades 13 scoop up the plastic crushed pieces settled at the bottom of the container on the hook-shaped surface by the standing pieces 13a and the inclined pieces 13b, and carry the pieces upward along the inner circumference of the container. .

On the outer surfaces of both sides of the discharge sheet 8, partitioning pieces 14 are formed to fall. The front portion 9c of the material supply chute 9 that has entered the container is
Located between. Therefore, the crushed plastic pieces supplied from the input port 9d of the material supply chute 9 float or settle in the space between the two partition pieces. The partition piece 14 has a lower end located at a position slightly away from the bottom of the container so as not to hinder the scraping operation of the lifting blade 13.

Above the rear part 9a of the material supply chute, there is provided a quantitative supply device 10 for plastic crushed pieces before sorting. The fixed amount supply device 10 includes a hopper 10a and a fixed amount feeding member 10b provided below the hopper 10a. The constant-rate feeding device 10 is configured such that the unsorted plastic crushed pieces sent out from the constant-rate feeding member 10b are connected to the rear part 9 of the material supply chute 9.
The cantilever is supported by the support frame 7 above the vertical plate so as to drop to a.

The container 1 is fixed to the gantry 15 together with the base (see FIG. 1). The upper surface of the gantry is inclined, and the outlet of the container 1 is positioned slightly below the support frame 7 to which the material is supplied. The inclination angle is not particularly limited. The range is appropriately set within a range in which the plastic crushed pieces stay in the container for a time required for separation. The angle of inclination changes depending on the diameter and length of the container 1 or the amount of material (plastic crushed pieces and surface tension relaxation liquid) fed from the material supply chute 9 per hour.

A tank (not shown) of a surface tension relaxing liquid is provided inside the gantry. The surface tension relaxing liquid is composed of, for example, an aqueous solution obtained by dissolving a surfactant in water and diluting the same. An appropriate amount of a surfactant is added in a range that improves the wettability of the plastic crushed piece surface. Further, an appropriate solute is added to the surface tension relaxation liquid according to the specific gravity of the crushed plastic pieces to be separated, and the specific gravity is adjusted. No such solutes are added when separating plastic fragments with a specific gravity of 1 as a boundary. When the separation is performed by using one or more reference specific gravities, adjustment by salt content or the like is performed so that the entire surface tension relaxation liquid has the reference specific gravity. Conversely, when the separation is to be performed based on the reference specific gravity of 1 or less, alcohols and the like are used. Further, in the tank, a submersible pump for pumping the surface tension relaxation liquid to the discharge chute 8 and the material supply chute 9 via the two pipes 11 and 16 is provided.

Reference numeral 17 in the drawing denotes a container for receiving separated plastic crushed pieces placed on a gantry. Outflow cylinder 5
Below the opening is a receiving container for floating plastic fragments, and below the tip of the discharge chute is a receiving container for sedimented plastic fragments. Each container 17 has a bottom surface formed of a mesh material, receives only plastic crushed pieces and remains in the container, and returns the passed surface tension relaxation liquid to the tank in the gantry. Reference numeral 18 in the figure denotes a control box with an operation panel fixed to the upper end of the support frame 7, and a circuit for controlling driving of a motor and a pump, operation of the quantitative supply device 10 for plastic crushed pieces, and the like are accommodated therein. ing.

The operation of the apparatus will be described with reference to FIGS. 6 and 7. When the switch on the operation panel 18 is turned on, the pump and the motor are driven to cause the surface tension relaxing liquid to flow into the container from the material supply chute 9 and to rotate the container 1 little by little. Since the container 1 is inclined, the surface tension relaxation liquid flows slowly from the lower edge of the discharge port to the outside of the container as shown in FIG. When the surface tension relaxation liquid in the container reaches a certain amount, the quantitative supply device 10 is operated, and the crushed plastic crushed pieces contained in the hopper 10a, for example, the PET crushed pieces and the PE crushed pieces or the PP crushed pieces are mixed. Send out crushed pieces. The mixed crushed pieces sent out fall into the rear part 9a of the material supply chute 9 and move in the material supply chute together with the surface tension relaxation liquid to reach the inside of the container from the charging port 9d.

The mixed crushed pieces entered into the container slowly move toward the discharge port 4 along with the flow of the surface tension relaxing liquid. During that time, the PET crushed pieces D having a specific gravity of 1 or more settle below the liquid, and the PE crushed pieces or PP crushed pieces C of 1 or less float in the upper layer of the liquid. Since the liquid is an aqueous solution that relieves surface tension unlike simple water, plastic crushed pieces C,
The fractionation according to the specific gravity is performed without being affected by the hydrophobicity of D.

The settled PET crushed pieces D do not accumulate at a specific location in the longitudinal direction of the container 1 due to the inclination of the container 1 but move little by little toward the discharge port. With the rotation of the container 1, the scraper blades 13 on the inner periphery of the container rotate. The PET crushed pieces D that settled at the bottom of the container are
3 and is moved upward along the inner circumference of the container. As shown in FIG. 7, the scraping blade 13 is located near the rising piece 13 a of the blade at the beginning, but the inclined piece 13 b moves sideways as it is lifted, and falls at a position above the discharge chute 8. Is received by the discharge chute 8. During the scraping operation, the scraping blade 13 drops the surface tension relaxing solution together with the PET crushed pieces D at the upper position in order to scoop a small amount of the surface tension relaxing solution on the surface. Therefore, PET
There is no possibility that the crushed pieces D adhere to the blade surface and hardly fall. Since the surface tension-reducing liquid is flowing from the rear end to the discharge chute 8, P
The ET crushed pieces D move smoothly on the chute surface and are stored in the receiving container 17 from the tip.

On the other hand, PE floating in the upper layer of the surface tension relaxing liquid
The crushed pieces or the PP crushed pieces C flow toward the discharge port 4 in the liquid area separated on both sides by the partition pieces 14 because the mixed crushed pieces C and D are introduced between the partition pieces 14 (FIG. 7). For this reason, even if the PET crushed pieces D fall into the liquid in the middle of the scraping operation, they do not mix with the floating PE crushed pieces or PP crushed pieces C. The PE crushed pieces or the PP crushed pieces C that have advanced in the liquid region between the partition pieces are guided from the discharge port 4 to the receiving container 17 through the outflow cylinder 5.

In the present embodiment, the crushed pieces at the time of separation are separated according to the volume (diameter and length) and the inclination angle of the inner space of the vessel, the inclination angle, the rotation speed of the vessel, the concentration of the surface tension relaxation liquid, and the supply amount of the plastic crushed pieces. Although there were some differences in the quality and the actual yield, fractionation that was significantly superior to the conventional example could be performed.
In some cases, if the mixed crushed pieces are agitated by ventilating into the container space near the material input port, the crushed pieces do not adhere to each other, so that higher-quality separation can be performed.

[0027]

As described above, according to the present invention, the separation of plastic crushed pieces utilizing the difference in specific gravity is performed in the surface tension relaxation liquid, so that the influence on the hydrophobicity of the plastic crushed pieces is affected. Separation can be performed reliably and efficiently without receiving.

Further, according to the present invention, it is possible to separate plastic crushed pieces without requiring a blade member or a feed blade for hitting and stirring the water surface layer portion, so that the apparatus is not increased in size. Moreover, it can be implemented at a relatively low running cost.

Further, according to the apparatus in which the crushed pieces settled in the lower layer of the liquid are scraped off by a scraping means and dropped into a discharge path different from the floating crushed pieces to be discharged, the crushed pieces having a high specific gravity after separation can be easily obtained. With the configuration, it can be discharged outside.

Further, according to the apparatus provided with the partition plate for partitioning the flow area of the floating crushed pieces, the plastic crushed pieces having different specific gravities while flowing from one side of the container to the other side are separated from each other once. Separation can be performed more appropriately without re-mixing.

[Brief description of the drawings]

FIG. 1 is an external front view of a state in which an apparatus according to an embodiment of the present invention is fixed to a gantry.

FIG. 2 is a cross-sectional view of the apparatus as viewed from the front.

FIG. 3 is a right side view of the device.

FIG. 4 is a longitudinal sectional view in which a part of FIG. 2 is omitted.

FIG. 5 is a perspective view showing a main part of the apparatus in a partial cross section.

FIG. 6 is an explanatory view showing a relationship between a scraping blade and a discharge chute of the apparatus.

FIG. 7 is an explanatory view showing a state of discharging plastic crushed pieces separated by the apparatus.

FIG. 8 is a conceptual configuration diagram showing an example of a conventional device.

[Explanation of symbols]

1 ... substrate 2 ... drum-shaped container 3 ... opening on one side 4 ... outlet on the other side 5 ... ... Outflow cylinder 6 ... Rotary shaft 6a ... Roller 7 ... Support frame 8 ... Discharge chute 9 ... · Material supply chute 9d ·············································································································································· 15 ·······························································································

Claims (16)

[Claims] 1. A plurality of types of plastic crushed pieces having different specific gravities are charged into a container containing a surface tension relieving liquid, and the input plastic crushed pieces are sorted to adjust to a required specific gravity. A method for separating plastic crushed pieces into different materials, wherein the method separates those that settle in the liquid from those that float and separates those that settle and floats separately from the container. 2. A surface tension-reducing liquid and a plurality of types of plastic crushed pieces having different material specific gravities are supplied from one side of the vessel into the vessel, and the injected plastic crushed pieces are separately adjusted to a required specific gravity. While flowing from one side of the container to the other side together with the above surface tension relaxing liquid, it is divided into those that settle in the surface tension relaxing liquid and those that float, and the floating plastic fragments are taken out of the container together with the surface tension relaxing liquid. The plastic crushed piece material, characterized in that the plastic crushed piece settled is scraped up from the bottom of the container while being discharged, and is discharged out of the container through an outflow path different from the flow path of the floating plastic crushed piece. Separation method. 3. The method according to claim 1, wherein the surface tension relaxing liquid is an aqueous solution of a surfactant. 4. The material separation of the crushed plastic pieces according to claim 1, wherein the specific gravity of the surface tension relaxing liquid is set to a value of 1 or more by adding a solute to the surface tension relaxing liquid. Law. 5. The method for separating plastic crushed pieces according to claim 1, wherein the specific gravity of the surface tension relaxing liquid is set to a value of 1 or less. 6. The plastic crushed pieces of the plurality of types are continuously supplied in a constant amount from one end of the container, and the plastic crushed pieces separated from the material are continuously discharged from the other end of the container. Item 6. The method for separating materials from plastic crushed pieces according to Item 1 to 5. 7. A method for separating plastic crushed pieces according to claim 1 or 2, wherein aeration is performed in a surface tension relaxation liquid near a place where the plastic crushed pieces are charged. 8. A horizontal cylindrical container containing a plurality of types of plastic crushed pieces having different specific gravities and a surface tension relaxation liquid adjusted to a specific gravity necessary for separating these plastic crushed pieces, A supply means for supplying the plastic crushed piece and the surface tension relaxation liquid provided at one end, and a plastic tension crushed piece of the plastic crushed piece from the one end of the container to the other side end of the plastic crushed piece supplied into the container. First discharging means for discharging the plastic crushed pieces floating in the upper part of the surface tension relaxing liquid while flowing together with the surface tension relaxing liquid to the outside of the container from the other end of the container, and the plastic crushing supplied into the container Among the pieces, the plastic shards settled in the lower part of the surface tension relaxing liquid while flowing along with the surface tension relaxing liquid from one end of the container to the other end. And a second discharge means for discharging the pieces to the outside of the container, the material sorting apparatus of the plastic fragments, characterized in that. 9. A horizontal cylindrical container for accommodating a surface tension relaxation liquid and a plurality of types of plastic crushed pieces having different material specific gravities, an input port of the plastic crushed piece provided at one end of the container, and the surface. An inlet for the strain-relaxing liquid, an outlet provided at the other end of the container for discharging separated plastic fragments, and an upper part of the inner space of the container extending in the axial direction of the container, with a tip above the outlet. An open-top discharge path protruding forward from the container, and rotating in the inner circumferential direction of the container to scrape the sedimented plastic crushed pieces at the bottom of the container at the lower position, and remove the plastic crushed pieces scraped and held at the upper position to the discharge path. Means for inclining the storage space for the surface tension-reducing liquid in the container toward the lower end of the discharge port; and a discharge path for flowing the plastic crushed pieces on the discharge path toward the tip. A fluid supply means for supplying, wherein the surface tension relaxation liquid is adjusted to a specific gravity required for sorting plastic crushed pieces having different specific gravities to be charged into the container; home,
While the plastic crushed pieces floating on the surface layer of the surface tension relaxation liquid supplied into the container from the inflow port are caused to flow out together with the surface tension relaxation liquid from the outlet, the plastic crushed pieces settled in the lower layer of the surface tension relaxation liquid are removed. A material sorting device for crushed plastic pieces, wherein the material is scraped by the scraping means, dropped into a discharge path, and discharged from the discharge path together with the fluid. 10. The apparatus according to claim 8, wherein the surface tension relaxation liquid is an aqueous solution of a surfactant. 11. The apparatus according to claim 8, wherein said supply means is a fixed amount supply means. 12. The surface tension relieving liquid, wherein the surface tension relieving liquid is guided from the storage tank into the container and onto the discharge path, and the surface tension relieve liquid flows out from the discharge port and the end of the discharge path. The apparatus according to claim 9, wherein the liquid is returned to the storage tank and used for circulation. 13. The scraping means is fixed to an inner wall of the container, and is integrally rotated by rotating the container by a rotating means, and the discharge path extends from one side of the container to the other side. The device according to claim 9, wherein the device is arranged so as to be fixed without being affected by rotation of the container. 14. The container according to claim 8, wherein the container is fixed on the gantry so as to be inclined downward to the other end, and a storage tank for the surface tension relaxation liquid is provided in the gantry together with the submersible pump. An apparatus according to any of the preceding claims. 15. The discharge path, wherein a partition plate extends downward at both ends in the width direction of the bottom surface without reaching the bottom of the container, and the plastic crushed pieces are introduced between the two partition plates. An apparatus according to any of claims 9 to 13. 16. The apparatus according to claim 9, wherein said scraping means has a large number of scraping blades spaced in the inner circumferential direction of the container and extending in the axial direction of the container.