JP5424791B2 - Plastic bottle and beverage product using the same - Google Patents

Description

  The present invention relates to a plastic bottle, and more particularly to the shape of a body portion of a plastic bottle.

  Plastic bottles are widely used as containers for beverages such as water, tea, carbonated drinks and juices. Such plastic bottles are increasing in importance on various functional designs, but there are also complaints regarding usability. For example, the container is soft and is likely to drop when held, difficult to hold without a dent or catch, difficult to hold with one hand, and easy to spill. This is particularly noticeable with large-capacity plastic bottles of about 2 liters.

  For such large capacity plastic bottles, the mass is quite heavy and requires considerable force to lift and pour out. Further, as the capacity increases, there is a problem that the waist of the container becomes larger and it is difficult to hold it with one hand.

  In view of this, a container has been proposed in which the body is designed so that it can be easily handled while being held with one hand in a stable state. For example, each of the opposite portions of the torso has recesses that are recessed, both recesses have a height and a width that allow the fingertip of one hand holding the torso to enter with a sufficient margin, and This is a plastic bottle having such a depth that the fingertip that has entered can be strongly caught (see, for example, Patent Document 1).

JP-A-8-230856

  However, plastic bottles including the technique described in Patent Document 1 can hold the container by hooking the thumb and index finger (middle finger) into the recess provided in the body of the container. In addition to the index finger (middle finger), it is difficult to hold the crotch part and palm part between the thumb and index finger (middle finger) in close contact with the container, and it is difficult to say that the pouring operation can be performed stably. Here, the pouring operation is a series of operations for lifting the container and subsequently tilting the container body.

  In addition, the container design that pursues “ease of use” of plastic bottles, especially “ease of use” in pouring, is mainly ambiguous and qualitative. It was difficult to determine and it was necessary to design many times.

  Therefore, an object of the present invention is to design a plastic in the shape of a plastic bottle based on the result of objective and quantitative evaluation of the physical burden (muscle burden) in a series of pouring operations in which the container is lifted and then the container body is tilted. Propose a bottle. That is, it is to propose a plastic bottle that can reduce the strain on the pouring operation.

As a result of intensive studies to solve the above-mentioned problems, the present inventors pay attention to the contact area between the plastic bottle and the hand when holding the plastic bottle, and provide a tapered surface on the body of the plastic bottle. Thus, the contact area between the plastic bottle and the hand is increased, and as a result, it has been found that the strain on the pouring operation can be reduced, and the present invention has been completed. That is, the plastic bottle according to the present invention is a plastic bottle in which a mouth portion, a shoulder portion, a trunk portion, and a bottom portion are formed by molding a thermoplastic synthetic resin into a bottle. A tapered surface is provided on each of two opposing wall surfaces of the short side of the body portion, the distance from the main shaft of the container being increased downward, and an inclination angle of the tapered surface with respect to the main shaft of the container is , Ri 8 to 12 ° der, two opposed wall surfaces of the longitudinal sides of the barrel, in the region of the same height as the respective height the tapered surface is formed, the main shaft parallel to the plane of the container And the planar portion has an upper end side .

  In the plastic bottle according to the present invention, it is preferable that the body portion has a constricted portion, and the tapered surface is provided so as to be connected to a lower end of the constricted portion. At the constricted portion, the waist of the plastic bottle becomes smaller and can be gripped strongly. Further, since the finger is caught in the constricted portion, it becomes difficult to slip, and it is not necessary to apply an extra force.

  In the plastic bottle which concerns on this invention, it is preferable that the upper end of the said taper surface is located in the height center part of a container. By grasping the center of gravity of the plastic bottle, the pouring operation is stabilized.

  In the plastic bottle according to the present invention, a bluff plane parallel to the main axis of the container is provided below the tapered surface, and the bluff plane is widened toward the bottom, and the upper end of the bluff plane is It is preferable to provide on a taper surface. Ideally, the plastic bottle should have a horizontal cross-sectional shape that is close to a square or a rectangle in order to ensure a sufficient capacity while maintaining a size that allows the waist to be gripped. In the plastic bottle according to the present invention, the general shape of the horizontal cross-sectional shape of the trunk is a rectangle. The tapered surface can be smoothly connected to the rectangular portion of the trunk through the precipice plane. Moreover, by setting it as a divergent shape, the area of a taper surface can be provided widely and the contact area of a plastic bottle and a hand can be made wider.

The plastic bottle according to the present invention includes a form in which the tapered surface is a part of a curved surface of a slanted elliptic cylinder or a slanted cylinder or a part of a curved surface of a truncated cone. In the plastic bottle which concerns on this invention, it is preferable that the upper end side of the said taper surface exists in the same height as the upper end side of the said plane part.

  The beverage product according to the present invention is characterized in that the plastic bottle according to the present invention is filled with a beverage.

  The present invention proposes a plastic bottle whose shape is designed based on the objective and quantitative evaluation of the physical burden (muscle burden) in a series of pouring operations in which the container is lifted and then the container body is tilted. can do. That is, it is possible to propose a plastic bottle that can reduce the strain on the pouring operation.

It is a perspective view which shows schematic shape of an example of the plastic bottle which concerns on this embodiment. It is a front view (longitudinal surface) which shows a schematic shape of an example of a plastic bottle concerning this embodiment. It is a side view (short side) showing an outline shape of an example of a plastic bottle concerning this embodiment. It is an outer peripheral line of the XX fracture surface of FIG. It is an outer peripheral line of the YY fracture surface of FIG. It is an enlarged perspective view (a) of a taper part of a plastic bottle concerning this embodiment, and a schematic diagram (b) of a hand, and is a figure for explaining a contact area of a plastic bottle and a hand. It is an enlarged front view of the trunk | drum of the plastic bottle which concerns on this embodiment. It is an outer peripheral line of the AA, BB, CC, DD, EE fracture | rupture cross section of FIG. It is a side view which shows the schematic shape of another example in the plastic bottle which concerns on this embodiment, (a) is a boundary line of a precipice plane, and (b) is a trapezoidal boundary line of a precipice plane. It is the graph which showed the relationship between the inclination-angle of a taper surface, the measurement object container, and the contact area of a hand. It is a figure which shows how to hold the plastic bottle in the pouring operation. It is a figure which shows the skeletal muscle of a hand and an arm. The relationship between the maximum strength ratio of the superficial digital flexor muscle and the subjective evaluation of the subject with respect to the muscle load is shown. The specific reference | standard (Borg scale) of the numerical value of the test subject's subjective evaluation of the vertical axis | shaft in FIG. 13 is shown. It is the graph which showed the maximum muscular strength ratio (% MVC) of each operation | movement muscle of the operation | movement which lifts. It is the graph which showed the maximum muscular strength ratio (% MVC) of each action muscle of pouring action. It is the graph shown as a burden in the operation | movement which raises the sum total of the maximum muscular strength ratio of a 1st dorsal interosseous muscle, a long thumb abductor, and a total finger extensor muscle, and pouring operation | movement.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not construed as being limited to these descriptions. As long as the effect of the present invention is exhibited, the embodiment may be variously modified.

FIG. 1 is a perspective view illustrating a schematic shape of an example of a plastic bottle according to the present embodiment. FIG. 2 is a front view showing a schematic shape of an example of a plastic bottle according to the present embodiment. FIG. 3 is a side view showing a schematic shape of an example of the plastic bottle according to the present embodiment. FIG. 4 is a sectional view taken along line XX in FIG. As shown in FIGS. 1 to 4, the plastic bottle 100 according to the present embodiment is a plastic bottle in which a mouth portion 10, a shoulder portion 20, a body portion 30, and a bottom portion 40 are formed by molding a thermoplastic synthetic resin into a bottle. The body 30 is a rectangle whose horizontal cross-sectional shape has rounded corners, and the distance from the main axis O of the container increases on each of the two wall surfaces 61 facing the short side S of the body 10 as it goes downward. the tapered surface 32 is provided, the inclination angle θ with respect to the main axis O of the container of the tapered surface 32, Ri 8 to 12 ° der, two wall surfaces 62 of opposing longitudinal sides L of the body portion 30, tapered surface 32 respectively form In a region having the same height as the height, a flat portion parallel to the main axis O of the container is provided, and the flat portion has an upper end side.

  The plastic bottle 100 is obtained by molding a thermoplastic synthetic resin into a bottle shape. Examples of the thermoplastic synthetic resin include polyethylene terephthalate resin (PET), polybutylene terephthalate resin, polyethylene naphthalate resin, polyethylene resin, polypropylene resin, cycloolefin copolymer resin, ionomer resin, poly-4-methylpentene-1 resin, Polymethyl methacrylate resin, polystyrene resin, polyvinylidene chloride resin, polyamide resin, polyamideimide resin, polyacetal resin, polycarbonate resin, polysulfone resin, or tetrafluoroethylene resin, acrylonitrile-styrene resin, acrylonitrile-butadiene-styrene resin Can be illustrated. Among these, PET is particularly preferable. The plastic bottle 100 has a capacity of, for example, 200 ml to 2000 ml, but it is particularly preferable here to have a capacity of 1000 ml to 2000 ml.

  The mouth portion 10 is usually formed with a diameter of 1.5 to 4 cm so that the liquid as the contents can be poured easily, and a cap (not shown) is detachably screwed to the screw portion 11. The shoulder portion 20 has a cone shape with a diameter increasing toward the trunk portion 30 so as to be connected to the trunk portion 30. 1 to 3 is formed with a curved surface, it may be formed with a plurality of cut surfaces. The body part 30 is a place that is mainly gripped by the consumer, and a product display label (not shown) such as a shrink label or a roll label is attached to the body part 30 on the outside thereof. The bottom portion 40 is connected with a body diameter substantially the same as that of the body portion 30. Further, annular ribs 35 and 41 are provided between the shoulder portion 20 and the body portion 30 and between the body portion 30 and the bottom portion 40, particularly improving the strength against stress from the side surface and deforming the bottle. To prevent. A recessed grip portion 34 is provided on the wall surface 62 of the longitudinal side L adjacent to the lower side of the annular rib 35 in the trunk portion 30. The grip part 34 is provided in order to improve grip properties by allowing the fingertip to enter the recessed part in which the grip part 34 is depressed when the consumer grips the upper part of the body part 30.

  As shown in FIG. 4, the trunk | drum 30 is a rectangle which the horizontal cross-sectional shape rounded off the corner | angular. Here, the rectangle is a general shape of the body portion 30 in consideration of a deformed portion such as a concave portion in the grip portion 34 and a curved surface of a tapered surface 32 described later. As for the horizontal cross-sectional shape, the long side L and the short side S of the rectangle may have the same length, that is, a square, but a rectangular shape is more preferable. By making it rectangular, a short side can be provided, and even a person with a small hand can easily hold it, and can be easily housed in a refrigerator. In the case of a large-capacity plastic bottle, it is ideal that the horizontal cross-sectional shape be close to a rectangle or a square in order to ensure an internal volume while maintaining a size that can grip the waist. In addition, when a predetermined quantity is packed and transported in cardboard, etc., or displayed at a storefront, a plastic bottle whose body (bottom) has a rectangular or square horizontal cross-section has a horizontal section of the body (bottom). There is also an advantage that the floor area efficiency is higher than that of a circular shape.

  FIG. 5 is a YY fracture surface of FIG. In FIG. 5, O ′ is a parallel line of the main axis O of the container. As shown in FIG. 5, the taper surface 32 has an inclination angle θ with respect to the container main axis O (O ′) of 8 to 12 °. The range of 8 to 12 ° is a range including an error during molding, and more preferably 10 °. Here, the inclination angle θ is an inclination angle in a longitudinal section passing through the main axis O of the container and vertically dividing the wall surface 61 of the short side S. FIG. 6 is an enlarged perspective view of the tapered portion of the plastic bottle according to the present embodiment and a schematic diagram of the hand, and a diagram for explaining the contact area between the plastic bottle and the hand. As shown in FIG. 6, the shape formed by the arch U ′ of the thumb / index finger (middle finger) and the inclination angle T ′ of the palm approximates the shape formed by the curve U of the tapered portion and the inclination angle T of the taper. Yes. Accordingly, the contact area between the plastic bottle and the hand increases, and as a result, the pouring operation with a small force becomes possible.

  In the plastic bottle according to the present embodiment, the body portion 30 preferably has a constricted portion 31 and is provided with a tapered surface 32 connected to the lower end of the constricted portion 31. FIG. 7 is an enlarged front view of the body portion of the plastic bottle according to the present embodiment. 8 is an outer peripheral line of the AA, BB, CC, DD, and EE fracture surface of FIG. As shown in FIG.7 and FIG.8, since the waist of a plastic bottle becomes small in the constriction part 31 (AA broken surface), it can hold | grip strongly. Further, since the finger is caught on the constricted portion 31, it becomes difficult to slip, and it is not necessary to apply an extra force.

  In the plastic bottle according to the present embodiment, it is preferable that the upper end of the tapered surface 32 is located at the center of the height of the container. Here, the height central portion of the container is near or below the center of gravity of the plastic bottle. Specifically, it is from the position of the center of gravity to a position about 15 mm below the position of the center of gravity. This is because the pouring operation is stabilized by gripping the vicinity of the center of gravity of the container.

  In the plastic bottle according to the present embodiment, a bluff plane 33 parallel to the main axis O of the container is provided below the tapered surface 32, and the bluff plane 33 is widened toward the bottom, and the upper end of the bluff plane 33 is widened. Is preferably provided on the tapered surface 32. The precipice plane 33 will be described with reference to FIG. The precipice plane 33 is provided in order to fit the tapered surface into the contour of a predetermined body (bottom) of the plastic bottle (in FIG. 8, a rectangle with a long side L and a short side S). The contour of the body portion (bottom portion) of the plastic bottle is designed in shape and dimensions in consideration of various requirements such as ease of gripping, inner volume, display area at stores, and the like. Since the taper surface 32 becomes larger as the distance from the main axis O of the container goes downward (A to E in FIG. 8), a predetermined body portion designed at a certain time (CC plane in FIG. 8). The outline of (bottom) will be exceeded. Therefore, by providing the precipice plane 33, the tapered surface can be accommodated in the contour of a predetermined trunk (bottom).

  As shown in FIG. 3, the precipice plane has a divergent shape that widens as it goes downward, and the upper end portion 33 a of the precipice plane 33 is preferably provided on the tapered surface 32. Since the area of the taper surface 32 can be provided large, the contact area between the plastic bottle and the hand can be increased, and the taper surface and the body having a rectangular horizontal cross-section connected below the taper surface; Can be connected smoothly. In FIG. 3, the precipice plane 33 is drawn by the boundary line of the reverse parabola, but is not limited to this in the plastic bottle according to the present embodiment. In FIG. 9, the side view which shows the schematic shape of another example in the plastic bottle which concerns on this embodiment was shown. As shown in FIG. 9, the precipice plane may be, for example, (a) the boundary line of the precipice plane is a triangle, and (b) the boundary line of the precipice plane is a trapezoid.

  The plastic bottle according to the present embodiment includes a form in which the tapered surface 32 is a part of a curved surface of a slanted elliptic cylinder or a slanted cylinder or a part of a curved surface of a truncated cone. In the illustrated form, the tapered surface is a part of the curved surface of the oblique elliptic cylinder. However, as another form, the tapered surface may be a part of the curved surface of the oblique cylinder, or may be a part of the curved surface of the truncated cone. In the case of a part of a curved surface of an oblique elliptic cylinder or oblique cylinder, as shown in FIG. 8, the radius of curvature (ra, rb, rc, rd, re) on the tapered surface is constant, and the center of curvature radius (a, b , C, d, e) move to the wall surface 61 side of the short side S as going down the container. On the other hand, when it is a part of the curved surface of the truncated cone (not shown), the radius of curvature increases as it goes down the container, and the center of the radius of curvature is a slanted ellipse as it goes on the main axis O of the container or below the container. It moves to the wall surface side of the short side S smaller than when it is a part of the curved surface of a column or a slanted cylinder.

  The beverage product according to this embodiment is characterized in that a beverage is filled in the plastic bottle according to this embodiment. The beverage is, for example, water, tea, carbonated beverage or juice.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not construed as being limited to the examples.

  The container to be measured has a rectangular shape with rounded corners on the body of the body and a 2 liter plastic bottle. Four kinds of plastic bottles having inclination angles of 0, 10, 20, and 30 degrees were prepared. For these containers to be measured, the contact area between the container and the hand was measured. Moreover, the load in the pouring operation was evaluated by the method of estimating the pouring operation. The subject had a length of 17.0 cm from the boundary between the wrist and palm to the tip of the middle finger.

(Measures contact area between container and hand)
The container gripping method was specified such that the center of the height of the plastic bottle was at the position of the middle finger and the middle finger was directed horizontally. The method for measuring the contact area is as follows. That is, paper was wrapped around the side surface of the container to be measured, ink was applied to the subject's hand, and the image was captured with a scanner after the ink had dried. The portion of the image captured by the scanner that has a color (the contact portion between the container and the hand) and the portion that has not been colored are binarized, and the number of pixels that are blackened by binarization is counted. The area was calculated from the number. FIG. 10 is a graph showing the relationship between the inclination angle of the tapered surface and the contact area between the container to be measured and the hand. As shown in FIG. 10, it was found that the contact area between the container and the hand was the largest when the inclination angle of the tapered surface was 10 °.

(Evaluation of the load in the pouring operation by the method of estimating the load of the pouring operation)
The method of estimating the load of the pouring operation is a method for estimating a subjective evaluation by objectively and quantitatively evaluating the physical burden in a series of pouring operations in which the container body is lifted and then the container body is tilted. . In other words, the action muscle that works during the pouring operation is specified, and the action muscle is poured through the myoelectric potential information acquisition step, the myoelectric potential information acquisition step, and the maximum muscle strength ratio calculation step during maximum voluntary isometric contraction. Evaluate the burden of unloading. Since the method for estimating the load of the pouring operation uses the maximum muscle strength ratio as an index, it is difficult for individual differences to occur. Therefore, it is not necessary to collect a large number of subjects as in the sensory evaluation, the body burden in the pouring operation can be objectively evaluated, and it can be expressed quantitatively because it can be expressed by the numerical value of the maximum muscle strength ratio. Moreover, if a specific number of subjects with different physical characteristics (men and women, hand size, etc.) are collected and measured as subjects, the body in the pouring operation is assumed assuming the subjects including the physical characteristics. It becomes possible to grasp the burden. For example, by selecting people who are located at the boundary of the subject population, such as people with large hands, small people, people with large grip strength, small people, etc. in the population, taking data of these people, The container most suitable for the population can be estimated.

  In the measurement, the gripping method and the pouring operation were specified as follows. That is, in the gripping method, the plastic bottle is gripped so that the center of the height of the plastic bottle is at the position of the middle finger and the middle finger faces the horizontal direction. The pouring operation is lifted in 2 seconds, stopped for 3 seconds, tilted in 2 seconds, and stopped for 3 seconds. In addition, the way of holding the plastic bottle in the pouring operation was the way shown in FIG. The above pouring operation was tried 8 times, and the myoelectric potential was converted into the maximum muscle strength ratio and averaged. At this time, the maximum muscle strength ratio was calculated separately for the lifting operation and the pouring operation.

(Identification of movement muscle)
In the pouring operation, the movement of each joint of the upper limb is as follows.
(1) Hold. That is, the movement of bending of the thumb, adduction, and bending of the second to fifth fingers.
(2) Lift up. That is, elbow joint flexion, wrist joint flexion, extension movement.
(3) Pour into a cup. That is, abduction of the shoulder joint, flexion of the wrist joint, and movement of the crook.

  As a result of selecting a muscle capable of measuring an electromyogram from among the working muscles working in the operations (1) to (3), in the lifting operation, the first dorsal interosseous muscle, the long thumb abductor muscle In the operation of pouring (tilting the container body), the first dorsal interosseous muscle, the superficial digital flexor, the total finger extensor, and the heel side carpal extensor were included. As the skeletal muscles of the hands and arms, there are the muscles shown in Fig. 12 (Source: Mori, Ogawa et al., Supervised by Kanehara: Shared Anatomy 1 Review, Osteology, Anthropology, Mysology, Kanehara Publishing Co., Ltd., 1982). . The function of each skeletal muscle is, for example, the first dorsal interosseous muscle is the adduction of the thumb (movement close to the index finger), the long thumb abduction muscle is the abduction of the thumb (movement away from the index finger), The total finger extensor muscle is the extension of the second to fifth fingers (the operation of extending fingers other than the thumb).

The electromyogram is a graph in which the elapsed time of the myoelectric potential is on the horizontal axis and the myoelectric potential is on the vertical axis. Muscles contract in response to commands from the brain, but these commands are transmitted as electrical signals. The electric signal measured by an electrode fixed on the skin surface is called myoelectric potential. Myoelectric potential is not only a measurement system but also has large individual differences such as muscle mass, skin thickness, and the appearance of muscle activity with respect to load. Therefore, it is also referred to as “maximum voluntary contraction” (hereinafter referred to as “MVC: maximum voluntary contraction”). ) When using a relative value (% MVC) where the myoelectric potential at time is 100%, errors such as individual differences can be reduced. % MVC is the maximum muscle strength ratio, and can be obtained from Equation 1.
(Equation 1) Maximum muscle strength ratio = Myoelectric potential during movement / Myoelectric potential during maximum voluntary isometric contraction

  The relationship between the maximum muscle strength ratio and the subject's subjective evaluation of muscle load (for example, easy, somewhat easy, slightly tight, tight, etc.) can be handled as a logarithmic function. FIG. 13 shows the relationship between the maximum muscle strength ratio of the superficial digital flexor and the subjective evaluation of the subject with respect to the muscle load. FIG. 14 shows a specific standard (Borg scale) of the numerical value of the subjective evaluation of the subject on the vertical axis in FIG. In the pouring operation, the first dorsal interosseous muscle, the long thumb abductor muscle, and the total thumb abductor muscle, which had a significant correlation with the subjective evaluation in the lifting operation and the pouring operation, as a result of taking the average of the section where the myoelectric potential was constant It was decided to evaluate finger extensor muscles.

(Acquisition process of EMG information during maximum voluntary isometric contraction of moving muscle)
The myoelectric potential at the maximum voluntary isometric contraction was determined for each of the selected moving muscles. The myoelectric potential was measured by a known method using an electromyograph, for example, by attaching an electrode to the muscle part of the hand / arm and measuring the myoelectric potential.

(Acquisition process of action muscle EMG information)
Next, the myoelectric potential information of the working muscle when the pouring operation was performed was acquired. The method for measuring the myoelectric potential is the same as that for acquiring myoelectric potential information during the maximum voluntary isometric contraction of the working muscle.

(Maximum strength ratio calculation process)
As described above, instead of simply comparing the myoelectric potentials, in order to eliminate the variation factors of the measured values such as individual differences, the relative value (% MVC = 100%) is taken as the myoelectric potential at the maximum voluntary isometric contraction. The maximum muscle strength ratio is used for comparison. % MVC is the maximum muscle strength ratio, and was calculated by Equation 1.

  By passing through the above process, the value of the maximum strength ratio was calculated for each muscle for the container to be measured. FIG. 15 is a graph showing the maximum muscular strength ratio (% MVC) of each motion muscle of the lifting motion. FIG. 16 is a graph showing the maximum muscle strength ratio (% MVC) of each operating muscle of the pouring action. From FIG. 15, it can be seen that as the inclination angle of the taper surface increases, the muscle burden on the first dorsal interosseous muscle decreases, but the burden on the long thumb abductor and the total finger extensor muscles increase. This is because when the inclination angle of the taper surface is increased, it is not necessary to invert the thumb, but when the inclination angle is 20 ° or 30 °, the wrist joint is pushed up, so that it is difficult to take the designated gripping posture.

  FIG. 16 shows that when the inclination angle of the tapered surface is 20 ° or 30 °, the burden on the long thumb abductor and the total finger extensor is increased. When the inclination angle of the tapered surface is increased, it is necessary to increase the angle at which the container is inclined. As a result, it is necessary to bend the wrist a lot.

  FIG. 17 is a graph showing the load in the operation of lifting and pouring the sum of the maximum muscle strength ratios of the first dorsal interosseous muscle, long thumb abductor and total extensor muscle. The horizontal axis is the load in the lifting operation, and the vertical axis is the load in the pouring operation. The element at the lower left of the graph can be said to be a container with a smaller load of pouring operation. From FIG. 17, it was confirmed that the container having the tapered surface having an inclination angle of 10 ° has the smallest burden in the pouring operation (the lifting operation and the pouring operation).

  From the measurement results of the contact area between the container and the hand, the contact area between the container and the hand is increased by providing a tapered surface with a tilt angle of 10 ° on the body of the container. As a result, pouring out with a small force It was confirmed that operation was possible. From the evaluation result of the method for estimating the burden of the pouring operation, it is objective and quantitative that the strain on the pouring operation can be reduced most when the tapered surface of the container body is provided with a tapered surface having an inclination angle of 10 °. It could be confirmed.

  It can be used for all containers with pouring operation. For example, detergents, seasonings and oils.

10, mouth portion 20, shoulder portion 30, body portion 31, constricted portion 32, tapered surface 33, precipice plane 33 a, top portion 34 of the precipice plane, grip portions 35 and 41, annular rib 40, bottom portion 61, short portion of the trunk portion Hand side wall 62, barrel long side wall 100, plastic bottle S, barrel short side L, barrel long side O, container main axis O ', container main axis parallel line θ, tapered surface Inclination angle U, taper curve U ', thumb / index finger (middle finger) arch T, taper inclination angle T', palm inclination angles a, b, c, d, e, center of curvature ra, rb, rc, rd, re, radius of curvature at tapered surface

Claims (7)

In the plastic bottle in which the mouth, shoulder, trunk, and bottom formed by molding a thermoplastic synthetic resin into the bottle,
The trunk is a rectangle whose horizontal cross-sectional shape has rounded corners,
The two opposed wall surfaces of the short Tehen of the barrel, the distance between each container of the main shaft is provided with a larger tapered surface toward the downward,
Angle of inclination with respect to the main axis of the container of the tapered surface, Ri 8 to 12 ° der,
The two wall surfaces facing the longitudinal sides of the body portion each have a plane portion parallel to the main axis of the container in a region having the same height as the tapered surface, and the plane portion has an upper end. A plastic bottle characterized by having a side . The trunk portion has a constricted portion;
The plastic bottle according to claim 1, wherein the tapered surface is connected to a lower end of the constricted portion.   3. The plastic bottle according to claim 1, wherein an upper end of the tapered surface is located at a central portion of the height of the container. A precipitous plane parallel to the main axis of the container is provided below the tapered surface,
It is a divergent shape that widens as the precipice plane goes downward,
The plastic bottle according to claim 1, wherein an upper end portion of the precipice plane is provided on the tapered surface.   5. The plastic bottle according to claim 1, wherein the tapered surface is a part of a curved surface of a slanted elliptic cylinder or a slanted cylinder or a part of a curved surface of a truncated cone. The plastic bottle according to claim 1, 2, 3, 4, or 5, wherein an upper end side of the tapered surface is at the same height as an upper end side of the flat portion. A beverage product, wherein the plastic bottle according to any one of claims 1 to 6 is filled with a beverage.