Laminated, blow-molded container and process for forming one or more air intake holes

Abstract

Disclosed is a process for forming one or more air intake holes wherein the punch-cutter to be used has a cylindrical blade at the tip, and also has a hooking portion or portions, which is/are disposed on an inner peripheral surface of the cylindrical blade and which performs a function of hooking into a portion of the outer layer that has come inside the cylindrical blade to prevent the cylindrical blade from slipping out of that portion of the outer layer at a time when the cylindrical blade is moved backward, the cylindrical blade is pressed forward until the blade edge comes to a position close to the outer layer, and at this position, the outer layer is not yet cut out completely, but there remains a circular uncut portion ahead of the blade edge, then, the cylindrical blade is moved backward.

Claims

1. A process for forming one or more air intake holes in a blow-molded container comprising an outer layer of a synthetic resin that forms an outer shell in a fixed shape and an inner layer of a synthetic resin that forms an inner bag to be laminated with this outer layer in a peelable manner, wherein the outer layer is cut through with a punch-cutter at a predetermined position or positions of a neck to form one or more air intake holes, wherein: the punch-cutter to be used has a cylindrical blade at the punch cutter tip, and also has a hooking portion or portions, which is/are disposed on an inner peripheral surface of the cylindrical blade and which perform a function of hooking into a portion of the outer layer that has come inside the cylindrical blade so as to prevent the cylindrical blade from slipping out of this portion of the outer layer at a time when the cylindrical blade is moved backward, the cylindrical blade is pressed forward until a blade edge comes to a position quite close to an inner surface of the outer layer, and at this position, the outer layer is not yet cut through completely, but there still remains a circular uncut portion ahead of the blade edge, then, the cylindrical blade is moved backward, and a cut piece inside the cylindrical blade is also moved backward along with the uncut portion because of the function of the hooking portion or portions that can hook into a portion of the outer layer that has come inside the cylindrical blade so as to prevent the cylindrical blade from slipping out of this portion of the outer layer, and the uncut portion is broken due to this backward movement, and the cut piece is taken out in a completely cut shape so that the air intake hole is cut out as a through-hole.

2. The process for forming one or more air intake holes according to claim 1 wherein diameter-reduced step portions are disposed in places on the inner peripheral surface of the cylindrical blade of the punch-cutter, and are used as the hooking portion or portions.

3. The process for forming one or more air intake holes according to claim 2 wherein the inner peripheral surface of the cylindrical blade is formed so that a bore diameter widens in a tapered manner over an area ranging from the edges of the diameter-reduced step portions to the blade edge.

4. The process for forming one or more air intake holes according to claim 2 wherein the diameter-reduced step portions are disposed at intervals in the circumferential direction.

5. The process for forming one or more air intake holes according to claim 1 wherein a diameter-reduced taper portion is formed on the inner peripheral surface of the cylindrical blade of the punch-cutter by reducing the diameter toward the blade edge in a tapered manner, and is used as the hooking portion.

6. The process for forming one or more air intake holes according to claim 3 wherein the diameter-reduced step portions are disposed at intervals in the circumferential direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view of a dispensing container with a pump, partially shown in a vertical section, wherein the container of this invention in one embodiment is used as the container body.

(2) FIG. 2(a) is an enlarged vertical section of an important portion near an air intake hole cut in the container of FIG. 1, and FIG. 2(b) is a front view of an air intake hole taken from the direction of a bold arrow in FIG. 2(a).

(3) FIG. 3 is a schematic diagram showing the process for forming one or more air intake holes of this invention.

(4) FIGS. 4(a)-(c) show an embodiment of a punch-cutter used in forming the air intake hole of FIG. 1, in which FIG. 4(a) is a vertical section, FIG. 4(b), an enlarged view of a cylindrical blade and its vicinity; and FIG. 4(c), a further enlarged view of the blade edge and its vicinity.

(5) FIG. 5(a) is a bottom view of the punch-cutter of FIG. 4, and FIG. 5(b), an enlarged view of the blade edge of FIG. 5(a).

(6) FIGS. 6(a)-(c) are schematic diagrams showing the steps of forming an air intake hole.

(7) FIGS. 7(a)-(b) show another embodiment of the punch-cutter, in which FIG. 7(a) is a vertical section; and FIG. 7(b), an enlarged view of the blade edge and its vicinity.

(8) FIGS. 8(a)-(b) show still another embodiment of the punch-cutter, in which FIG. 8(a) is a vertical section; and FIG. 8(b) is an enlarged view of the blade edge and its vicinity.

(9) FIG. 9 is an explanatory diagram schematically showing a conventional process for molding air intake holes.

(10) FIG. 10 is a vertical section showing a state of lamination for the outer and inner layers near a conventional air intake hole.

PREFERRED EMBODIMENTS OF THE INVENTION

(11) The features and action-and-effects of this invention are further described with respect to preferred embodiments, now referring to the drawings, in which FIG. 1 is a side view of a dispensing container with a pump, shown partially in a vertical section, wherein the container of this invention in one embodiment is used as the container body. The container 1, which is an easy-to-delaminate bottle, has a laminated wall structure comprising an outer layer 11 made of a synthetic resin that forms an outer shell in a fixed shape and an inner layer 12 made of a another synthetic resin that forms an inner bag, which is laminated with the outer layer 11 in a peelable manner. A neck 2 is disposed at an upper end of a cylindrical body 4 having a bottom, by way of a shoulder 3 in a tapered cylindrical shape, with diameter reduced upward. The neck 2 has a screw thread spirally disposed on the outer peripheral surface, and one or more air intake holes 14 are cut out with a punch-cutter in a neck portion of the outer layer 11 under this screw thread. The container 1 of this embodiment has the outer layer 11 made of a high-density polyethylene (HDPE) and the inner layer 12 made of a nylon resin. In general, a pair of air intake holes 14 is cut out in the front and rear sides (one on the right, the other on the left in FIG. 1).

(12) A dispensing pump 25 having a nozzle head 26 is fitted to the container 1 by forming a brim-like fitting flange 27 on an upper end of the main part of the dispensing pump 25, putting this brim-like fitting flange 27 on the upper end of the neck 2, with a gasket ring 28 placed in between, under a condition that the main body of the dispensing pump 25 has been inserted into the container 1, and then by pushing up the fitting flange 27 onto the underside of an inwardly-projecting top plate 23 of a cap 21 provided with a screw-threaded cylindrical wall 22, which is engaged with a screw-threaded cylindrical wall of the neck 2. FIG. 1 shows the outer layer 11 and the inner layer 12 in a state in which a peeled space S has been formed near the air intake hole 14.

(13) FIG. 2(a) is an enlarged vertical section of an important portion near an air intake hole of the container of FIG. 1, and FIG. 2(b) is a front view of the air intake hole taken from the direction of a bold arrow shown in FIG. 2(a). As shown by a horn-shaped area 14a in FIGS. 2(a) and 2(b), the inside opening of the air intake hole 14 has a horn shape with an increased diameter on the inner-surface side of the outer layer 11. A peripheral area of this inside opening of the air intake hole 14 on the inner-surface side of the outer layer 11 is cross-hatched in FIGS. 2(a) and 2(b). This peripheral area is an irregular surface area 11c caused by flash which has developed during the punch-cutting step using a punch-cutter. The horn-shaped area 14a and the flash-caused irregular surface area 11c are formed by employing the process for forming one or more air intake holes of this invention. The shapes of the horn-shaped area 14a and the irregular surface area 11c can be adjusted by setting appropriately the shape of the cylindrical blade 44 and the position at which the cylindrical blade 44 of the punch-cutter 43 is cut into the outer layer 11. This adjustment can also be made so that the horn-shaped area 14a and/or the irregular surface area 11c would not be formed substantially if it is a desired choice.

(14) When the inside opening of each air intake hole 14 has a horn-shaped area 14a as described above, notch-like interspace, N, is formed between the outer layer 11 and the inner layer 12 in a peripheral area of the inside opening of the air intake hole 14, as found in the vertical section of FIG. 2(a). This notch-like interspace, N, performs a function as a starting point for the peeling to proceed. As shown by a two-dot chain line in FIG. 2(a), a peeled space, S, is widened by allowing the laminate peeling between the outer layer 11 and the inner layer 12 to begin and go on. As a result, outside air, A, can be easily taken into the interspace between the outer layer 11 and the inner layer 12 by way of the air intake hole or holes 14.

(15) Furthermore, the irregular surface area 11c caused by the flash is formed along the edge of the inside opening of each air intake hole 14 on the inner-surface side of the outer layer 11. This irregular surface area 11c prevents the tight contact of the outer layer 11 with the inner layer 12 along the edge of the inside opening of each air intake hole 14. In addition to the existence of the notch-like interspace, N, the irregular surface area 11c also helps the outer and inner layers 11, 12 to start and continue the peeling from each other reliably.

(16) In a case of a conventional air intake hole 14 shown in FIG. 10, the outer layer 11 and the inner layer 12 are peeled from each other at one time, and the tight contact of these layers is tentatively released over the entire region. Thereafter, air is blown through the neck to bring the outer layer 11 and the inner layer 12 back to a laminated state. Even in that case, it often becomes difficult to start the peeling between the outer layer 11 and the inner layer 12 because there is no portion serving as the starting point, such as the notch-like interspace, N, shown in FIG. 2 or because the layers partially return to a tight contact state. For example, the dispensing container, such as shown in FIG. 1, may face with a decrease in workability in dispensing the content fluid.

(17) Next, the process for forming one or more air intake holes of this invention will be described below. FIG. 3 is a schematic explanatory diagram showing the process for forming one or more air intake holes of this invention. The overall structure of the punch-cutting machine in use is similar to that shown in FIG. 9. The punch-cutting machine comprises a support rod 34 having a cutter stop 36 disposed at a lower end thereof, the support rod 34 being inserted into the neck 2 of the container 1, and a punch-cutter 43 disposed at a position opposite this cutter stop 36. If a pair of the air intake holes 14 is to be formed, as is the case of the container 1 shown in FIG. 1, then the punch-cutting machines are disposed at bilaterally symmetric positions, and a pair of punch-cutters 43 is disposed on the left as well as on the right for dual punch-cutting operations.

(18) Roughly, the process for forming one or more air intake holes of this invention comprises:

(19) a) having the cylindrical blade 44 of a punch-cutter 43 cut into the outer layer 11 forcibly,

(20) b) leaving a circular uncut portion 11b to stay ahead of the blade edge without cutting through the outer layer 11 completely, and then

(21) c) moving the punch-cutter 43 backward to break the uncut portion 11b by utilizing the function of later-described hooking portion or portions 45 that can hook into a portion of the outer layer 11 that has come inside the cylindrical blade 44 so as to prevent the cylindrical blade 44 from slipping out of this portion of the outer layer 11, and thereby, to form one or more air intake holes 14. Thus, the air intake hole or holes 14 can be cut out by the process for forming one or more air intake holes of this invention, while keeping the inner layer 12 intact without leaving in it any vestige of cut caused by the blade edge of the punch-cutter. This is because the edge of the cylindrical blade 44 disposed at the tip of the punch-cutter 43 remains inside the outer layer 11 and does not come in direct contact with the inner layer 12.

(22) FIGS. 4 and 5 show the punch-cutter 43 used in this embodiment, in which FIG. 4(a) is a vertical section of the punch-cutter 43; FIG. 4(b), an enlarged view of the cylindrical blade 44 and its vicinity; FIG. 4(c), a further enlarged view of the blade edge 44p and its vicinity; FIG. 5(a), a bottom view of the punch-cutter 43; and FIG. 5(b), an enlarged view of the blade edge 44p shown in FIG. 5(a). This punch-cutter 43 has the cylindrical blade 44 at the tip. Diameter-reduced step portions 45a are an embodiment of the hooking portion 45, and are disposed on the inner peripheral surface of this cylindrical blade 44 at four positions with a space in between.

(23) A range between the edges of the diameter-reduced step portions 45a and the blade edge 44p is a taper portion 45a1 where the diameter is increased in a tapered manner. In addition to the diameter-reduced step portions 45a that are spaced from one another, the diameter-increased taper portion 45a1 makes it possible for the cylindrical blade 44 to cut into the outer layer 11 forcibly and to move forward or move backward. The blade edge 44p of this punch-cutter 43 has a diameter of 4 mm, and the taper portion 45a1 has a height, h, of 0.8 mm from the diameter-reduced step portion 45a to the blade edge 44p (See FIG. 4(b)).

(24) FIG. 6(a)(b)(c) are schematic diagrams explaining the steps of forming an air intake hole 14. Individually, FIG. 6(a) shows a state of the cylindrical blade 44 in which it is located at a position of limit where it no longer can move forward; FIG. 6(b) is an enlarged view of blade edge 44p, and its vicinity, of the cylindrical blade 44 shown in FIG. 6(a); and FIG. 6(c) shows a state of the cylindrical blade 44 in which it has been moved backward from the limit for forward movement. As shown in FIG. 6(a), the blade edge 44p is disposed at the position of limit for forward movement, and stops short of the inner peripheral wall of the outer layer 11. In this embodiment, a lower portion of the neck 2 to be cut out for the air intake holes 14 has a thickness of 2.5 mm. The limit for forward movement is positioned at 0.02 mm from the inner peripheral surface of the outer layer 11. Under these conditions, the outer layer 11 is not cut out completely, and a cut piece 11a remains inside the cylindrical blade 44 in a state in which an uncut portion 11b is left to stay ahead of the blade edge 44p.

(25) Then, the punch-cutter 43 is moved backward from the state shown in FIG. 6(a). Because of the hooking function of the diameter-reduced step portions 45a that prevents the cut piece 11a from being left in place, the cut piece 11a remaining inside the cylindrical blade 44 is hooked and moved backward along with the uncut portion 11b that has not yet been cut out, as shown in FIG. 6(c). This backward movement allows the uncut portion 11b to be broken, and the cut piece 11a is taken out in a completely cut shape so that the air intake hole 14 is cut out as a through-hole.

(26) If the cut piece 11a is displaced in the direction of a bold arrow in FIG. 6(c) by the hooking function of the diameter-reduced step portions 45a, shearing stress acts on the uncut portion 11b in a direction shown by Sf in FIG. 6(b). Because the uncut portion 11b is broken due to this shearing stress, a horn-shaped area 14a having a larger diameter than the hole diameter is formed around the inside opening of the air intake hole 14. In addition, at the time when the uncut portion 11b is broken, the synthetic resin (HDPE resin in this embodiment) is more or less drawn and deformed. As a result, an irregular surface area 11c is formed by the flash that develops from the breakage in an area shown by cross-hatching in an enlarged view circled in FIG. 6(c).

(27) The shape of the punch-cutter 43, and especially the shape of the hooking portion or portions 45, can be determined by paying attention to a balance among the ability of the cylindrical blade 44 to cut into the outer layer 11 forcibly and move forward, the cutting workability of the outer layer 11, and the function of the hooking portion or portions 45 that serve(s) to prevent the punch-cutter 43 from slipping out of the outer layer 11, while taking into consideration the material of the synthetic resin to be used for the outer layer 11. FIGS. 7 and 8 show other embodiments of the punch-cutter. In the embodiment of FIG. 7, a diameter-reduced step portion 45a is used as the hooking portion or portions 45, as is the case of the punch-cutter of FIG. 4, but this diameter-reduced step portion 45a is characterized in that it is disposed along the entire circumference of the inner peripheral surface of the cylindrical blade 44. As other features, the diameter of the step portion 45a is reduced to a less extent, and the height, h, from the edge to the blade edge 44p is set at as small as 0.4 mm, while giving consideration to the balance between the ability to cut into the outer layer 11 forcibly and move forward and the hooking function of the cylindrical blade 44.

(28) In the case of a punch-cutter 43 shown in FIG. 8(a)(b), a diameter-reduced taper portion 45b is formed by reducing the bore diameter of the cylindrical blade 44 toward the blade edge 44p to enable the tapered surface of this diameter-reduced taper portion 45b to perform the hooking function. Since there is no step portion in this case, the punch-cutter 43 of this type has a good ability to cut into the outer layer 11 forcibly and move forward and a favorable hooking function.

(29) This invention has been described with respect to its features and action-and-effects while referring to the drawings. However, it is to be understood that this invention should not be construed as limitative to these embodiments. For example, the punch-cutters to be used were described in three embodiments, but a further variety of punch-cutters can be adopted for this invention, giving consideration to the ability of the cylindrical blade 44 to cut into the outer layer 11 forcibly and move forward, and the hooking function that prevent the cut piece from being left in place. Thus, the punch-cutter can also have a hooking portion comprising a plural number of projections in an appropriate shape disposed along the circumference of the inner peripheral surface of the cylindrical blade. The laminated, blow-molded container of an easy-to-delaminate type of this invention can also be used as a dispensing container with a comb attachment fitted to the neck of the bottle, or as an easy-to-delaminate container of a squeeze type, in addition to the dispensing container with a pump.

INDUSTRIAL APPLICABILITY

(30) As described above, the process for forming one or more air intake holes of this invention allows the air intake holes to be formed while keeping the inner layer intact without leaving in it any vestige of cut caused by the blade edge of the punch-cutter. The laminated, blow-molded container of this invention ensures that the peeling of the inner layer from the outer layer would go on smoothly and reliably around the inside opening of each air intake hole on the inner-surface side of the outer layer. Thus, the container of this invention is expected to have wide applications of use in the field of easy-to-delaminate containers which are convenient to use.

DESCRIPTION OF REFERENCE SIGNS

(31) 1. Container 2. Neck 3. Shoulder 4. Body 11. Outer layer 11a. Cut piece 11b. Uncut portion 11c. Irregular surface (caused by flash) 12. Inner layer 14. Air intake hole 14a. Horn-shaped area S. Peeled space N. Notched interspace A. Outside air 21. Cap 22. Screw-threaded inner wall of the cap 23. Top plate of the cap 25. Dispensing pump 26. Nozzle head 27. Fitting flange 28. Gasket ring 30. Punch-cutting device 31. Stationary member 32. Support section 33. Support shaft 34. Support rod 36. Cutter stop 36a. Opposed surface 37. Bolt 40. Cutting member 41. Sliding member 42. Cutter holder 43. Punch-cutter 44. Cylindrical blade 44p. Blade edge 45. Hooking portion 45a. Diameter-reduced step portion 45a1. Diameter-increased taper portion 45b. Diameter-reduced taper portion 46. Through-hole t. Gap