JP4668076B2 - Synthetic resin cap, closing device, beverage-containing closing device, and synthetic resin cap manufacturing method - Google Patents

Description

  The present invention relates to a synthetic resin cap for closing a container mouth, a closing device using the cap, a beverage containing closing device, and a method for manufacturing the synthetic resin cap.

  2. Description of the Related Art Conventionally, a synthetic resin cap that includes a top plate portion and a cylindrical portion that hangs down from the peripheral edge thereof and has a washing water introduction hole formed in the cylindrical portion has been widely used (see, for example, Patent Document 1).

  In this synthetic resin cap, the cleaning water can be guided to the inside through the cleaning water introducing hole to clean the mouth portion of the container.

In recent years, a synthetic resin cap in which information (for example, a trade name, a company name) such as characters, symbols, and figures is printed on the top surface of the top plate portion by a lithographic printing method or the like is used. In order to prevent peeling of printing, surface treatment may be applied to the top surface of the top plate part prior to printing.
JP 2004-244074 A

  However, in the synthetic resin cap, the introduction of cleaning water into the interior is insufficient, and the container mouth may be insufficiently cleaned.

  The present invention has been made in view of the above circumstances, and provides a synthetic resin cap, a closing device, a beverage containing closing device, and a method for producing the synthetic resin cap that enable sufficient cleaning of the container mouth. For the purpose.

  The synthetic resin cap of the present invention comprises a top plate portion and a cylindrical portion that hangs down from the periphery thereof, a cleaning water introduction hole is formed in the cylindrical portion, printing is performed on the top surface of the top plate portion, and the cleaning Of the outer surface of the cylindrical portion including the peripheral edge of the water introduction hole and the top surface of the top plate portion, only the top surface of the top plate portion is improved in wettability by surface treatment.

  In the synthetic resin cap of the present invention, the contact angle of 10 μL of water droplets on the outer surface of the cylindrical portion at least including the peripheral portion of the cleaning water introduction hole is larger than the contact angle of 10 μL of water droplets on the top surface of the top plate, The difference is preferably 30 degrees or more.

  The contact angle of a 10 μL water droplet at the portion of the outer surface of the cylindrical portion is preferably 95 degrees or more.

  The closing device of the present invention includes the synthetic resin cap and a container in which the synthetic resin cap can be attached to the mouth portion.

  The beverage containing closure device of the present invention includes the synthetic resin cap and a container in which the synthetic resin cap can be attached to the mouth portion, and the container is filled with a beverage.

  The method of manufacturing a synthetic resin cap according to the present invention includes a top plate portion and a cylindrical portion that hangs down from the periphery thereof, a cleaning water introduction hole is formed in the cylindrical portion, and printing is performed on the upper surface of the top plate portion. A method of manufacturing a synthetic resin cap, in which only the top surface of the top surface of the cylindrical portion outer surface including the peripheral portion of the cleaning water introduction hole and the top surface of the top surface are flame-treated. The wettability of the top surface of the top plate is enhanced.

  In the synthetic resin cap of the present invention, the wettability of the outer surface of the cylindrical portion is relatively low because only the top surface of the top plate portion is improved in wettability by the surface treatment. For this reason, the cleaning water supplied to the outer surface of the cap easily flows into the cap through the cleaning water introduction hole. Accordingly, the mouth portion of the container can be sufficiently cleaned.

  FIG. 1 and FIG. 2 show an example of the closing device of the present invention, and this closing device is composed of a container 20 and a synthetic resin cap 1 attached to the mouth portion 21 thereof.

  The container 20 may be made of a synthetic resin such as polyethylene terephthalate (PET), glass, metal or the like. The mouth portion 21 is a cylindrical portion to which the cap 1 is attached, and a male screw 22 is formed on the outer surface thereof.

  The cap 1 includes a cap body 4 having a top plate portion 2 and a cylindrical portion 3 hanging from the peripheral edge thereof.

  The cylindrical portion 3 is partitioned by a horizontal score 6 (weakening line) into a main portion 8 and a tamper evidence ring portion 9 (TE ring portion 9) connected to the lower end of the main portion 8 by a plurality of bridges 7. .

  On the inner surface of the main portion 8, a screw portion 10 having a shape along the male screw 22 of the container mouth portion 21 is formed. On the outer surface of the main portion 8, a knurl 16 is formed as a convex portion extending in the hanging direction (vertical direction in the figure). Many knurls 16 are formed at intervals in the circumferential direction.

  A cleaning water introduction hole 17 is formed in the upper part of the cylindrical portion 3 so that the cleaning water can be guided to the inside of the cap 1. The cleaning water introduction hole 17 is preferably formed in a slit shape extending in the circumferential direction of the cap 1.

  The circumferential length of the cleaning water introduction hole 17 can be set to 0.5 to 5 mm, for example. The maximum width (interval) of the cleaning water introduction hole 17 can be set to 0.01 to 0.1 mm, for example.

  In the cap 1, only the top surface 2 b of the top plate portion 2 among the outer surface 3 a of the cylindrical portion 3 including the peripheral edge portion of the cleaning water introduction hole 17 and the top surface 2 b of the top plate portion 2 has improved wettability. . Thereby, the upper surface 2b of the top plate portion 2 has higher wettability than the portion of the outer surface 3a of the cylindrical portion 3.

  The top surface 2 b of the top plate portion 2 may have higher wettability than the entire outer surface 3 a of the tube portion 3.

  The wettability can be evaluated by the contact angle of a 10 μL water droplet supplied to the surface to be measured. As shown in FIG. 4, the contact angle refers to the contact angle α of the water droplet 34 on the measurement target surface 33. The larger the contact angle, the lower the wettability.

  The top surface 2b of the top plate portion 2 can be improved in wettability by flame treatment described later. The contact angle of the upper surface 2b of the top plate portion 2 can be set to less than 95 degrees, for example.

  The contact angle of the said part of the outer surface 3a of the cylinder part 3 can be 95 degree | times or more (preferably 100 degree | times or more), for example.

  When measuring the contact angle, the number of samples is preferably 3 or more, preferably 5 or more, and the average value thereof is preferably calculated. The contact angle of the upper surface 2b of the top plate portion 2 can be measured at a portion where the printing 15 is not present. Further, since the knurl 16 is formed on the outer surface 3a of the cylindrical portion 3, the contact angle may be increased by 10 to 30 degrees compared to the case where the knurl 16 is not affected.

  The contact angle in the said part of the outer surface 3a of the cylinder part 3 is larger than the contact angle of the upper surface 2b of the top-plate part 2, and the difference is 30 degrees or more (preferably 40 degrees or more). When this difference is less than the above range, the cleaning water may not be easily introduced into the cleaning water introduction hole 17.

  A plurality of tabs 11 are provided on the inner surface of the TE ring portion 9. The tab 11 is a locking protrusion that is locked to the bulging step portion 23 of the container mouth portion 21 to prevent the movement of the TE ring portion 9 when the cap 1 is opened. The tab 11 has a substantially rectangular plate shape that can be raised and lowered, and is formed along the circumferential direction.

  On the lower surface 2 a of the top plate portion 2, an annular inner seal protrusion 12 inserted into the container mouth portion 21, an annular opening end seal protrusion 13 that contacts the opening end of the container mouth portion 21, and the mouth portion 21 An outer seal protrusion 14 that abuts the outer surface is formed.

  As shown in FIG. 2, printing 15 is performed on the upper surface 2 b of the top plate portion 2.

  The print 15 forms characters, symbols, graphics, etc. (for example, trade names, company names), and can be formed by a planographic printing method (for example, offset printing method), an intaglio printing method, a relief printing method, an inkjet method, or the like. .

  Examples of the synthetic resin material constituting the cap 1 include polypropylene and polyethylene.

  Next, an example of a method for manufacturing the cap 1 will be described.

  After the cap 1 is formed, the following surface treatment is performed on the upper surface 2b of the top plate portion 2.

  FIG. 3 shows a flame treatment apparatus that treats the upper surface 2 b of the top plate 2. This processing apparatus includes a conveyor 31 that conveys the cap 1 and a burner 32 that emits a flame 18.

  The upper surface 2b of the top plate portion 2 is exposed to the flame 18 while the cap 1 is conveyed by the conveyor 31 in a direction perpendicular to the paper surface. As a result, the upper surface 2b is heated to change its surface state, and the wettability is increased.

  At this time, only the upper surface 2 b of the top plate 2 is treated with the flame 18. That is, the width W1 of the flame 18 emitted by the burner 32 is made substantially equal to the diameter D1 of the top plate 2 so that the flame 18 does not reach the outer surface 3a of the cylinder portion 3.

  By subjecting only the upper surface 2b of the top plate 2 to flame treatment, the cap 1 having improved wettability only on the upper surface 2b is obtained.

  Next, the printing 15 is applied to the upper surface 2b of the top plate 2 by a planographic printing method (for example, offset printing method), an intaglio printing method, or the like. Since the upper surface 2b is flame-treated, the print 15 is firmly bonded, and the print 15 is hardly peeled off.

  In order to clean the outer surface of the mouth portion 21 of the container 20 to which the cap 1 is attached, cleaning water is supplied to the outer surface of the cap 1. The cleaning water flows into the cap 1 through the cleaning water introduction hole 17, flows down the outer surface of the mouth portion 21, and flows out from the cap 1. As a result, the mouth portion 21 is washed.

  In the cap 1, since the wettability of the portion of the outer surface 3 a of the cylindrical portion 3 is lower than that of the upper surface 2 b of the top plate portion 2, the cleaning water supplied to the outer surface of the cap 1 is supplied with a cleaning water introduction hole. 17 easily flows into the cap 1. Accordingly, the mouth portion 21 can be sufficiently cleaned.

  The reason why the cleaning water is easily introduced into the cleaning water introduction hole 17 due to the relatively low wettability of the outer surface 3a of the cylindrical portion 3 is not clear, but the following estimation is possible.

  When the wettability of the outer surface 3a is high, the cleaning water flows down so as to cover the outer surface 3a, so that it is difficult for the cleaning water to flow into the cap 1 from the cleaning water introduction hole 17. On the other hand, when the wettability of the outer surface 3a is low, it is considered that the cleaning water tends to flow into the cap 1 from the cleaning water introduction hole 17 as small water droplets.

  The said closure apparatus can be set as the drink containing closure apparatus filled with the drink by filling drinks, such as fruit juice drink, tea drink, coffee drink, carbonated drinks, in a container, and attaching a cap to a mouth part.

  In addition to the flame treatment method, the surface treatment method for the top surface of the top plate includes a plasma treatment method, an ozone treatment method, a corona discharge treatment method, and the like.

Example 1
The cap 1 shown in FIGS. 1 and 2 was produced as follows.

  After forming the cap 1, the top surface 2 b of the top plate 2 was exposed to the flame 18 using the flame treatment apparatus shown in FIG. 3.

  At this time, the width W1 of the flame 18 is made substantially equal to the diameter D1 of the top plate 2 so that only the upper surface 2b of the top plate 2 is treated with the flame 18.

  The wettability of the upper surface 2b of the top plate portion 2 and the outer surface 3a of the tube portion 3 was evaluated as follows. After the cap 1 was installed so that the measurement target surface (the upper surface 2b or the outer surface 3a) was horizontal, 10 μL of water was supplied to the measurement target surface. The contact angle of the water droplet immediately after supply was measured. The contact angle of the outer surface 3 a of the cylindrical portion 3 was measured at the peripheral edge of the cleaning water introduction hole 17.

For the measurement of the contact angle, a contact angle / wettability measuring apparatus FTÅ125 (manufactured by First Ten ngstroms) was used. The results are shown in Table 1.
(Comparative Example 1)
As shown in FIG. 5, the cap is processed and the contact angle is measured in the same manner as in Example 1 except that the width of the flame 43 emitted from the burner 42 is significantly larger than the diameter D1 of the top plate 2. did. The results are shown in Table 1.

(Examples 2 and 3 and Comparative Example 2)
The cap was treated in the same manner as in Example 1 except that the contact angle of the tube portion and the top plate portion was adjusted to the value shown in Table 2 by adjusting the width of the flame emitted by the burner of the flame treatment device. Was measured. The number of samples was 5, and the average of these is shown in Table 2.

  When the contact angle between the top plate and the cylinder was measured without performing the flame treatment, the contact angle on the top surface of the top plate was 85.13 degrees and the contact angle on the outer surface of the cylinder was 113.89 degrees. (Both average of 5 samples).

  The caps of the example and the comparative example were attached to the container 20 in which colored water adhered to the outer surface of the mouth part 21, and water was sprayed from above toward the container for 3 minutes.

  When the cap was opened and the mouth portion 21 was confirmed, colored water remained in the mouth portion 21 in the comparative example, but almost no colored water remained in the example.

  From these results, it was confirmed that the wettability of the outer surface 3a of the cylinder part 3 was lowered and the cleaning performance could be improved in the example in which the flame treatment was not affected by the outer surface 3a of the cylinder part 3. It was done.

It is sectional drawing which shows the closing apparatus using an example of the cap of this invention. It is a top view which shows the cap shown in FIG. It is a schematic block diagram which shows the flame processing apparatus which can be used for manufacture of the cap shown in FIG. It is explanatory drawing of a contact angle. It is a schematic block diagram which shows the flame processing apparatus used by the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cap, 2 ... Top plate part, 2b ... Upper surface, 3 ... Tube part, 3a ... Outer surface, 15 ... Printing, 17 ... Washing water introduction hole, 20 ... Container, 21 ... Mouth part.

Claims (6)

It comprises a top plate portion and a cylindrical portion that hangs down from its peripheral edge, a washing water introduction hole is formed in the cylindrical portion, and printing is performed on the upper surface of the top plate portion,
Of the synthetic resin, the wettability of only the top surface of the top portion of the cylindrical portion outer surface including the peripheral portion of the cleaning water introduction hole and the top surface of the top plate is enhanced by surface treatment. cap.   The contact angle of 10 μL of water droplets on the outer surface of the cylindrical portion at least including the peripheral edge of the cleaning water introduction hole is larger than the contact angle of 10 μL of water droplets on the top surface of the top plate, and the difference is 30 degrees or more. The synthetic resin cap according to claim 1, wherein   3. The synthetic resin cap according to claim 1, wherein a contact angle of a 10 μL water droplet in the portion of the outer surface of the cylindrical portion is 95 degrees or more.   A closure device comprising: the synthetic resin cap according to any one of claims 1 to 3; and a container capable of mounting the synthetic resin cap on a mouth portion.   It comprises the synthetic resin cap according to any one of claims 1 to 3 and a container capable of mounting the synthetic resin cap on the mouth portion, and the container is filled with a beverage, Beverage closing device to do. A method of manufacturing a synthetic resin cap that includes a top plate portion and a cylindrical portion that hangs from the peripheral edge thereof, has a washing water introduction hole formed in the cylindrical portion, and is printed on an upper surface of the top plate portion. ,
Of the outer surface of the cylindrical portion including the peripheral edge portion of the cleaning water introduction hole and the top surface of the top plate portion, only the top surface of the top plate portion is flame treated, thereby improving the wettability of the top surface of the top plate portion. A method for producing a synthetic resin cap.

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