JP4432507B2 - Patterning method for transparent container and its mold - Google Patents

Description

  The present invention relates to a patterning method for a transparent container in which characters or patterns are placed in an arbitrary part in a transparent container for storing food and the like, and a mold thereof.

Traditionally, printing or ink-jet printing etc. has been used as a method of putting letters and designs in transparent containers used for hams and sausages etc. As the number increases, a technique for aligning the pattern at an arbitrary position is difficult, and the printing cost per sheet is also expensive. Further, in order to perform arbitrary printing even in ink jet printing, an expensive apparatus as described in Patent Document 1, for example, is required.
On the other hand, the purpose of C-PET of A-PET by performing partial heating is to ensure heat resistance and rigidity by heating and crystallizing only the screw tightening portion in a PET bottle or the like.

JP 2001-245758 A

  An object of the present invention is to provide an inexpensive method for patterning a transparent container and a mold for the same that can put a pattern or characters at an arbitrary position even when the container is molded.

The present invention
(1) A transparent container or a member thereof mainly composed of amorphous polyethylene terephthalate (A-PET), polybutylene terephthalate or a copolymer thereof, and partially heating a sheet or molded product in a transparent state, A patterning method for a transparent container in which an opaque part is formed by promoting crystallization and a character or pattern is placed;
(2) A method for putting a pattern in a transparent container according to (1), wherein a transparent barrier layer is laminated on the sheet or molded product,
(3) In the method for placing a pattern in a transparent container described in (1) or (2), a mold for placing a pattern by the method,
It is.

  Since the patterning method and mold of the transparent container of the present invention can form a pattern by heating and whitening any part at the same time as forming the transparent container, a transparent container with a pattern can be easily produced at low cost. I can do it.

The present invention relates to a transparent container for storing food or the like, or a member thereof, which is a transparent sheet mainly composed of amorphous polyethylene terephthalate (A-PET), polybutylene terephthalate, or a copolymer thereof. Alternatively, it is a patterning method for a transparent container in which a portion where a character or a pattern is to be put is partially heated with respect to a molded article to promote crystallization of the resin to form an opaque portion.
The method of the present invention can be used either during container molding or after molding. In order to carry out this method, use a mold in which a part in which a character / pattern has been engraved in a convex shape in advance is fitted into a mold for container molding, and the surroundings are insulated so that only a specific part can be heated. Heating, molding, filling, and sealing can be performed as a series of operations.
The mold temperature is set to 120 ° C. to 220 ° C., and almost no crystallization is performed at 120 ° C. or lower. When the temperature is 220 ° C. or higher, the resin is close to the melting point of the resin and is thus bonded to the mold. By heating any part of the container and crystallizing to produce white crystals in the transparent part, it is possible to make a designable character or pattern as shown in FIG.

The thickness of the sheet or molded product used in the present invention is preferably 50 to 1200 μm, but is not particularly defined. In addition, a transparent barrier layer such as an oxygen barrier layer may be laminated on a sheet or molded product containing amorphous polyethylene terephthalate, polybutylene terephthalate, or a copolymer thereof as a main component. Any method such as a method of dry lamination of two or more films including a sealing layer, or a method of laminating these by coextrusion can be used.
As the transparent barrier layer of the present invention, an inorganic film such as alumina and silica can be used, including a resin layer such as ethylene / vinyl alcohol copolymer, polyvinylidene chloride, nylon MXD6, polyacrylonitrile and the like.

A mold having a sectional view as an example of the present invention shown in FIG. 2 was used. This mold is one in which the pattern forming unit 3 is built in the container shape forming unit 1.
The pattern forming unit 3 has a built-in heater 4 and a temperature controller 5 for controlling the heater 4. By increasing the temperature of the part, it is possible to promote resin crystallization and form an opaque part. It becomes. The temperature controller 5 is installed at a position equidistant from the distance from the heater to the pattern forming portion so that the temperature of the portion can be accurately controlled.
Further, the container shape forming portion (other than the pattern forming portion) is heated by providing the heat insulating material 8 and the space (air gap) 10 between the container shape forming portion and flowing the cooling water through the cooling water hole 2. The original appearance of the transparent container can be maintained without whitening.

<Examples and Comparative Examples>
The above mold was attached to the bottom of a molding die of a deep drawing packaging machine manufactured by Murchi, and the mold temperature was set to 120 ° C. to 220 ° C., and container molding was performed by pressure air molding using a 250 μm A-PET sheet.
The molding results in relation to the mold temperature and the pressure forming time are summarized in Table 1. The symbols in Table 1 indicate the results of “×: not whitened, ○: slightly whitened, ◎: clearly whitened, XX: welded to the mold”.

When the mold temperature was set at 110 ° C. and molding was carried out with a pressure forming time of 15 seconds, almost no whitening phenomenon occurred on the surface.
When the mold temperature was set to 225 ° C. and molding was performed with a pressure forming time of 1 second, the sheet adhered to the mold and did not become a container.
When the container was molded with the pattern portion of the mold being a concave shape, the sheet did not reach the heated mold portion, and a pattern due to crystallization was not obtained.

  The transparent container patterning method and mold of the present invention can put white characters or patterns in the transparent container, and thus can provide a transparent container with excellent design.

It is a photograph of the transparent container to which the present invention is applied. The letters “CEL” that appear to float in white feel the design. It is sectional drawing of a metal mold | die.

Explanation of symbols

1. 1. Container shape forming unit 2. Cooling water hole 3. Pattern (or character) formation part 4. Heating heater 5. Temperature controller Outer frame 7. Inner frame 8. Insulation material9. Bottom plate 10. Space (air gap)

Claims (2)

Amorphous Polyethylene Polyethylene terephthalate (A-PET), a polybutylene terephthalate or transparent container forming mold having a container shape forming unit for processing the sheet is a copolymer main component thereof,
The container shape forming part has a pattern forming part,
A mold for forming a transparent container, wherein the pattern forming unit includes a heating device and a temperature control device and is thermally insulated from a portion other than the pattern forming unit of the container shape forming unit.   A method for producing a transparent container comprising a step of processing a sheet mainly composed of amorphous polyethylene polyethylene terephthalate (A-PET), polybutylene terephthalate or a copolymer thereof into a container using a container forming mold. The method for producing a transparent container, wherein the container forming mold is the transparent container forming mold according to claim 1.

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