JPS60251026A - Cloudy bottle made of polyester resin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a cloudy bottle made of polyester resin.

So-called cloudy bottles have conventionally been produced by making the mold surface for remolding a rough surface rather than a flat surface, but this has the drawback of requiring various steps and resulting in high costs.

The present invention eliminates the above-mentioned drawbacks, and will be described below with reference to the drawings.

1 is a bottle made of polyester resin manufactured by the method of the present invention, 2 is a bottom wall thereof, 3 is a body part, 4 is a cap bar 5
, and a mouth and neck having a flange 6. The body and bottom wall are made extremely thin by biaxial stretching, and the body has a plurality of alternating protrusions 7 and grooves 8 for reinforcement.

The entire outer surface is whitened to look like cloudy glass, and the rest of the surface except for the outer surface, that is, the inner surface, is transparent.

The above bottle may be formed as follows.

Initially, a polyester tubular material 9 with an open end at the bottom is formed by injection molding. The mouth and neck part 10 of the material is
The end strip 5a and the flange 6a are formed so that the end strip 5a and the flange 6a can be used as it is, that is, without being biaxially stretched like the trunk 11 and the bottom wall 12, as the neck of the pathology mouth.

The tubular material is heated to a temperature suitable for biaxial stretching, and is expanded by injection blowing to form the molded bottle 1. During heating, only the outer surface temperature of the tubular material is increased to approximately 130°C. Molding is carried out by heating to a temperature above 10°C. However, the heating is from the outer surface to the center, and if the entire wall thickness is heated to the above temperature, the entire wall will crystallize, making blow molding impossible.

The outer surface of the tubular material crystallizes and causes a whitening phenomenon due to the above-mentioned outer surface heating of about 130°C or more, so by injection blowing the material, a bottle is obtained in which the outer surface is cloudy and white, and the remainder is transparent. I can do it.

The above-mentioned whitening phenomenon is a characteristic observed in polyester resins, which crystallizes and appears in the above temperature range. The temperature range varies depending on the difference in the intrinsic viscosity (IV value) of the materials, but the temperature graph generally looks like the one shown in Figure 3. That is, in the case of IVli150.6, it whitens at about 130°C, and in the case of IVli 1.2, it whitens at about 175°C.

The concentration of cloudiness can be varied as much as possible by controlling the outer surface temperature by manipulating the heating temperature, and a high concentration of cloudiness can be obtained by increasing the temperature.

Good results were obtained when the wall thickness of the tubular material was 2.8 m, but the thickness of approximately 2.8 m was obtained.
It seems to be effective if it is N or more. However, it is preferable to design the thickness distribution to be as thin as possible so that the temperature distribution is the same.

The present invention has the above-mentioned structure, and uses the characteristics of polyester resin to crystallize and whiten only the outer surface. Therefore, unlike conventional methods, the mold surface is roughened or the outer surface of the bottle is made fine. There is no need to make many scratches, the cost is low and it is easy to make a cloudy bottle. In addition, the above-mentioned whitening normally makes the bottle brittle, but in the case of the present invention, only the outer surface of the polyester resin bottle is whitened, and the inner surface except for the line surface is not whitened, so the bottle does not become brittle as described above. On the contrary, due to the above-mentioned external whitening, the bottle has appropriate rigidity, so that the bottle is less likely to be elastically deformed, especially when it is made into a thin-walled bottle, making the bottle convenient for use.

[Brief explanation of drawings]

Figure 1 is a sectional view of a bottle according to the present invention, Figure 2 is a sectional view of a tubular material as an intermediate product for remolding, and Figure 3 shows the whitening phenomenon of polyester resin as a function of material (IV value) and temperature. This is shown in the graph shown in the relationship. 1... Polyester resin bottle 2... Polyester resin tubular material! 4TV

Claims (1)

[Claims] A cloudy bottle made of polyester resin that is transparent except for the outer surface of the bottle, and the outer surface of the bottle is made opaque by a whitening phenomenon to give it a cloudy glass-like appearance.