JPH09277407A - Production of paper cup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strengthen a top curl part without bringing about an increase in cost and making the top curl part unpleasant to the palate by molding a paper cup having the top curl part by using a blank provided with a resin layer and subsequently heating the top curl part to the melting temp. of the resin of the resin layer or higher. SOLUTION: A paper cup 1 having a top curl part 4 is molded by using a blank having a resin layer having heat sealability formed to at least one surface thereof and the top curl part 4 is heated to the melting temp. of the resin of the resin layer or higher to be strengthened. The top curl part 4 of the paper cup 1 is heated by hot air 41 having temp. equal to or higher than the m.p. of the resin of the resin layer within a hot air device 42 and subsequently cooled. By this constitution, the paper cup having the strengthened top curl part having no problem from an aspect of molding, not increased in cost and pleasant to the palate at a time of direct drinking from a mouth can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a paper cup, and more particularly to a method for manufacturing a paper cup having a reinforced top curl portion.

[0002]

2. Description of the Related Art Conventionally, in order to strengthen the top curl portion of a paper cup, the basis weight of the base paper to be used is increased, and the thickness of the paper is increased to strengthen the material. There is a method of crushing and strengthening by using ultrasonic waves.

[0003]

However, the above method of strengthening the top curl portion has a problem. In the method of increasing the basis weight of the base paper to be used and strengthening the material by increasing the thickness of the paper, the mechanical suitability at the time of molding the paper cup is deteriorated and the cost is increased. Also, in the method of crushing the top curl part by crushing it using heat, ultrasonic waves, etc., when the top curl part has a crushed cross-sectional shape, the rounded shape disappears, and when compared to a rounded shape The disadvantage is that it has a bad taste. On the other hand, the present invention is a method for producing a paper cup that has no problem in molding the paper cup, is not expensive, has a pleasant mouthfeel when directly drinking by mouth, and has a reinforced top curl portion. I will provide a.

[0004]

DISCLOSURE OF THE INVENTION As a result of studies to solve the above problems, the present invention uses a blank having at least one surface provided with a resin layer having a heat-sealing property to obtain a top curl portion. After molding a paper cup having, the top curl portion is heated to a melting temperature of the resin of the resin layer or higher to strengthen the top curl portion. .

According to the present invention, a paper cup which has no problem in molding the paper cup, is not expensive, has a pleasant mouthfeel when directly drinking by mouth, and has a reinforced top curl portion is obtained. be able to.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below with reference to the drawings. Paper cup 1
Is composed of a body portion 2 and a bottom portion 3 as shown in FIG. The upper end of the body 2 is curled outward to form a top curl portion 4, and the lower end is curled inward to a bottom curl portion 5.
Is formed. In this bottom curl portion 5, the body portion 2 and the bottom portion 3 are integrated. Further, the body blank 6 and the bottom blank 7 as shown in FIG. 2 are molded by the paper cup molding machine to manufacture the paper cup 1. Generally, the body blank 6 used is one that has been punched out in the previous step,
The bottom blank 7 is punched out on a paper cup molding machine.

The process of producing the paper cup 1 using the body blank 6 and the bottom blank 7 will be briefly described. First, in order to bond the body blank 6 into a tubular shape, the body blank 6 is attached. The joining portion is preheated with hot air to melt the resin on the surface. Next, the body blank 6 is wound around a body-wrapping type (mandrel), pressure-bonded, and bonded to a tubular body-wrapping paper. Subsequently, the bottom blank 7 is fitted into the body-wrapping paper, and at the same time, the resin in the bonding portion of the body-wrapping paper and the bottom blank 7 is preheated with hot air. And
The lower end of the body-wrapping paper is curled inward and pressure-bonded to form the bottom curl portion 5. Further, the upper end of the body-wrapping paper is curled outward to form the top curl portion 4, and the paper cup 1 is completed.

An example of a paper cup molding machine is shown in FIG. This molding machine 11 is composed of three parts: (A) body roll forming part, (B) bottom curl part, and (C) top curl part. The process of this paper cup molding machine will be described in detail. The body blank 6 sent from the feeder has a cylindrical portion that is preheated with hot air 12 and the surface resin is melted (A) body roll. It is sent to the molding section. (A) In the body-wrapping portion, the body-wrapping paper is wound around the body-wrapping mold 13 while being sucked, and the body-wrapping paper is heat-sealed. The tubular wrapping paper heat-sealed is sent to the bottom curl portion (B). (B) At the bottom curl portion, the punched bottom blank 7 is first suction-fixed at the position of the mold 20, and then the cylinder paper is inserted at the position of the mold 21.
Next, at the positions of the mold 22, the mold 23, and the mold 24, the portion where the body wrapping paper and the bottom blank 7 are bonded is preheated with hot air, and at the position of the mold 25, the lower end of the body wrapping paper is curled while being curled inward. By doing so, the body portion 2 and the bottom portion 3 are integrated. This cup-shaped product is (C)
Handed over to the top curl section. (C) At the top curl portion 5, the upper end of the body portion 2 is curled outward at the positions of the mold 31, the mold 32, and the mold 33 by being fitted into the mold of the mold 30 and applied with lubricating oil. Finally, the paper cup 1 is manufactured by discharging with the mold 34.

Next, the composition of the material used for the paper cup 1 of the present invention is based on the fact that paper is the main strength material and the innermost layer has a thermoplastic resin. Examples include paper / polyethylene, polyethylene / paper / polyethylene, polypropylene / paper / polypropylene, paper / polyethylene / aluminum / polyethylene, polyethylene / paper / polyethylene / aluminum / polyethylene, polyethylene / aluminum / paper / polyethylene.

As the paper which is the main strength material, it is preferable to use a cup base paper having good suitability for forming a paper cup. The basis weight is not particularly limited, but is 15 due to suitability for forming a paper cup.
The range of 0 to 300 g / m ² is more preferable.

The thermoplastic resin used for the innermost layer has a function of protecting the contents, in particular, preventing leakage even when a liquid substance is put therein. Also, heat sealing enables the body portion to be bonded and the body portion and the bottom portion to be bonded. Must have the ability to Specific examples include polyethylene, polypropylene, polyester, ethylene-vinyl acetate copolymer and the like.
The thickness is preferably in the range of 15 to 60 μm. These thermoplastic resins are formed in the innermost layer by extrusion or laminating.

Next, a description will be given of a strengthening processing method for producing a paper cup having a reinforced top curl portion according to the present invention by using the above materials. As shown in FIG. 4, the top curl portion 4 of the paper cup 1 is cooled by heating hot air 41 having a temperature equal to or higher than the melting point of the resin of the innermost layer with a hot air device 42. The temperature condition is preferably in the range of 120 to 400 ° C. The heating time is preferably 3 seconds to 3 minutes.
In any case, the temperature condition that the resin in the innermost layer is melted is necessary. As a heating method, a method using a gas flame, a microwave, an electric heater or the like can be used in addition to hot air. It is preferable to heat-process only the top curl part from the viewpoint of aesthetics, but even if other parts of the thermoplastic resin exposed on the surface are heated at the same time, the heated part causes foaming etc., It is possible to obtain the effect of improving the strength of the flange portion.

Further, with respect to the paper cup having the reinforced top curl portion according to the present invention, the strength of the top curl portion is improved after the top curl portion of various paper cup samples shown in Table 1 is actually reinforced. The results obtained are shown in Table 2. The condition of the strengthening process is to stand in a drying oven at 120 ° C for 3 minutes. Further, FIG. 5 shows a method of evaluating strength. 10m toward the top curl of the paper cup
The load required for m compression was measured, and the value is expressed as the strength of the top curl portion.

[0014]

[Table 1]

[0015]

[Table 2]

From the above test results, in all the samples,
The strength of the top curl portion after the strengthening process is higher than that before the strengthening process.

[0017]

EFFECTS OF THE INVENTION According to the present invention, there is no problem in molding a paper cup, the cost is not high, the mouthfeel is not bad when drinking directly by mouth, and the top curl portion is strengthened. Can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a paper cup according to a method for manufacturing a paper cup of the present invention.

FIG. 2 is a plan view showing a body blank bottom blank before molding a paper cup according to the present invention.

FIG. 3 is a schematic view showing a paper cup molding machine for carrying out the paper cup manufacturing method of the present invention.

FIG. 4 is a schematic view of a strengthening process which is a method for manufacturing a paper cup according to the present invention.

FIG. 5 is a schematic view showing a method for evaluating the strength of the flange portion of the paper cup according to the present invention.

[Explanation of symbols]

 1 Paper cup 2 Body part 3 Bottom part 4 Top curl part 5 Bottom curl part 6 Body blank 7 Bottom blank 11 Paper cup molding machine A Body roll molding part B Bottom curl part C Top curl part 12 Hot air 13 Body roll type 14 Pickup 15 Transfer 20-37 Mold (mandrel) 41 Hot air 42 Hot air device

Claims (1)

[Claims] 1. A paper cup having a top curl portion is molded using a blank having a resin layer having a heat-sealing property on at least one surface thereof, and the top curl portion is melted at a melting temperature of a resin of the resin layer. A method for manufacturing a paper cup, which comprises heating the above to strengthen the top curl portion.