KR102332249B1 - Pressure forming apparatus for heat resistant pet or pla vessel and method thereof - Google Patents

Abstract

The present invention relates to a method and apparatus for manufacturing a heat-resistant PET or PLA container by air pressure molding. More specifically, the present invention relates to a method and apparatus for manufacturing a heat-resistant PET or PLA container by air pressure molding, which produces the heat-resistant PET or PLA container by attaching a temperature control device in front of an air injection nozzle in a mold of a general pressure (vacuum) molding machine that produces various disposable containers. The present invention has high heat resistance and easy recycling effect.

Description

Method and apparatus for manufacturing heat-resistant PET or PLA container by air pressure molding

The present invention relates to a method and apparatus for manufacturing a heat-resistant PET (Polyethylene Terephthalate), PLA (Poly Lactic Acid) container by air pressure molding, and more particularly, an air injection nozzle in the mold of a general air pressure molding machine for producing various disposable containers. It relates to a method and apparatus for manufacturing a heat-resistant PET or PLA container by air pressure molding to produce a heat-resistant PET or PLA container by attaching a temperature control device in front.

To maintain the freshness of the food and for safe storage, the food is sealed with packaging materials such as packaging containers and packaging films. In particular, it is important to select an appropriate packaging material because a container for packaging a lunch box, porridge, or simply frozen food needs to be heated. Such packaging material is required to have functional properties in various parts. In addition, regulations on packaging materials in terms of food integrity, diversification of packaging technology, shelf life and form, and environmental aspects are increasingly being developed.

With the recent changes in dietary habits and distribution patterns, long-term preservation is the most important in the food packaging field. Factors that accelerate the deterioration of food include oxygen, heat, and moisture. Among them, gas barrier property is a property that determines the integrity of food. However, there are always points that are unsuitable for cooking in a microwave oven or oven for cooking food.

In general, general-purpose materials most often used as materials for product packaging include polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC). is a trend to

These PET or PLA containers are not distorted or corroded inside, and there is no risk of contents leaking due to tearing or abrasion like cartons. strength and gas permeability), so demand is rapidly increasing recently. Nevertheless, there are still many problems with heat resistance for microwave and oven cooking.

Accordingly, the present invention intends to propose a method and apparatus for manufacturing a heat-resistant PET or PLA container by air pressure molding to produce a heat-resistant PET or PLA container using a general air pressure molding machine.

An object of the present invention is to provide a heat-resistant PET or PLA container that maintains its original shape even when cooking in a microwave or oven with high heat resistance.

Another object of the present invention is to add an additive capable of improving physical properties such as talc to increase heat resistance, but to add a crystallization step to the molding step.

Another object of the present invention is to produce a PET or PLA container having high heat resistance that can replace a plastic container for a microwave oven of another material for recycling.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve this object, the method for manufacturing a heat-resistant PET or PLA container by air pressure molding of the present invention comprises the steps of: a heating device heat softening the PET or PLA sheet; Positioning the PET or PLA sheet heat softened by the heat softening step between the mold and the compressed air supply pipe; Crystallizing and molding a PET or PLA sheet while pressurizing using compressed air sprayed through the compressed air supply pipe; cooling the molded sheet by the temperature of the mold; and cutting, by a cutting device, the cooled sheet to fit a shape; includes

In this case, in the heat softening step, the heating device may maintain 280 to 400 degrees, and the PET or PLA sheet may maintain 240 to 250 degrees after heat softening.

In this case, in the forming step, a temperature control device may be further included in the compressed air supply pipe for crystallization of the PET or PLA sheet.

Here, the temperature control device, it is preferable to maintain the compressed air at 120 degrees Celsius to 170 degrees Celsius.

In addition, the forming step includes the steps of compressing, producing and storing air; adjusting the temperature to determine the temperature of the air stored in the temperature control device; delivering the conditioned air into the molding apparatus; includes

In addition, in the molding step, it may be molded for 3 seconds to 8 seconds depending on the crystal temperature.

In addition, after the molding step, the step of exhausting the air inside the molding apparatus through an exhaust port; separating the compressed air supply pipe; further includes

In this case, in the cooling step, the temperature of the mold may be maintained at 30 to 50 degrees.

In addition, the present invention provides an apparatus for implementing the method, comprising: a heating apparatus for heat softening PET or PLA sheet; a mold positioned under the PET or PLA sheet and formed to contact or separate from the PET or PLA sheet; a compressed air supply pipe that is located on the upper part of the mold and that forms an internal space of the molding apparatus while going up and down and receives compressed air; a compressor for supplying compressed air to the inside of the molding device; an air jet nozzle for jetting the compressed air supplied through the compressed air supply pipe into the molding apparatus; an exhaust port for exhausting empty gas inside the molding apparatus; a cutting device for cutting the molded product; includes

In this case, the heating device may maintain an internal temperature of 280 degrees Celsius to 400 degrees Celsius.

In this case, a temperature control device for adjusting the crystal temperature of the molded PET or PLA sheet between the air injection nozzle and the compressor may be further included.

Here, the temperature controller may maintain the temperature of the compressed air at a temperature of 120 degrees Celsius to 170 degrees Celsius.

The present invention is to improve the problem of a food container made of a polyester sheet that cannot be used because of its low heat resistance and cannot maintain its original shape when cooked in a microwave or oven, and is an air spray nozzle in the mold of a general air pressure molding machine. By attaching a temperature control device in front, PET or PLA containers with excellent heat resistance can be produced.

In addition, the present invention can improve convenience by adding a crystallization process to the molding process, rather than adding an additive capable of improving physical properties such as talc to increase heat resistance.

In addition, the present invention can manufacture PET or PLA containers with high heat resistance that can replace plastic containers for microwave ovens made of other materials for recycling.

Effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 shows a flow chart of the present invention.
2 is a view showing the process of air pressure forming of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings of the present invention. These examples are only provided by way of example to explain the present invention in more detail, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not limited by these examples. .

Further, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and in case of conflict, this specification, including definitions description will take precedence.

In order to clearly explain the invention proposed in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification. And, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated. In addition, "unit" described in the specification means one unit or block that performs a specific function.

In each step, the identification number (first, second, etc.) is used for convenience of description, and the identification number does not describe the order of each step, and each step does not clearly describe a specific order in context. It may be performed differently from the order specified above. That is, each step may be performed in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

1 is a flowchart of the present invention. Referring to FIG. 1 , the heating device 120 heats and softens the PET or PLA sheet 110 by heat (S210), the heat softening step (S210). Step (S220) in which the softened PET or PLA sheet 110 is positioned between the mold 130 and the compressed air supply pipe 140, while pressing using the compressed air sprayed through the compressed air supply pipe 140 Crystallizing and molding the sheet 110 (S230), cooling the molded sheet 110 by the temperature of the mold 130 (S240), the cutting device 190 is the cooled sheet 110 ) is shown for easy understanding along with the drawing step (S250) of cutting to fit the shape.

Through the heat softening step (S210), the PET or PLA sheet 110 is melted to make a state easy to mold. At this time, the internal temperature of the heating device 120 is maintained at 280 to 400 degrees Celsius to heat soften the PET or PLA sheet 110 to make it soft, and the temperature of the heating device 120 is the PET or PLA sheet 110. The temperature can be adjusted according to the thickness or material of the Thereafter, the PET or PLA sheet 120 is positioned between the mold 130 and the compressed air supply pipe 140 in a state of maintaining 240 to 250 degrees Celsius (S220). In this step, the PET or PLA sheet 110 is positioned and fixed on the mold 130 .

Thereafter, the compressed air supply pipe 140 may be lowered to inject compressed air generated from the compressor 150 through the air injection nozzle 170 into the inside 165 of the molding apparatus to pressurize the compressed air (S230). The compressor 150 is a machine that compresses and produces air, stores it at high pneumatic pressure, and supplies it as needed.

In order to crystallize the PET or PLA sheet 110 while pressing, only compressed air is sprayed at the initial stage of pressing, but in the crystallization step, the sheet 110 must be maintained at a good temperature for crystallization. In addition, since the PET or PLA sheet 110 is cooled due to the temperature of the mold 130 located below, a temperature control device 160 of compressed air is required to crystallize the sheet 110 . The temperature control device 160 may be further included between the air injection nozzle 170 and the compressor 150, and the temperature control device 160 must maintain the compressed air at about 120 to 170 degrees Celsius ( 110) is promoted. That is, in order to form while crystallizing, the stored compressed air must be supplied through the temperature control device 160, and at this time, the temperature control device 160 sets the temperature at a temperature at which the PET or PLA sheet 110 is easy to crystallize. It is necessary to adjust to heat the compressed air. The compressed air heated in this way is injected into the inside 165 of the molding apparatus through the air injection nozzle 170 . At this time, it is preferable that the high-temperature compressed air injected through the air injection nozzle 170 is injected for about 3 to 8 seconds. If it is sprayed for a time shorter than 3 seconds, the crystallization rate may be small, and if it is greater than 8 seconds, there is a problem in that productivity is lowered due to an increase in molding time.

After the step (S230) of pressurizing and molding the inside of the molding apparatus 165 through the combination of the mold 130 and the compressed air supply pipe 140, the exhaust port 180 exhausts the air inside the molding apparatus 165. It may further include the step of separating the compressed air supply pipe (140). In this case, the exhaust port 180 is a small hole created in the mold 130 , and air inside the molding apparatus 165 may be exhausted through the hole.

Thereafter, to cool the molded sheet 110 through the mold 130, the temperature of the mold 130 is cooled to about 30 to 50 degrees Celsius (S240), and the cooled molded product 195 is cut by a cutting device 190 ) is cut to fit the shape (S250), and the molded product 195 and the scrap are discharged to the outlet, respectively. Here, in the cutting process (S250), the cutting cuts the part fixed to the mold in the position step (S220) in the molding apparatus, and since this part is in an amorphous state by the mold temperature, it is possible to cut as desired.

In addition, the heat-resistant PET or PLA container manufacturing apparatus 100 by the air pressure molding of the present invention implementing the above method,

A heating device 120 for heat softening the PET or PLA sheet 110 and a mold 130 positioned under the PET or PLA sheet 110 and formed to contact or separate the PET or PLA sheet 110 and the The compressed air supply pipe 140 that is located in the upper part of the mold 130 and supplies compressed air or high-temperature compressed air to the space inside the molding apparatus 165 while going up and down, and the compressed air is supplied to the inside 165 of the molding apparatus. an air injection nozzle 170 for injecting compressed air supplied through the compressor 150 and the compressed air supply pipe 140 into the molding apparatus, and an exhaust port 180 for exhausting the air inside the molding apparatus 165 and a cutting device 190 for cutting the molded product 195 .

Referring back to FIG. 1 , first, the PET or PLA sheet 110 is melted by passing it through the heating device 120 so as to be in a soft state suitable for molding, and the internal temperature of the heating device 120 is 280 to 400 degrees Celsius. It is desirable to maintain the degree. At this time, the internal temperature of the heating device 120 can be adjusted according to the thickness or material of the PET or PLA sheet 110, and the heating device 120 is composed of a device such as a heater. The PET or PLA sheet 110, which has been heated and softened in this way, is preferably maintained at a temperature of about 240 to 250 degrees Celsius.

After the PET or PLA sheet 110 is heat softened, it is positioned between the mold 130 and the compressed air supply pipe 140 . Here, when the compressed air supply pipe 140 moves up and down and is combined with the mold 130 , a space inside the molding apparatus 165 may be formed. Air is compressed and produced in the compressor 150 and stored at high pneumatic pressure, and the compressed air is injected into the inside 165 of the molding device through the air injection nozzle 170 when the compressed air is compressed.

At this time, when the temperature of the mold 130 is about 10 degrees and the PET or PLA sheet 110 is positioned on the mold 130 , the PET or PLA sheet 110 is cooled. A temperature control device 160 may be further included between the air jet nozzle 170 and the compressor 150 in order to supply high-temperature compressed air for crystallization of the sheet during the pneumatic molding process, which is a characteristic of the present invention. The temperature control device 160 is composed of a device such as a heater, and maintains a temperature of about 120 to 170 degrees Celsius to increase the temperature of the compressed air stored in the compressor 150 . During molding, at the beginning, only compressed air is injected into the molding apparatus and high-temperature compressed air is injected into the molding apparatus inside 165 during the process of pressurizing the PET or PLA sheet 110 to crystallize and mold the sheet. can In addition, it is preferable to crystallize the sheet 110 by spraying high-temperature compressed air injected through the compressed air supply pipe for 3 to 8 seconds.

Thereafter, the air inside the molding device 165 is exhausted through the exhaust port 180 so that the molded PET or PLA sheet 110 discharges the molded product 195 and the scrap from the cutting device 190 to the outlets, respectively. can

Figure 2 is a view showing the process of air pressure forming of the present invention to explain the air pressure forming step in detail.

Referring to FIG. 2 , the compressor 150 compresses and produces air for pneumatic molding and stores it at high pneumatic pressure. Here, the compressor 150 is a device that compresses and produces air, stores it at high pneumatic pressure, and supplies it as needed.

When the temperature of the PET or PLA sheet is lowered to 170 degrees Celsius or less while pressing using compressed air in the initial stage during air pressure molding, high temperature compressed air of 120 to 170 degrees Celsius is used for crystallization of the PET or PLA sheet 110. Crystallization can be promoted by supplying it through the temperature control device 160 . To this end, the temperature control device 160 may be further included between the air injection nozzle 170 and the compressor 150, and the temperature control device 160 is maintained at about 120 to 170 degrees Celsius to keep the compressor ( 150) can receive the compressed air stored in the air to increase the temperature of the air.

That is, the compressed air compressed in the compressor 150 becomes high-temperature compressed air through the temperature control device 160, and the compressed air supply pipe 140 and the mold 130 are combined to form the inside 165 of the molding device. By supplying through the air jet nozzle 170 to the crystallization of the manufactured container, a PET or PLA container having heat resistance can be produced.

At this time, it is preferable that the supplied high-temperature compressed air is sprayed on the PET or PLA sheet 110 on the mold for 3 to 8 seconds.

After the air pressure molding step, the PET or PLA sheet 100 is separated through a cooling process by the temperature of the mold, and then a final product is produced through a cutting process.

By using the heat-resistant PET or PLA container manufacturing method and manufacturing apparatus of the present invention as described above, the PET or PLA container can produce a container with excellent heat resistance, so that it can be used in various containers, such as a container that can be used in a microwave oven.

In addition, it is effective to conveniently manufacture heat-resistant PET or PLA containers by adding a crystallization process to the existing molding process, rather than adding additives that can improve physical properties such as talc to increase heat resistance.

Although the present invention has been described as above, those of ordinary skill in the art to which the present invention pertains will recognize that the present invention may be implemented in other forms while maintaining the technical spirit and essential features of the present invention. .

The scope of the present invention will be defined by the claims, but all changes or modifications derived from the configuration directly derived from the claims, as well as the configuration equivalent thereto, are also included in the scope of the present invention. should be interpreted as being

100: PET manufacturing device 110: PET sheet
120: heating device 130: mold
140: compressed air supply pipe 150: compressor
160: temperature control device 165: molding device inside
170: air injection nozzle 180: exhaust port
190: cutting device 195: molded product

Claims (12)

Heating and softening the PET or PLA sheet by a heating device;
Positioning the PET or PLA sheet heat softened by the heat softening step between the mold and the compressed air supply pipe;
Crystallizing and molding a PET or PLA sheet while pressurizing using compressed air sprayed through the compressed air supply pipe;
cooling the molded sheet by the temperature of the mold; and
cutting, by a cutting device, the cooled sheet to fit a shape;
comprised of
In the forming step,
Further comprising a temperature control device for maintaining the compressed air in the compressed air supply pipe at 120 degrees Celsius to 170 degrees Celsius for crystallization of the PET or PLA sheet,
In the step of positioning the PET or PLA sheet between the mold and the compressed air supply pipe, the heated PET or PLA sheet is fixed to the mold,
In the step of the cutting device cutting the cooled sheet to fit the shape, heat-resistant PET or PLA container by air pressure molding, characterized in that cutting the amorphous part on the edge of the PET or PLA molded product cooled by the cutting device manufacturing method. The method of claim 1,
In the heat softening step,
The heating device is maintained at 280 degrees Celsius to 400 degrees Celsius,
Heat-resistant PET or PLA container manufacturing method by air pressure molding, characterized in that the PET or PLA sheet is maintained at 240 to 250 degrees Celsius after heat softening. delete delete The method of claim 1,
In the forming step,
A method for manufacturing a heat-resistant PET or PLA container by air pressure molding, characterized in that the high-temperature, high-pressure compressed air sprayed through the compressed air supply pipe is sprayed for 3 to 8 seconds. The method of claim 1,
In the forming step,
Compressed production and storage of air;
adjusting the temperature to determine the temperature of the air stored in the temperature control device;
delivering the conditioned air into the molding apparatus;
Heat-resistant PET or PLA container manufacturing method by air pressure molding comprising a. 6. The method of claim 1 or 5,
After the forming step,
exhausting air inside the molding apparatus through an exhaust port;
separating the compressed air supply pipe;
Heat-resistant PET or PLA container manufacturing method by air pressure molding further comprising. The method of claim 1,
In the cooling step,
Heat-resistant PET or PLA container manufacturing method by air pressure molding, characterized in that the temperature of the mold is maintained at 30 to 50 degrees Celsius. Heating device for heat softening PET or PLA sheet;
a mold positioned under the PET or PLA sheet and formed to contact or separate from the PET or PLA sheet;
a compressed air supply pipe located on the upper part of the mold and configured to supply compressed air or high-temperature compressed air to the inner space of the molding apparatus while going up and down;
a compressor for supplying compressed air to the inside of the molding device;
an air injection nozzle for injecting compressed air supplied through the compressed air supply pipe into the molding apparatus;
an exhaust port for exhausting air inside the molding apparatus;
a cutting device for cutting the molded article;
comprised of
Further comprising a temperature control device for matching the crystal temperature of the PET or PLA sheet between the air injection nozzle and the compressor,
The temperature control device is
The temperature of the compressed air is maintained at a temperature of 120 to 170 degrees Celsius, and the compressed air supplied through the compressed air supply pipe is sprayed for 3 to 8 seconds to crystallize the sheet,
The cutting device is a heat-resistant PET or PLA container manufacturing device by air pressure molding, characterized in that cutting the amorphous part on the edge of the cooled PET or PLA molded product. delete delete 10. The method of claim 9,
The heating device is
Heat-resistant PET or PLA container manufacturing apparatus by air pressure molding, characterized in that the internal temperature is maintained at 280 to 400 degrees Celsius.

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