WO2024021197A1

WO2024021197A1 - Manufacturing process for film-covered paper container, film-covered paper container, and recycling method

Info

Publication number: WO2024021197A1
Application number: PCT/CN2022/113261
Authority: WO
Inventors: 蔡宇
Original assignee: 上海晨壤机械电子科技有限公司
Priority date: 2022-07-29
Filing date: 2022-08-18
Publication date: 2024-02-01
Also published as: CN115418888A

Abstract

Disclosed in the present invention are a manufacturing process for a film-covered paper container, a film-covered paper container, and a recycling method. The manufacturing process comprises: providing a paper container and a plastic bottle preform, fixing the plastic bottle preform to a tool, heating the plastic bottle preform and then sleeving same in the paper container, then carrying out mold combination, stretching and blow molding, blow-attaching the plastic bottle preform to an inner wall of the paper container, and forming a layer of plastic film, so as to obtain a film-covered paper container.

Description

Manufacturing process of coated paper containers, coated paper containers and recycling methods

Technical field

The present invention relates to the field of packaging technology, and in particular to a manufacturing method of a coated paper container, a coated paper container and a recycling method, and a manufacturing process of a coated paper container.

Background technique

Paper container products are widely used in daily life, such as paper cups, paper straws, paper dinner plates, paper bottles, etc. The paper containers currently on the market generally come in various shapes. They are mainly formed by vacuum adsorption of paper pulp using molds. After drying and deep processing, it can be used by people instead of metal and plastic. The main features are: light weight, non-toxic and odorless, environmentally friendly, and naturally degradable. These are the prerequisite advantages for paper containers to be widely used in our country.

However, existing paper containers still have certain shortcomings. The first situation is that if a waterproof film (such as a plastic film) is not formed on the inner wall of the paper container, the liquid cannot be stored for a long time and is usually used as a disposable These are all restricting the further development of paper containers. The second case is that in order to be waterproof, the inner wall of the paper container will be coated with film. The manufacturing process of the coated container is: coat the surface of the flat cardboard with film, then shape the cardboard into a certain shape, and cut off the excess part. The joints are glued, etc., so the shapes of paper containers manufactured in this way are very limited. They are generally used for paper cups. Many containers such as cans and bottles are not suitable for transformation into paper containers, and the range of use is very limited.

Contents of the invention

The main technical problem solved by the present invention is to provide a manufacturing process for film-coated paper containers, which uses a blow molding process to blow a layer of plastic film on the inner wall of the paper container, making the paper container waterproof, moisture-proof, penetration-proof and leak-proof, and is suitable for a variety of The production of shaped paper containers has a wide range of uses.

In order to solve the above technical problems, the present invention provides a manufacturing process for coated paper containers. It provides a paper container and a plastic bottle preform, fixes the plastic bottle preform on a tool, heats it and inserts it into the paper container, and then closes the mold and stretches it. In blow molding, the plastic bottle embryo is blown onto the inner wall of the paper container and forms a layer of plastic film to obtain a coated paper container.

Furthermore, the paper container has an integrated structure, and the manufacturing process includes the following steps:

S1: Paper container forming: The paper container is formed by pulp molding: the pulp is formed by vacuum adsorption, and after drying, a semi-finished paper container is obtained;

Alternatively, the paper container is made of commercially available ordinary paper connected together;

S2: Trimming: fix the paper container on the jig and cut off excess trim;

S3: Blow molding: Fix the plastic bottle preform on the tool, put it into the paper container after heating, then close the mold for stretch blow molding, and blow the plastic bottle preform to the inner wall of the paper container.

Furthermore, the paper container has a split structure, and the paper container includes multiple partial paper containers. Any two adjacent partial paper containers are connected directly or indirectly to form an integral paper container. Some paper containers are paper containers made according to the following steps S1 and S2;

The manufacturing process includes the following steps:

S1: Paper container forming: the paper container is formed by pulp molding: the paper pulp is formed by vacuum adsorption, and after drying, the partial paper containers of each section of the semi-finished product are respectively produced;

Alternatively, some of the paper containers are made of commercially available ordinary paper connected together;

S2: Trimming: Fix the part of the paper container described in each section on the jig, and cut off the excess edge material;

S21: Connect multiple sections of partial paper containers to form a whole paper container;

Furthermore, the commercially available ordinary paper is selected from kraft paper, white cardboard, coated paper or offset paper. But not limited to this. Furthermore, the first split structure of the paper container is: the paper container further includes several intermediate connecting sleeves; step S21 of the manufacturing process refers to: connecting any two adjacent sections through the intermediate connecting sleeves. The paper containers are connected together; until a whole paper container is formed.

The second split structure of the paper container is: any two adjacent partial paper containers of the paper container are directly connected, and the end of one partial paper container has a shrinking structure or an expanding structure. The mouth structure or the flared structure can be inserted into the end of another section of the paper container;

Step S21 of the manufacturing process refers to inserting the end of one partial paper container into the end of another partial paper container until an integral paper container is formed.

The intermediate connecting sleeve can be a commercially available conventional paper connecting sleeve. Two adjacent sections of paper containers are located on the outer peripheral surface of the intermediate connecting sleeve. The three can also be bonded together through adhesive.

Of course, the intermediate connecting sleeve can also be located on the outer peripheral surfaces of two adjacent sections of paper containers.

Further, step S3 includes the following steps:

A: Injection molding machine prepares plastic bottle preforms: Add the required raw materials to the injection molding machine, and then melt them through the screw of the injection molding machine to obtain a melt. The melt enters the injection mold and is demoulded and shaped to obtain a plastic bottle preform;

B: The blow molding machine completes the blow molding composite: fix the plastic bottle preform on the tool and preheat and soften it, then put a paper container on the preheated plastic bottle preform, and then clamp the paper container on the outer mold and pull it The extension rod stretches the plastic bottle preform, and at the same time, the blowing system of the blow molding machine blows air to blow mold the plastic bottle preform and blow it onto the inner wall of the paper container.

Preferably, step A is specifically: add the required raw materials into the hopper of the injection molding machine, and then melt them through the screw of the injection molding machine to obtain a melt. The melt enters the injection mold for filling, pressure maintaining, cooling, and demoulding to obtain plastic. Bottle preform.

Furthermore, step B is specifically: fix the prepared plastic bottle preform on a tool, preheat and soften it in an oven, the temperature during baking is 100-250°C, and then put it on the preheated plastic bottle preform. Paper container, then the outer mold clamps the paper container, the clamping force is 0.2-0.8MPa, the stretch rod stretches the plastic bottle preform, and the blowing system of the blow molding machine blows air at the same time, the air pressure range is 1.3-3.0MPa , blow mold the plastic bottle preform and blow it onto the inner wall of the paper container, then exhaust and open the mold.

Preferably, the outer mold is provided with an exhaust hole, and an external vacuum system is connected to the exhaust hole, and then the micropores of the paper container itself or artificially processed micropores are used to eliminate the gas between the plastic bottle preform and the paper container. So that the blow molding compound can be successfully completed. Because the inner wall of the paper container will eventually be blown to form a layer of plastic film, the micropores of the paper container will not cause leakage of the stored liquid.

When baking, just choose the corresponding temperature according to different materials.

Furthermore, the thickness of the plastic film after the plastic bottle preform is blow molded on the inner wall of the paper container is 0.03-0.1mm.

Furthermore, the material of the plastic bottle preform is degradable plastic or non-degradable plastic, and the degradable plastic is selected from the group consisting of PLA (polylactic acid), PBAT (butylene adipate and butylene terephthalate). At least one of ester copolymer), PBS (polybutylene succinate), PEF (polyethylene furanone), PPC (polypropylene carbonate) and PHA (polyhydroxyalkanoate); but It is not limited to this and can also be made of other materials.

The non-degradable plastic is selected from PET (polyethylene terephthalate), PE (polyethylene), PP (polypropylene), ABS (acrylonitrile-butadiene-styrene copolymer), PC (polyethylene At least one of carbonate) and PMMA (polymethyl methacrylate); but is not limited to this, and can also be made of other materials.

Further, step S1 includes the following steps:

a: Pulping: When the product is formed, it needs to be pulped first. The pulping process includes pulping, refining and mixing, and adding oil-proof and waterproof agents and wet strength additives to adjust the concentration;

b: Molding and drying: including vacuum adsorption molding, press dehydration and hot press drying and shaping. Vacuum adsorption molding, pressing and dehydration is mainly completed by the upper and lower molding molds, and hot press drying and shaping is mainly completed by the upper and lower hot pressing molds.

Furthermore, step b is specifically as follows:

Vacuum adsorption molding press dehydration: First, immerse the lower mold into the pulp pool, start vacuuming, and the vacuum will draw away the water, leaving the pulp on the surface of the isolation net of the mold. When the pulp is adsorbed to the required product thickness on the mold surface, stop vacuuming ; After adsorption molding, the lower mold is closed to the upper mold, and vacuuming is started at the same time. Pressing and dehydration are carried out until the moisture content of the product is 50-70%. Vacuuming is stopped to form a wet embryo of the desired shape;

Hot pressing drying and shaping: The wet embryo is then moved from the upper forming mold to the lower hot pressing mold. The lower hot pressing mold is closed with the upper hot pressing mold. Vacuuming is started at the same time to remove the water vapor generated by heating. The mold closing is mainly completed. Hot pressing, drying and shaping, the time is 40-100 seconds, the temperature is 120-180°C, the pressure is 0.4-0.6Mpa, and finally the paper container is demolded.

For general pulp molded products, the high temperature of the hot-press drying process can achieve sterilization. For example, pulp products such as food packaging and tableware require further sterilization and disinfection, such as ultraviolet disinfection.

Furthermore, the moisture content of the paper container after hot pressing, drying and shaping is 8-10%; and the thickness is 0.5-1.2mm.

Furthermore, step S2 is: inserting and positioning the semi-finished paper container produced in step S1 on a jig. The jig is connected to a vacuum to adsorb the paper container, and then the excess edges are removed. To prevent shaking during cutting, the accuracy must be controlled within 0.2mm.

Furthermore, the coated paper container is a can-shaped container or a bottle-shaped container.

Furthermore, the present invention also provides a coated paper container. The coated paper container includes a paper container, and a layer of plastic film is formed on the inner wall of the paper container through blow molding and adsorption.

Furthermore, the paper container has an integrated structure, and the integrated structure means that the paper container is a whole body formed by a pulp molding process.

Furthermore, the paper container has a split structure;

The first split structure of the paper container is: the paper container also includes multiple sections of partial paper containers and a number of intermediate connecting sleeves; two adjacent sections of partial paper containers are connected through the intermediate connecting sleeves to finally form an integrated container. paper containers;

The second split structure of the paper container is: the paper container is composed of multiple partial paper containers, and the end of one of any two adjacent partial paper containers has a shrinking structure or an expanding structure, The shrinking structure or the expanding structure can be inserted into the end of another partial paper container, and finally form an integral paper container.

The present invention also provides a recycling method of coated paper containers. The coated paper containers are paper coated containers produced according to the manufacturing process of claim 3. The recycling method is: pressing the coated paper through external force. At the connection point of the film-paper container, separate the various parts of the paper container and separate the plastic film from the paper container. Afterwards, the paper container part and the plastic film part are recycled according to category.

The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly and implement them according to the contents of the description, preferred embodiments of the present invention are described in detail below.

Description of drawings

Figure 1 is one of the structural schematic diagrams of the manufacturing process of one embodiment of the present invention (the paper container has an integrated structure);

Figure 2 is the second structural schematic diagram of the manufacturing process of one embodiment of the present invention (the paper container has an integrated structure);

Figure 3 is a schematic structural diagram of Embodiment 2 and Embodiment 9 of the present invention;

Figure 4 is a schematic structural diagram of Embodiment 3 and Embodiment 10 of the present invention;

Figure 5 is one of the structural schematic diagrams of Embodiment 1 of the present invention;

Figure 6 is the second structural schematic diagram of Embodiment 1 of the present invention;

Detailed ways

Specific implementations of the present invention are described below through specific specific examples. Those skilled in the art can easily understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented in other different ways, that is, various modifications and changes can be made without departing from the scope of the invention.

In this embodiment, the coated paper container refers to the product after a layer of plastic film is blown on the inner wall of the paper container. The paper container refers to the semi-finished product before the plastic film is blown. The partial paper container refers to a part of the paper container. Or part, a whole paper container is composed of multiple partial paper containers. The whole paper container here not only refers to the paper container with a bottle mouth, but also refers to the paper container without the bottleneck above the bottle shoulder, or even The paper container can have a bottle mouth on the top and no bottle bottom on the bottom.

Embodiment 1: A manufacturing process of a coated paper container. As shown in Figures 1 and 2, the paper container 20 is an integrated structure and includes the following steps:

S1: Pulp molding

Vacuum adsorption molding press dehydration: First, immerse the lower mold into the pulp pool, start vacuuming, and the vacuum will draw away the water, leaving the pulp on the surface of the isolation net of the mold. When the pulp is adsorbed to the required product thickness on the mold surface, stop vacuuming ; After adsorption molding, the lower mold is closed to the upper mold, and vacuuming is started at the same time. Pressing and dehydration are carried out until the moisture content of the product is 60%. Vacuuming is stopped to form a wet embryo of the desired shape;

Hot pressing drying and shaping: The wet embryo is then moved from the upper forming mold to the lower hot pressing mold. The lower hot pressing mold is closed with the upper hot pressing mold. Vacuuming is started at the same time to remove the water vapor generated by heating. The mold closing is mainly completed. Hot pressing, drying and shaping, the time is 60 seconds, the temperature is 130°C, the pressure is 0.5Mpa, and finally the coated paper container is demolded.

The moisture content of the paper container after hot pressing, drying and shaping is 9%; and the thickness is 0.8mm.

S2: Trimming

The semi-finished paper container 20 produced in step S1 is inserted into and positioned on the jig. The jig is connected to a vacuum to adsorb the paper container, and then the excess edges are cut off. To prevent shaking during cutting, the accuracy must be controlled within 0.2mm.

S3: Blow molding

Step A is as follows: add the required raw materials into the hopper of the injection molding machine, and then melt them through the screw of the injection molding machine to obtain a melt. The melt enters the injection mold for filling, pressure maintaining and cooling, and is demoulded and shaped to obtain a plastic bottle preform.

Step B is specifically as follows: fix the prepared plastic bottle preform 10 on a tool, preheat and soften it in an oven, the temperature during baking is 100°C, then put a paper container on the preheated plastic bottle preform, and then put it on the outside The mold clamps the paper container with a clamping force of about 0.2MPa. The stretch rod stretches the plastic bottle preform. At the same time, the blowing system of the blow molding machine blows air with an air pressure range of 1.3MPa to blow mold the plastic bottle preform. , and blow it to form a layer of plastic film 30 on the inner wall of the paper container, and then exhaust and open the mold.

The main difficulty in blow molding the plastic film on the inner wall of the paper container is that the blow molding exhaust cannot be completed due to the obstruction of the paper container. The processing technology of the paper container in this embodiment makes the paper container itself have good exhaust performance and certain In order to improve the strength of the blow molding, an exhaust hole and a vacuum system are made on the blow mold to assist in exhausting, so that the blow molding compound can be successfully completed. When baking, just choose the corresponding temperature according to different materials.

The thickness of the plastic bottle preform after blow molding on the inner wall of the paper container is 0.05mm.

The plastic bottle preform is made of degradable plastic, and the degradable plastic is PLA.

In this embodiment, the paper container is made by molding pulp. Of course, it can also be made by connecting commercially available ordinary paper, such as connecting it into a cylinder or a square cylinder, and the shape is not limited.

The commercially available ordinary paper is selected from kraft paper, white cardboard, coated paper or offset paper, but is not limited thereto.

When recycling the film-attached paper container, you can use tools, such as scissors, to cut it open, and then press or twist it hard to separate the plastic film from the paper container, thus realizing the classification and recycling of paper and plastic.

As shown in Figure 1, the paper container in this embodiment not only refers to a paper container with a bottle mouth; as shown in Figures 5 and 6, it can also refer to a paper container without a bottleneck above the bottle shoulder; or even The upper end of the paper container has a bottle mouth, and the bottom can also be without a bottle bottom.

Embodiment 2: A manufacturing process of a coated paper container, as shown in Figure 3, is similar to Embodiment 1, except that in this embodiment, the paper container has a split structure, and the paper container It includes multiple sections of partial paper containers. The specific number of sections is determined according to the process needs, such as two sections or three sections. However, it is better to divide it into two sections of partial paper containers. In this embodiment, two sections are also used as an example for description, that is: The paper container includes an upper paper container 201 and a lower paper container 202. The upper paper container and the lower paper container are prepared according to steps S1 and S2 respectively, that is, each individual paper container is To be prepared through steps S1 and S2;

Then proceed to step S21: connect the upper paper container and the lower paper container through the intermediate connecting sleeve 203 to form a completed paper container, and then proceed to the next step S3.

The intermediate connecting sleeve can be a commercially available conventional paper connecting sleeve. The lower edge of the upper paper-partitioning container is fitted on the outer circumference of the upper end of the intermediate connecting sleeve. The upper edge of the lower paper-partitioning container is fitted on the outer circumference of the lower end of the intermediate connecting sleeve. On the other hand, the three can also be bonded together with adhesive.

Of course, the intermediate connecting sleeve can also be located on the outer peripheral surfaces of the upper paper separation container and the lower paper separation container.

In step b of step S1, press and dehydrate until the moisture content of the product is 50%; the mold closing mainly completes hot pressing, drying and shaping, the time is 40 seconds, the temperature is 120°C, and the pressure is 0.4Mpa; the paper after hot pressing is dried and shaped The moisture content of the container is 8%; and the thickness is 0.6mm.

In step B of step S3, the baking temperature is 150°C, the clamping force is 0.3MPa, and the air pressure range is 1.8MPa.

The thickness of the plastic bottle preform after blow molding on the inner wall of the paper container is 0.07mm.

The material of the plastic bottle preform is a mixture of PLA and PBAT.

In this embodiment, the paper container can have a split structure, that is, it can be made into an upper and lower split structure. After the blow molding is completed, the paper container can be separated up and down under the action of external force (such as pinching with hands). Separation of paper and plastic to facilitate sorting and recycling in the later market.

In this embodiment, some paper containers are made by molding pulp. Of course, they can also be made by connecting commercially available ordinary paper, such as multi-section cylinders or square tubes. The shape is not limited, and then the multi-section cylinders or The square tubes can be connected to form a whole paper container.

Embodiment 3: A manufacturing process of a coated paper container, as shown in Figure 4, is similar to Embodiment 2, except that:

The paper container is composed of multiple partial paper containers: any two adjacent partial paper containers of the paper container are directly connected, and the end of one partial paper container has a shrinking structure or an expanded structure, and the shrinking structure Or the flared structure can be inserted into the end of another section of the paper container;

"Connecting multiple partial paper containers to form an integral paper container" in step S2 of the manufacturing process refers to: S21: Insert the end of one partial paper container into the end of another partial paper container until a whole is formed. paper container.

In this embodiment, the paper container includes two partial paper containers, namely an upper partial paper container 201 and a lower partial paper container 202. The lower end of the upper partial paper container is inserted into the upper end of the lower partial paper container.

In step b of step S1, press and dehydrate until the moisture content of the product is 55%; the mold closing mainly completes hot pressing, drying and shaping, the time is 70 seconds, the temperature is 125°C, and the pressure is 0.6Mpa; the paper after hot pressing is dried and shaped The moisture content of the container is 10%; and the thickness is 0.9mm.

In step B of step S3, the baking temperature is 250°C, the clamping force is 0.8MPa, and the air pressure range is 3.0MPa.

The thickness of the plastic bottle preform after blow molding on the inner wall of the paper container is 0.08mm.

The material of the plastic bottle preform is a mixture of PBS, PPC and PHA.

Embodiment 4: A manufacturing process of coated paper containers is similar to Embodiment 1, except that in step b of step S1, press and dehydrate until the moisture content of the product is 65%; mold closing mainly completes hot pressing and drying. and shaping, the time is 80 seconds, the temperature is 140°C, and the pressure is 0.4Mpa; the moisture content of the paper container after hot-pressing drying and shaping is 8%; and the thickness is 0.7mm.

In step B of step S3, the baking temperature is 180°C, the clamping force is 0.4MPa, and the air pressure range is 2.0MPa.

The thickness of the plastic bottle preform after blow molding on the inner wall of the paper container is 0.09mm.

The material of the plastic bottle preform is a mixture of PET, PE and PP.

Embodiment 5: A manufacturing process of coated paper containers is similar to Embodiment 1, except that in step b of step S1, press and dehydrate until the moisture content of the product is 70%; mold closing mainly completes hot pressing and drying. and shaping, the time is 100 seconds, the temperature is 150°C, and the pressure is 0.6Mpa; the moisture content of the paper container after hot-pressing drying and shaping is 9%; and the thickness is 0.8mm.

In step B of step S3, the baking temperature is 220°C, the clamping force is 0.7MPa, and the air pressure range is 2.2MPa.

The thickness of the plastic bottle preform after blow molding on the inner wall of the paper container is 0.1mm.

The material of the plastic bottle preform is a mixture of ABS, PC and PMMA.

Embodiment 6: A manufacturing process of coated paper containers is similar to Embodiment 1, except that in step b of step S1, press and dehydrate until the moisture content of the product is 70%; mold closing mainly completes hot pressing and drying. and shaping, the time is 100 seconds, the temperature is 180°C, and the pressure is 0.6Mpa; the moisture content of the paper container after hot-pressing drying and shaping is 5%; and the thickness is 0.5mm.

The thickness of the plastic bottle preform after blow molding on the inner wall of the paper container is 0.03mm.

The material of the plastic bottle preform is PEF.

Embodiment 7: A manufacturing process of coated paper containers is similar to Embodiment 1, except that in step b of step S1, press and dehydrate until the moisture content of the product is 70%; mold closing mainly completes hot pressing and drying. and shaping, the time is 100 seconds, the temperature is 120°C, and the pressure is 0.6Mpa; the moisture content of the paper container after hot-pressing drying and shaping is 13%; and the thickness is 1.2mm.

The material of the plastic bottle preform is a mixture of PC and PMMA.

In the above embodiment, a paper container is obtained by pulp molding, a plastic bottle preform is prepared by an injection molding machine, and then the plastic bottle preform is placed inside the paper container, and then a layer of plastic film is blown on the inner wall of the paper container using a blow molding process, so that Paper containers are waterproof, moisture-proof, penetration-proof and leak-proof.

Embodiment 8: A coated paper container, as shown in Figures 1, 2, 5, and 6. The coated paper container includes a paper container 20, and the inner wall of the paper container is formed by blow molding and adsorption. layer of plastic film 30; the paper container has an integrated structure, and the integrated structure means that the paper container is a whole body formed by a pulp molding process.

Embodiment 9: A coated paper container, as shown in Figure 3, the coated paper container includes a paper container 20, the paper container is a first split structure, the paper container includes an upper paper container 201 and the lower paper container 202, and connect the upper paper container and the lower paper container through an intermediate connecting sleeve 203. The inner wall of the paper container forms a layer of plastic film 30 through blow molding and adsorption. Of course, the number of sections of the paper container including partial paper containers is not limited to two sections. The specific number of sections is determined according to process requirements, such as three sections or even more sections, but it is better to divide the partial paper container into two sections.

Embodiment 10: The paper container has a second split structure. As shown in Figure 4, the paper container is composed of multiple sections of paper containers: The two sections of the paper container are directly connected, and the end of one section of the paper container has a shrinking structure or an expanding structure, and the shrinking structure or expanding structure can be inserted into the end of the other section of the paper container. .

In this embodiment, taking the partial paper container with two sections as an example, the paper container includes two sections of partial paper containers, which are an upper paper container 201 and a lower paper container 202 respectively. The lower end of the upper paper container is Insert the upper end of the lower paper portion container.

Of course, the number of sections of the paper container including partial paper containers is not limited to two sections. The specific number of sections is determined according to process requirements, such as three sections or even more sections, but it is better to divide the partial paper container into two sections.

Embodiment 11: A method for recycling coated paper containers. The coated paper containers are paper-coated containers prepared according to the manufacturing process described in Examples 2 and 3. The recycling method is: pressing by external force. At the connection point of the coated paper container, separate each part of the paper container (each part here refers to: the partial paper container in each section and the intermediate connecting sleeve; or only include the partial paper container in each section), and separate the plastic film and The paper containers are separated, and then the paper container part and the plastic film part are recycled according to category.

The beneficial effects of the present invention are:

In the present invention, a plastic bottle preform is prepared through an injection molding machine, and then the plastic bottle preform is placed inside a paper container, and then a layer of plastic film is blown on the inner wall of the paper container using a blow molding process to make the paper container waterproof and moisture-proof;

The process of the present invention is to first obtain a paper container through a pulp molding process, prepare a plastic bottle preform through an injection molding machine, and then blow mold it into a layer of plastic film. Therefore, the shape of the paper container and the plastic bottle preform can be diversified according to needs, and finally the The coated paper containers have more shapes, such as paper bottles of various shapes, paper cans, etc., which are suitable for the production of paper containers of various shapes and have a wide range of uses;

Furthermore, in the present invention, a layer of plastic film is blown onto the inner wall of the paper container through blow molding. The plastic film has a strong bonding force with the inner wall of the paper container and will not separate or fall off;

Furthermore, the material of the plastic bottle preform of the present invention can be degradable plastic, so the produced coated paper container is completely naturally degradable, green and environmentally friendly, and has no burden on the environment;

Furthermore, the paper container of the present invention can have a split structure, that is, it can be made into an upper and lower split structure. After the blow molding is completed, the paper container can be separated from the upper and lower parts under the action of external force (such as pinching with hands). And paper-plastic separation to facilitate sorting and recycling in the later market.

The above are only examples of the present invention, and do not limit the scope of patent protection of the present invention. Any equivalent structures made using the description of the present invention, or directly or indirectly used in other related technical fields, are similarly included in this invention. The invention is within the scope of patent protection.

Claims

A manufacturing process for coated paper containers, which is characterized by: providing a paper container and a plastic bottle preform, fixing the plastic bottle preform on a tool, inserting it into the paper container after heating, and then closing the mold for stretch blow molding, and then the plastic bottle is The embryo is blown onto the inner wall of the paper container and forms a layer of plastic film to obtain a coated paper container.
The manufacturing process of coated paper containers according to claim 1, characterized in that: the paper container has an integrated structure, and the manufacturing process includes the following steps:

S1: Paper container forming: The paper container is formed by pulp molding: the pulp is formed by vacuum adsorption, and after drying, a semi-finished paper container is obtained;

Alternatively, the paper container is made of commercially available ordinary paper connected together;

S2: Trimming: fix the paper container on the jig and cut off excess trim;

S3: Blow molding: Fix the plastic bottle preform on the tool, put it into the paper container after heating, then close the mold for stretch blow molding, and blow the plastic bottle preform to the inner wall of the paper container.
The manufacturing process of coated paper containers according to claim 1, characterized in that: the paper container has a split structure, the paper container includes multiple partial paper containers, and any two adjacent partial paper containers are directly connected. Or indirectly connected to finally form an integral paper container. The partial paper containers described in each paragraph are all paper containers made according to the following steps S1 and S2;

The manufacturing process includes the following steps:

S1: Paper container forming: the paper container is formed by pulp molding: the paper pulp is formed by vacuum adsorption, and after drying, the partial paper containers of each section of the semi-finished product are respectively produced;

Alternatively, some of the paper containers are made of commercially available ordinary paper connected together;

S2: Trimming: Fix the part of the paper container described in each section on the jig, and cut off the excess edge material;

S21: Connect multiple sections of partial paper containers to form a whole paper container;

S3: Blow molding: Fix the plastic bottle preform on the tool, put it into the paper container after heating, then close the mold for stretch blow molding, and blow the plastic bottle preform to the inner wall of the paper container.
The manufacturing process of coated paper containers according to claim 3, characterized in that:

The first split structure of the paper container is: the paper container also includes several intermediate connecting sleeves; step S21 of the manufacturing process refers to: connecting any two adjacent sections of the paper container through the intermediate connecting sleeves. ; Until a whole paper container is formed.

The second split structure of the paper container is: any two adjacent partial paper containers of the paper container are directly connected, and the end of one partial paper container has a shrinking structure or an expanding structure. The mouth structure or the flared structure can be inserted into the end of another section of the paper container;

Step S21 of the manufacturing process refers to inserting the end of one partial paper container into the end of another partial paper container until an integral paper container is formed.
The manufacturing process of coated paper containers according to claim 2 or 3, characterized in that step S3 includes the following steps:

A: Injection molding machine prepares plastic bottle preforms: Add the required raw materials to the injection molding machine, and then melt them through the screw of the injection molding machine to obtain a melt. The melt enters the injection mold and is demoulded and shaped to obtain a plastic bottle preform;

B: The blow molding machine completes the blow molding composite: fix the plastic bottle preform on the tool and preheat and soften it, then put a paper container on the preheated plastic bottle preform, and then clamp the paper container on the outer mold and pull it The extension rod stretches the plastic bottle preform, and at the same time, the blowing system of the blow molding machine blows air to blow mold the plastic bottle preform and blow it onto the inner wall of the paper container.
The manufacturing process of coated paper containers according to claim 5, characterized in that step B specifically includes: fixing the prepared plastic bottle preform on a tool and preheating and softening it in an oven, and the temperature during baking is 100- 250℃, then put a paper container on the preheated plastic bottle preform, then clamp the paper container with the outer mold, the clamping force is 0.2-0.8MPa, the stretch rod stretches the plastic bottle preform, and the blow molding machine The air blowing system is used to blow air, and the air pressure range is 1.3-3.0MPa. The plastic bottle preform is blow molded and attached to the inner wall of the paper container, and then the air is exhausted and the mold is opened.
The manufacturing process of coated paper containers according to claim 1, 2 or 3, characterized in that: the thickness of the plastic film after the plastic bottle preform is blow-molded on the inner wall of the paper container is 0.03-0.1 mm.
The manufacturing process of coated paper containers according to claim 1, 2 or 3, characterized in that: the material of the plastic bottle preform is degradable plastic or non-degradable plastic;

The degradable plastic is selected from at least one of PLA, PBAT, PEF, PBS, PPC and PHA;

The non-degradable plastic is selected from at least one of PET, PE, PP, ABS, PC and PMMA.
The manufacturing process of coated paper containers according to claim 1, 2 or 3, characterized in that step S1 includes the following steps:

a: Pulping: When the product is formed, it needs to be pulped first. The pulping process includes pulping, refining and mixing, and adding oil-proof and waterproof agents and wet strength additives to adjust the concentration;

b: Molding and drying: including vacuum adsorption molding, press dehydration and hot press drying and shaping. Vacuum adsorption molding, pressing and dehydration is mainly completed by the upper and lower molding molds, and hot press drying and shaping is mainly completed by the upper and lower hot pressing molds.
The manufacturing process of coated paper containers according to claim 9, characterized in that step b is specifically:

Vacuum adsorption molding press dehydration: First, immerse the lower mold in the pulp pool, start vacuuming, and vacuum the water away. When the pulp is adsorbed to the required product thickness on the mold surface, stop vacuuming; after adsorption, the lower mold and the upper mold are Close the mold, start vacuuming at the same time, press and dehydrate until the moisture content of the product is 50-70%, stop vacuuming, and form a wet embryo of the desired shape;

Hot pressing drying and shaping: The wet embryo is then moved from the upper molding mold to the lower hot pressing mold. The lower hot pressing mold is closed with the upper hot pressing mold. Vacuuming is started at the same time. The mold closing mainly completes hot pressing, drying and shaping. The time is 40-100 seconds, the temperature is 120-180℃, the pressure is 0.4-0.6Mpa, and finally the paper container is demolded.
The manufacturing process of coated paper containers according to claim 9, characterized in that: the moisture content of the paper container after hot-pressing, drying and shaping is 5-13%; and the thickness is 0.5-1.2mm.
The manufacturing process of coated paper containers according to claim 2 or 3, characterized in that: step S2 is: inserting and positioning the semi-finished paper container produced in step S1 on a jig, and the jig is connected to a vacuum, Adsorb the paper container and then cut off any excess edges.
The manufacturing process of coated paper containers according to claim 1, 2 or 3, characterized in that: the coated paper containers are can-shaped containers or bottle-shaped containers.
A film-coated paper container, characterized in that: the film-coated paper container includes a paper container, and a layer of plastic film is formed on the inner wall of the paper container through blow molding and adsorption.
The coated paper container according to claim 14, characterized in that: the paper container has an integrated structure, and the integrated structure means that the paper container is a whole body formed by a pulp molding process.
The coated paper container according to claim 14, characterized in that: the paper container has a split structure;

The first split structure of the paper container is: the paper container also includes multiple sections of partial paper containers and a number of intermediate connecting sleeves; two adjacent sections of partial paper containers are connected through the intermediate connecting sleeves to finally form an integrated container. paper containers;

The second split structure of the paper container is: the paper container is composed of multiple partial paper containers, and the end of one of any two adjacent partial paper containers has a shrinking structure or an expanding structure, The shrinking structure or the expanding structure can be inserted into the end of another partial paper container to finally form an integral paper container.
A recycling method of coated paper containers, characterized in that: the coated paper container is a paper coated container produced according to the manufacturing process of claim 3, and the recycling method is: pressing the film by external force At the connection point of the paper container, separate each part of the paper container and separate the plastic film from the paper container. Then the paper container part and the plastic film part are recycled according to category.