Double-layer container made of composite materials and its forming method.

Abstract

This invention provides a method for forming a composite material double-layer container and the container made therefrom. The steps include: selecting a paper outer layer without a coating layer and stamping a tear line on the surface of the outer layer; forming an arc-shaped rolled edge with the upper edge of the outer layer facing outward; and attaching a paper without a coating layer to the inner surface of the bottom edge of the outer layer; the outer layer and the paper define a first chamber with an upward opening; selecting a plastic inner layer with a second chamber with an upward opening; fitting the inner layer into the first chamber; and having a rolled end on the upper edge of the inner layer, which is rolled and fixed to the arc-shaped rolled edge to form a composite material double-layer container.

Description

[Technical Field]

[0001] This invention is mainly used in containers for daily consumption, especially composite material containers that can hold beverages and are easy to recycle and classify. [Previous Technology]

[0002] Recently, due to the pandemic, global climate change, and rising sea levels, people have begun to consider how to coexist with the natural environment. At the same time, businesses are also considering how to protect the planet and achieve sustainable operation while achieving revenue growth. Now, companies must learn how to implement ESG (Environmental, Social, and Governance) in the ever-changing business environment to reduce the impact of risks. Large enterprises are beginning to disclose ESG-related information. ESG data is not just a static score, but a dynamic representation. Companies need to disclose not only past financial performance, but also how to achieve sustainable operation through ESG goals. ESG stands for Environmental Protection (E), Social Responsibility (S), and Governance (G). It is a set of data and indicators for dynamically assessing companies. ESG represents corporate social responsibility, and many companies and investors consider ESG scores as an important indicator for assessing a company's sustainability and for investment decisions. Environmental Protection represents the need for companies to prioritize environmental sustainability issues, covering greenhouse gas emissions, carbon emission reduction, climate change, environmental sustainability, carbon emissions, and pollution control.

[0003] In Taiwan, under the protection of sustainable environment, disposable plastic beverage cups are gradually becoming a thing of the past. Many shops have switched to paper cups in order to comply with the policy. Paper cups can be used to drink coffee, tea, water and beverages. However, in order to hold beverages, paper cups or paper containers have a waterproof plastic coating on their surface. There are many kinds of coatings, such as PE (polyethylene), PP (polypropylene), PLA (polylactic acid) and CPE (chlorinated polyethylene). The coatings of paper containers commonly used in Taiwan are mainly made of PE and PP. Different materials will also affect the durability of paper containers. Some paper cup coatings can withstand high temperatures of 95 degrees Celsius. For example, PP has the characteristics of acid and alkali resistance and high temperature resistance. Paper container recycling is a common issue in daily life. Many people pack up all paper containers, along with food scraps, and throw them into the trash after eating. However, food scraps contain a lot of moisture, which lowers the temperature and shortens the lifespan of incinerators. Paper containers with oil stains or residue also affect the willingness of downstream recycling systems to recycle them, reducing their reuse value. Furthermore, because paper containers have a waterproof and oil-resistant plastic coating, they need to be processed separately during recycling. They cannot be recycled with newspapers, cardboard boxes, or paper trays. If properly sorted and cleaned, recycled pulp can be made back into paper boxes and toilet paper, significantly increasing the chances of paper containers being recycled and reused. Recycling paper containers requires sending them to professional waste paper container processing plants to separate the coating and paper, increasing recycling costs and failing to meet environmental and economic efficiency.

[0004] Currently, cups are commonly used to hold hot beverages. Due to the high temperature of the cup body, an outer sleeve is usually required for consumers to use it. For example, Chinese Patent No. 200920148189.3 discloses a disposable paper-plastic insulated cup, which includes a cup body with an annular insulated sleeve on the outside of the cup body. The upper and lower ends of the annular insulated sleeve are fixed to the upper and lower ends or near the ends of the cup body. An air insulation layer is formed between the annular insulated sleeve and the cup body. The above-mentioned disposable paper-plastic insulated cup adopts a double-layer structure for the cup body, that is, a plastic cup body with a color-printable paper sleeve, and an air insulation layer is formed between the two, thereby achieving a good heat preservation effect; the cup body is made of plastic to prevent water leakage, while the insulated sleeve is made of paper and can be printed, thus achieving the effect of heat preservation, water prevention, and color printing at the same time. However, the inner and outer cups of the patent are glued together, making it difficult to separate the plastic from the paper sleeve during recycling. Even if they are separated, glue residue will remain on the outer plastic layer or the paper sleeve, increasing the processing steps and costs during recycling.

[0005] In addition to directly bonding the plastic inner cup and the paper outer cup with glue, some manufacturers have developed a double-layer container, such as Taiwan Invention Patent No. I714428, which provides a double-layer container including a plastic inner container with a bottom and a paper cylindrical outer layer. The outer layer is fitted over the inner container. A locking structure is provided between the outer layer and the inner container to lock the outer layer onto the outer circumferential surface of the inner container. The locking structure is located in the lower or lower middle part of the double-layer container and includes an annular groove and an annular protrusion. The annular groove is recessed radially along the inner container and thus formed on the outer circumferential surface of the inner container. It has upper and lower groove walls and is formed directly during the pressing and molding of the inner container. Its cross-sectional shape is arc-shaped. The annular protrusion is formed by winding on the inner circumferential surface of the outer layer. It is formed by winding from the bottom of the outer layer to the inner circumferential surface. Depending on the process, it can be wound into a circle or an ellipse. The annular protrusion is embedded in the annular groove and the width of the annular protrusion is greater than the depth of the annular groove, so that there is a gap between the outer wall of the inner container and the inner wall of the outer layer. To ensure sufficient clearance at the locking structure, the inner container near the bottom tapers inward, increasing the gap. This clearance is adjustable via a ring-shaped protrusion formed by winding; the outer diameter of the protrusion can be increased to accommodate larger gaps, making gap adjustment easier for different usage environments in actual production. However, this locking structure is complex. The bottom of the outer layer needs to be hollowed out to form the ring-shaped protrusion, and the inner container is only fixed to the upper edge of the outer layer by abutting. When drinking, the consumer's lips will come into contact with the paper outer layer, which can easily soften upon contact with moisture and detach from the inner container. Furthermore, Taiwanese regulations prohibit the use of recycled paper in food packaging materials that come into direct contact with food. If the outer paper outer layer uses uncoated recycled paper, it could easily become contaminated, leading to hygiene problems. Moreover, the lack of a bottom on the outer layer forces consumers to be extra careful not to touch the bottom of the inner container to avoid burns. [Summary of the Invention]

[0006] In view of the environmental problems such as the difficulty in recycling and reuse of composite containers on the market and the complicated manufacturing process, the inventor has developed a molding method for a double-layered composite container and the container made therefrom.

[0007] The purpose of this invention is to provide a method for forming a composite double-layer container that is easy to separate and recycle, comprising the following steps: Step 1: preparing uncoated paper; Step 2: forming a pattern on the surface of the uncoated paper; Step 3: applying environmentally friendly adhesive to the periphery of the side edges and bottom edges of the uncoated paper of a predetermined shape; Step 4: cutting the uncoated paper into a sheet of a predetermined shape; Step 5: transferring the cut sheet to a forming machine for winding, and using a heater to heat the environmentally friendly adhesive on the side edges of the sheet, so that the rolled part of the sheet is bonded and fixed, forming a cylindrical shape; Step 6: preparing a U-shaped bottom paper; Step 7: ... Step 8: Place the tubular sheet at the bottom inner edge and use a heater to heat the environmentally friendly adhesive at the bottom of the sheet, so that the tubular sheet and the bottom paper of the U-shaped body are bonded and fixed to form an outer layer with a first chamber; Step 9: Move the outer layer to the edge forming mechanism, and use the edge forming mechanism to roll the upper edge of the outer layer outward to form an arc-shaped edge; Step 10: Place an inner layer with a second chamber into the first chamber of the outer layer, the top edge of the inner layer forms a rolled end outward, the rolled end includes an extension section, the extension section extends downward to a covering section, the covering section and the body of the inner layer form a covering groove, the covering groove covers the arc-shaped edge of the outer layer; Step 11: Use the covering mechanism to heat and roll the upper edge of the combined inner and outer layers towards the inner layer, so that the upper edges of the inner and outer layers are rolled and fixed to form a composite material double-layer container.

[0008] Another objective of the present invention is to use the forming method described above to manufacture a composite material double-layer container, which includes: a paper outer layer without a coating layer, the upper edge of the outer layer forming an arc-shaped rolled edge, and a bottom paper without a coating layer bonded to the inner surface of the bottom edge of the outer layer, the outer layer and the bottom paper defining a first chamber with an upward opening; an inner layer fitted into the first chamber, the inner layer having a second chamber with an upward opening, and the top edge of the inner layer forming a rolled end, the rolled end including an extension section, the extension section extending downward to a covering section, the covering section and the body of the inner layer forming a covering groove, the covering groove covering the arc-shaped rolled edge of the outer layer, forming a composite material double-layer container.

[0009] In a further embodiment of the present invention, the paper may be one of food-grade virgin paper, recycled paper, industrial paper, etc.

[0010] In a further embodiment of the present invention, the inner layer is made of plastic, and the plastic material is environmentally friendly materials such as PP, PE, PET, PLA or degradable plastic materials.

[0011] In a further embodiment of the present invention, the outer body surface has a tear line, which forms a U-shaped body, a rectangular body, or the like.

[0012] In a further embodiment of the present invention, the tear line is not located at the bonding and fixing point of the sheet.

[0013] In a further embodiment of the present invention, the composite material double-layer container is one of a cup, box, bowl, tube, plate, etc.

[0014] The present invention uses the rolled end of the upper edge of the inner layer to roll and cover the arc-shaped rolled edge of the outer layer to fix it, so that the consumer's lips will not touch the paper outer layer when drinking. At the same time, the tear line design allows the consumer to tear the paper outer layer and the inner layer after use, which is convenient for recycling and reuse.

Implementation Method

[0016] The features of the present invention will be described in detail below through embodiments. First, please refer to Figure 1, which shows a method for forming a composite material double-layer container. The steps include: Step S101: Preparing uncoated paper, which is one of recycled paper, food-grade virgin paper, or industrial paper; Step S102: Forming a pattern on the surface of the uncoated paper, which can be formed by printing, embossing, laser, or branding; Step S103: Applying environmentally friendly adhesive to the side edges and bottom edges of the uncoated paper of a predetermined shape. In the embodiments of the present invention, the main component of the environmentally friendly adhesive is EVE (ethylene-vinyl acetate copolymer). The environmentally friendly adhesive is prepared by using an adhesive (such as water-based PLA (polylactic acid) glue or water-based PBS (butylene succinate) glue and drying it with a dryer; Step S104: The uncoated paper is cut into a sheet of a predetermined shape using a cutting machine, and tear lines can be cut on the sheet. In the embodiment of the present invention, the sheet is a fan-shaped sheet, including but not limited to the fan-shaped sheet; Step S105: The cut sheet is transferred to a winding and forming mechanism for winding, and the environmentally friendly adhesive is heated by ultrasound to bond and fix the rolled part of the sheet to form a tube; Step S106: A U-shaped base paper is prepared, which is also uncoated. The paper material of the membrane is one of recycled paper, virgin paper, or industrial paper, wherein an environmentally friendly adhesive can be applied to the periphery of the base paper; Step S107: Place the U-shaped base paper on the inner edge of the bottom of the cylindrical sheet and use a heater to heat the environmentally friendly adhesive at the bottom of the sheet to bond and fix the cylindrical sheet and the U-shaped base paper together. A knurling mechanism can be used to bond the base paper to the bottom of the cylindrical sheet. The cylindrical sheet and the base paper together form an outer layer with a first chamber; Step S108: Move the outer layer to the edge forming mechanism and use the edge forming mechanism to roll the upper edge of the outer layer outward to form an arc-shaped edge; Step S109: Place a membrane with The inner layer of the second compartment is fitted into the first compartment of the outer layer. In an embodiment of the present invention, the inner layer is made of plastic, such as environmentally friendly materials or degradable plastic materials like PP, PE, PET, and PLA. The second compartment can hold food or beverages. The top edge of the inner layer forms a rolled end, which includes an extension section. The extension section extends downward to form a covering section, which, together with the body of the inner layer, forms a covering groove. The inner layer and the rolled end are integrally formed by blow molding. When the inner layer is fitted into the outer layer, the covering groove of the inner layer covers the arc-shaped rolled edge of the outer layer. Step S110: The upper edge of the combined inner and outer layers is heated and rolled towards the inner layer using a covering mechanism, so that the rolled end of the inner layer and the arc-shaped rolled edge of the outer layer are rolled and fixed to form a composite material double-layer container.

[0017] Please refer to Figures 2-6. This invention uses the forming method described above to produce a composite material double-layer container, which includes: a paper outer layer 1 without a coating layer. The outer surface of the outer layer 1 can be printed with patterns or stamped with the required patterns using a steel stamping method. The paper can be one of virgin paper, recycled paper, or industrial paper. In this invention, a round cup is used as an example, including but not limited to the round cup. The outer layer 1 is composed of a fan-shaped sheet 11 with both ends rolled and glued together. Environmentally friendly adhesive 161 is applied at the rolled and glued area 16, and a base paper 2 without a coating layer is bonded to the inner surface of the bottom edge 12 of the outer layer 1. The bonding method is to apply environmentally friendly adhesive 161 to the inner surface of the bottom edge 12 of the outer layer 1 or to the periphery of the base paper 2. The upper edge of the outer layer 1 forms an arc-shaped rolled edge 13. 1 and the base paper 2 define a first chamber 14 with an upward opening; and an inner layer 3 fitted inside the first chamber 14. The inner layer 3 can be made of environmentally friendly materials such as PP, PE, PET, PLA, or biodegradable plastic materials. The inner layer 3 has a second chamber 31 with an upward opening, which can hold beverages such as coffee, hot water, tea, etc. The top edge of the inner layer 3 forms a rolled end 32. Please refer to Figures 5-6. The rolled end 32 includes an extension 321 extending outward from the upper edge of the inner layer 3. The extension 321 extends downward to a covering section 322. The covering section 322 and the inner layer 3 body 33 form a covering groove 34. The covering groove 34 covers the arc-shaped rolled edge 13 of the outer layer 1, thereby forming a composite material double-layer container A.

[0018] Referring again to Figures 3, 7, and 8, in a further embodiment of the present invention, the surface of the outer layer 1 has a tear line 15, which forms a U-shaped, U-shaped, or rectangular tear piece 151. Since the two outer layers 1 overlap at the rolled-up adhesive joints 16 at both ends of the outer layer 1, the adhesive joints 16 become thicker and are not easy to tear apart. In the embodiment of the present invention, the tear line 15 is set at the rolled-up adhesive joints 16 at both ends of the non-fan-shaped piece 11. When the consumer finishes using the double-layer container A, since the outer layer 1 is a single layer, the consumer can easily press the tear line 15 of the U-shaped or U-shaped body with their fingers to break the outer layer 1, and then tear the outer layer 1 and the inner layer 3 apart for easy sorting and recycling.

[0019] The above structural design has the following advantages: 1. It fully utilizes uncoated paper, eliminating the need for coating the outer layer and reducing production costs. 2. Using recycled paper enhances the value of circular economy reuse, reducing carbon emissions and environmental pollution. 3. The combination of the uncoated outer and inner layers provides heat insulation and is particularly suitable for holding heated beverages. 4. Because of the use of the uncoated double-layer container, it can be directly microwaved, unlike traditional coated containers where the coating melts and contaminates food when microwaved. 5. The tear line on the outer layer is designed at a non-coated area, allowing consumers to easily separate the torn outer and inner layers for easy sorting. 6. The uncoated outer paper can be directly dissolved and recycled after recycling, eliminating the need for separating the coating from the paper.

[0020] However, the above description is only a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All simple equivalent changes and modifications made in accordance with the scope of the patent application and the description of the invention shall still fall within the scope of the patent of the present invention. [Simplified Explanation of the Diagram]

[0015] Figure 1 is a flowchart of the steps of the present invention. Figure 2 is an exploded view of the fan-shaped sheet and the base paper of the present invention. Figure 3 is a perspective view of the outer layer of the present invention. Figure 4 is an exploded perspective view of the outer layer and the inner layer of the present invention. Figure 5 is a perspective sectional view of the outer layer and the inner layer of the present invention. Figure 6 is a combined sectional view of the outer layer and the inner layer of the present invention. Figure 7 is a schematic diagram of the tear line of the outer layer of the present invention. Figure 8 is another schematic diagram of the tear line of the outer layer of the present invention.

Claims

1. A method for forming a composite material double-layer container, comprising the following steps: Step 1: preparing a non-coated paper; Step 2: forming a pattern on the surface of the non-coated paper; Step 3: applying environmentally friendly adhesive to the periphery of the side edges and bottom edges of the non-coated paper of a predetermined shape; Step 4: cutting the non-coated paper into a sheet of a predetermined shape; Step 5: transferring the cut sheet to a forming machine for winding, and using a heater to heat the environmentally friendly adhesive on the side edges of the sheet to bond and fix the rolled portion of the sheet, forming a cylindrical sheet; Step 6: preparing a U-shaped bottom paper; Step 7: placing the U-shaped bottom paper on the inner edge of the bottom of the cylindrical sheet and using a heater to heat the environmentally friendly adhesive on the bottom of the cylindrical sheet, so that the cylindrical sheet and the U-shaped bottom paper are bonded and fixed, forming an outer layer having a first chamber; Step 8: Move the outer layer to the edge-forming mechanism, and use the edge-forming mechanism to roll the upper edge of the outer layer outward to form an arc-shaped edge; Step 9: Insert an inner layer with a second chamber into the first chamber of the outer layer. The top edge of the inner layer forms a rolled end outward. The rolled end includes an extension section, which extends downward to a covering section. The covering section and the body of the inner layer form a covering groove, which covers the arc-shaped edge of the outer layer. The inner layer is a pre-shaped plastic container; Step 10: Use the covering mechanism to heat and roll the covering section toward the inner layer, so that the upper edges of the inner and outer layers are rolled and fixed to form a composite material double-layer container.

2. The method for forming a composite material double-layer container as described in claim 1, wherein the uncoated paper is one of food-grade virgin paper, recycled paper, or industrial paper.

3. The method for forming a composite material double-layer container as described in claim 1, wherein the container is one of a cup, box, bowl, cylinder, plate, etc.

4. A method for forming a composite material double-layer container as described in claim 1, wherein the heater is ultrasonic.

5. A method for forming a composite material double-layer container as described in claim 1, wherein the inner layer is plastic, and the plastic material is PP, PE, PET, PLA or a degradable plastic material.

6. The method for forming a composite material double-layer container as described in claim 1, wherein the pattern described in step 2 can be formed on the surface of the outer layer by printing, stamping, laser engraving, or branding.

7. The method for forming a composite material double-layer container as described in claim 1, wherein the bottom paper in step 6 is further coated with an environmentally friendly adhesive around its periphery.

8. The method for forming a composite material double-layer container as described in claim 1, wherein in step 4 a tear line is further cut out, the tear line forming a U-shape, a rectangle or the like.

9. A method for forming a composite material double-layer container as described in claim 8, wherein the tear line is not located at the roll-up of the sheet.

10. A composite material double-layer container made according to claim 1, comprising: an outer paper body without a coating layer, the upper edge of the outer body forming an arc-shaped rolled edge outward, and an inner paper without a coating layer bonded to the inner surface of the bottom edge of the outer body, the outer body and the bottom paper defining a first chamber with an upward opening; an inner body fitted into the first chamber, the inner body having a second chamber with an upward opening, the top edge of the inner body forming a rolled end outward, the rolled end including an extension section, the extension section extending downward to a covering section, the covering section and the body of the inner body forming a covering groove, the covering groove covering the arc-shaped rolled edge of the outer body, forming a composite material double-layer container.

11. The composite material double-layer container as claimed in claim 10, wherein the outer layer has a tear line on its surface.

12. The composite material double-layer container as described in claim 11, wherein the tear line forms a U-shape, a rectangle, or the like.

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