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US-12617166-B2 - Composite inner cup and double-layer cup manufacturing method

US12617166B2US 12617166 B2US12617166 B2US 12617166B2US-12617166-B2

Abstract

The invention relates to a composite inner cup and double-layer cup manufacturing method. First, a metal cup body with a top convex ring is prefabricated. Then, a lower ring is placed in a mold, and the metal cup body is placed with the lower ring positioned at the bottom edge of the top convex ring. Next, an upper ring is placed on the inner side of the top convex ring. Then, upon closing the mold, the upper and lower rings are clamped. And then, injection processing is performed on the periphery of the top convex ring, so that the cup rim portion is injected and integrated with the upper and lower rings to cover the top convex ring to complete an inner cup. Finally, the outer cup and the cup rim portion of the inner cup can be combined by ultrasonic welding to form a composite double-layer cup.

Inventors

  • TSAI-HUI LIN

Assignees

  • TSAI-HUI LIN

Dates

Publication Date
20260505
Application Date
20240408

Claims (6)

  1. 1 . A composite inner cup manufacturing method, mainly by injecting a cup rim portion of a metal cup body using a mold, comprising the steps of: S 1 ) prefabricating the metal cup body: prefabricating the metal cup body, and forming an annular top convex ring at an opening of the metal cup body; S 2 ) preparing a mold: setting up a female mold and a corresponding male mold, wherein the female mold has a mold cavity for holding the metal cup body, a cup rim space forming the cup rim portion is provided in the mold cavity corresponding to the top convex ring of the metal cup body, and a stepped bottom edge formed between the cup rim space and the mold cavity, wherein the male mold has a module arranged corresponding to the mold cavity, and a stepped pressing edge formed on the module corresponding to the cup rim space; S 3 ) placing an upper ring and a lower ring: prefabricating the upper ring and the lower ring, wherein placing the lower ring on the bottom edge of the mold cavity, and placing the metal cup body into the mold cavity of the female mold, so that the top convex ring of the metal cup body is pressed against the lower ring, and then placing the upper ring on an inner end surface of the top convex ring; S 4 ) closing the mold: closing the male mold to the female mold so that an underside of the top convex ring of the metal cup body is pressed against the lower ring and the upper ring is placed on an inner end surface of the top convex ring; and S 5 ) injecting molding: injecting plastic into the cup rim space through injection molding, allowing the plastic to melt and fuse together with the upper ring placed on the inner end surface of the top convex ring and the lower ring pressed against the underside of the top convex ring of the metal cup body, thereby integrally forming the cup rim portion, which encloses both the inner end surface and an outer side of the top convex ring.
  2. 2 . The composite inner cup manufacturing method as claimed in claim 1 , wherein the upper ring, the lower ring, and the cup rim portion are made of the same material.
  3. 3 . A composite double-layer cup manufacturing method, comprising the steps of: S 1 ) prefabricating the metal cup body: prefabricating the metal cup body, and forming an annular top convex ring at an opening of the metal cup body; S 2 ) preparing a mold: setting up a female mold and a corresponding male mold, wherein the female mold has a mold cavity for holding the metal cup body, a cup rim space forming the cup rim portion is provided in the mold cavity corresponding to the top convex ring of the metal cup body, and a stepped bottom edge formed between the cup rim space and the mold cavity, wherein the male mold has a module arranged corresponding to the mold cavity, and a stepped pressing edge formed on the module corresponding to the cup rim space; S 3 ) placing an upper ring and a lower ring: prefabricating the upper ring and the lower ring, wherein placing the lower ring on the bottom edge of the mold cavity, and placing the metal cup body into the mold cavity of the female mold, so that the top convex ring of the metal cup body is pressed against the lower ring, and then placing the upper ring on an inner end surface of the top convex ring; S 4 ) closing the mold: closing the male mold to the female mold so that an underside of the top convex ring of the metal cup body is pressed against the lower ring and the upper ring is placed on an inner end surface of the top convex ring; S 5 ) injecting molding: injecting plastic into the cup rim space through injection molding, allowing the plastic to melt and fuse together with the upper ring placed on the inner end surface of the top convex ring and the lower ring pressed against the underside of the top convex ring of the metal cup body, thereby integrally forming the cup rim portion, which encloses both the inner end surface and an outer side of the top convex ring to complete an inner cup; S 6 ) prefabricating an outer cup: using a plastic material that is different from the metal cup body of the inner cup to make the outer cup; and S 7 ) joining the two cups: placing the inner cup into the outer cup, and correspondingly combining the cup rim portion of the inner cup with the opening of the outer cup to complete the double-layer cup.
  4. 4 . The composite double-layer cup manufacturing method as claimed in claim 3 , wherein the upper ring, the lower ring and the cup rim portion are made of the same material.
  5. 5 . The composite double-layer cup manufacturing method as claimed in claim 3 , wherein the outer cup and the cup rim portion of the inner cup are made of the same material.
  6. 6 . The composite double-layer cup manufacturing method as claimed in claim 3 , wherein the outer cup and the cup rim portion of the inner cup are combined by ultrasonic welding.

Description

BACKGROUND OF THE PRESENT INVENTION Field of Invention The present invention relates to a composite inner cup and double-layer cup manufacturing method, in particular to a manufacturing method of a composite double-layer cup that is used in a metal inner cup and a plastic outer cup. Description of Related Arts Currently, thermal cups are mostly made of plastic, stainless steel, or ceramic materials. Plastic thermal cups are not heat-resistant and easily release toxic substances when heated, making them unsuitable for tea, coffee, and other hot beverages. Stainless steel thermal cups are mostly made of double-layer cup bodies using vacuum technology, resulting in high production costs. In recent years, ceramic thermal cups have gained popularity among consumers due to their good texture, good thermal insulation effect, and non-leaching heavy metals or toxic substances when used to hold hot drinks. Most eco-friendly and thermal insulation cups for containing high-temperature hot drinks such as hot coffee and hot tea adopt a double-layer structure, which reduces heat conduction by the distance between the inner and outer cups, allowing the temperature of the inner cup with the hot drink to be slow or unable to transfer to the outer cup held by hand, thus avoiding the situation of scalding. The main problem to be solved when using a double-layer cup is how to connect the inner and outer cups, and the next problem is how to ensure that liquid does not seep into the gap between the inner and outer cups. When the inner and outer cups are both made of plastic materials, the inner and outer cups will have different shrinkage rates after injection molding due to uneven inner and outer wall thicknesses, which will cause the problem of inaccurate matching dimensions of the inner and outer cups, thus affecting the assembly accuracy and quality of the finished double-layer cup. As a result, most plastic double-layer cups use high-frequency bonding between the inner and outer cups, or, as described in Taiwan Patent No. M639368, use a screw assembly relationship to allow the easy disassembly or combination of the inner cup and outer cup. However, the aforementioned plastic inner cup is not heat-resistant and easily releases toxic substances when heated, and the cup body with screw disassembly cannot have good thermal insulation and isolation. Therefore, the industry is actively developing composite double-layer cups, which use a plastic ring to bond the opening end of the metal inner cup, and are fixed by combining the plastic ring and the plastic outer cup. However, this technology has the following disadvantages: 1. Complex processing procedures. The process requires the preparation of a plastic ring first, and the plastic ring needs to have a groove for the metal inner cup to fit into. Then, an adhesive that can bond with the plastic outer cup is applied to the groove, which needs to be manually bonded and fixed. This process involves multiple steps and is time-consuming and labor-intensive.2. The metal inner cup is often used alternately between hot and cold, which can easily cause the adhesive to deteriorate or dissolve. The dissolved adhesive is harmful to the human body.3. When the adhesive deteriorates or dissolves, gaps are formed that can easily accumulate dirt and are difficult to clean, which is not hygienic in use. SUMMARY OF THE PRESENT INVENTION The main purpose of the present invention is to provide a composite inner cup and double-layer cup manufacturing method, particularly a method for manufacturing a composite double-layer cup including a metal inner cup and a plastic outer cup. The main purpose and effect of the composite inner cup and double-layer cup manufacturing method of the present invention are achieved by the following specific technical means: it mainly prefabricates a metal cup body with a top convex ring. Then, a lower ring is placed in a mold, and the metal cup body is placed with the lower ring positioned at the bottom edge of the top convex ring. Next, an upper ring is placed on the inner side of the top convex ring. During closing of the mold, the upper and lower rings are clamped, and the top convex ring of the metal cup body is positioned by the upper and lower rings. Then, injection processing is performed on the periphery of the top convex ring of the metal cup body corresponding to the mold, so that the cup rim portion is injected and integrated with the upper and lower rings to cover the top convex ring, thereby completing the production of an inner cup. In this way, the outer cup and the cup rim portion of the inner cup are made of the same material and can be combined by ultrasonic welding to form a composite double-layer cup, which reduces the processing procedures and has the advantages and effects of being safe, non-toxic and hygienic in use. A preferred embodiment of the composite inner cup and double-layer cup manufacturing method of the present invention, wherein the compos