Glue-free modular upholstered furniture and production process thereof

Abstract

The invention relates to the field of furniture manufacturing, in particular to glue-free modular upholstered furniture and a production process thereof. The production process comprises the following steps: proportionally blending the hot melt fibers and the PU prepolymer, mixing, injecting into a mold, implanting the magnetic film, and foaming to obtain the elastic foam; the heated supporting frame with the tenon is pressed into the foam for hot press molding, the foam is wrapped by the 3D knitted breathable fabric welded through ultrasonic waves, and finally the buckle and the spring are installed in the supporting frame. Parameters of all the steps are described in detail, such as the blending proportion of the hot melting fiber and the PU prepolymer, the foaming temperature and time, the water content of the birch and the like. The upholstered furniture manufactured based on the technology is composed of a supporting frame, elastic foam and a wrapping layer, the supporting frame and the elastic foam are connected through a mortise and tenon joint structure, the elastic foam is high-resilience polyurethane sponge with specific density, the surface of the elastic foam is covered with a magnetic film, the wrapping layer is made of breathable fabric, and buckles and springs are further arranged in the furniture.

Description

Technical Field

[0001] The present invention relates to the field of furniture manufacturing, and in particular to a glue-free modular soft furniture and a production process thereof. Background Art

[0002] As consumers' pursuit of environmental protection, personalization, and convenience continues to rise, the production process of upholstered furniture faces numerous challenges that need to be addressed. The extensive use of glue in traditional upholstered furniture production creates serious environmental issues. Harmful substances like formaldehyde contained in this glue not only evaporate in the production workshop, polluting the work environment and endangering worker health, but also continue to be slowly released during the use of the furniture, affecting indoor air quality over the long term and posing a potential threat to consumer health. For example, excessive indoor formaldehyde levels can cause respiratory illnesses, skin allergies, and even serious illnesses such as cancer.

[0003] The connection methods used for upholstered furniture components also have significant flaws. Traditionally, they often relied on gluing, nailing, or complex mortise and tenon joints. These methods either make the furniture difficult to disassemble, resulting in wasted space and increased risk of damage during transportation and installation; or they require specialized craftsmen for installation, which is costly and inefficient. For example, the inability to disassemble large sofas often requires a significant amount of space, increasing logistics costs. Furthermore, fixed components are susceptible to damage from collisions during handling. Traditional upholstered furniture also struggles to meet consumers' individual needs. Due to its fixed overall structure, it's difficult to flexibly adjust and combine to suit consumers' varying spatial layouts, usage habits, and aesthetic preferences. As consumers change their living spaces or their lifestyle needs evolve, traditional upholstered furniture often fails to adapt and is eliminated, resulting in a waste of resources. Traditional production processes also have shortcomings in terms of raw material utilization. For example, many domestic furniture factories rely primarily on manual labor for leather cutting. Due to the natural imperfections of raw leather, manual cutting is not only inefficient and prone to errors, but also results in low leather utilization and increases production costs. Summary of the Invention

[0004] To address the above-mentioned issues, the present invention aims to provide a production process and product for glue-free modular upholstered furniture. Through innovative process steps and unique structural design, the present invention achieves environmentally friendly, efficient, and personalized upholstered furniture manufacturing, thereby meeting the market's urgent demand for high-quality upholstered furniture. The specific technical solutions are as follows: A production process for glue-free modular soft furniture, comprising the following steps: S1: Precisely adjust the ratio of hot-melt fiber and PU prepolymer according to the elasticity and strength requirements of furniture parts, and fully mix them in a professional mixing equipment to obtain a mixed raw material; S2: Pour the mixed raw materials into the mold and simultaneously implant the magnetic film according to the design requirements to ensure that the film is intact without damage or displacement; S3: Foam the material in the mold, apply a stable pressure of 0.3MPa simultaneously, and precisely control the foaming temperature and time to make the raw material foam and expand, forming an elastic core layer of high-resilience polyurethane sponge with a density of ≥30kg / m³, and then cool it to shape; S4: The formed foam with magnetic film is moved to the hot pressing station. A birch frame with tenons heated to 100°C is pressed into the foam. The foam is hot pressed at 180°C ± 10°C and 0.5 MPa pressure for 30 seconds. After cooling, a mechanical interlocking structure is formed. S5: Select 3D knitted breathable fabric with a weight of ≥200g / m² and use a 2000W ultrasonic generator to weld the cut edges of the fabric to make it fit tightly to the furniture core. S6: The furniture modules that have been hot-pressed, covered and sewn are connected to the main body through mortise and tenon clips and magnetic films, and the detachable metal spring units with anti-rust treatment on the surface are connected to the main body with ABS plastic clips, and assembled into complete furniture according to the design requirements.

[0005] Preferably, in step S1, the mixing ratio of the hot-melt fiber and the PU prepolymer is, when used to make the elastic core layer of a sofa, the hot-melt fiber accounts for 15%-20%, and the PU prepolymer accounts for 80%-85%; when used to make the elastic core layer of a mattress, the hot-melt fiber accounts for 10%-15%, and the PU prepolymer accounts for 85%-90%.

[0006] Preferably, in step S2, the thickness of the magnetic film is 0.1-0.3 mm, and when the magnetic film is implanted, a positioning fixture is used to ensure that the position accuracy error of the film in the mold does not exceed ±0.2 mm.

[0007] Preferably, in step S3, the foaming temperature is controlled at 80°C-100°C, and the foaming time is determined according to the mold size and the amount of mixed raw materials. When the mold volume is less than 50L, the foaming time is 15-20 minutes; when the mold volume is greater than 50L, the foaming time is 20-30 minutes.

[0008] Preferably, in step S4, the tenon length of the birch frame is 15-20 mm, the tenon width is 8-12 mm, and the moisture content of the birch frame is controlled at 8%-12%.

[0009] Preferably, in step S5, the air permeability of the 3D knitted breathable fabric is not less than 500 mm / s, and the welding speed is 0.5-1 m / min when the ultrasonic generator is used for welding.

[0010] Preferably, in step S6, the surface anti-rust treatment of the detachable metal spring unit adopts a galvanizing process, the thickness of the galvanized layer is not less than 8 μm, and the tensile strength of the ABS plastic buckle is not less than 50 MPa.

[0011] A glue-free modular soft furniture is manufactured based on the above-mentioned production process of glue-free modular soft furniture, including a support frame, elastic foam, and a wrapping layer; a tenon is provided on the outside of the support frame, a reinforcing rod is provided on the inside of the support frame, a placement groove is provided at the bottom of the elastic foam, and a mortise is provided on the inner wall of the placement groove; the support frame is arranged in the placement groove and is tightly attached to the inner wall of the placement groove, and the support frame and the elastic foam are fixedly connected by the tenon and the mortise; a number of groups of buckles are symmetrically provided on both side walls inside the support frame, a spring is commonly provided between the two symmetrical buckles in each group, and the spring is tightly attached to the end face of the placement groove; the wrapping layer is a 3D knitted breathable fabric with a gram weight ≥ 200g / m², and the wrapping layer is wrapped around the outer surface of the elastic foam group.

[0012] Preferably, the elastic foam is a high-resilience polyurethane sponge with a density of ≥30kg / m³ formed by mixing hot-melt fiber and PU prepolymer, the hot-melt fiber accounts for 15%-20% of the elastic foam, and the PU prepolymer accounts for 80%-85%; when the soft furniture is a mattress, the hot-melt fiber accounts for 10%-15% of the elastic foam, and the PU prepolymer accounts for 85%-90%.

[0013] Preferably, the surface of the elastic foam is coated with a magnetic film, and the thickness of the magnetic film is 0.1-0.3 mm.

[0014] The beneficial effects of the present invention are: 1. The present invention does not require the use of glue during the entire production process and product assembly, thus avoiding the pollution of indoor environment by volatile organic compounds such as formaldehyde and benzene contained in glue in traditional furniture production, and reducing potential harm to human health. The furniture is particularly suitable for use in homes and offices that value environmental protection and health.

[0015] 2. Since the components of the present invention are physically connected through mechanical interlocking, magnetic connection, mortise and tenon fasteners, rather than chemical bonding, the modular components can be disassembled and separated more conveniently after the furniture is discarded. The elastic core layer formed by the mixture of hot-melt fiber and PU prepolymer, the birch frame, 3D knitted fabric, metal spring unit and other materials can be recycled separately, reducing resource waste and environmental pollution, and conforming to the concept of circular economy.

[0016] 3. This invention precisely adjusts the ratio of hot-melt fiber to PU prepolymer based on the different functional requirements of furniture components. Combined with the controlled foaming in S3 to form a high-rebound polyurethane sponge with a density of ≥30kg / m³, the elastic core layer can meet the sitting support requirements of the sofa while also adapting to the sleeping support performance of the mattress, achieving a balance between comfort and durability.

[0017] 4. The present invention uses a positioning fixture to ensure that the position accuracy error of the magnetic film is ≤±0.2mm. In S4, the birch frame is hot-pressed into the foam under specific temperature and pressure to form a mechanical interlocking structure. Combined with the mortise and tenon buckles, magnetic adsorption and ABS plastic buckle connections in S6, the connection between each module is tight and firm, reducing loosening and displacement problems during use, and improving the overall structural stability and service life of the furniture.

[0018] 5. In the present invention S5, a 3D knitted breathable fabric with a gram weight of ≥200g / m² and an air permeability of not less than 500mm / s is selected. Combined with an ultrasonic welding process, the fabric is ensured to fit tightly to the inner core without obstructing air circulation, effectively improving the breathability of the furniture, reducing dampness and stuffiness, and enhancing user comfort.

[0019] 6. The tenon design of the birch frame of the present invention is combined with the hot pressing process, which not only utilizes the strength and supporting characteristics of the wood, but also reduces the impact of wood deformation on the structure by controlling the moisture content; the thickness of the magnetic film is controlled at 0.1-0.3mm, while ensuring the magnetic adsorption effect, avoiding excessive impact on the thickness and elasticity of the elastic core layer.

[0020] 7. The galvanized anti-rust treatment of the metal spring unit of the present invention and the tensile strength of the ABS plastic buckle ≥ 50 MPa improve the corrosion resistance and connection reliability of the components, maximizing the utilization of material properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The invention discloses a production process for glue-free modular soft furniture.

[0022] Figure 2 The figure is a cross-sectional schematic diagram of a glue-free modular soft furniture according to the present invention.

[0023] Figure 3 This is a schematic diagram of the relationship between the elastic core layer and the supporting frame of a glue-free modular soft furniture according to the present invention.

[0024] Figure 4 This is a schematic diagram of the support frame and spring unit of a glue-free modular soft furniture.

[0025] In the figure: In the figure: 1. Support frame; 2. Elastic foam; 3. Wrapping layer; 4. Magnetic film; 5. Buckle; 6. Spring; 7. Reinforcement rod; 8. Tenon; 9. Mortise; 10. Placement slot. DETAILED DESCRIPTION

[0026] A production process for glue-free modular soft furniture, comprising the following steps: S1: Precisely adjust the ratio of hot-melt fiber and PU prepolymer according to the elasticity and strength requirements of furniture parts, fully mix them in a professional stirring device to obtain a mixed raw material, inject the mixed raw material into the mold, and simultaneously implant the magnetic film 4 according to the design requirements, ensuring that the magnetic film 4 is intact without damage or displacement; S2: Foam the material in the mold, apply a stable pressure of 0.3MPa simultaneously, and precisely control the foaming temperature and time to make the raw material foam and expand. After cooling and shaping, an elastic foam 2 of a high-resilience polyurethane sponge with a density of ≥30kg / m³ is obtained; S3: The molded foam with the magnetic film is moved to a hot pressing station, and the support frame 1 heated to 100°C and provided with the tenon 8 is pressed into the elastic foam 2, so that the tenon 8 and the mortise 9 are locked together. The molded foam is hot pressed at 180°C ± 10°C and a pressure of 0.5 MPa for 30 seconds to obtain a semi-finished furniture product with the support frame 1 and the elastic foam 2. S4: Select a 3D knitted breathable fabric with a weight of ≥200g / m² and use an ultrasonic generator with a power of 2000W to weld the cut edges of the fabric to obtain a wrapping layer 3, making it fit tightly against the elastic foam 2; S5: Turn over the semi-finished furniture with the support frame 1, the elastic foam 2, and the wrapping layer 3, and fix several groups of buckles 5 on the inner side walls of the support frame 1, and set a spring 6 between two symmetrical buckles 5 in each group.

[0027] In step S1 , when the elastic foam 2 is prepared, the hot-melt fiber accounts for 15%-20% and the PU prepolymer accounts for 80%-85%.

[0028] In step S1 , the thickness of the magnetic film 4 is 0.1-0.3 mm. When the magnetic film 4 is implanted, a positioning fixture is used to ensure that the position accuracy error of the film in the mold does not exceed ±0.2 mm.

[0029] In step S2, the foaming temperature is controlled at 80°C-100°C, and the foaming time is determined according to the mold size and the amount of mixed raw materials. When the mold volume is less than 50L, the foaming time is 15-20 minutes; when the mold volume is greater than 50L, the foaming time is 20-30 minutes.

[0030] In step S3, the support frame 1 is made of birch, and the moisture content of the birch is controlled at 8%-12%.

[0031] In step S4, the air permeability of the 3D knitted breathable fabric is not less than 500 mm / s, and the welding speed is 0.5-1 m / min when the ultrasonic generator is used for welding.

[0032] In step S5 , the surface of the spring 6 is subjected to rust prevention treatment by a galvanizing process, the thickness of the galvanized layer is not less than 8 μm, and the tensile strength of the buckle 5 is not less than 50 Ma.

[0033] A glue-free modular soft furniture is manufactured based on the above-mentioned production process of glue-free modular soft furniture, characterized in that it includes a support frame, elastic foam, and a wrapping layer; A tenon is provided on the outside of the support frame, a reinforcing rod is provided on the inside of the support frame, a placement groove is provided at the bottom of the elastic foam, and a mortise is provided on the inner wall of the placement groove; The support frame is arranged in the placement groove and is close to the inner wall of the placement groove. The support frame and the elastic foam are fixedly connected by the tenon and mortise. Several groups of buckles are symmetrically arranged on both side walls of the support frame, and a spring is arranged between the two symmetrical buckles in each group, and the spring is tightly attached to the end surface of the placement slot; The wrapping layer is a 3D knitted breathable fabric with a gram weight ≥ 200g / m², and the wrapping layer is wrapped around the outer surface of the elastic foam group.

[0034] Elastic foam is a high-resilience polyurethane sponge with a density of ≥30kg / m³ formed by mixing hot-melt fiber and PU prepolymer. The hot-melt fiber accounts for 15%-20% of the elastic foam, and the PU prepolymer accounts for 80%-85%; when the soft furniture is a mattress, the hot-melt fiber accounts for 10%-15% of the elastic foam, and the PU prepolymer accounts for 85%-90%.

[0035] The surface of the elastic foam is covered with a magnetic film, and the thickness of the magnetic film is 0.1-0.3mm.

Claims

1. A production process for glue-free modular soft furniture, characterized in that: The following steps are involved: S1: The hot-melt fiber and the PU prepolymer are precisely mixed in proportion according to the elasticity and strength requirements of the furniture parts, and are fully mixed in a professional stirring device to obtain a mixed raw material. The mixed raw material is injected into the mold, and the magnetic film (4) is implanted at the same time according to the design requirements to ensure that the magnetic film (4) is intact without damage or displacement; S2: Foaming the material in the mold, applying a stable pressure of 0.3 MPa simultaneously, and precisely controlling the foaming temperature and time to allow the raw material to foam and expand, and cooling and shaping to obtain an elastic foam (2) of a high-resilience polyurethane sponge with a density ≥30 kg / m³; S3: The formed foam with the magnetic film is moved to a hot pressing station, and the support frame (1) heated to 100°C and provided with the tenon (8) is pressed into the elastic foam (2), so that the tenon (8) and the mortise (9) are locked with each other, and hot pressing is performed at 180°C ± 10°C and 0.5 MPa pressure for 30 seconds to obtain a semi-finished furniture product with the support frame (1) and the elastic foam (2); S4: Select a 3D knitted breathable fabric with a gram weight of ≥200g / m², and use an ultrasonic generator with a power of 2000W to weld the cut edges of the fabric to obtain a wrapping layer (3) so that it fits tightly with the elastic foam (2); S5: Furniture semi-finished product with support frame (1), elastic foam (2), and wrapping layer (3) is turned over, and several groups of buckles (5) are fixedly installed on the inner side walls of support frame (1), and springs (6) are arranged between two symmetrical buckles (5) in each group.

2. The production process of a glue-free modular soft furniture according to claim 1, characterized in that: In the step S1, the mixing ratio of the hot-melt fiber and the PU prepolymer is such that, when used to make the elastic foam (2), the hot-melt fiber accounts for 15%-20% and the PU prepolymer accounts for 80%-85%.

3. The production process of a glue-free modular soft furniture according to claim 1, characterized in that: In the step S1, the thickness of the magnetic film (4) is 0.1-0.3 mm. When the magnetic film (4) is implanted, a positioning fixture is used to ensure that the position accuracy error of the film in the mold does not exceed ±0.2 mm.

4. The production process of a glue-free modular soft furniture according to claim 1, characterized in that: In the step S2, the foaming temperature is controlled at 80°C-100°C, and the foaming time is determined according to the mold size and the amount of mixed raw materials. When the mold volume is less than 50L, the foaming time is 15-20 minutes; when the mold volume is greater than 50L, the foaming time is 20-30 minutes.

5. The production process of a glue-free modular soft furniture according to claim 1, characterized in that: In the step S3, the support frame (1) is made of birch, and the moisture content of the birch is controlled at 8%-12%.

6. The production process of a glue-free modular soft furniture according to claim 1, characterized in that: In step S4, the air permeability of the 3D knitted breathable fabric is not less than 500 mm / s, and the welding speed is 0.5-1 m / min when the ultrasonic generator is used for welding.

7. The production process of glue-free modular soft furniture according to claim 1, characterized in that: In the step S5, the surface rust prevention treatment of the spring (6) adopts a galvanizing process, the thickness of the galvanized layer is not less than 8 μm, and the tensile strength of the buckle (5) is not less than 50 Ma.

8. A glue-free modular soft furniture manufactured based on the production process of glue-free modular soft furniture according to any one of claims 1 to 7, characterized in that: Including support frame, elastic foam and wrapping layer; The outer side of the support frame is provided with a tenon, the inner side of the support frame is provided with a reinforcing rod, the bottom of the elastic foam is provided with a placement groove, and the inner wall of the placement groove is provided with a mortise; The support frame is arranged in the placement groove and is close to the inner wall of the placement groove, and the support frame and the elastic foam are fixedly connected by the tenon and the mortise; The inner side walls of the support frame are symmetrically provided with a plurality of groups of buckles, and a spring is provided between the two symmetrical buckles of each group, and the spring is closely attached to the end surface of the placement groove; The wrapping layer is a 3D knitted breathable fabric with a gram weight of ≥200g / m², and the wrapping layer is wrapped around the outer surface of the elastic foam group.

9. The glue-free modular soft furniture according to claim 8, characterized in that: The elastic foam is a high-resilience polyurethane sponge with a density of ≥30kg / m³ formed by mixing hot-melt fibers and PU prepolymers. The hot-melt fibers account for 15%-20% of the elastic foam, and the PU prepolymer accounts for 80%-85%; when the soft furniture is a mattress, the hot-melt fibers account for 10%-15% of the elastic foam, and the PU prepolymer accounts for 85%-90%.

10. The glue-free modular soft furniture according to claim 9, characterized in that: The surface of the elastic foam is coated with a magnetic film, and the thickness of the magnetic film is 0.1-0.3 mm.

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