Double-layer composite floor and preparation method thereof

Abstract

The present invention relates to a floor, in particular to a double-layer composite floor and a preparation method thereof; belonging to the technical field of floor manufacturing. It comprises a hard core layer and an elastic surface layer, wherein the elastic surface layer covers the hard core layer at least on the upper surface and part of the side surface of the floor; and a matching structure is formed between the hard core layer and the elastic surface layer; the matching structure comprises a plurality of unit elements formed on the surface of the hard core layer and a plurality of corresponding elements formed on the surface of the elastic surface layer; the unit element is a strip structure with a convex or concave cross-section arranged along the length direction of the floor. The present invention arranges a matching structure between the elastic surface layer and the hard foam core layer, so that the elastic surface layer is firmly covered on the hard foam core layer, so that the present invention has the advantages of both the hard foam core layer and the elastic surface layer, and has high compressive strength and good surface contact.

Description

Technical Field

[0001] The invention relates to a floor, in particular to a double-layer composite floor and a preparation method thereof, and belongs to the technical field of floor manufacturing. Background Art

[0002] Elastomers such as rubber, synthetic rubber, and thermoplastic elastomers have good touch, soft texture, and good elasticity. This makes the boards with elastomeric surfaces have incomparable advantages in decoration compared to other polymer materials.

[0003] The patent application document with the international publication number WO2018 / 154287 A1 discloses a low heat absorption and flame retardant polyurethane wood-like material, and the polyurethane board produced by the material has the characteristics of surface flame retardancy, low heat absorption, antibacterial and soft touch. However, the material belongs to polyurethane foam material. When used as flooring, the bending strength of the polyurethane board is low and the material cost is high. At the same time, since polyurethane is a flammable material, a large amount of flame retardant needs to be added to meet the use requirements. Summary of the invention

[0004] The present invention aims to solve the above problems and thus provides a double-layer composite floor.

[0005] The technical solution of the present invention to solve the above problems is as follows:

[0006] A double-layer composite floor, comprising a hard core layer with a Shore hardness of more than 80HD and an elastic surface layer with a Shore hardness of less than 40HD, wherein the elastic surface layer covers the hard core layer on the upper surface and at least part of the side surface of the floor; a matching structure is arranged between the elastic surface layer and the hard core layer, wherein the matching structure comprises a plurality of unit elements formed on the surface of the hard core layer and a plurality of corresponding elements formed on the surface of the elastic surface layer; the unit element is a strip-shaped structure with a convex or concave cross-section arranged along the length direction of the floor;

[0007] When the cross section of the single element is in a convex shape, the corresponding element is a convex matching element with a concave cross section covering the convexity;

[0008] When the cross section of the unit element is in the shape of a groove, the corresponding element is a groove matching element embedded in the groove and having a convex cross section;

[0009] The material of the elastic surface layer is selected from one or more of natural rubber, synthetic rubber or thermoplastic elastomer;

[0010] The hard core layer is selected from one of metal profiles, wood-plastic hot extruded solid board, wood-plastic hot extruded hollow board, hard foamed self-skinning board, hard foamed co-extruded coated board, and hard foamed co-extruded coated reinforced board.

[0011] In the above technical solution of the present invention, the elastic surface layer and the hard core layer are connected by a matching structure, so it is no longer required that the elastic surface layer and the hard core layer have good compatibility in material selection, which can significantly expand the range of material selection. The material selected for the hard core layer is above Shore hardness 80HD, such as polyethylene, polyethylene mixed with wood powder, polyvinyl chloride, polyvinyl chloride mixed with wood powder or stone powder, and common metals. At the same time, in order to reduce the overall weight of the floor, the hard core layer can also be made into a hollow structure, or the hard core layer can be made into a hard foam filling body. Further, the material of the hard core layer can be a polyethylene wood-plastic material with a hollow structure, a hard polyvinyl chloride foam material, or a metal profile with a hollow structure. Further, the hard core layer is selected from one of aluminum alloy profiles, wood-plastic hot extrusion solid board, wood-plastic hot extrusion hollow board, hard foam self-skin board, hard foam co-extruded coated board, and hard foam co-extruded coated reinforced board.

[0012] The material of the elastic surface layer may be one or more of natural rubber, synthetic rubber or thermoplastic elastomer.

[0013] For the convenience of description, the surface of the hard core layer in contact with the elastic surface layer is hereinafter referred to as surface A, and the surface of the elastic surface layer in contact with the hard core layer is hereinafter referred to as surface B. Surface A has a plurality of unit elements, and surface B has a plurality of corresponding elements.

[0014] In the above technical solution of the present invention, the metal profile is a profile made by metal processing technology and is suitable for use as a hard core layer of a composite floor, such as an aluminum alloy profile. Its upper surface and side surfaces are in direct contact with the elastic surface layer, thus constituting the surface A and having all the characteristics of the above surface A.

[0015] In the above technical solution of the present invention, the wood-plastic hot extruded solid board refers to a solid board prepared by mixing resin raw materials, plant fiber powder and processing aids through a conventional hot extrusion process, and the upper surface and side surface of the board also constitute the surface A and have all the characteristics of the above surface A. In the board, the commonly used plastic is polyolefin, more commonly polyethylene and polypropylene.

[0016] In the above technical solution of the present invention, the raw materials used for the wood-plastic hot extrusion hollow board are the same as those used for the wood-plastic hot extrusion solid board, but the processing molds are different. Because the mold has a core rod extending out of the die opening, the board forms a hollow structure at the corresponding position of the core rod. Similarly, the upper surface and side surface of the wood-plastic hot extrusion hollow board constitute the surface A, and have all the characteristics of the surface A.

[0017] In the above technical solution of the present invention, the rigid foamed self-skinning board is a rigid board prepared by a foaming extrusion process using raw materials containing resin and foaming agent, and the board has a self-skinning layer, and the thickness of the self-skinning layer is usually between 0.1 and 1.0 mm. Because the inventors consider that the mechanical properties of the rigid PU foamed board are low and the cost is high; therefore, in the present invention, the rigid foamed self-skinning board specifically refers to the rigid PVC foamed self-skinning board made of PVC resin. Due to the different properties of PVC and elastomer materials and the poor compatibility between the two, this composite board cannot be produced according to the previous process of PU board, because no matter whether the composite floor is produced by molding or co-extrusion, the elastomer surface layer and the PVC foam core layer will have the problem of weak bonding. In view of this, the present invention sets a matching structure between the rigid core layer and the elastic surface layer; through the mutual interlocking relationship of the above matching structure, the elastic surface layer is firmly bonded to the rigid core layer as the substrate to avoid cracking between the core and the surface layers.

[0018] In the above technical solution of the present invention, the rigid foamed co-extruded coated board is realized by co-extruding and wrapping a layer of rigid plastic layer on the basis of the above rigid foamed self-skinning board; this is based on the fact that the thickness of the self-skinning layer is relatively thin at 0.1~1.0mm, and the mechanical properties need to be improved.

[0019] In the above technical solution of the present invention, the rigid foam co-extruded coated reinforced plate is a reinforced plate with better mechanical properties than the above rigid foam co-extruded coated plate by adding a reinforcing layer between the co-extruded coating layer and the rigid foam core layer of the plate. The reinforcing layer is formed by impregnating glass fiber mesh cloth with resin and then curing; considering the convenience of processing, it is preferably not completely cured, and has a certain degree of flexibility in production, such as the degree of curing can be 92~98%.

[0020] As a preferred embodiment of the above technical solution, the matching structure also includes multiple first connection units and multiple second connection units; the first connection unit is formed by the surface of the hard core layer in contact with the elastic surface layer, and is arranged between two adjacent unit components; the second connection unit is formed by the surface of the elastic surface layer in contact with the hard core layer, and is arranged between two adjacent corresponding components; the first connection unit and the second connection unit are matched and arranged.

[0021] As a preferred embodiment of the above technical solution, when the cross section of the unit element is in a convex shape, the convex matching component with a concave cross section has a necking structure;

[0022] When the cross section of the unit element is in a groove shape, the unit element with the groove shape in cross section has a necking structure.

[0023] In the above technical solution of the present invention, the shrinkage structure refers to a component with a horizontal surface having a recessed portion, and the internal space of the recessed portion is wide while the connection between the recessed portion and the horizontal surface is relatively narrow, so a shrinkage structure is formed at the connection, so that after a second component with a corresponding structure is matched with the recessed portion, the second component is difficult to escape from the recessed portion with the shrinkage structure, thereby greatly improving the bonding force between the component and the second component.

[0024] As a preferred embodiment of the above technical solution, the surface of the hard core layer in contact with the elastic surface layer and the surface of the elastic surface layer in contact with the hard core layer are provided with the unit components and corresponding components at the transitional connection between the horizontal and vertical directions of the floor.

[0025] As a preferred embodiment of the above technical solution, the surface of the first connection unit and the second connection unit is a plane or a surface with a sawtooth cross section. It is a common setting that the surface of the first connection unit and the second connection unit is a plane, and when the cross section of the surface of the first connection unit and the second connection unit is a sawtooth surface, the contact area between the surface A and the surface B can be significantly increased, and the resistance generated between the elastic surface layer and the hard core layer when subjected to horizontal force can also be significantly increased, thereby improving the bonding force and strain resistance between the elastic surface layer and the hard core layer.

[0026] As a preferred embodiment of the above technical solution, the rigid foamed self-skinning board material is composed of a rigid foamed core formed of a first foaming raw material containing a first resin and a skinning layer also formed of the first foaming raw material and covering the rigid foamed core.

[0027] As a preferred embodiment of the above technical solution, the rigid foam co-extruded coated plate is composed of a rigid foam core, a skin layer covering the rigid foam core, and a co-extruded shell covering the skin layer; the rigid foam core and the skin layer are formed of a first raw material including a first resin and a foaming agent, and the co-extruded shell is formed of a second raw material including a second resin and no foaming agent. The second resin and the first resin may be the same or different.

[0028] In the above technical solution of the present invention, the rigid foamed co-extruded coated reinforced plate is composed of a rigid foamed core, a glass fiber reinforced layer and a co-extruded shell, wherein the glass fiber reinforced layer is arranged between the rigid foamed core and the co-extruded shell; the rigid foamed core and the crust layer are formed by a first raw material including a first resin and a foaming agent, and the co-extruded shell is formed by a second raw material including a second resin and no foaming agent; the glass fiber reinforced layer is formed by curing a glass fiber mesh cloth impregnated with a resin. The second resin and the first resin may be the same or different.

[0029] In the above technical solution of the present invention, the foaming agent includes both chemical foaming agents, such as those added to the resin raw material in the form of materials; and physical foaming agents, such as those not added to the raw materials, but introduced into the supercritical carbon dioxide fluid through another inlet of the extruder, and then mixed with the resin raw material inside the extruder.

[0030] In the above technical solution of the present invention, a glass fiber reinforcement layer is arranged in the hard core layer to improve the mechanical strength of the hard core layer, thereby ultimately improving the mechanical properties of the entire board, especially improving the bending modulus of the entire board; so that the entire board still exhibits good bending resistance at a larger span; this can significantly reduce the amount of keels used, bringing great convenience to installation, transportation, and cost control.

[0031] Another object of the present invention is to provide a method for producing the above-mentioned double-layer composite floor.

[0032] A method for producing a double-layer composite floor comprises the following steps:

[0033] a. providing a casting mold, spraying a mold release agent into the casting mold, and pouring a liquid raw material for forming an elastic surface layer into the casting mold after drying to form an elastic surface layer precursor with a thickness of a; the elastic surface layer precursor is an uncured and fluid liquid;

[0034] b. placing the hard core layer having the unit elements on the upper and side surfaces into the casting mold;

[0035] c. applying a pressure to the hard core layer to make it lower in the mold, so that the elastic surface layer precursor rises along the gap between the inner wall of the mold and the surrounding contour of the hard core layer, and at least overflows the unit element on the side surface of the hard core layer, so that the thickness of the elastic surface layer precursor decreases from a to b;

[0036] d. Maintaining the pressure applied in step c to solidify the elastic surface layer precursor in the mold to obtain the double-layer composite floor.

[0037] In the above technical solution of the present invention, the hard core layer is prefabricated and made into a board by a molding method. The advantage of the molding method over other methods is that the pattern or design of the mold can be very clearly copied, so that the appearance simulation of the board reaches an extremely high level, and the grade of the board is significantly improved. The present invention places the hard core layer having the unit element on at least the upper surface and the side surface in the center into a mold containing an elastic surface layer precursor with a thickness of a, and then applies pressure to form a fitting structure with the elastic surface layer and the unit element, and covers the hard core layer, and finally forms a double-layer composite floor with an elastomeric surface layer covering the hard core layer.

[0038] In the above technical solution of the present invention, the thickness of the elastic surface layer precursor in step c becomes b, which means that the original thickness of the elastic surface layer precursor becomes thinner due to coating the hard core layer, so the original thickness is reduced from a to b.

[0039] As a preferred embodiment of the above technical solution, the gaps around the inner wall of the casting mold and the hard core layer are of equal width.

[0040] As a preferred embodiment of the above technical solution, the casting mold is a casting mold with a wood texture.

[0041] As a preferred embodiment of the above technical solution, the hard core layer is a hard foam co-extruded coated reinforced plate; the equipment used to prepare the hard foam co-extruded coated reinforced plate includes a main extruder, an auxiliary extruder, a co-extrusion die and a shaping die;

[0042] The co-extrusion mold is formed by docking a plurality of mold plates including a mold feed plate, a flow channel forming plate, and a mold discharge plate; the co-extrusion mold is provided with a main flow channel, a reinforcement material channel, and a co-extrusion flow channel, and the main flow channel, the reinforcement material channel, and the co-extrusion flow channel are independent of each other in the mold; the reinforcement material channel includes a first channel and a second channel distributed on both sides of the main flow channel, and the first channel and the second channel form a first discharge port and a second discharge port located on both sides of the main flow channel discharge port on the mold discharge plate; the co-extrusion flow channel forms a surface discharge port on the mold discharge plate, and the surface discharge port is a rectangular ring structure and is sleeved around the main flow channel discharge port, and the first discharge port and the second discharge port are arranged between the main flow channel discharge port and the surface discharge port;

[0043] The surface discharge port is provided with a structure corresponding to the shape of the unit element;

[0044] The reinforcing material channel comprises an input section and an output section, wherein the input section is connected to the output section; the angle between the input section and the main channel gradually decreases along the material feeding direction until it is zero; the reinforcing material feed port of the input section is arranged on the channel forming plate;

[0045] The co-extrusion flow channel comprises a feed section, a casting section and a molding section which are interconnected. The main part of the feed section is arranged on the second flow channel forming plate of the co-extrusion mold, the main body of the casting section is arranged on the first flow channel forming plate of the mold, and the molding section is arranged on the discharge plate of the mold; the feed section forms two branch channels on the second flow channel forming plate, and the casting section is two mutually interconnected inclined channels formed on the first flow channel forming plate; the branch channels are connected to the inclined channels, and the inclined channels are connected to the molding section; the inner end face of the discharge plate of the mold is connected to the outer end face of the first flow channel forming plate, and the inner end face of the first flow channel forming plate is connected to the outer end face of the second flow channel forming plate; the rectangular annular structure of the cross section of the molding section gradually shrinks in size along the discharge direction, and forms the surface discharge port on the discharge plate of the mold;

[0046] The method for preparing the rigid foamed co-extruded coated reinforced sheet is as follows:

[0047] A first raw material including a first resin and a foaming agent is fully mixed and then fed into a main extruder, and the main extruder extrudes the first raw material into a main channel of a mold, and then extrudes the first raw material from the main channel to form a pressure-retaining core;

[0048] At the same time, two glass fiber reinforcement layers are input from the first channel and the second channel respectively;

[0049] At the same time, the second raw material containing the second resin and not containing the foaming agent is fully mixed and fed from the coextrusion flow channel of the coextrusion die through the auxiliary extruder, and extruded from the surface layer outlet to obtain a coextrusion shell with a frame-shaped cross section;

[0050] The pressure-retaining core, the glass fiber reinforced layer and the co-extruded shell are extruded from their respective flow channels to form a mold blank; at the same time, the mold blank is passed into a shaping die, and the pressure-retaining core is foamed in the co-extruded shell constrained by the inner wall of the shaping die in the shaping die to fill the co-extruded shell, and at the same time, the mold blank is compounded and shaped in the shaping die to form the hard core layer; the mold blank is composed of a pressure-retaining core, a glass fiber reinforced layer and a co-extruded shell from the inside to the outside, and a preformed foaming space is provided between the pressure-retaining core and the co-extruded shell.

[0051] In the above technical solution of the present invention, the entire co-extrusion mold is formed by a mold feed plate, a plurality of flow channel forming plates and a mold discharge plate. The mold feed plate and the mold discharge plate are respectively arranged at the two ends of the mold, and the plurality of flow channel forming plates are arranged between the mold feed plate and the mold discharge plate. According to the method of using the co-extrusion mold, the mold plate at one end where the material enters is the mold feed plate, and the mold plate at one end where the product is extruded is the mold discharge plate. The plurality of flow channel plates are arranged in such a way that the first flow channel forming plate is the closest to the mold discharge plate, the second flow channel forming plate is the second flow channel forming plate, and so on. The inner end face of the mold discharge plate refers to a surface of the mold discharge plate facing the first flow channel forming plate, the outer end face of the first flow channel forming plate refers to a surface of the first flow channel forming plate facing the mold discharge plate, the inner end face of the first flow channel forming plate refers to a surface of the first flow channel forming plate facing the second flow channel forming plate, and the outer end face of the second flow channel forming plate refers to a surface of the second flow channel forming plate facing the first flow channel forming plate.

[0052] The above technical solution of the present invention provides a production method in which a glass fiber reinforcement layer is arranged inside a hard core layer. This is difficult for those skilled in the art, because it is generally understood that in order to fuse the glass fiber reinforcement layer with the foaming core, the reinforcing material channel must be connected to the main channel, so that the glass fiber reinforcement layer can be integrated into the foaming layer. The problem with this is that there is a large pressure inside the main channel. Once the reinforcing material channel is connected to the main channel, the pressure will be released in the reverse direction along the reinforcing material channel, and the material in the main channel will naturally be squeezed into the reinforcing material channel, and even further foamed, thereby blocking the reinforcing material channel, making it difficult to continue to input the glass fiber reinforcement layer, forcing production to be interrupted; generally speaking, the mold needs to be disassembled and the reinforcing material channel needs to be cleaned within a very short production cycle. In addition, the hard core layer that is barely produced has premature pressure relief and premature foaming in some areas, which also makes it difficult to control the quality of the hard core layer.

[0053] In the above technical solution of the present invention, the above problems are solved by changing the production method and modifying the mold. It is mainly manifested in the following aspects: in the mold, 1. The main channel is designed to maintain pressure in the entire mold; 2. A co-extrusion channel is added; 3. The reinforcing material channel, the co-extrusion channel and the main channel are independent of each other, and they are merged at the port of the mold discharge plate; 4. A shaping mold is installed at the mold outlet; in terms of method, 1. Abandon the previous idea of ​​forming a composite sheet from the mold outlet, 2. Introduce a co-extrusion shell, so that when the materials converge at the mold outlet, although compounding is not achieved, the automatic assembly required for compounding is achieved, and then enter the shaping mold for compounding. The front half of the shaping mold realizes the compounding of the sheet, and the rear half realizes the shaping of the sheet.

[0054] In the above technical solution of the present invention, the first resin is PVC resin. The second resin is selected from one or more of PVC, ASA, PE, PC, PP, ABS and the like.

[0055] As a preferred embodiment of the above technical solution, the sufficient mixing is that the first raw material is mixed in a high-speed mixer at a mixing temperature of 100-130° C. for 10-15 minutes, and then transferred to a cold mixer to be cooled to below 40° C.

[0056] In summary, the present invention has the following beneficial effects:

[0057] 1. The present invention provides a matching structure between the elastic surface layer and the rigid foam core layer, so that the elastic surface layer is firmly coated on the rigid foam core layer, so that the present invention has the advantages of both the rigid foam core layer and the elastic surface layer, with high compressive strength and good surface contact;

[0058] 2. The present invention further improves the compressive strength of the composite floor by arranging a glass fiber reinforcement layer inside the rigid foam core layer, and significantly improves the bending modulus of the composite floor, which can increase the span when laying the floor, reduce the amount of keels, reduce the laying cost, and improve the laying efficiency; more importantly, the present invention has better mechanical properties at high temperatures, and can still maintain a bending strength of more than 20MPa at 80°C;

[0059] 3. The present invention provides a method for compounding a rigid foam core and an elastic surface layer precursor, based on which the elastic surface layer precursor can better cover the rigid foam core; after curing, the rigid foam core forms a rigid core layer of the composite floor, and the elastic surface layer precursor forms an elastic surface layer; and the composite floor has the advantage of high integrity;

[0060] 4. The present invention provides a method for producing a rigid foam core, especially a method for producing a rigid foam core with a glass fiber reinforcement layer, which constitutes another technical core of the present invention; the rigid foam core produced by this method can give the composite floor a higher compressive strength, a higher bending failure load and a higher bending elastic modulus;

[0061] 5. The present invention adds a certain amount of wear-resistant additives to the raw materials of the elastic surface layer, so that the elastic surface layer has better surface wear resistance than the prior art while slightly improving the surface hardness. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a schematic diagram of the structure of the present invention;

[0063] Figure 2 It is a schematic diagram of the mold structure of the present invention;

[0064] Figure 3 is a schematic diagram of the outer end surface of the first flow channel forming plate of the present invention;

[0065] In the figure, 1-elastic surface layer, 2-hard core layer;

[0066] 201-coextruded shell, 202-glass fiber reinforcement layer, 203-rigid foam core;

[0067] 10-main channel, 20-reinforcement material channel, 30-coextrusion channel;

[0068] 11-main channel outlet, 21-first channel, 22-second channel;

[0069] 211-first discharge port, 221-second discharge port;

[0070] 31-surface discharge port;

[0071] 201-input segment, 202-output segment;

[0072] 301-feeding section, 302-casting section, 303-forming section;

[0073] 3011-branch channel, 3021-sloped channel. DETAILED DESCRIPTION

[0074] The present invention is further explained below in conjunction with the accompanying drawings.

[0075] This specific implementation is only an explanation of the present invention, not a limitation of the present invention. Any changes made by those skilled in the art after reading the specification of the present invention will be protected by the patent law as long as they are within the scope of the claims.

[0076] Embodiment 1

[0077] like Figure 1 As shown, a double-layer composite floor comprises a hard core layer 2 and an elastic surface layer 1 made of PU material, wherein the elastic surface layer 1 wraps and covers the hard core layer 2 on the upper surface and the side surface of the floor.

[0078] A matching structure is provided between the elastic surface layer 1 and the hard core layer 2, and the matching structure includes a plurality of unit elements formed on the surface A, a plurality of corresponding elements formed on the surface B, and a plurality of connection units.

[0079] The surface A is the surface of the hard core layer 2 that contacts the elastic surface layer 1 , and the surface B is the surface of the elastic surface layer 1 that contacts the hard core layer 2 .

[0080] The connection unit includes a first connection unit arranged between two adjacent unit elements and a second connection unit arranged between two adjacent corresponding elements; the unit element is a strip structure with a groove-shaped cross section arranged along the length direction of the floor; the corresponding element is a concave matching component with a convex cross section embedded in the groove; the first connection unit and the second connection unit are arranged in a matching manner. The unit element with a groove-shaped cross section has a concave structure.

[0081] In this embodiment, the rigid core layer 2 is a rigid foam co-extruded coated reinforced plate. The rigid foam co-extruded coated reinforced plate is composed of a rigid foam core 203, a glass fiber reinforced layer 202 and a co-extruded shell 201, wherein the glass fiber reinforced layer 202 is disposed between the rigid foam core 203 and the co-extruded shell 201; the rigid foam core 203 and its crust layer are formed by a first raw material including a first resin and a foaming agent, and the co-extruded shell 201 is formed by a second raw material including a second resin and no foaming agent; the glass fiber reinforced layer is formed by curing a glass fiber mesh cloth impregnated with resin. The thickness of the co-extruded shell is about 2 mm.

[0082] In this embodiment, the first resin is PVC resin, the foaming agent is AC foaming agent, and the second resin is also PVC resin.

[0083] The production method of the double-layer composite floor comprises the following steps:

[0084] a. Provide a casting mold, spray 5 g of magnesium stearate as a release agent and 50 g of a finishing paint containing nano-alumina into the casting mold in sequence, and after drying, mix 2200 g of polyether polyol, 15 g of talcum powder, 600 g of isocyanate and 4 g of a curing agent for 5 minutes and pour into the mold, and then form an elastic surface layer precursor with a thickness of about 2 cm in the casting mold with a depth of about 3 cm; the elastic surface layer precursor is in a liquid state;

[0085] b. placing the hard core layer 2 having grooves on the upper surface and the side surface into the casting mold;

[0086] c. After the hard core layer 2 is laid flat, a pressure is applied to it to lower its position in the mold, so that the elastic surface layer precursor rises along the gap between the inner wall of the mold and the surrounding contour of the hard core layer, and at least overflows the groove on the side surface of the hard core layer, so that the thickness of the elastic surface layer precursor is reduced from 2 cm to about 0.5 cm;

[0087] d. Maintain the pressure applied in step c for 20-25 minutes to allow the elastic surface layer precursor to solidify in the mold to obtain the double-layer composite floor.

[0088] In this embodiment, the hard core layer is a hard foamed co-extruded reinforced board.

[0089] The equipment used to prepare the rigid foamed co-extruded coated reinforced plate includes a main extruder, an auxiliary extruder, a co-extrusion die and a shaping die;

[0090] like Figure 2-3 As shown, the co-extrusion die is formed by connecting a plurality of die plates including a die feed plate, a flow channel forming plate, and a die discharge plate.

[0091] The co-extrusion mold is provided with a main channel 10, a reinforcement material channel 20 and a co-extrusion channel 30, and the main channel 10, the reinforcement material channel 20 and the co-extrusion channel 30 are independent of each other in the mold; the reinforcement material channel 20 includes a first channel 21 and a second channel 22 distributed on both sides of the main channel 10, and the first channel 21 and the second channel 22 form a first discharge port 211 and a second discharge port 221 located on both sides of the main channel discharge port 11 on the mold discharge plate; the co-extrusion channel 30 forms a surface discharge port 31 on the mold discharge plate, and the surface discharge port 31 is a rectangular ring structure and is sleeved around the main channel discharge port 11, and the first discharge port 211 and the second discharge port 221 are arranged between the main channel discharge port 11 and the surface discharge port 31.

[0092] The surface discharge port 31 is provided with a structure corresponding to the shape of the unit element.

[0093] The reinforcing material channel 20 includes an input section 201 and an output section 202, and the input section 201 and the output section 202 are connected; the angle between the input section 201 and the main channel 10 gradually decreases along the material feeding direction until it is zero; the reinforcing material feed port of the input section 201 is set on the channel forming plate.

[0094] The co-extrusion flow channel 30 comprises a feed section 301, a casting section 302 and a forming section 303 which are interconnected. The main part of the feed section 301 is arranged on the second flow channel forming plate of the co-extrusion mold, the main part of the casting section 302 is arranged on the first flow channel forming plate of the mold, and the forming section 303 is arranged on the discharge plate of the mold; the feed section 301 forms two branch channels 3011 on the second flow channel forming plate, and the casting section 302 is formed on the first flow channel forming plate. Channel 3021; ​​the branch channel 3011 is connected to the inclined channel 3021, and the inclined channel 3021 is connected to the forming section 303; the inner end face of the mold discharge plate is connected to the outer end face of the first flow channel forming plate, and the inner end face of the first flow channel forming plate is connected to the outer end face of the second flow channel forming plate; the rectangular ring structure of the cross section of the forming section 303 gradually shrinks in size along the discharge direction, and forms the surface discharge port 31 on the outer end face of the mold discharge plate.

[0095] The entire co-extrusion die is formed by the butt joint combination of a die feed plate, a plurality of flow channel forming plates and a die discharge plate. The die feed plate and the die discharge plate are respectively arranged at the two ends of the die, and a plurality of flow channel forming plates are arranged between the die feed plate and the die discharge plate. According to the method of using the co-extrusion die, the die plate at one end where the material enters is the die feed plate, and the die plate at one end where the product is extruded is the die discharge plate. The plurality of flow channel plates are arranged in such a way that the first flow channel forming plate is the closest to the die discharge plate, the second flow channel forming plate is the second closest to the die discharge plate, and so on. The inner end face of the die discharge plate refers to a surface of the die discharge plate facing the first flow channel forming plate, the outer end face of the first flow channel forming plate refers to a surface of the first flow channel forming plate facing the die discharge plate, the inner end face of the first flow channel forming plate refers to a surface of the first flow channel forming plate facing the second flow channel forming plate, and the outer end face of the second flow channel forming plate refers to a surface of the second flow channel forming plate facing the first flow channel forming plate.

[0096] The preparation method of the above-mentioned hard core layer 2 is as follows:

[0097] The first raw material including the first resin and the foaming agent is fully mixed (100 kg of PVC resin, 50 kg of calcium carbonate, 0.5 kg of stearic acid, 0.5 kg of magnesium stearate, 5 kg of calcium zinc stabilizer, 1 kg of AC foaming agent, and 0.5 kg of zinc oxide, mixed in a high-speed mixer for 15 minutes at a mixing temperature of 120° C., and then placed in a cold mixer to cool to 30° C.), and then input into a main extruder, and the main extruder extrudes the first raw material into the main channel 10 of the mold, and then extrudes from the main channel 10 to form a pressure-retaining core;

[0098] At the same time, two glass fiber reinforcement layers are respectively input from the first channel 21 and the second channel 22;

[0099] At the same time, the second raw material containing the second resin but not containing the foaming agent (100 kg of PVC resin, 20 kg of hollow glass microspheres, 50 kg of calcium carbonate, and 2.0 kg of magnesium stearate) is fully mixed and fed from the co-extrusion flow channel 30 of the co-extrusion die through the auxiliary extruder, and extruded from the surface layer outlet 31 to obtain a co-extrusion shell with a frame-shaped cross section;

[0100] The pressure-retaining core, glass fiber reinforced layer and co-extruded shell are extruded from their respective runners to form a mold blank; at the same time, the mold blank is passed into a shaping die, and the pressure-retaining core is foamed in the co-extruded shell constrained by the inner wall of the shaping die, and the co-extruded shell is filled, and the mold blank is compounded and shaped in the shaping die to form the hard core layer. The mold blank is composed of a pressure-retaining core, a glass fiber reinforced layer and a co-extruded shell from the inside to the outside, and there is a preformed foaming space between the pressure-retaining core and the co-extruded shell.

[0101] The process temperature, speed and pressure are shown in the following table:

[0102]

[0103] Embodiment 2

[0104] The difference from the first embodiment is that the rigid core layer includes a PVC rigid foam core, a PVC skin layer covering the PVC rigid foam core, and a co-extruded shell covering the PVC skin layer. That is, the glass fiber reinforcement layer is not included, the thickness of the PVC skin layer is about 0.5 mm, and the thickness of the co-extruded shell is about 2 mm.

[0105] The preparation method of the hard core layer is as follows:

[0106] After the PVC foaming material is fully mixed (100kg of PVC resin, 50kg of calcium carbonate, 0.5kg of stearic acid, 0.5kg of magnesium stearate, 5kg of calcium zinc stabilizer, 1kg of AC foaming agent, 0.5kg of zinc oxide, mixed in a high-speed mixer for 15 minutes at a mixing temperature of 120°C, and then placed in a cold mixer to cool to 30°C), it is extruded from the die of the mold through the main extruder;

[0107] At the same time, the second raw material (100 kg of PVC resin, 20 kg of hollow glass microspheres, 50 kg of calcium carbonate, and 2.0 kg of magnesium stearate) containing the second resin but not containing the foaming agent is fully mixed and fed from the co-extrusion flow channel of the co-extrusion die through the auxiliary extruder, and extruded from the surface discharge port to obtain a co-extrusion shell with a frame-shaped cross-section;

[0108] The pressure-retaining core and the co-extruded shell are extruded from their respective runners to form a mold blank; at the same time, the mold blank is passed into a shaping die, and the pressure-retaining core is foamed in the co-extruded shell constrained by the inner wall of the shaping die, and the co-extruded shell is filled, and at the same time, the mold blank is compounded and shaped in the shaping die to form the hard core layer. There is a preformed foaming space between the pressure-retaining core and the co-extruded shell.

[0109] Compared with the co-extrusion die in the first embodiment, the co-extrusion die in the present embodiment lacks the reinforcing material channel portion, and the rest is the same.

[0110] Embodiment 3

[0111] The difference from the first embodiment is that the hard core layer is a preformed aluminum alloy profile. The preparation method is the same as the first embodiment.

[0112] Embodiment 4

[0113] The difference from the first embodiment is that the hard core layer is a wood-plastic hot extruded solid board; the wood-plastic hot extruded solid board refers to a solid board prepared by mixing resin raw materials, plant fiber powder and processing aids through a conventional hot extrusion process, and the upper surface and side surface of the board also constitute the surface A and have all the characteristics of the above surface A. In this board, the commonly used plastic is polyolefin. The resin used in this embodiment is a mixture of polyethylene and polypropylene, including 38kg of polyethylene, 2kg of polypropylene, and 100kg of plant fiber powder.

[0114] The preparation method is the same as that of Example 1.

[0115] Embodiment 5

[0116] The difference from the first embodiment is that the hard core layer is a wood-plastic hot extruded hollow board; the wood-plastic hot extruded hollow board uses the same raw materials as the above-mentioned wood-plastic hot extruded solid board, but the processing mold is different. Because the mold has a core rod extending out of the die, the board forms a hollow structure at the corresponding part of the core rod. Similarly, the upper surface and side surface of the wood-plastic hot extruded hollow board constitute the surface A, and have all the characteristics of the above-mentioned surface A.

[0117] The preparation method is the same as that of Example 1.

[0118] Comparative Example 1

[0119] According to WO2018154287A1, a PU board is prepared by a method disclosed in a low heat absorption flame retardant polyurethane wood-like material.

[0120] The products of Example 1 and Example 2 and the product of Comparative Example 1 were tested in accordance with the relevant contents of GB / T24508-2009, GB / T24137-209, GB / T2411-2008 and GB / T18102-2007 to measure their bending failure load, bending strength, surface hardness and surface wear resistance. The results are shown in the following table.

[0121]

Claims

1. A double-layer composite floor, characterized by: The floor comprises a hard core layer (2) with a Shore hardness of more than 80HD and an elastic surface layer (1) with a Shore hardness of less than 40HD, wherein the elastic surface layer (1) covers the hard core layer (2) on the upper surface and at least part of the side surface of the floor; a matching structure is provided between the elastic surface layer (1) and the hard core layer (2), wherein the matching structure comprises a plurality of unit elements formed on the surface of the hard core layer and a plurality of corresponding elements formed on the surface of the elastic surface layer; the unit elements are strip-shaped structures with a groove-shaped cross section arranged along the length direction of the floor; the corresponding elements are groove matching components with a convex cross section embedded in the groove shape; The material of the elastic surface layer is selected from one or more of natural rubber, synthetic rubber or thermoplastic elastomer; The hard core layer is a hard foamed co-extruded coated reinforced plate; The rigid foam co-extruded coated reinforced plate is composed of a rigid foam core, a glass fiber reinforcement layer and a co-extruded shell, wherein the glass fiber reinforcement layer is arranged between the rigid foam core and the co-extruded shell; the rigid foam core and the crust layer are formed of a first raw material including a first resin and a foaming agent, and the co-extruded shell is formed of a second raw material including a second resin and no foaming agent; the glass fiber reinforcement layer is formed by curing a glass fiber mesh cloth impregnated with a resin; The method for preparing the rigid foamed co-extruded coated reinforced plate is as follows: A first raw material comprising a first resin and a foaming agent is fully mixed and then fed into a main extruder, and the main extruder extrudes the first raw material into a main channel (10) of a mold, and then extrudes the first raw material from the main channel (10) to form a pressure-retaining core; At the same time, two glass fiber reinforcement layers are respectively input from the first channel (21) and the second channel (22); At the same time, a second raw material containing a second resin but not containing a foaming agent is fully mixed and fed into a coextrusion flow channel (30) of a coextrusion die through an auxiliary extruder, and extruded from a surface layer outlet (31) to obtain a coextrusion shell having a frame-shaped cross section; The pressure-retaining core, the glass fiber reinforced layer and the co-extruded shell are extruded from respective flow channels to form a mold blank; at the same time, the mold blank is passed into a shaping die, and the pressure-retaining core is foamed in the co-extruded shell constrained by the inner wall of the shaping die in the shaping die, and the co-extruded shell is filled, and at the same time, the mold blank is compounded and shaped in the shaping die to form the hard core; The mold blank comprises a pressure-maintaining core, a glass fiber reinforcement layer and a co-extruded shell from the inside to the outside, and a preformed foaming space is provided between the pressure-maintaining core and the co-extruded shell; The first resin is PVC resin; the second resin is selected from one or more of PVC, ASA, PE, PC, PP, and ABS.

2. The double-layer composite floor according to claim 1, characterized in that: The matching structure also includes multiple first connection units and multiple second connection units; the first connection unit is formed by the surface of the hard core layer in contact with the elastic surface layer, and is arranged between two adjacent unit components; the second connection unit is formed by the surface of the elastic surface layer in contact with the hard core layer, and is arranged between two adjacent corresponding components; the first connection unit and the second connection unit are matched and arranged.

3. The double-layer composite floor according to claim 1, characterized in that: The unit element with a groove-shaped cross section has a necking structure.

4. The double-layer composite floor according to claim 1, characterized in that: The surface of the hard core layer in contact with the elastic surface layer and the surface of the elastic surface layer in contact with the hard core layer are provided with the unit components and corresponding components at the transitional connection between the horizontal direction and the vertical direction of the floor.

5. The double-layer composite floor according to claim 2, characterized in that: The surfaces of the first connection unit and the second connection unit are planes or surfaces with sawtooth cross sections.

6. A method for producing a double-layer composite floor according to any one of claims 1 to 5, comprising the following steps: a. providing a casting mold, spraying a mold release agent into the casting mold, and pouring a liquid raw material for forming an elastic surface layer (1) into the casting mold after drying, thereby forming an elastic surface layer precursor with a thickness of a; the elastic surface layer precursor is an uncured and fluid liquid; b. placing the hard core layer (2) having the unit elements on the upper and side surfaces into the casting mold; c. applying a pressure to the hard core layer to make it lower in the mold, so that the elastic surface layer precursor rises along the gap between the inner wall of the mold and the surrounding contour of the hard core layer, and at least overflows the unit element on the side surface of the hard core layer, so that the thickness of the elastic surface layer precursor decreases from a to b; d. Maintaining the pressure applied in step c to solidify the elastic surface layer precursor in the mold to obtain the double-layer composite floor.

7. The method for producing a double-layer composite floor according to claim 1, characterized in that: The equipment used to prepare the rigid foamed co-extruded coated reinforced plate includes a main extruder, an auxiliary extruder, a co-extrusion die and a shaping die; The co-extrusion die is formed by connecting a plurality of die plates including a die feed plate, a flow channel forming plate, and a die discharge plate; the co-extrusion die is provided with a main flow channel (10), a reinforcing material channel (20), and a co-extrusion flow channel (30); the main flow channel (10), the reinforcing material channel (20), and the co-extrusion flow channel (30) are independent of each other in the die; the reinforcing material channel (20) comprises a first channel (21) and a second channel (22) distributed on both sides of the main flow channel (10); the first channel (21) and the second channel (22) are connected to each other. The second channel (22) forms a first discharge port (211) and a second discharge port (221) on the die discharge plate, which are located on both sides of the main channel discharge port (11); the co-extrusion channel (30) forms a surface discharge port (31) on the die discharge plate, the surface discharge port (31) is a rectangular ring structure and is sleeved around the main channel discharge port (11), and the first discharge port (211) and the second discharge port (221) are arranged between the main channel discharge port (11) and the surface discharge port (31); The surface layer discharge port (31) is provided with a structure corresponding to the shape of the unit element; The reinforcing material channel (20) comprises an input section (201) and an output section (202), wherein the input section (201) and the output section (202) are connected; the angle between the input section (201) and the main channel (10) gradually decreases along the material feeding direction until it becomes zero; the reinforcing material feed port of the input section (201) is arranged on the channel forming plate; The co-extrusion flow channel (30) comprises a feed section (301), a casting section (302) and a forming section (303) which are interconnected. The main part of the feed section (301) is arranged on the second flow channel forming plate of the co-extrusion die, the main part of the casting section (302) is arranged on the first flow channel forming plate of the die, and the forming section (303) is arranged on the discharge plate of the die. The feed section (301) forms two branch channels (3011) on the second flow channel forming plate, and the casting section (302) is formed on the first flow channel forming plate. The branch channel (3011) is connected to the bevel-shaped channel (3021), and the bevel-shaped channel (3021) is connected to the molding section (303); the inner end surface of the mold discharge plate is connected to the outer end surface of the first flow channel forming plate, and the inner end surface of the first flow channel forming plate is connected to the outer end surface of the second flow channel forming plate; the rectangular ring structure of the cross section of the molding section (302) gradually shrinks in size along the discharge direction, and forms the surface discharge port (31) on the mold discharge plate.

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