Double-layer synchronous laminating device for LVT flooring, and laminating process thereof

Abstract

Disclosed in the present invention is a double-layer synchronous laminating device for LVT flooring, comprising a calendering device. The calendering device is three pairs of calendering rollers fixed on a frame, which are respectively a first calendering roller and a second calendering roller used for controling the thickness of a hot middle-layer material, a third calendering roller and a fourth calendering roller used for controlling the thickness of a hot bottom-layer material, and a sixth calendering roller and a fifth calendering roller used for pressing the hot middle-layer material, a glass fiber mesh and the hot bottom-layer material in a vertical direction and controlling the thickness. The rotation speed and the temperature of each calendering roller can be independently controlled, and at least one calendering roller in each pair of calendering rollers is connected to a lifting / lowering assembly. The design of one-step lamination of the three-layer structure in the present invention greatly improves the production efficiency and can reduce deformation caused by step-by-step lamination.

Description

LVT floor double-layer synchronous laminating equipment and laminating process Technical Field

[0001] The present invention belongs to the technical field of artificial floor manufacturing, and in particular relates to a double-layer synchronous laminating device for LVT flooring and a laminating process thereof. Background Art

[0002] WPC, LVT, and SPC flooring are all new decorative flooring products that have recently appeared on the market. Their primary ingredients are polyvinyl chloride (PVC) and calcium powder. These floors are lightweight, wear-resistant, resilient, fire-retardant, moisture-resistant, and sound-absorbing. Installation is also simple, convenient, and pollution-free.

[0003] After just a few years of development, the company has expanded from producing only marble-like hard floors to producing floors of various thicknesses, soft and hard, imitation wood floors, foamed lightweight floors, and environmentally friendly methane-free plastic wood grain floors. It has been widely recognized and used in large and medium-sized cities at home and abroad.

[0004] The flooring production process can be summarized as follows: Mixed plastic materials undergo melting, shear mixing, and other processes under the influence of heat and shear forces, achieving a fluid state and good plasticity (this is called plasticization). They are then shaped and extruded through a mold into sheets (called the base material). While still hot, they are cooled and shaped by related equipment (such as a calender or forming plate). Simultaneously, the surface is covered with a cover (composed of a wear-resistant layer, color film, and LVT base material). The surface is then treated with a UV coating line for wear-resistant protection. Finally, the base material is slotted and sliced ​​by a slotting machine, and the finished product is packaged.

[0005] LVT flooring, also known as "high-end vinyl flooring," is a soft, flexible, and resilient flooring material. Professionally described as "semi-rigid sheet plastic flooring," it can even be bent into rolls. The internal structure of LVT flooring generally includes a UV paint layer, a wear-resistant layer, a color film layer, and an LVT mid-base layer. The mid-base is typically composed of two layers of LVT laminated together.

[0006] In order to improve the dimensional stability of the floor, customers will ask the factory to add fiberglass mesh to the mid-base material layer to reduce the deformation of the floor caused by temperature changes.

[0007] The bottom layer material is often more resilient and not easy to break. It is made of polyvinyl chloride, calcium powder, plasticizer and other materials. The middle layer material is easier to break. Therefore, the bottom material and the middle layer material together can play a stretching role, making the board less likely to warp.

[0008] The added PVC is a non-toxic, odorless white powder with high chemical stability and good plasticity.

[0009] PVC is the most widely used and important polymer in the world, but pure PVC is actually the most unstable polymer, so the advantages of PVC can only be realized after adding appropriate stabilizers and other additives.

[0010] Currently, most LVT flooring production processes on the market are mainly divided into the following two types.

[0011] The first method is to use a press to press the PVC raw materials after they are plasticized in an internal mixer and then cut into sheets.

[0012] The second method is to use an extruder production line to extrude a single-layer base material in one step, and then press it online through a calender roller. The wear-resistant layer and the color film layer are pressed on the upper surface of the middle layer base material through a steering roller via a cylinder. Then, a pre-made rolled LVT base material is used, which is heated twice and passed through a film feeding device and a steering roller device to the bottom of the middle layer base material. It is then pressed through a calender to form a whole.

[0013] The disadvantages of the first method are that the equipment is large, occupies a lot of space, has high energy consumption, causes great pollution, and has complicated procedures.

[0014] The disadvantage of the second method is that it can only extrude a single layer of LVT-based material. Although a back sticker will be attached later, it cannot completely solve the problem of product warping. Both methods cannot meet the development needs of energy conservation, environmental protection and sustainable development in today's society.

[0015] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0016] The purpose of the present invention is to provide a double-layer synchronous laminating device for LVT flooring, thereby overcoming the above-mentioned defects in the prior art.

[0017] To achieve the above objectives, the present invention provides a dual-layer synchronous laminating device for LVT flooring, comprising a calendering device comprising three pairs of calendering rollers fixed to a frame: a first calendering roller and a second calendering roller for setting the thickness of a hot middle layer; a third calendering roller and a fourth calendering roller for setting the thickness of a hot bottom layer; and a sixth calendering roller and a fifth calendering roller for laminating the hot middle layer, glass fiber mesh, and hot bottom layer together to set the thickness. The speed and temperature of each calendering roller are independently controllable, and at least one calendering roller in each pair (the first and second calendering rollers, the third and fourth calendering rollers, and the sixth and fifth calendering rollers) is connected by a lifting assembly. The temperature of each calendering roller is determined in advance based on experimental results for different raw materials and formulations.

[0018] Preferably, in the above technical solution, the feeding ends of the first calendering roller and the second calendering roller correspond to the extrusion port of the hot middle layer material extrusion device, and the discharging ends of the first calendering roller and the second calendering roller correspond to the feeding ends of the sixth calendering roller and the fifth calendering roller;

[0019] The feeding end of the third calendering roller and the fourth calendering roller corresponds to the output end of the swing-arm conveyor belt of the hot bottom material, and the discharging end of the third calendering roller and the fourth calendering roller corresponds to the feeding end of the sixth calendering roller and the fifth calendering roller;

[0020] The discharge end of the glass fiber mesh conveying device corresponds to the feed end of the sixth calendering roller and the fifth calendering roller;

[0021] The discharge speeds of the first calendering roller and the second calendering roller, the discharge speeds of the third calendering roller and the fourth calendering roller, and the discharge of the glass fiber mesh conveying device are basically the same.

[0022] Preferably, when the thickness of the intermediate material is less than 1.5mm, the first and second calendering rollers, which are used to maintain the hot intermediate material thickness, will deform due to the strong pressure exerted by the two rollers. Therefore, either roller should be designed as a medium-high roller, meaning that the diameter of the roller at the center is 0.2mm larger than the diameter of the two sides. A linear transition is formed from the center to the sides. When the thickness of the intermediate material is 1.5-2mm, either roller should be designed as a medium-high roller, meaning that the diameter of the roller at the center is 0.07mm larger than the diameter of the two sides. A linear transition is formed from the center to the sides. When the thickness of the intermediate material is greater than 2mm, both the first and second calendering rollers should be flat rollers.

[0023] Preferably, when the thickness of the hot base material is less than 1.5mm, the third and fourth calendering rollers for constant thickness should be designed as medium-high rollers, because the strong squeezing of the two rollers will cause certain deformation of the rollers. Therefore, either the third or fourth calendering roller should be designed as a medium-high roller, that is, the diameter of the roller in the middle is 0.2mm larger than the diameter of the two sides. The middle transitions linearly to the two sides. When the thickness of the base material is 1.5-2mm, either the third or fourth calendering roller should be designed as a medium-high roller, that is, the diameter of the roller in the middle is 0.07mm larger than the diameter of the two sides. The middle transitions linearly to the two sides. When the thickness of the base material is greater than 2mm, the third and fourth calendering rollers are both flat rollers.

[0024] Preferably, in the above technical solution, the discharge end of the conveying device for the glass fiber mesh is arranged between the discharge ends of the first calendering roller and the second calendering roller and between the discharge ends of the third calendering roller and the fourth calendering roller.

[0025] Preferably, the above technical solution also includes powered rollers and auxiliary heating and heat preservation devices, which are arranged between the discharge ends of the fifth calendering roller and the sixth calendering roller and the LVT floor online laminating calender.

[0026] Preferably, the above technical solution further includes a middle layer material mixing device, a feeder, a middle layer material extrusion host and an extrusion die distributed in sequence, and the extrusion die corresponds to the input end of the first calendering roller and the second calendering roller.

[0027] Preferably, the above technical solution also includes a bottom material mixing device, a bottom material extrusion main unit, a horizontal conveyor belt, and a swing-arm conveyor belt distributed in sequence, and the swing-arm conveyor belt corresponds to the input end of the third calendering roller and the fourth calendering roller.

[0028] A laminating process for LVT flooring, wherein the middle layer material is plasticized and extruded to form a sheet structure, which is then extruded into the first and second calendering rollers to determine the thickness; the bottom layer material is plasticized and extruded to form a rod structure, which is then extruded into the third and fourth calendering rollers to determine the thickness; the middle layer material, glass fiber mesh, and bottom layer material of determined thickness are simultaneously laminated into the fifth and sixth calendering rollers to determine the thickness.

[0029] The temperature control method of the calendering roller is to connect the oil temperature controller and the roller through a pipe. The oil temperature controller heats the oil and then pumps it into the roller. Then it returns to the oil temperature controller. The oil temperature is controlled by the oil temperature controller. There is an oil storage tank in the oil temperature controller. The oil heater in the oil tank heats the thermal oil. There is also a thermometer in the oil storage tank to detect the temperature of the thermal oil. There is a cooling water pipe outside the oil tank. If the oil temperature is too high, the solenoid valve opens to cool the water.

[0030] To control the roller spacing, we first use a feeler gauge to mechanically determine the distance between the two rollers, then enter the measured starting value into the program, and then we use the servo motor to control the lifting distance of the worm gear elevator to achieve the purpose of adjusting the wall thickness.

[0031] The thickness is measured by a motor-controlled screw that raises and lowers the rollers, adjusting the gap between the two rollers and thus controlling the sheet thickness. The thickness is displayed on a PLC touchscreen, and the roller lift distance is controlled by an electronic ruler or servo pulses. This application effectively solves the warping problem of the backing film by laminating three layers in one go. After one-shot molding, flatness testing confirms compliance with requirements.

[0032] Preferably, in the above technical solution, the thickness of the fixed-thickness middle layer material is 0.9mm to 5mm, the specific gravity is 1.95±0.05g / cm³, and the hardness is: 60±2 degrees for commercial use; 68±2 degrees for lock. The thickness of the fixed-thickness bottom layer material is 0.6mm to 1.5mm, the specific gravity is 1.65±0.05g / cm³, and the hardness is: 54±2 degrees for commercial use; 64±2 degrees for lock.

[0033] Preferably, in the above technical solution, when the thickness of the hot middle layer material is less than 1.5 mm, the first calendering roller and the second calendering roller will produce a certain deformation due to the strong squeezing of the two rollers. Therefore, any one of the first calendering roller and the second calendering roller should be made into a medium-high roller, that is, the diameter of the roller in the middle is 0.2 mm larger than the diameter of the two sides; the middle transitions linearly to the two sides; when the thickness of the middle layer material is 1.5-2 mm, any one of the first calendering roller and the second calendering roller should be made into a medium-high roller, that is, the diameter of the roller in the middle is 0.07 mm larger than the diameter of the two sides; the middle transitions linearly to the two sides; when the thickness of the middle layer material is greater than 2 mm, the first calendering roller and the second calendering roller are both flat rollers;

[0034] The third and fourth calendering rollers for hot base material with fixed thickness: when the base material thickness is less than 1.5mm, the strong squeezing of the two rollers will produce a certain deformation, so any one of the third and fourth calendering rollers must be made into a medium-high roller, that is, the diameter of the middle of the roller is 0.2mm larger than the diameter of the two sides; the middle transitions linearly to both sides; when the base material thickness is 1.5-2mm, any one of the third and fourth calendering rollers must be made into a medium-high roller, that is, the diameter of the middle of the roller is 0.07mm larger than the diameter of the two sides, and the middle transitions linearly to both sides; when the base material thickness is greater than 2mm, the third and fourth calendering rollers are both flat rollers.

[0035] Preferably, in the above technical solution, the plasticizing and extrusion process of the middle layer material is specifically as follows: after the materials are mixed in a certain proportion, they are fed into the middle layer material extrusion main unit through a feeder, and the screw in the barrel of the middle layer material extrusion main unit is sheared and meshed at 180-200° under vacuum negative pressure to form a paste, and then shaped and extruded into sheets through an extrusion die to obtain the middle layer material.

[0036] Preferably, in the above technical solution, the plasticizing and extrusion process of the base material is specifically as follows: the raw materials are put into the LVT base material extrusion main unit, and the screw in the barrel of the base material extrusion main unit is sheared and meshed under high temperature and vacuum negative pressure. After plasticization, the rod material is extruded through the head, and is transported to the swing arm conveyor belt through the horizontal conveyor belt, and then the swing arm conveyor belt directly puts the extruded rod material into the pressing roller at a certain speed for extrusion and sheeting as the LVT base material.

[0037] A double-layer synchronous laminating device for LVT flooring includes a calendering device, which is composed of three pairs of calendering rollers fixed on a frame, namely a third calendering roller and a fourth calendering roller for determining the thickness of a hot middle layer material, a first calendering roller and a second calendering roller for determining the thickness of a hot bottom layer material, and a sixth calendering roller and a fifth calendering roller for pressing the hot middle layer material, glass fiber mesh and hot bottom layer material together to determine the thickness. The speed and temperature of each calendering roller can be independently controlled, and at least one calendering roller in each pair of calendering rollers is connected to a lifting assembly.

[0038] Preferably, in the above technical solution, the middle layer extruder 2 is placed directly below the main machine platform. The middle layer material passes through the die and enters the third and fourth calendering rollers. The glass fiber mesh unwinding mechanism and swing-arm conveyor belt are placed on the main machine platform. The bottom layer extruder 2 is placed on the ground, parallel to the main machine platform. A horizontal conveyor belt delivers the bottom layer material to the swing-arm conveyor belt, which then transports it to the first and second calendering rollers. The fifth and sixth rollers function identically to the previous ones, again serving to bond the three layers of sheet material. The primary purpose of interchanging the middle layer extruder 2 and bottom layer extruder 3 is to accommodate the varying thicknesses of the middle and bottom layers of the sheet material being produced. Sheets extruded through die 13 can be produced with a thickness of 2 mm or greater, while sheets extruded through swing-arm conveyor belt 14 can only be produced with a thickness of less than 2 mm. Sheets extruded through die 13 can be produced with a thickness of 2 mm or greater, while sheets extruded through swing-arm conveyor belt 14 typically produce thin sheets. Sheets extruded through die 13 can be produced with a thickness of 2 mm or greater, while sheets extruded through swing-arm conveyor belt 14 typically produce thin sheets. Some customers prefer a thicker top layer, while others prefer a thicker bottom layer. Custom designs can be made based on customer needs.

[0039] A laminating process for LVT flooring as described above, wherein the middle layer material is plasticized and extruded to form a sheet structure, which is then extruded into the third and fourth calendering rollers to determine the thickness; the bottom layer material is plasticized and extruded to form a rod structure, which is then extruded into the first and second calendering rollers to determine the thickness; the middle layer material, glass fiber mesh, and bottom layer material of determined thickness are simultaneously entered into the fifth and sixth calendering rollers for lamination and thickness determination.

[0040] Preferably, in the above technical solution, the middle layer material is extruded through the mold of the middle layer material extrusion main machine and enters the third calendering roller and the fourth calendering roller for extrusion to determine the thickness; the bottom layer material extrusion main machine sends the bottom layer material to the swing arm conveyor belt through the horizontal conveyor belt, and transports it to the first calendering roller and the second calendering roller through the swing arm conveyor belt, and transports the bottom layer material to the first calendering roller and the second calendering roller through the swing arm conveyor belt; at this time, the thickness of the bottom layer material is less than the thickness of the middle layer material.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The present invention provides an LVT double-layer lamination one-time molding production line, which has the advantages of continuous production, saving site area, saving manpower, and reducing production costs. It solves the problem in the existing technology that production is not continuous enough and each process is processed independently, resulting in each process occupying a certain area of ​​raw material area and finished product area, resulting in a large required factory area, which is not conducive to management. At the same time, each independent processing process requires a large amount of manpower, which increases the production and operation costs of the enterprise.

[0043] The present invention not only optimizes the production process, shortens the production cycle, and reduces energy consumption, but also greatly reduces equipment costs and labor costs, reduces production and processing steps, reduces labor intensity, is more energy-saving and environmentally friendly, has a high degree of automation in the production line, good production continuity, simple operation, and high production capacity, thereby making the LVT floor produced using our company's LVT double-layer laminating one-time molding extrusion production line more competitive. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG1 is a schematic diagram showing the principle of a novel LVT double-layer lamination production process according to the present invention.

[0045] Figure 2 is a top view of Figure 1, which is used to better illustrate the positional relationship of the equipment.

[0046] FIG3 shows the glass fiber mesh unwinding mechanism 15, conveying roller device 16 and film feeding device 17 placed below the host platform 1 after the bottom layer of the material is removed and extruded from the host 3 in FIG1 .

[0047] 4 and 5 are schematic diagrams of Example 2.

[0048] In the figure: main machine platform 1; middle layer material extrusion main machine 2; bottom layer material extrusion main machine 3; swing arm conveyor belt 4; first calendering roller 5; second calendering roller 6; third calendering roller 7; fourth calendering roller 8; fifth calendering roller 9; sixth calendering roller 10; frame 11; lifting component 12; extrusion die 13; horizontal conveyor belt 14. Implementation Method

[0049] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0050] Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "include" or "comprising", etc., will be understood to include the stated elements or components but not to exclude other elements or other components. Example 1

[0051] The invention provides a novel LVT double-layer laminating one-step forming device.

[0052] We constructed a mainframe platform 1, upon which the high-yield conical double-layer extruder 2 is placed. The barrel outlet is connected to an extrusion die 13. The LVT raw material primarily consists of polyethylene, calcium powder, and plasticizer, mixed in a specific proportion. This mixture is then fed into the middle-layer extruder 2 via a feeder. The screws within the barrel of the conical double-layer extruder 2 shear and mesh under high temperature and vacuum pressure, forming a paste (this is called plasticization). This is then shaped and extruded into sheets through the extrusion die 13, which serve as the LVT middle layer. The thickness of the middle layer ranges from 0.9mm to 5mm, adjustable according to production needs. The specific gravity is 1.95±0.05g / cm³, and the hardness is 60±2° for commercial use and 68±2° for locking.

[0053] An example of the formula ratio is as follows: for a 2.5mm board, the thickness ratio of the middle layer material and the bottom layer material is about 1:2, that is, the color film layer is 0.07mm, the wear-resistant layer is 0.3mm, the middle layer material is 1.4mm, the purpose of the glass fiber layer is to increase the overall toughness of the board, and the bottom layer is 0.7mm.

[0054]

[0055] Directly beneath the mainframe platform 1, two glass fiber mesh unwinding mechanisms 15 are placed. Pre-rolled glass fiber mesh is placed on these mechanisms. The mesh is then conveyed via a conveyor roller assembly 16 and a film feeder 17 to the fifth and sixth calendering rollers 9 and 10, where it is laminated to the LVT middle and bottom layers, where it enters the next process.

[0056] The LVT base material extruder 3 is placed on the ground beside the main machine platform 1, parallel to the middle material extruder 2. Raw material is fed into the LVT base material extruder 3. The screw in the barrel of the base material extruder 3 shears and meshes under high temperature and vacuum pressure. After plasticization, it is extruded through the die head into rods. These rods are then transported via a horizontal conveyor 14 to a swing-arm conveyor 4. The swing-arm conveyor 4 then feeds the extruded rods directly to the lamination rollers at a constant speed for extrusion and sheeting, which serves as the LVT base material. The base material has a thickness of 0.6mm to 1.5mm, adjustable according to actual production needs. The specific gravity is 1.65±0.05g / cm³, and the hardness is: 54±2° for commercial use; 64±2° for lock.

[0057] When the thickness of the hot middle layer material is less than 1.5mm, the first calendering roller 5 and the second calendering roller (6) will produce a certain deformation due to the strong squeezing of the two rollers. Therefore, any one of the first calendering roller 5 and the second calendering roller 6 must be made into a medium-high roller, that is, the diameter of the roller in the middle is 0.2mm larger than the diameter of the two sides; the middle transitions linearly to the two sides; when the thickness of the middle layer material is 1.5-2mm, any one of the first calendering roller 5 and the second calendering roller 6 must be made into a medium-high roller, that is, the diameter of the roller in the middle is 0.07mm larger than the diameter of the two sides; the middle transitions linearly to the two sides; when the thickness of the middle layer material is greater than 2mm, the first calendering roller 5 and the second calendering roller 6 are both flat rollers;

[0058] The third calendering roller 7 and the fourth calendering roller 8 of the fixed thickness of the hot base material have the following characteristics: when the thickness of the base material is less than 1.5mm, the strong squeezing of the two rollers will produce a certain deformation, so any one of the third calendering roller 7 and the fourth calendering roller 8 must be made into a medium-high roller, that is, the diameter of the middle of the roller is 0.2mm larger than the diameter of the two sides; the middle transitions linearly to both sides; when the thickness of the base material is 1.5-2mm, any one of the third calendering roller 7 and the fourth calendering roller 8 must be made into a medium-high roller, that is, the diameter of the middle of the roller is 0.07mm larger than the diameter of the two sides, and the middle transitions linearly to both sides; when the thickness of the base material is greater than 2mm, the third calendering roller 7 and the fourth calendering roller 8 are both flat rollers.

[0059] The frame 11 is provided with six calendering rollers for calendering and laminating. The temperature of each calendering roller is controlled by an oil temperature controller to ensure that the temperature on each calendering roller meets the production requirements. Each calendering roller is equipped with an independent speed reducer, which can be adjusted to meet the process requirements.

[0060] The frame 11 is provided with three lifting assemblies 12, each of which is equipped with an independent speed reducer and can be electrically lifted and manually fine-tuned.

[0061] The first calendering roller 5, the fourth calendering roller 8, and the fifth calendering roller 9 are fixed on the frame 11, and the second calendering roller 6, the third calendering roller 7, and the sixth calendering roller 10 can be electrically raised and lowered and manually fine-tuned.

[0062] The LVT middle layer material enters the first calendering roller 5 and the second calendering roller 6 in a hot state. A lifting component 12 is provided above the second calendering roller. The position of the second calendering roller 6 is adjusted by the lifting component 12 to ensure that the gap between the two calendering rollers meets the production requirements. The plate is preliminarily thickness-calibrated and transported to the sixth calendering roller 10 so that it is covered on the sixth calendering roller 10.

[0063] The LVT base material is fed into the third calendering roller 7 and the fourth calendering roller 8 through the swing arm conveyor belt 4. A lifting component 12 is provided under the third calendering roller 7. The position of the fourth calendering roller 8 is adjusted by the lifting component 12 to ensure that the gap between the two calendering rollers meets the production requirements. The preliminary thickness is determined and the material is conveyed to the fifth calendering roller 9 so that it is covered on the fifth calendering roller 9.

[0064] The LVT middle layer material and the glass fiber mesh enter the sixth calendering roller 10 and the fifth calendering roller 9 with the bottom layer material at the same time. A lifting component 12 is provided above the sixth calendering roller 10. The position of the sixth calendering roller 10 is adjusted by the lifting component 12 to ensure that the gap between the two calendering rollers meets the production requirements. Secondary thickness setting is performed, and the thickness is set according to actual production needs. While controlling the wall thickness of the plate, the LVT middle layer material and the glass fiber mesh are also preliminarily bonded to the bottom layer material through the two calendering rollers.

[0065] After the LVT middle layer material, glass fiber mesh and bottom layer material are pressed together by the fifth calender roller 9 and the sixth calender roller 10, they pass through powered rollers and a heating and insulation device to the LVT floor online laminating calender for embossing the bottom pattern, applying the color film, applying the wear-resistant layer and embossing the surface pattern. After being cooled by the cooling device, they pass through the traction machine, shearing machine and lifting platform, and finally are trimmed, grooved and packaged according to customer requirements. Example 2

[0066] The main structure of this embodiment is the same as that of embodiment 1, with the main differences being that the middle layer material is calibrated in thickness by the third calendering roller 7 and the fourth calendering roller 8, and the bottom layer material is calibrated in thickness by the first calendering roller 5 and the second calendering roller 6.

[0067] A double-layer synchronous laminating device for LVT flooring, the calendering equipment comprises three pairs of calendering rollers fixed on a frame, namely a third calendering roller 7 and a fourth calendering roller 8 for determining the thickness of a hot middle layer material, a first calendering roller 5 and a second calendering roller 6 for determining the thickness of a hot bottom layer material, and a sixth calendering roller 10 and a fifth calendering roller 9 for pressing the hot middle layer material, glass fiber mesh and hot bottom layer material together to determine the thickness. The speed and temperature of each calendering roller can be independently controlled, and at least one calendering roller in each pair of calendering rollers is connected to a lifting assembly.

[0068] The middle layer material extrusion machine 2 is placed directly below the main machine platform 1. The middle layer material passes through the die 13 and enters the third calender roller 7 and the fourth calender roller 8. The glass fiber mesh unwinding mechanism 15 and the swing-arm conveyor belt 4 are placed on the main machine platform 1. The bottom layer material extrusion machine 3 is placed on the ground and parallel to the main machine platform 1. The bottom layer material is sent to the swing-arm conveyor belt 4 via the horizontal conveyor belt 14. The swing-arm conveyor belt 4 is then transported to the first calender roller 5 and the second calender roller 6. The material extruded through the die 13 can be made into thick plates of more than 2mm, while the material extruded through the swing-arm conveyor belt 4 is usually made into thin plates.

[0069] A laminating process for LVT flooring involves extruding the middle layer through a die 13 of a middle layer extrusion machine 2 and then passing through third and fourth calendering rollers 7 and 8 for calibrating thickness. The base layer extrusion machine 3 delivers the base layer via a horizontal conveyor belt 14 to a swinging arm conveyor belt 4, which then conveys it to first and second calendering rollers 5 and 6. At this point, the base layer is thinner than the middle layer. The calibrated middle layer, glass fiber mesh, and base layer simultaneously pass through fifth and sixth calendering rollers 9 and 10 for lamination and calibrating.

[0070] Compared to existing technologies, this invention utilizes simultaneous extrusion of the LVT middle and bottom layers. Using two extruders, the formulation and processing techniques can be adjusted to meet specific needs to produce middle and bottom layers with varying performance. This balances the deformation issues that can occur during production due to the varying shrinkage and tension between the color film and the wear-resistant layer, caused by different materials and formulations. Simultaneous lamination of the three layers effectively resolves the deformation issues that can occur during the production of LVT floors of varying specifications, improving product quality.

[0071] Testing agency: SGS-CSTC Standards Technical Services (Shanghai) Co., Ltd.

[0072] Warpage test conditions: After standing in an 80° oven for 6 hours, take out the plate and measure whether the plate is flat:

[0073]

[0074] After inspection, all flatness tests meet the requirements.

[0075] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A double-layer synchronous laminating device for LVT floor, comprising a calendering device, characterized in that: The calendering equipment comprises three pairs of calendering rollers fixed on a frame, namely a first calendering roller (5) and a second calendering roller (6) for determining the thickness of a hot middle layer material, a third calendering roller (7) and a fourth calendering roller (8) for determining the thickness of a hot bottom layer material, and a sixth calendering roller (10) and a fifth calendering roller (9) for pressing the hot middle layer material, the glass fiber mesh and the hot bottom layer material up and down to determine the thickness. The rotation speed and temperature of each calendering roller can be independently controlled, and at least one calendering roller in each pair of calendering rollers is connected to a lifting component.

2. The LVT floor double-layer synchronous laminating device according to claim 1 is characterized in that: The feeding ends of the first calendering roller (5) and the second calendering roller (6) correspond to the extrusion port of the hot middle layer material extrusion device, and the discharging ends of the first calendering roller (5) and the second calendering roller (6) correspond to the feeding ends of the sixth calendering roller (10) and the fifth calendering roller (9); The feeding ends of the third calendering roller (7) and the fourth calendering roller (8) correspond to the output end of the swing-arm conveyor belt (4) of the hot bottom material, and the discharging ends of the third calendering roller (7) and the fourth calendering roller (8) correspond to the feeding ends of the sixth calendering roller (10) and the fifth calendering roller (9); The discharge end of the glass fiber mesh conveying device corresponds to the feed end of the sixth calendering roller (10) and the fifth calendering roller (9); The discharge speeds of the first calendering roller (5) and the second calendering roller (6), the discharge speeds of the third calendering roller (7) and the fourth calendering roller (8), and the discharge speed of the glass fiber mesh conveying device are substantially the same.

3. The LVT floor double-layer synchronous laminating device according to claim 1 is characterized in that: When the thickness of the middle material is less than 1.5 mm, any one of the first calendering roller (5) and the second calendering roller (6) is a medium-high roller, that is, the diameter of the roller in the middle is 0.2 mm larger than the diameter of the two sides, and the middle transitions to the two sides linearly; when the thickness of the middle material is 1.5-2 mm, any one of the first calendering roller (5) and the second calendering roller (6) is a medium-high roller, that is, the diameter of the roller in the middle is 0.07 mm larger than the diameter of the two sides, and the middle transitions to the two sides linearly; when the thickness of the middle material is greater than 2 mm, the first calendering roller (5) and the second calendering roller (6) are both flat rollers; When the thickness of the bottom material is less than 1.5 mm, any one of the third calendering roller (7) and the fourth calendering roller (8) is a medium-high roller, that is, the diameter of the roller in the middle is 0.2 mm larger than the diameter of the two sides. The middle transitions to the two sides linearly. When the thickness of the bottom material is 1.5-2 mm, any one of the third calendering roller (7) and the fourth calendering roller (8) must be made into a medium-high roller, that is, the diameter of the roller in the middle is 0.07 mm larger than the diameter of the two sides. The middle transitions to the two sides linearly. When the thickness of the bottom material is greater than 2 mm, the third calendering roller (7) and the fourth calendering roller (8) are both flat rollers.

4. The LVT floor double-layer synchronous laminating device according to claim 1, characterized in that: The discharge end of the glass fiber mesh conveying device is arranged between the discharge ends of the first calendering roller (5) and the second calendering roller (6) and between the discharge ends of the third calendering roller (7) and the fourth calendering roller (8).

5. The LVT floor double-layer synchronous laminating device according to claim 1, characterized in that: It also includes powered rollers and a heating and heat preservation device, wherein the powered rollers and the heating and heat preservation device are arranged between the discharge ends of the fifth calendering roller (9) and the sixth calendering roller (10) and the LVT floor online laminating calender.

6. The LVT floor double-layer synchronous laminating device according to claim 1, characterized in that: It also includes a middle layer material mixing device, a feeder, a middle layer material extrusion main machine (2) and an extrusion die (13) which are sequentially distributed, and the extrusion die (13) corresponds to the input ends of the first calendering roller (5) and the second calendering roller (6).

7. The LVT floor double-layer synchronous laminating device according to claim 5, characterized in that: It also includes a bottom layer material mixing device, a bottom layer material extrusion main machine (3), a horizontal conveyor belt (14), and a swing arm conveyor belt (4) which are sequentially distributed. The swing arm conveyor belt (4) corresponds to the input end of the third calender roller (7) and the fourth calender roller (8). The LVT bottom layer material extrusion main machine (3) is parallel to the middle layer material extrusion main machine (2).

8. A laminating process for LVT flooring as described in claim 1, characterized in that: The middle layer material is plasticized and extruded to form a sheet-like structure, which enters the first calendering roller (5) and the second calendering roller (6) for extrusion and thickness setting; the bottom layer material is plasticized and extruded to form a rod-like structure, which enters the third calendering roller (7) and the fourth calendering roller (8) for extrusion and thickness setting; the middle layer material with fixed thickness, the glass fiber mesh, and the bottom layer material with fixed thickness simultaneously enter the fifth calendering roller (9) and the sixth calendering roller (10) for lamination and thickness setting.

9. The bonding process according to claim 5, characterized in that: The thickness of the fixed thickness middle layer material is 0.9mm~5mm, the specific gravity is 1.95±0.05g / cm³, the hardness is: 60±2 degrees for commercial use; 68±2 degrees for locking. The thickness of the fixed thickness bottom layer material is 0.6mm~1.5mm, the specific gravity is 1.65±0.05g / cm³, the hardness is: 54±2 degrees for commercial use; 64±2 degrees for locking.

10. The bonding process according to claim 7, characterized in that: When the thickness of the hot middle layer material is less than 1.5 mm, the first calendering roller (5) and the second calendering roller (6) are used to calibrate the thickness of the hot middle layer material. Since the two rollers strongly squeeze the rollers, a certain deformation will occur. Therefore, any one of the first calendering roller (5) and the second calendering roller (6) must be made into a medium-high roller, that is, the diameter of the roller in the middle is 0.2 mm larger than the diameter of the two sides; the middle transitions linearly to the two sides; when the thickness of the middle layer material is 1.5-2 mm, any one of the first calendering roller (5) and the second calendering roller (6) must be made into a medium-high roller, that is, the diameter of the roller in the middle is 0.07 mm larger than the diameter of the two sides; the middle transitions linearly to the two sides; when the thickness of the middle layer material is greater than 2 mm, the first calendering roller (5) and the second calendering roller (6) are both flat rollers; The third calendering roller (7) and the fourth calendering roller (8) of the hot bottom material with a fixed thickness are used. When the bottom material thickness is less than 1.5 mm, the two rollers will produce a certain deformation due to the strong squeezing of the rollers. Therefore, any one of the third calendering roller (7) and the fourth calendering roller (8) must be made into a medium-high roller, that is, the diameter of the roller in the middle is 0.2 mm larger than the diameter of the two sides, and the middle transitions to the two sides linearly; when the bottom material thickness is 1.5-2 mm, any one of the third calendering roller (7) and the fourth calendering roller (8) must be made into a medium-high roller, that is, the diameter of the roller in the middle is 0.07 mm larger than the diameter of the two sides, and the middle transitions to the two sides linearly; when the bottom material thickness is greater than 2 mm, the third calendering roller (7) and the fourth calendering roller (8) are both flat rollers.

11. The bonding process according to claim 7, characterized in that: The plasticizing and extrusion process of the middle layer material is specifically as follows: after the materials are mixed in a certain proportion, they are fed into the middle layer material extrusion main machine (2) through a feeder, and the screw in the barrel of the middle layer material extrusion main machine (2) is sheared and meshed at 180-200 degrees under vacuum negative pressure to form a paste, and then the paste is shaped and extruded into a sheet through an extrusion die (13), thereby obtaining the middle layer material.

12. The bonding process according to claim 7, characterized in that: The plasticizing and extruding process of the base material is as follows: the raw material is put into the LVT base material extrusion main machine (3), and the screw in the barrel of the base material extrusion main machine (3) is sheared and meshed under high temperature and vacuum negative pressure. After plasticization, the rod material is extruded through the die head, and is transported to the swing arm conveyor belt (4) through the horizontal conveyor belt (14). The swing arm conveyor belt (4) then directly puts the extruded rod material into the pressing roller at a certain speed for extrusion and sheeting, which serves as the LVT base material.

13. A double-layer synchronous laminating device for LVT floor, comprising a calendering device, characterized in that: The calendering equipment comprises three pairs of calendering rollers fixed on a frame, namely a third calendering roller (7) and a fourth calendering roller (8) for determining the thickness of a hot middle layer material, a first calendering roller (5) and a second calendering roller (6) for determining the thickness of a hot bottom layer material, and a sixth calendering roller (10) and a fifth calendering roller (9) for pressing the hot middle layer material, the glass fiber mesh and the hot bottom layer material up and down to determine the thickness. The rotation speed and temperature of each calendering roller can be independently controlled, and at least one calendering roller in each pair of calendering rollers is connected to a lifting component.

14. The LVT floor double-layer synchronous laminating device according to claim 14, characterized in that: The middle layer material extrusion main machine (2) is placed directly below the main machine platform (1), and the middle layer material passes through the die (13) and enters the third calender roller (7) and the fourth calender roller (8); the glass fiber mesh unwinding mechanism (15) and the swing arm conveyor belt (4) are placed on the main machine platform (1); the bottom layer material extrusion main machine (3) is placed on the ground and parallel to the main machine platform (1), and the bottom layer material is sent to the swing arm conveyor belt (4) through the horizontal conveyor belt (14), and then transported to the first calender roller (5) and the second calender roller (6) through the swing arm conveyor belt (4).

15. A laminating process for LVT flooring as described in claim 14, characterized in that: The middle layer material is plasticized and extruded to form a sheet structure, which enters the third calendering roller (7) and the fourth calendering roller (8) for extrusion and thickness setting; the bottom layer material is plasticized and extruded to form a rod structure, which enters the first calendering roller (5) and the second calendering roller (6) for extrusion and thickness setting; the middle layer material with fixed thickness, the glass fiber mesh, and the bottom layer material with fixed thickness simultaneously enter the fifth calendering roller (9) and the sixth calendering roller (10) for lamination and thickness setting.

16. The laminating process according to claim 15, characterized in that: The middle layer material is extruded through the die (13) of the middle layer material extrusion main machine (2) and enters the third calendering roller (7) and the fourth calendering roller (8) for extrusion to determine the thickness; the bottom layer material is extruded through the main machine (3) by means of the horizontal conveyor belt (14) and sent to the swing arm conveyor belt (4), and then transported to the first calendering roller (5) and the second calendering roller (6) by means of the swing arm conveyor belt (4); at this time, the thickness of the bottom layer material is smaller than that of the middle layer material.

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