Formula of light microcellular foamed pet floor and production process for same

Abstract

The present invention relates to the technical field of PET floors. Disclosed are a formula of a light microcellular foamed PET floor and a production process for same. The formula comprises 20%-30% of modified PET, 60%-70% of CaCO3 having a particle size of 300 meshes or above, 2%-6% of a lubricant and 4%-7% of a PET toughening agent. The modified PET and CaCO3 are main materials of the product, wherein the modified PET mainly serves as a binder, and the CaCO3 having a particle size of 300 meshes or above serves as a filler and is mainly used for forming a main body serving as the structure and frame of the product. The light microcellular foamed PET floor provided by the present invention is forward-looking; PET is free of halogens and is environmentally friendly, and, unlike PVC wallboards which is prone to decomposition under light and heat exposure, is safe and environmentally friendly and conforms to modern industrial design standards and the development trend in the furniture industry; furthermore, the light microcellular foamed PET floor does not contain a traditional chemical foaming agent and is colorless and odor-free, and is thus relatively environment-friendly; the product is lightweight and is thus convenient to carry, and also achieves a better sound insulation effect than traditional solid floors.

Description

Formula and production process of a lightweight micro-foamed PET floor Technical Field

[0001] The invention relates to the technical field of PET floors, and in particular to a formula and production process of a light micro-foamed PET floor. Background Art

[0002] PET flooring is a new type of flooring in the industry, with properties similar to SPC flooring. However, SPC flooring achieves significant lightweighting through sophisticated micro-foaming technology. This technology reduces SPC's weight by 15-25% while retaining its performance and texture. This makes it highly popular with customers and holds a promising market outlook. However, there is currently no micro-foamed PET flooring available in the flooring market, nor is there a production technology for this type of flooring. Therefore, a comprehensive technology for producing PET flooring could fill this gap and meet market demand. Currently, PET foam materials are primarily used in wind turbine blade applications, not flooring. Furthermore, the formulation requires a PET content of over 50%, and equipment costs in the tens of millions, resulting in excessively high overall costs. Furthermore, the material also suffers from poor fire resistance, making it difficult to commercialize in the flooring market. Therefore, existing foaming processes and technologies can only serve as a reference, and a new PET foaming technology suitable for the vinyl flooring market must be developed. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a formula and production process for a lightweight micro-foamed PET floor, so as to solve the problem that there is no production technology for low-cost micro-foamed PET floor in the existing market. Technical Solution

[0004] In order to solve the above problems, the technical solution provided by the present invention is:

[0005] A formula for a light micro-foamed PET floor comprises 20%-30% of modified PET, 60%-70% of CaCO3 with a mesh size of 300 or more, 2%-6% of a lubricant, and 4%-7% of a PET toughening agent.

[0006] Furthermore, modified PET and CaCO3 are the main ingredients of the product, wherein the modified PET is mainly used as an adhesive, and CaCO3 above 300 mesh is used as a filler, mainly used to make the main body of the product structure and frame.

[0007] Furthermore, lubricants and toughening agents are used as auxiliary materials. The lubricant is made of small molecule compounds to ensure that the various materials can be fully and evenly mixed, and to ensure that the materials can be smoothly extruded from the barrel and film during the extrusion process without sticking to the mold, screw, and barrel surface; the PET toughening agent is made of an elastomer of a long-chain polymer compound. The PET material itself has strong rigidity, and a toughening agent needs to be added to increase toughness to ensure that the finished product has a certain toughness and will not break easily when subjected to force to prevent the product from being too brittle.

[0008] Also disclosed is a formula production process for a lightweight micro-foamed PET floor, the process flow of which is as follows:

[0009] S01 mixed materials;

[0010] S02 extrudes the base material into a micro-foamed PET substrate;

[0011] S03 sequentially laminating a PET color film and a PET wear-resistant layer on the PET substrate to form a PET semi-finished substrate;

[0012] S04 performs surface coating and tempering on the PET semi-finished substrate;

[0013] S05: Laminating balance paint on the back of PET semi-finished product and tempering again;

[0014] S06 is divided into pieces and grooved to form the finished floor.

[0015] Furthermore, in the above step S02, the extrusion temperature of the base material is set to 180-280°C from the feeding end to the extrusion mold, and a conical twin-screw extruder is used to extrude the mixed material, and the mixed material is extruded into a micro-foamed PET substrate through the conical twin-screw extruder.

[0016] Furthermore, the setting temperature of the conical twin-screw extruder is set in multiple stages from high to low from the feeding end to the extruded film, and the difference between adjacent temperatures is 5-10°C.

[0017] Furthermore, during the actual use of the conical twin-screw extruder, the body temperature of the conical twin-screw extruder needs to be adjusted according to the discharge situation. Since the temperature of the material is low and the texture of the material is hard when it just enters the conical twin-screw extruder, it is necessary to increase the temperature of the conical twin-screw extruder to quickly heat up the material and soften the material. After the material enters the conical twin-screw extruder, the twin screws rotate and extrude, forming friction shear on the material, during which a large amount of heat is released. At this time, the temperature of the barrel of the conical twin-screw extruder in the middle and rear sections can be appropriately lowered to ensure that the flow state before and after the material is softened is consistent, thereby ensuring the consistency of the overall extrusion fluidity. Therefore, the temperature of the conical twin-screw extruder is set from high to low from the feeding end to the extrusion film.

[0018] Furthermore, in actual operation, when the ambient temperature is low, the temperature of the conical twin-screw extruder needs to be appropriately increased; when the ambient temperature is high, the temperature of the conical twin-screw extruder needs to be appropriately reduced; when making thicker substrates, the temperature of the conical twin-screw extruder can be slightly reduced; when making thinner substrates, the temperature of the conical twin-screw extruder can be slightly increased.

[0019] Furthermore, the set temperature of the lowest conical twin-screw extruder is set to 180-220°C (with a 5-10°C interval) during the hottest summer months (around 40°C). The set temperature of the highest conical twin-screw extruder is set to 240-280°C (with a 5-10°C interval) during the coldest winter months (-5°C). The overall temperature variation of the conical twin-screw extruders does not exceed the range of 180-280°C.

[0020] Furthermore, the distance between the screw head and the barrel head of the conical twin-screw extruder is set to 50-100mm. The purpose of this setting is to deliberately leave a certain space in the screw head to facilitate the storage of a small amount of air. When the screw pushes the material into the confluence core, the air is evenly taken away to form blast holes, which are evenly distributed in the substrate to achieve the effect of micro-foaming.

[0021] Furthermore, in the above step S03, the product density of the semi-finished PET substrate prepared is 1.6 g / cm³.

[0022] Furthermore, in the above steps S04 and S05, the first tempering and the second tempering are both required to be at a temperature of 90° C. and tempering for 15 minutes, and both tempering steps need to be left to stand for 48 hours.

[0023] Furthermore, when the conical twin-screw extruder extrudes the micro-foamed PET substrate, a PET color film and a PET wear-resistant layer are directly hot-laminated online to form a semi-finished PET substrate with a density of approximately 1.6g / cm³. The surface is then coated with a film to enhance the surface's scratch resistance and adjust the glossiness. Due to the substrate's inherent large shrinkage, tempering is required to reduce its shrinkage. Furthermore, since the large shrinkage of the wear-resistant layer on the substrate surface can cause product warping, a back-balance coating is required to control overall warping. Furthermore, a single tempering is insufficient to reduce overall shrinkage, so a second tempering is required to control product shrinkage. Both tempering steps require a 48-hour standstill period to allow the substrate to cool and stabilize.

[0024] Furthermore, the surface coating paint and the back balancing paint have different coating weights and light curing energies in different specifications and structural combinations, and can be directly set in a timely manner according to design requirements.

[0025] Furthermore, the portion of the semi-finished PET substrate having the PET color film and the PET wear-resistant layer is the surface, and the portion of the semi-finished PET substrate not having the PET color film and the PET wear-resistant layer is the back. Beneficial effects

[0026] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0027] The lightweight micro-foamed PET floor proposed in the present invention is forward-looking. PET is halogen-free and environmentally friendly. It will not decompose easily when exposed to light or heat like PVC wallboard. It is safe and environmentally friendly, and complies with current industrial design standards and development trends in the furniture industry. In addition, the lightweight micro-foamed PET floor of the present invention does not use traditional chemical foaming agents, is colorless and odorless, and is relatively environmentally friendly. The product is lightweight and easy to carry, and has better sound insulation effect than traditional solid floors. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a flow chart of a production process proposed in an embodiment of the present invention; DETAILED DESCRIPTION

[0029] In order to further understand the content of the present invention, the present invention is described in detail with reference to the accompanying drawings and embodiments.

[0030] A formula for a lightweight micro-foamed PET floor, characterized by comprising 20%-30% modified PET, 60%-70% CaCO3 with a mesh size of 300 or larger, 2%-6% lubricant, and 4%-7% PET toughening agent.

[0031] Modified PET is a PET material that has undergone both temperature and viscosity modifications. This process lowers the processing temperature and increases the viscosity of conventional PET. The normal processing temperature of PET is above 280°C, typically 300°C. This extremely high processing temperature significantly impacts equipment load, service life, energy consumption, and the risk of operator burns. Conventional extruders currently operate at temperatures between 130°C and 240°C. Therefore, modification reduces the processing temperature of PET, facilitating better processing. Conventional PET also suffers from insufficient viscosity, requiring less than 50% stone powder as a binder. Modified PET increases its viscosity, allowing the stone powder content to exceed 60%.

[0032] Modified PET and CaCO3 are the main ingredients of the product, among which modified PET is mainly used as an adhesive, and CaCO3 above 300 mesh is used as a filler, mainly used to make the main body of the product structure and frame.

[0033] Lubricants and toughening agents are used as auxiliary materials. The lubricant is made of small molecule compounds to ensure that the various materials can be fully and evenly mixed, and to ensure that the materials can be smoothly extruded from the barrel and film during the extrusion process without sticking to the mold, screw, and barrel surface; PET toughening agent is made of an elastomer of long-chain polymer compounds. PET material itself has strong rigidity, and toughening agent needs to be added to increase toughness to ensure that the finished product has a certain toughness and will not break easily when subjected to stress to prevent the product from being too brittle.

[0034] In conjunction with Figure 1, a formula production process for a light micro-foamed PET floor, the process flow is as follows:

[0035] S01 mixed materials;

[0036] S02 extrudes the base material into a micro-foamed PET substrate;

[0037] S03 sequentially laminating a PET color film and a PET wear-resistant layer on the PET substrate to form a PET semi-finished substrate;

[0038] S04 performs surface coating and tempering on the PET semi-finished substrate;

[0039] S05: Laminating balance paint on the back of PET semi-finished product and tempering again;

[0040] S06 is divided into pieces and grooved to form the finished floor.

[0041] In the above step S02, the extrusion temperature of the base material is set to 180-280°C from the feeding end to the extrusion mold, and a conical twin-screw extruder is used to extrude the mixed material into a micro-foamed PET substrate.

[0042] The setting temperature of the conical twin-screw extruder is set from high to low from the feeding end to the extrusion film, and is set to multiple sections of gradually decreasing temperature, with a temperature difference of 5-10°C between adjacent sections.

[0043] During the actual use of the conical twin-screw extruder, the body temperature of the conical twin-screw extruder needs to be adjusted according to the discharge situation. Since the temperature of the material is low when it just enters the conical twin-screw extruder and the material texture is hard, it is necessary to increase the temperature of the conical twin-screw extruder to quickly heat up the material and soften the material. After the material enters the conical twin-screw extruder, the twin screws rotate and extrude, forming friction shear on the material, during which a large amount of heat is released. At this time, the temperature of the barrel of the conical twin-screw extruder in the middle and rear sections can be appropriately lowered to ensure that the flow state before and after the material is softened is consistent, thereby ensuring the consistency of the overall extrusion fluidity. Therefore, the temperature of the conical twin-screw extruder is set from the feeding end to the extrusion film, from high to low.

[0044] In actual operation, when the ambient temperature is low, the temperature of the conical twin-screw extruder needs to be appropriately increased; when the ambient temperature is high, the temperature of the conical twin-screw extruder needs to be appropriately reduced; when making thicker substrates, the temperature of the conical twin-screw extruder can be slightly reduced; when making thinner substrates, the temperature of the conical twin-screw extruder can be slightly increased.

[0045] The set temperature for the lowest conical twin-screw extruder is: 180-220°C (with a 5-10°C interval) during the hottest summer months (around 40°C). The set temperature for the highest conical twin-screw extruder is: 240-280°C (with a 5-10°C interval) during the coldest winter months (around -5°C). The overall temperature variation of the conical twin-screw extruder does not exceed the range of 180-280°C.

[0046] The distance between the screw head and the barrel head of the conical twin-screw extruder is set to 50-100mm. The purpose of this setting is to deliberately leave a certain space in the screw head to facilitate the storage of a small amount of air. When the screw pushes the material into the confluence core, the air is evenly taken away to form blast holes, which are evenly distributed in the substrate to achieve the effect of micro-foaming.

[0047] In the above step S03, the product density of the semi-finished PET substrate produced is 1.6 g / cm³.

[0048] In the above steps S04 and S05, the first tempering and the second tempering are both required to be at a temperature of 90° C. and tempering for 15 minutes, and both tempering steps need to be left to stand for 48 hours.

[0049] When a conical twin-screw extruder extrudes a micro-foamed PET substrate, a PET color film and a PET wear-resistant layer are directly hot-laminated online to form a semi-finished PET substrate with a density of approximately 1.6g / cm³. The surface is then coated with a film to enhance scratch resistance and adjust gloss. Due to the substrate's inherent large shrinkage, tempering is required to reduce shrinkage. Furthermore, since the shrinkage of the wear-resistant layer on the substrate surface can cause product warping, a back-balance coating is applied to control overall warping. Furthermore, a single tempering step is insufficient to reduce overall shrinkage, so a second tempering step is required to control shrinkage. Both tempering steps require a 48-hour rest period to allow the substrate to cool and stabilize.

[0050] The surface coating paint and back balancing paint have different coating weights and light curing energies in different specifications and structural combinations, so they can be set directly and in time according to design requirements.

[0051] The portion of the semi-finished PET substrate having the PET color film and the PET wear-resistant layer is the surface, and the portion of the semi-finished PET substrate not having the PET color film and the PET wear-resistant layer is the back.

[0052] After completing the above steps, the PET floor is divided into pieces and grooved to produce the finished product.

[0053] In a general implementation, the prepared materials are first put into the mixer according to the formula ratio for thorough stirring and mixing. The thoroughly mixed materials are put into the feeding port of the conical twin-screw extruder, that is, the feeding end. The distance between the screw head and the barrel of the conical twin-screw extruder is 80 mm. The temperature inside the conical twin-screw extruder is set to a temperature range of 200-250°C from the feeding end to the extrusion die. The temperature is set in multiple stages with a temperature difference of 5°C. The screw is turned on to extrude and plasticize the mixed materials through screw extrusion, and then squeezed into the extrusion die with air. The micro-foamed PET substrate extruded from the die outlet is directly and sequentially hot-laminated with a PET color film layer and a PET wear-resistant layer online to form a dense The semi-finished PET substrate with a density of 1.6g / cm³ is then coated on the surface of the semi-finished PET substrate. The coating process requirements can be changed in time according to design needs to enhance the surface scratch resistance and adjust the glossiness. After the coating is completed, it is tempered at 90℃ for 15 minutes to offset part of the substrate shrinkage effect. The substrate after the first tempering is then cooled and left to stand for 48 hours. The back of the substrate is then coated with a balance paint to control the overall warping and tempered at 90℃ for 15 minutes again to control the product shrinkage. The tempered substrate is then cooled and left to stand for 48 hours. After completing the above steps, the substrate is sliced ​​and grooved to make the finished PET floor. The coating on the surface and back and the two temperings can be integrated into one production line.

[0054] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs a structure and embodiment similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A formula for a lightweight micro-foamed PET floor, characterized in that: It includes 20%-30% modified PET, 60%-70% CaCO3 above 300 mesh, 2%-6% lubricant and 4%-7% PET toughening agent.

2. The formula of a light micro-foamed PET floor according to claim 1, characterized in that: Lubricants are small molecule compounds that act as lubricants.

3. The formula of a light micro-foamed PET floor according to claim 1, characterized in that: PET toughening agent is an elastomer of long-chain polymer compounds.

4. A production process for a lightweight micro-foamed PET floor, characterized in that: S01 A mixed material according to the formula of the lightweight micro-foamed PET flooring as claimed in claim 1; S02 extrude the base material into a micro-foamed PET substrate; S03 sequentially laminating a PET color film and a PET wear-resistant layer on the PET substrate to form a PET semi-finished substrate; S04 Surface coating and tempering of PET semi-finished substrate; S05: Laminating the back of the PET semi-finished product with a balanced coating and re-tempering; S06 is cut into pieces and grooved to make finished flooring.

5. The production process of a light micro-foamed PET floor according to claim 4, characterized in that: In the above step S02, the extrusion temperature of the base material is set to 180-280° C. from the feeding end to the extrusion mold, and a conical twin-screw extruder is used for extrusion.

6. The production process of a light micro-foamed PET floor according to claim 5, characterized in that: The temperature setting of the conical twin-screw extruder is set in multiple stages from high to low from the feeding end to the extruded film, and the adjacent temperature difference is 5-10℃.

7. The production process of a light micro-foamed PET floor according to claim 5, characterized in that: The distance between the screw head and the barrel head of the conical twin-screw extruder is set to 50-100 mm.

8. The production process of a light micro-foamed PET floor according to claim 4, characterized in that: In the above step S03, the product density of the semi-finished PET substrate is 1.6±0.15 g / cm³.

9. The production process of a light micro-foamed PET floor according to claim 4, characterized in that: In the above steps S04 and S05, the first tempering and the second tempering are both required to be at a temperature of 90° C. and for a tempering time of 15 minutes.

10. The production process of a light micro-foamed PET floor according to claim 9, characterized in that: Both tempering steps require a 48-hour rest period.

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