Plastic sheet with through-body texture and preparation method therefor

Abstract

Disclosed are a plastic sheet with through-body texture and a preparation method therefor. All three methods of the present invention are applicable to various raw materials and do not require pre-granulation into particles of different hardness / softness levels, and can be achieved using base materials of the same formulation but different colors. The core ideas of the first method and the second method are to employ an intensive mixer-extrusion system or a co-extrusion system to separately plasticize base materials of different formulations or the same formulation, so as to form rubber blocks of different colors; and then to mix the rubber blocks and knead the mixed rubber blocks until the rubber blocks of different colors are initially blended, avoiding color blending caused by over-mixing, and ensuring that the extrusion-molded base plate has clear and natural texture. The third method is to utilize the combined action of a swing conveyor and a calender to cause the rubber blocks to accumulate and be calendered on the calender, so as to achieve mixing of different colors. Compared with the existing production processes for through-colored flooring, all the three methods of the present invention enable continuous production, feature simpler processes, and offer better compatibility.

Description

Plastic sheet with whole-body texture and preparation method thereof Technical Field

[0001] The present invention belongs to the technical field of home decoration boards, and particularly relates to a plastic board with a texture throughout and a preparation method thereof. Background Art

[0002] SPC flooring is currently the leading choice among rigid plastic floorings. Its production method involves extruding a base material through an extruder, then laminating a colored film and a wear-resistant layer onto the surface. The pattern and texture are printed, and thus cannot achieve the realistic and natural look of natural stone or wood. For example, natural marble-patterned flooring, due to long-term marble mining, is becoming increasingly scarce, and the mining process is environmentally damaging. Therefore, existing technology often replaces some of the marble with ceramic tiles, using digital printers to print marble patterns. Marble slabs are also popular. However, ceramic tiles and slabs consume too much energy, are time-consuming and labor-intensive to install, and the auxiliary materials are not environmentally friendly. The environmental friendliness and ease of processing of plastic flooring have earned it a place in the market, with PVC being particularly widely used.

[0003] In plastic flooring, there are two ways to replace natural marble patterns. One is to laminate a printed marble color film on any color substrate, and then use a wear-resistant layer as protection on the surface. However, the wear-resistant layer has a large shrinkage rate, which easily causes the warping problem of the board. It is usually necessary to add a balancing layer at the bottom of the board to reduce the warping phenomenon. The other is a permeable floor, such as patent CN103707526A. Its process is to mix PVC, calcium powder, auxiliary materials and pigments with a high-speed mixer and then granulate them into PVC particles of different colors (base material particles, color-adjusting particles, and drawing particles). The required particles are then put into an extruder and extruded at high temperature to obtain a floor with a full-body pattern. However, this method has certain limitations. It is necessary to pre-granulate and allocate particles of different colors corresponding to different hardnesses in the early stage. Different PVC formulas are designed for particles with different functions. For example, the amount of lubricant used for drawing particles needs to be increased to improve their softness, thereby pulling out patterns with better ductility. The above extrusion process is only applicable to granulation materials with different PVC formulas. If the same PVC formula is used, the strong mixing of the extruder will only cause all the particles of different colors to be mixed, and finally a single-color sheet will be extruded, instead of forming a whole material with distinct colors. In addition, the pre-granulation process is relatively cumbersome and cannot achieve continuous production.

[0004] Therefore, there is an urgent need for a continuous production process for whole-body panels with simpler process and better compatibility. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a plastic sheet with a texture throughout and a preparation method thereof.

[0006] According to one aspect of the present invention, a plastic sheet having a texture throughout is provided, comprising a substrate having a texture throughout, wherein the substrate is made by any of the following methods:

[0007] Method 1: A banburying extrusion system is used, which includes two or more banburying devices and a mixing device. The discharge port of the banburying device is connected to the feed port of the mixing device. The mixing device is an extruder or a mixer. Different colors of base materials are fed into the banburying device one by one. The base materials are plasticized into a rubber block by the banburying device and then enter the mixing device. The degree of mixing is controlled according to the desired texture style. After mixing, the substrate is formed.

[0008] Method 2: A co-extrusion system is used, which includes two or more extruders, a T-die, and a static mixer provided between the extruder and the T-die. Different colored base materials are fed into the extruders one by one. After being plasticized by the extruders, the base materials enter the static mixer, where the degree of mixing is controlled according to the desired texture style, and then enter the T-die for extrusion molding to obtain the substrate.

[0009] Method 3: A co-extrusion system is used, which includes two or more extruders, a distributor, a swing conveyor and a calender. Different colored base materials are put into the extruder one by one. After the base materials are plasticized by the extruders, they are compounded through the distributor to form color-layered rubber blocks. The rubber blocks enter the swing conveyor and are accumulated at the feed port of the calender under the lateral reciprocating swing of the swing conveyor. They are then calendered and formed by the calender to obtain the substrate.

[0010] The calender is placed below the discharge port of the swing conveyor. The existing swing conveyor and calender are primarily used to increase the width of the substrate. The lateral reciprocating swing of the swing conveyor allows a small amount of molten base material to be deposited on the calender rollers. Increasing the width of the rollers allows the base material to be more laterally squeezed during the calendering process, thereby increasing the base material's width. In method three of the present invention, since the different colors are mixed by accumulating and calendering the rubber blocks on the calender, the deposit thickness can be controlled to be higher, resulting in a better mixing effect.

[0011] In some embodiments of the present invention, the base material includes a main ingredient and color powder, wherein the main ingredient includes a thermoplastic polymer, a filler, and an additive. Different colored base materials can use the same or different main ingredients. The thermoplastic polymer is PVC, PP, PETG, or PET. Furthermore, the additive is at least one of a lubricant and a stabilizer. Furthermore, the filler is calcium carbonate.

[0012] In some embodiments of the present invention, the mass ratio of the thermoplastic polymer to the filler is 1:(1-4.5).

[0013] In some embodiments of the present invention, the main material further includes non-melting particles, which are infusible at the plasticizing temperature of the thermoplastic polymer. After the substrate is formed, the non-melting particles on the surface of the substrate are removed by subsequent processing, and the resulting plastic sheet has a travertine-like texture effect.

[0014] In some embodiments of the present invention, the thermoplastic polymer is PVC or PP, and the non-melting particles are PET. The plasticizing temperature of PVC is generally between 140-160°C, while that of PET is generally between 250-260°C. Therefore, PET is used as the template material for forming the travertine texture and is added to the base material. Even after plasticizing, mixing, and extrusion, PET is incompatible with PVC. The PET particles on the surface of the board can be easily removed later, while the PET particles inside the board serve as filler.

[0015] In some embodiments of the present invention, the substrate surface is sanded to remove the unmelted particles.

[0016] In some embodiments of the present invention, in method 1, a horizontally arranged set of calibrating rollers is provided near the mixer's discharge port. After the material has been mixed in the mixer, it is fed into the calibrating rollers for rolling and shaping. A conveyor belt may be provided between the mixer and the calibrating rollers to convey the material from the mixer to the calibrating rollers.

[0017] In some embodiments of the present invention, in method 1, the extruder is a single-screw extruder. The mixing degree can be controlled by controlling the length of the single-screw extruder.

[0018] In some embodiments of the present invention, in method 2, the static mixer is a spiral mixer, and the degree of mixing is controlled by controlling the number of spiral blades in the static mixer. Preferably, the number of spiral blades is 1-5. More preferably, the number of spiral blades is 1-2.

[0019] In some embodiments of the present invention, in method three, a die head is further provided behind the distributor. After the base materials are plasticized by the extruders, they pass through the distributor and the die head in sequence before entering the swing conveyor. Method three does not require the shape of the die head. The die head is provided primarily to control pressure and extrusion speed. The die head increases flow resistance to control pressure during extrusion, helping to ensure stable melt flow and good pressure distribution during extrusion.

[0020] In some embodiments of the present invention, after the substrate is prepared, a CCD camera captures a texture image of the substrate and transmits it to a digital printer. The digital printer then prints a pattern or pattern identical to the texture of the substrate on the surface of the substrate.

[0021] In some embodiments of the present invention, the overall texture is marble or wood grain.

[0022] In some embodiments of the present invention, the plastic sheet is made into a locking plate.

[0023] In some embodiments of the present invention, the plastic sheet is made into a coil.

[0024] In some embodiments of the present invention, the surface of the plastic sheet is chamfered.

[0025] In some embodiments of the present invention, the substrate surface is further provided with a PUR layer, a UV paint layer, or a wax layer. Furthermore, the UV paint layer is surface treated, and the surface treatment includes at least one of lamination, excimer lamp matte treatment, or EB irradiation treatment.

[0026] In some embodiments of the present invention, in method 1 and / or method 2, after the substrate is prepared, the substrate is subjected to a calender to determine the thickness. The calender can further lengthen and widen the texture on the substrate.

[0027] In some embodiments of the present invention, after the substrate is prepared, the substrate surface is embossed. Furthermore, the embossing process uses an embossing plate or roller. Stone or wood grain can be pressed onto the surface according to the overall texture of the substrate.

[0028] According to a preferred embodiment of the present invention, there are at least the following beneficial effects:

[0029] 1. The present invention does not require pre-granulation, and can directly input powder raw materials to continuously produce substrates with full-body textures. The equipment is simple and existing equipment can be directly connected to the production line. The plate does not require a printed film and a wear-resistant layer, has no warping problem, and has more stable shrinkage.

[0030] 2. The whole body pattern of the present invention is randomly generated, no piece is repeated, and it is closer to the real marble pattern.

[0031] 3. The panels can be assembled with locks or paved with glue, which makes them easier to install than tiles and rock panels.

[0032] 4. The three methods of the present invention are all applicable to a variety of raw materials, and do not need to be granulated into particles of different hardness in advance. It can also be achieved by using base materials of the same formula but different colors. Among them, the core idea of ​​method one and method two is to use a mixing extrusion system or a co-extrusion system to separately plasticize base materials of different formulas or the same formula to form rubber blocks of different colors, and then mix these rubber blocks and mix them until the rubber blocks of different colors are initially blended, avoiding excessive mixing to cause color miscibility, and the texture of the extruded substrate is clear and natural. Method three is to use a co-extrusion system to separately plasticize base materials of different formulas or the same formula, and compound them through a distributor to form color-layered rubber blocks. Under the combined action of a swing conveyor and a calender, the rubber blocks are piled and calendered on the calender to achieve mixing of different colors. Compared with the existing production process of permeable flooring, the three methods of the present invention can all be produced continuously, with simpler processes and better compatibility.

[0033] 5. All three methods of the present invention can produce substrates with full-body textures. Each method has its own advantages. For example, considering the equipment cost, the equipment cost of the co-extrusion system is much lower than that of the internal mixing system. The cost of the internal mixing device is relatively higher, but the internal mixing system is more suitable for certain formulas, such as formulas with higher softness. For example, considering process compatibility, method three has a wider range of applications than method two. Method two may have certain limitations for base materials with large differences in plasticizing temperatures, because the spiral blades of the static mixer have a blocking pressure on the colloid. If the plasticizing temperatures of the colloids differ too much, it is easy to cause different colloid flow rates, thereby affecting the preset mixing effect. The distributor of method three can control the flow path and speed of the plastic melt in the distributor, helping to eliminate the unevenness and instability of the melt flow during the extrusion process, but method two also has the advantage of relatively higher flexibility. Therefore, the three methods of the present invention each have their own characteristics and can be selected according to actual needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0035] FIG1 is a schematic diagram of a mixing and extrusion system (continuous extruder) according to Example 1 of the present invention;

[0036] FIG2 is a schematic diagram of a mixing and extrusion system (with a mixer) according to Example 2 of the present invention;

[0037] FIG3 is a schematic structural diagram of a static mixer according to embodiment 3 of the present invention.

[0038] Reference numerals: internal mixing device 100 , single screw extruder 200 , mixer 300 , thickness-setting roller set 400 . DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with the embodiments to fully understand the purpose, features and effects of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0040] Example 1

[0041] This embodiment prepares a plastic floor with a full-body marble pattern. Referring to FIG1 , the specific process is as follows:

[0042] A banburying extrusion system was used, consisting of two banburying devices and a single-screw extruder. The discharge ports of the two banburying devices were connected to the feed port of the single-screw extruder and connected to a T-die. Two colors of base materials were added to the banburying device one by one. Except for the color of the toner, the two base materials had the same main ingredient formula, as shown in Table 1. The base materials were plasticized into rubber blocks by the banburying device and then entered the single-screw extruder. The banburying temperature was 190°C and the temperature of the single-screw extruder was 180°C. The discharge speeds of the two banburying devices into the single-screw extruder were adjusted to be different. After mixing, the rubber materials were discharged from the T-die to form a substrate with long strips of texture. The substrate was then calendered to a fixed thickness by two rollers to further lengthen and widen the texture. Subsequently, an embossing roller was used to emboss the texture to obtain a plastic floor with a full-body marble pattern.

[0043] Table 1 Main ingredient formula

[0044] Example 2

[0045] This embodiment prepares a plastic floor with a full-body marble pattern. Referring to FIG2 , the specific process is as follows:

[0046] A banburying extrusion system was used, consisting of two banburying devices and a mixer. The discharge ports of the two banburying devices were connected to the feed port of the mixer, and a horizontally arranged thickness-setting roller group was provided near the discharge port of the mixer (the center line connecting the two thickness-setting roller shafts was in the horizontal direction). Two colors of base materials were put into the banburying device one by one. Except for the color of the toner, the two base materials had the same main ingredient formula, as shown in Table 1. The base materials were plasticized into rubber blocks by the banburying device and then entered the mixer. The banburying temperature was 190°C and the mixer temperature was 180°C. The discharge speeds of the two banburying mixers into the mixer were adjusted to be different. After mixing, the rubber materials were discharged from the mixer discharge port and fell into the thickness-setting roller group for calendering and shaping to obtain a substrate with long strips of drawing. Subsequently, an embossing roller was used to emboss the texture to obtain a plastic floor with a full-body marble texture.

[0047] Example 3

[0048] This embodiment prepares a plastic floor with a marble pattern throughout. The specific process is as follows:

[0049] A co-extrusion system is used, consisting of two extruders, each connected to a T-die at the front end. A static mixer is connected between the extruders and the T-die. The static mixer is a spiral mixer, and its structure is shown in Figure 3. In this embodiment, the number of spiral blades of the static mixer is two. Two colors of base materials are fed into the two extruders one by one. The two base materials differ in color except for the color of the toner, and the other main ingredients are the same. The main ingredient formula is shown in Table 1. After being plasticized by the extruders, the base materials enter the static mixer and then enter the T-die for extrusion molding. The extruder temperature is 190-210°C, and the die temperature is 200°C. A substrate with long strips of texture is obtained. The substrate is then calendered to a fixed thickness by two rollers, so that the texture is further stretched and widened. Subsequently, an embossing roller is used to emboss the texture to obtain a plastic floor with a full-body marble pattern.

[0050] Example 4

[0051] This embodiment prepares a plastic floor with a marble pattern throughout. The floor surface has a travertine effect. PET particles are added to the surface of Example 1 and sanding is performed. The specific process is as follows:

[0052] A banbury extrusion system was used, consisting of two banbury mixers and a single-screw extruder. The discharge ports of the two banbury mixers were connected to the feed port of the single-screw extruder and connected to a T-die. Two base materials of different colors were fed into the banbury mixers one by one. The two base materials had the same main ingredient formula except for the color of the toner. The main ingredient formula is shown in Table 2, wherein the PET particles were prepared according to the formula shown in Table 3. The base materials were plasticized into a rubber block by the banbury mixer and then fed into the single-screw extruder. The banbury temperature was 190°C and the temperature of the single-screw extruder was 180°C. The discharge speeds of the two banbury mixers into the single-screw extruder were adjusted to be different. After mixing, the rubber materials were discharged from the T-die to form a substrate with long strips of texture. The substrate was then calendered to a fixed thickness by two rollers to further elongate and widen the texture. The surface of the substrate was then treated with a sander to remove the PET particles on the surface, resulting in a plastic floor with a full-body marble and travertine effect.

[0053] Table 2 Main ingredient formula

[0054] Table 3 PET granule formula

[0055] Example 5

[0056] This embodiment prepares a plastic floor with a marble pattern throughout. The specific process is as follows:

[0057] A co-extrusion system is adopted, which consists of two extruders, a swing conveyor and a calender. The front ends of the two extruders are equipped with distributors and die heads. The two colors of base materials are fed into the two extruders one by one. Except for the color of the toner, the two base materials have the same main ingredient formula. The main ingredient formula is shown in Table 1. After the base materials are plasticized in the extruders, they are compounded through the distributor to form color-layered rubber blocks. The rubber blocks enter the swing conveyor and are accumulated at the feed port of the calender under the horizontal reciprocating swing of the swing conveyor. After being calendered by the calender, a substrate with long strips of drawing is obtained. The extruder temperature is 190-210℃. Subsequently, an embossing roller is used to press out the texture to obtain a plastic floor with a full-body marble pattern.

[0058] While the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. A plastic sheet with a texture throughout, characterized in that: The invention comprises a substrate having a whole-body texture, wherein the substrate is made by any of the following methods: Method 1: A banburying extrusion system is used, which includes two or more banburying devices and a mixing device. The discharge port of the banburying device is connected to the feed port of the mixing device. The mixing device is an extruder or a mixer. Different colors of base materials are fed into the banburying device one by one. The base materials are plasticized into a rubber block by the banburying device and then enter the mixing device. The degree of mixing is controlled according to the desired texture style. After mixing, the substrate is formed. Method 2: A co-extrusion system is used, which includes two or more extruders, a T-die, and a static mixer provided between the extruder and the T-die. Different colored base materials are fed into the extruders one by one. After being plasticized by the extruders, the base materials enter the static mixer, where the degree of mixing is controlled according to the desired texture style, and then enter the T-die for extrusion molding to obtain the substrate. Method 3: A co-extrusion system is used, which includes two or more extruders, a distributor, a swing conveyor and a calender. Different colored base materials are put into the extruder one by one. After the base materials are plasticized by the extruders, they are compounded through the distributor to form color-layered rubber blocks. The rubber blocks enter the swing conveyor and are accumulated at the feed port of the calender under the lateral reciprocating swing of the swing conveyor. They are then calendered and formed by the calender to obtain the substrate.

2. The plastic sheet with a texture throughout according to claim 1, characterized in that: The base material includes a main material and color powder, and the main material includes a thermoplastic polymer, a filler and an additive. Base materials of different colors can use the same or different main materials. The thermoplastic polymer is PVC, PP, PETG or PET.

3. The plastic sheet with a texture throughout according to claim 2, characterized in that: The main material also includes infusible particles, which are infusible at the plasticizing temperature of the thermoplastic polymer. After the substrate is made, the infusible particles on the surface of the substrate are removed by subsequent processing, and the obtained plastic sheet has a travertine texture effect.

4. The plastic sheet with a texture throughout according to claim 1, characterized in that: The surface of the plastic plate is chamfered.

5. The plastic sheet with a texture throughout according to claim 3, characterized in that: The substrate surface is sanded to remove the infusible particles.

6. The plastic sheet with a texture throughout according to claim 1, characterized in that: The substrate surface is further provided with a PUR layer, a UV paint layer or a wax layer; the UV paint layer is surface treated, and the surface treatment includes at least one of film pressing, excimer lamp matte treatment or EB irradiation treatment.

7. The plastic sheet with a texture throughout according to claim 1, characterized in that: In the second method, the static mixer is a spiral mixer, and the degree of mixing is controlled by controlling the number of spiral blades in the static mixer.

8. The plastic sheet with a texture throughout according to claim 1, characterized in that: In the third method, a die head is further provided behind the distributor. After the base materials are plasticized by the extruder, they pass through the distributor and the die head in sequence and then enter the swing conveyor.

9. The plastic sheet with a texture throughout according to claim 1, characterized in that: After the substrate is manufactured, the substrate is photographed by a CCD to capture the texture image of the substrate and transmit it to a digital printer. The digital printer then prints a pattern or pattern identical to the substrate texture on the surface of the substrate; or, after the substrate is manufactured, the surface of the substrate is embossed.

10. The plastic sheet with a texture throughout according to claim 1, characterized in that: The whole body texture is marble or wood grain; the plastic sheet is made into a locking plate.

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