A reverse-pressed integrally formed concave-convex ceramic slab and its manufacturing method

Abstract

This invention relates to the field of architectural ceramics technology, and more particularly to a reverse-pressed, one-piece dry-pressed concave-convex ceramic slab and its manufacturing method. The slab can be pressed and formed in a single operation, enabling standardized mass production of this shaped ceramic slab. Furthermore, in this invention, the concave-convex shaped surface of the blank faces downwards during pressing. Compared to conventional brick-pushing methods, which would damage the shaped surface and prevent subsequent glazing without flipping, this invention innovatively employs a robotic arm in conjunction with a suction method. After demolding, the blank is vertically lifted upwards and removed from the press before being flipped, ensuring the shaped surface faces upwards. This guarantees the integrity of the blank and its concave-convex shaped surface, as well as stability during subsequent transport, thus improving production quality.

Description

Technical Field

[0001] This invention relates to the field of building ceramics technology, and in particular to a reverse-pressed integrally formed concave-convex ceramic slab and its manufacturing method. Background Technology

[0002] With the development of building technology and materials, ceramic slab products have gradually gained widespread application in various places due to their superior physical and chemical properties and the ability to digitally reproduce numerous exquisite patterns and pre-defined structural shapes. In decoration and renovation, attention is not only paid to the decorative effect of floor or wall tiling, but also to the combination of practicality and aesthetics in kitchen and bathroom countertops and appliances.

[0003] In response to the aforementioned needs, ceramic manufacturers are also researching the application of ceramic slabs in existing home kitchens and bathrooms. Existing ceramic slabs typically have a flat surface or shallowly textured surfaces. When preparing various kitchen, bathroom, and teaware countertops with predetermined shapes and deeper textures from these slabs, one method involves using a one-piece pressing molding technique to create textured slabs with significant height differences. This method essentially uses a pre-shaped upper mold to press powder with a flat overall shape. Therefore, the thickness of the powder distribution in this method is generally uniform, and the powder distribution does not pre-form a male-female matching mold. The first shaping step results in uneven density and significant differences in the pressed blank, making it prone to delamination. This leads to a series of problems, including poor drainage and oxidation during firing, large deformation after firing, easy surface cracking, and even breakage of the entire sheet. In addition, there is a pressing solution using a pre-defined convex upper mold to press flat fabric. This solution solves the problems in pressing and firing by dispersing and squeezing the powder through the inverted conical position of the convex ridge during pressing. However, this solution is only effective when the width of the convex ridge is less than 30mm. When the width of the convex ridge is greater than 30mm, it cannot dissipate the powder, thus failing to achieve uniform and dense pressing of a large area of ​​concave and convex surfaces.

[0004] In addition, when ceramic slabs are used for installation, in order to ensure a firm bond, the back of the slab is usually textured with a depth of no more than 2mm and a width of no more than 10mm. The ceramic slabs improve the adhesion by forming a bond between these textures and cement mortar, concrete, or tile adhesive. However, when such slabs with shallow, almost flat textures are used on floors and walls, the ceramic slabs have a low water absorption rate and a small surface area for bonding with the floor or wall, resulting in weak grip and adhesion. Over time, the underlying concrete may shrink unevenly, causing the slabs to loosen.

[0005] In existing technologies, such as the technical solution with publication number CN112060290B, although it mentions that the back of the tile contains inward concave and convex textures, the height of these textures is 1mm-5mm, the width of the concave textures is 3mm-8mm, and the width of the convex textures is 3mm-10mm. However, the height and width of these textures are too small. It is well known in the industry that during the pressing process of ceramic slabs, the blank is formed by the upper and lower molds of the press acting on all six sides of the mold cavity. At the final pressing, the ceramic slab blank possesses internal stress under the same force. During the demolding process, as the upper and lower molds clamp the formed blank and it floats out of the mold cavity, and during the rapid separation of the upper mold from the blank, the entire blank expands evenly in all directions, releasing internal stress. The overall increase in blank size after expansion is approximately 0.5% to 1.5%. Therefore, the back of most ceramic slabs can only have shallow textures or trapezoidal convexities. This shape facilitates demolding during the pressing process and does not damage the blank. Because the blank has expansion characteristics when it leaves the mold cavity, while the mold does not change, if the blank is pre-set with a side that is concave inward, and the angle between its concave side and the vertical direction is greater than 15°, its expansion rate and the angle will not match. The protruding part of the blank and the concave part of the mold will not be completely separated, resulting in incomplete demolding and causing the protruding top corner to be easily broken. Therefore, the hook design of this mold scheme only utilizes the expansion characteristics of the blank during demolding in the dry pressing process for angle design, and it is also based on conventional shallow background texture. Its purpose is only to give the tile better grip during installation. However, because the background texture is shallow and small, with a raised texture height of 1mm to 5mm and a width of 3mm to 10mm, the specific surface area for bonding with the ground and wall is not large, and the grip and adhesion are not strong. Over time, the underlying concrete will shrink unevenly, making it easy to loosen. Moreover, it does not reveal the realization of the raised / depressed planar area size with a width of not less than 30mm and a continuous length of not less than 100mm, so it also has limitations.

[0006] Based on the above, the industry is focusing on developing ceramic slabs for wall and floor tiling. These slabs not only offer a wider range of pre-designed textures to meet diverse countertop decoration and personalized market demands, but also possess superior grip and adhesion. They can achieve a strong, interlocking bond with cement mortar, concrete, or tile adhesives, similar to a snap-fit ​​method. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a reverse-pressed integral dry-pressed concave-convex ceramic slab and its manufacturing method, which aims to solve the problems of existing concave-convex slabs which are obtained by pressing powder of a flat shape with a pre-designed upper mold. This method does not pre-form a preliminary shape that corresponds to the male and female molds of the powder, resulting in uneven density and large differences in the pressed blank, and easy delamination.

[0008] The technical solution of the present invention is as follows:

[0009] A method for manufacturing a concave-convex ceramic slab formed by reverse-pressing, comprising the following steps:

[0010] a. Raw material preparation: Prepare the raw materials needed to make the concave-convex ceramic slabs;

[0011] b. Mold design: The mold shape is designed in reverse according to the predetermined shape of the front and back of the concave-convex ceramic slab. The upper surface of the lower mold is the concave-convex shaped surface. The concave-convex shaped surface and the concave-convex shaped surface of the concave-convex ceramic slab are a matching male and female matching shape design.

[0012] c. Fabric spreading: The raw material is spread flat inside the press mold cavity using a fabric spreading mechanism;

[0013] d. Pressing: The raw material laid flat in the press cavity is pressed into a blank by a press through a pre-shaped mold;

[0014] e. Suction: The blank is vertically lifted upwards and removed from the press;

[0015] f. Drying: Drying the blank;

[0016] g. Firing: The dried blank is fired to obtain a semi-finished product;

[0017] h. Processing: Cool the semi-finished product and grind its edges to obtain the concave-convex ceramic plate.

[0018] Optionally, in step a, the raw materials required for making the concave-convex ceramic slabs are prepared, wherein the moisture content of the raw materials is not higher than 9%; the raw materials are conventional ceramic powders with a residue of more than 85% after passing through a 60-mesh sieve or mixtures composed of these conventional ceramic powders and particles with a predetermined gradation and color.

[0019] Optionally, in step b, the size of the mold is designed by the following method: the size of the concave-convex ceramic plate is enlarged by 1% to 3% to adapt to the edge grinding and cutting requirements to design the semi-finished size of the concave-convex ceramic plate after firing, and the mold size is designed based on the firing shrinkage rate of the ceramic plate of 8.5% to 10.5%.

[0020] Optionally, in step c, the fabric-laying mechanism can be a conventional one-time fabric-laying mechanism, or a mechanical and digitally controlled digital fabric-laying mechanism.

[0021] The material placement method involves using a material placement mechanism to distribute the raw material into the mold cavity, forming a flat overall layout when viewed from the mold cavity surface. Because the upper surface of the lower mold is a pre-designed concave-convex shape surface, the powder only needs to be laid flat within the mold cavity, eliminating the need for pre-shaped material placement. This results in faster material placement and better molding effects.

[0022] In step d, a press is used to press the flat raw material in the press cavity into a blank through a pre-shaped mold. The pressure of the press can be 220 bar to 250 bar.

[0023] In step e, the blank is pressed by the upper and lower molds of the press, which exert force on all six sides of the mold cavity. During the final pressing, the blank has internal stress with the same force. In the blank demolding process, the upper and lower molds hold the formed blank and float out of the mold cavity. During the rapid separation of the upper mold and the blank, the entire blank expands uniformly to the surroundings and releases internal stress. Its linear expansion rate is about 0.3% to 0.8%.

[0024] Viewed from any cross-section of the plate's central vertical axis, the side of the convex surface region (hereinafter referred to as the convex surface) of the plate, which does not pass through the central vertical axis, near the central vertical axis, or the side of the concave surface region (hereinafter referred to as the concave surface), away from the central vertical axis, forms an angle of 0° < a ≤ 15° with the vertical axis. (This angle is calculated based on the comprehensive and coordinated matching of the linear expansion rate of the blank after pressing and demolding, the height or depth of the surface region, and the distance from the surface region to the central vertical axis. Specifically, the linear expansion coefficient is set as ε, the distance from the projection of the bottom vertex of the slope to the vertical axis is set as L, and the thickness of the convex surface region is set as H. Therefore, to ensure that the blank can be vertically sucked up after pressing and expansion and can smoothly exit the tip of the mold, the following equation must be satisfied: tan a ≤ εL / [H(1+ε)], and 0° < a ≤ 15°, see...) Figure 1As shown), the horizontal projection of the raised surface near the end side or the concave surface away from the end side coincides with the horizontal projection of the surface of the raised surface or the plane of the concave surface. The included angle is 0°<a≤15°, and the side formed is a lateral inward bevel (reverse slope) design. If the lower surface of the upper mold using the forward molding method is a concave-convex molding surface, the blank is not fully expanded when the upper mold rises and separates, and it is easy to smash the reverse slope corner of the raised surface. Therefore, the upper surface of the lower mold used in this invention is a concave-convex molding surface, and the lower surface of the upper mold is a whole flat surface or a combination of a plane at a predetermined position and a small conventional concave-convex texture (a plane at a predetermined position is conducive to the subsequent suction of the blank). The lower surface of the upper mold with this design is basically flat, which can effectively avoid the phenomenon that the blank is not fully expanded when the upper mold rises and separates and smashes the reverse slope corner of the raised surface.

[0025] Optionally, a robotic arm is used to vertically lift the blank upwards and remove it from the press before flipping it and placing it on the glaze line, ensuring the convex and concave surfaces of the blank are facing upwards. Since the convex and concave surfaces of the blank after the pressing process are facing downwards, conventional brick-pushing methods would damage these surfaces. Without flipping, the blank cannot move on the glaze line in subsequent processes. Therefore, using a robotic arm to vertically lift the blank upwards and remove it from the press before flipping it and placing it on the glaze line, ensuring the convex and concave surfaces are facing upwards, guarantees the integrity of the blank and the stability during subsequent transport.

[0026] Optionally, after step e and before step f, a glazing / slurry application step is also included: spraying / applying glaze / slurry onto the dried body surface (referring to a surface with raised and recessed shapes) to form a surface decorative layer. The spraying / applying of glaze / slurry can be achieved through the following methods:

[0027] Method 1: Apply a layer of protective glaze;

[0028] Method 2: First spray a layer of glaze / slurry, then apply glaze / slurry / dry granule glaze.

[0029] Optionally, in step g, the maximum firing temperature can be 1140℃~1220℃.

[0030] A reverse-pressed integrally dry-pressed concave-convex ceramic slab, wherein the concave-convex ceramic slab has at least one concave or convex surface on the front or back side, the planar dimensions of the concave or convex surface are a width greater than or equal to 30 mm and a length greater than or equal to 100 mm, and the minimum drop between the concave and convex surfaces of the concave-convex ceramic slab is greater than or equal to 3 mm.

[0031] Optionally, the concave or convex ceramic slab has at least one concave or convex surface on its front or back side, the concave or convex surface having a width greater than or equal to 50 mm and a length greater than or equal to 100 mm, and the minimum height difference between the concave and convex surfaces of the concave or convex ceramic slab being greater than or equal to 5 mm.

[0032] Optionally, viewed from any cross-section of the central vertical axis of the concave-convex ceramic slab, the side of the convex surface near the central vertical axis (not passing through the central vertical axis) or the side of the concave surface away from the central vertical axis forms an angle of 0° < a ≤ 15° with the vertical axis. The angle 'a' varies with the height or depth of the convex or concave surface and the distance from the surface area to the central vertical axis. Furthermore, the horizontal projection of the side of the convex surface near the central vertical axis or the side of the concave surface away from the central vertical axis coincides with the horizontal projection of the convex surface or the concave surface plane. The side formed by the angle 0° < a ≤ 15° is a laterally inwardly inclined side. The inverted slope formed by this inwardly inclined side provides better adhesion during the application of the product, resulting in a more secure installation. Since the entire body expands outwards during the demolding process after pressing and emerging from the mold cavity, this angle design ensures smooth pressing and molding of the body without affecting demolding.

[0033] Optionally, from any cross-section of the central vertical axis of the concave-convex ceramic plate, the side of the convex or concave surface near the central vertical axis forms an angle of 0° < b ≤ 75° with the vertical axis, and the horizontal projection of the side of the convex or concave surface near the central vertical axis does not coincide with the horizontal projection of the convex surface or concave plane.

[0034] Optionally, the angle between the side of the convex or concave surface of the concave-convex ceramic slab and the vertical direction is 0°<b≤75°, and the vertical projection of any side of the convex or concave surface on the plane of the concave-convex ceramic slab does not coincide; the side formed by the angle of 0°<b≤75° is a lateral outward inclined side. This angle design will not affect either pressing or demolding, and can be applied to various shapes of the slab.

[0035] Alternatively, the angle between the side of the convex or concave surface of the embossed ceramic slab and the vertical direction is 0°, and any side of the convex or concave surface coincides with the vertical projection of the embossed ceramic slab plane. This angle design will not affect either pressing or demolding, and can be applied to various shapes of the slab.

[0036] Optionally, the main body shape of the convex-concave ceramic slab is any one of a triangle, quadrilateral, circle, ellipse, rhombus, trapezoid, or polygon; the shape of the convex or concave surface of the convex-concave ceramic slab is any one or a combination of triangles, quadrilaterals, circles, ellipses, rhombuses, trapezoids, and polygons. The slab and its convex or concave surface can be designed with predetermined irregular shapes as needed, providing designers and users with a choice of personalized and differentiated products. It should be noted that the main body refers to the slab excluding the protruding parts, or the slab excluding the horizontal portion containing the concave parts.

[0037] Optionally, the convex or concave surface of the front of the concave-convex ceramic slab is further provided with several small grooves or small raised strips. The width of the small grooves or small raised strips is 10mm to 20mm, and the depth or height is 3mm to 10mm. This design of small grooves or small raised strips can be used as a drain groove on a tea set table. Because its design depth or height is relatively small and its arrangement is uniform, it does not affect the density of the overall powder layout of the body. Therefore, it is not necessary to use a specific method of material distribution. The effect of the predetermined small grooves or small raised strips can be formed simply by pressing the flat material with a predetermined molding die. It is well known in the industry that flat material distribution is the most efficient and convenient material distribution method in the production process of porcelain tiles. This innovative design of the present invention satisfies the requirement that the flat material distribution method can achieve the predetermined effect, reduce the difficulty of production technology control, and improve efficiency.

[0038] Optionally, the sheet material may be a solid color, a mixed color containing particles, or may also contain predetermined color areas / lines.

[0039] Optionally, the surface of the embossed ceramic slab may further contain a glaze / slurry and / or a decorative effect layer containing an inkjet pattern.

[0040] Optionally, the concave or convex surface of the front side of the embossed ceramic slab can serve as the back side of the product. It should be noted that when the concave or convex surface of the front side of the embossed ceramic slab serves as the back side of the product, the back side of the embossed ceramic slab serves as the front side of the product, and the front side of the product does not need to have a decorative layer formed.

[0041] Optionally, the surface of the convex-concave ceramic plate is a glossy surface, a brushed polished surface, a matte dry granule surface, or a matte glaze surface.

[0042] The present invention has the following main advantages:

[0043] 1. The present invention provides a reverse-pressed integral dry-pressed concave-convex ceramic plate, the convex or concave surface of which has different designs: First, the angle between the side of the convex or concave surface of the plate and the vertical direction is 0°<b≤75°, and the vertical projection of any side of the convex or concave surface on the plate plane does not coincide (when the angle is 0°, they coincide). The side formed by this angle is a lateral outward bevel or vertical edge design, which can be applied to various shapes of the board. The board described in this invention can be designed with predetermined shapes and concave and convex shapes of surface areas as needed. For example, the raised edges around the board can prevent water from overflowing onto the countertop in kitchens, bathrooms, tea sets, and other predetermined countertop applications. The predetermined concave or convex shaped surface areas on the board can be used to place predetermined items, which is both beautiful and practical. The above design not only achieves the effect of combining practicality and decoration, but also provides designers and users with personalized and differentiated material choices for products. Secondly, from any cross-section of the vertical axis of the board, the side of the convex surface near the vertical axis or the side of the concave surface away from the vertical axis forms an angle of 0° < a ≤ 15° with the vertical axis, and the horizontal projection of the side of the convex surface near the vertical axis or the side of the concave surface away from the vertical axis is perpendicular to the surface of the convex surface or the concave surface away from the vertical axis. The horizontal projection of the concave plane coincides with the side, which is innovatively designed with an inward slope. This design, when used in wall and floor tiling, not only provides excellent grip and interlocking force but also supports the surface. Especially when tiling a wall, the inward slope of the convex side near the vertical axis of the board's center allows for a strong, interlocking bond with cement mortar, concrete, or tile adhesives. Compared to conventional outward slope designs, which only have adhesive force but lack support and embedding force, loosening can occur over time, leading to safety issues. This inward slope design of the present invention provides both ordinary adhesive force and specific support and embedding force with the adhesive material. Obviously, the force required for this type of adhesion, which can hold and embed, is significantly different from ordinary adhesion, thus further improving the interlocking force and durability of the bond.

[0044] 2. This invention provides a reverse-pressed, one-piece dry-pressed concave-convex ceramic slab and its manufacturing method. Firstly, this invention utilizes innovative design and preparation of the molding die. Specifically, it employs an angle of 0° < a ≤ 15° between the side of the convex surface near the central vertical axis (not passing through the central vertical axis) and the side of the concave surface away from the central vertical axis, and the vertical axis. Furthermore, the horizontal projection of the side of the convex surface near the central vertical axis or the side of the concave surface away from the central vertical axis coincides with the horizontal projection of the convex surface or the concave surface plane. This creates a mold for reverse-pressed, inwardly sloped slab products. Because the blank expands outwards during demolding, this angle design also fully considers matching the expansion rate of the blank and the angle between the side of the convex or concave surface near the central vertical axis and the vertical axis. The combination of outward-facing sloped sides with an included angle of 0° < b ≤ 75° ensures easy demolding between the concave and convex shaped surfaces of the lower mold and the blank during the pressing process, while preventing the blank from being damaged by the sloped top corner. Secondly, the pressing method of this invention does not require pre-shaping of the powder in the press cavity. Since the upper surface of the lower mold is a concave and convex shaped surface, it is only necessary to use the conventional one-time flat material distribution method to fill the mold cavity with the powder to press out products containing the predetermined concave and convex surface areas. It is well known in the industry that flat material distribution is the most efficient and simplest material distribution method in ceramic tile production. The innovative design of this invention satisfies the innovative realization of this one-time material distribution to form the predetermined shape, which not only produces the predetermined innovative design effect, but also reduces the difficulty of production technology control and improves production efficiency.

[0045] 3. This invention provides an integrally dry-pressed concave-convex ceramic slab and its manufacturing method. The slab can be pressed and formed in one step, enabling standardized mass production of this shaped ceramic slab. In addition, the concave-convex shaped surface of the blank in the pressing method of this invention faces downwards. Compared with the conventional method of pushing the blank, which would damage the shaped surface, and without flipping the blank, it cannot run on the glaze line in the subsequent process, this invention innovatively uses a robotic arm in conjunction with a suction method to vertically lift the blank upwards after demolding and remove it from the press before flipping it, so that the shaped surface faces upwards. This ensures the integrity of the blank and its concave-convex shaped surface, as well as the stability in the subsequent transmission process, thereby improving the production quality.

[0046] 4. The present invention provides an integrally dry-pressed concave-convex ceramic slab and its manufacturing method. First, the concave-convex surface design of the slab during application and laying greatly saves the weight of the blank and materials compared with the integral slab with shallow concave-convex background. The energy consumption for firing during product manufacturing is greatly reduced. In addition, the raw materials prepared at the source of production are greatly reduced. Therefore, the weight cost of each link in the transportation and turnover of products with the same area of ​​raw materials is greatly reduced. Thus, the reduction of product load and cost saving are obvious and more in line with the green, low-carbon and environmentally friendly development direction. Attached Figure Description

[0047] Figure 1 This is a schematic diagram illustrating the slope angle of the sheet metal product according to an embodiment of the present invention;

[0048] Figure 2 These are front views of the sheet metal products of Embodiments 1 and 2 of the present invention;

[0049] Figure 3 for Figure 2 Cross-sectional view of section M-M (Example 1);

[0050] Figure 4 This is a cross-sectional schematic diagram of the sheet metal product according to Embodiment 1 of the present invention;

[0051] Figure 5 for Figure 2 Cross-sectional view of section M-M (Example 2);

[0052] Figure 6 This is a cross-sectional schematic diagram of the sheet metal product according to Embodiment 2 of the present invention;

[0053] Figure 7 This is a front view of the sheet metal product of Embodiment 3 of the present invention;

[0054] Figure 8 for Figure 7 Cross-sectional view of section G-G;

[0055] Figure 9 This is a cross-sectional schematic diagram of the sheet metal product of Embodiment 3 of the present invention;

[0056] Figures 10-18 This is a front view of the sheet metal product of Embodiment 7 of the present invention;

[0057] Figure 19 This is a front view of the back of the sheet material product of Embodiment 3 of the present invention, which is a planar view.

[0058] Figure 20-22 This is a front view of the back of the sheet material of Embodiment 8 of the present invention, which is a combination of a flat surface and a small conventional embossed texture at a predetermined position.

[0059] Explanation of the markings in the attached diagram

[0060] 1: The planar surface area of ​​the board; 2: The raised or recessed surface area of ​​the board; a: The angle formed by the side of the raised surface area near the central vertical axis (not passing through the central vertical axis) and the vertical axis of the concave surface area (not passing through the central vertical axis); b: The angle formed by the side of the raised or recessed surface area near the central vertical axis and the vertical axis of the board; or the angle between the side of any cross-section of the raised or recessed surface area of ​​the board and the vertical direction. Detailed Implementation

[0061] This invention provides a reverse-pressed, one-piece dry-forming concave-convex ceramic slab and its manufacturing method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0062] First, it should be noted that the surface of the concave-convex ceramic slab has raised or recessed areas. The area of ​​the surface other than the raised or recessed areas is called the planar area.

[0063] Example 1

[0064] Combination Figure 2-4 As shown, taking a square embossed ceramic slab with a length of 800mm and a thickness of 10mm as an example, and four rectangular raised areas with a length of 150mm, a width of 60mm, and a height of 10mm are set at a distance of 283mm from the center point of each side with the central vertical axis of the bottom plane as the center, and the side of the raised area with an inward slope near the central vertical axis forming an angle α of 8° with the vertical axis, and the other sides forming an outward slope forming an angle b of 25° with the vertical direction, the details are as follows:

[0065] (1) Mold design: Design and manufacture a lower mold with a side length of 890mm according to the predetermined shape of the back of the ceramic slab to be produced. Match and install an upper mold of the same size as the lower mold and with an integral flat design on the lower surface on the ceramic press of the production line.

[0066] (2) Raw material preparation: Prepare green body material with a moisture content of 8% and a particle size of more than 85% of the residue after passing through a 60-mesh sieve.

[0067] (3) Machine preparation: Install the conventional primary feeding mechanism connected to the ceramic press, and feed the blank material from step (2) into the feeding hopper of the feeding mechanism;

[0068] (4) Fabric feeding: The blank material in the fabric hopper is fed into the fabric grid, and the blank material is framed by the fabric grid to form an overall planar layout in the press mold cavity;

[0069] (5) Pressing: The press presses the planar layout raw material in the mold cavity into a blank with a side length of 899mm (the linear expansion rate of the blank after pressing is about 0.5%) and a planar surface thickness of 11mm. At the center of the bottom plane, the vertical axis is 318mm away from the center of the four sides of the blank. There are rectangular raised areas with a length of 165mm, a width of 66mm, and a height of 11mm. The side of the raised area that is close to the center of the vertical axis of the bottom plane of the plate has an inward slope with an angle a of 8° with the vertical axis. The other sides are side outward slopes with an angle b of 25° with the vertical direction. Then, the blank is vertically lifted and removed from the press by a robot arm. The blank is then flipped so that the shape of the blank is facing upward. The fabric grid returns to the fabric mechanism to continue the next round of operation.

[0070] (6) Drying: The formed billet is dried in a drying kiln at a temperature of 180°C for 75 minutes. After drying, the moisture content of the billet is less than 0.3%.

[0071] (7) Firing: Firing in a kiln with a maximum temperature of 1140℃~1200℃ for 70 minutes to obtain a semi-finished product;

[0072] (8) Processing: Cooling and edge cutting. By calculating the firing shrinkage rate of about 9% and the edge cutting rate of about 2%, a rectangular raised area with a length of 800mm and a thickness of 10mm is made. The center vertical axis of the bottom plane is 283mm away from the center point of each edge. A rectangular raised area with a length of 150mm, a width of 60mm and a height of 10mm is set. The side of the raised area that is close to the center vertical axis of the bottom plane of the plate has an inward slope with an angle α of 8° with the vertical axis. The other sides are outward slopes with an angle b of 25° with the vertical direction. The convex and concave ceramic plate is square.

[0073] Example 2

[0074] Combination Figure 2 , 5 As shown in Figure 6, the difference between this embodiment and Embodiment 1 is that the thickness of the planar surface area in this embodiment is 20mm. Four rectangular recessed areas with a length of 150mm, a width of 60mm, and a depth of 10mm are provided at a distance of 283mm from the center point of each side with the central vertical axis of the bottom plane as the center. The side of the recessed area away from the central vertical axis has an inward slope with an angle α of 8° with the vertical axis, and the other side has an outward slope with an angle b of 25° with the vertical direction, forming a square concave-convex ceramic plate.

[0075] Example 3

[0076] Combination Figure 7-9 and Figures 19-20 As shown, this embodiment takes a ceramic slab with a length of 1500mm, a width of 800mm, a thickness of 25mm (20mm for the flat surface and 5mm for the raised surface on all four sides), a width of 100mm for the raised surface on all four sides, and an angle b of 73° between the side connecting the flat surface and the raised surface and the vertical direction, and a flat quadrilateral back as an example. The details are as follows:

[0077] (1) Mold Design: Prepare the upper and lower molds according to the design to create the desired shape for pressing, and install them on the ceramic press on the production line; the molds to be made are as follows:

[0078] Based on the predetermined shape of the surface of the ceramic slab to be produced, a lower mold with a length of 1670mm and a width of 905mm is designed and manufactured in reverse. An upper mold with the same size as the lower mold and a flat bottom surface is matched.

[0079] It should be noted that the recessed edges around the lower mold are not limited to four recessed edges. They can be any design from 1 to 4 edges as needed. The edge width parameters can be designed and manufactured as needed. The four edges can be equal or unequal. (This embodiment adopts a four-recessed edge design.)

[0080] (2) Raw material preparation: Prepare green body material with a moisture content of 8% and a particle size of more than 85% of the residue after passing through a 60-mesh sieve.

[0081] (3) Machine preparation: Install the conventional primary feeding mechanism connected to the ceramic press, and feed the blank material from step (2) into the feeding hopper of the feeding mechanism;

[0082] (4) Fabric feeding: The blank material in the fabric hopper is fed into the fabric grid, and the blank material is framed by the fabric grid to form an overall planar layout in the press mold cavity;

[0083] (5) Pressing: The press presses the planar layout material in the mold cavity into a blank with a length of 1678mm and a width of 910mm (the linear expansion rate of the blank after pressing is about 0.5%). Then, the blank is vertically lifted and removed from the press by a robot arm in conjunction with the suction method. The blank is then flipped so that the shape of the blank is facing upwards, and the fabric grid returns to the fabric feeding mechanism to continue the next round of operation.

[0084] (6) Drying: The formed billet is dried in a drying kiln at a temperature of 180°C for 75 minutes. After drying, the moisture content of the billet is less than 0.3%.

[0085] (7) Firing: Firing in a kiln with a maximum temperature of 1140℃~1200℃ for 70 minutes to obtain a semi-finished product;

[0086] (8) Processing: Cooling and edge cutting. By calculating the firing shrinkage rate of about 9% and the edge cutting rate of about 2%, a concave-convex ceramic plate with a length of 1500mm, a width of 800mm, a planar surface with a length of 1268mm, a width of 568mm, a thickness of 20mm, a thickness of 5mm for the raised surface on all four sides, a distance of 16mm between the nearest side of the planar surface and the raised surface on all four sides, an angle b of 73° between the side connecting the planar surface and the planar surface of the raised surface and the vertical direction, and a width of 100mm for the raised surface on all four sides is obtained.

[0087] Example 4

[0088] In this embodiment, a step is added between steps (6) and (7) of embodiment 3: glaze is applied to the surface of the dried blank, and then a pattern is printed by inkjet printing to form a decorative layer, thereby obtaining the concave-convex ceramic plate with a predetermined decorative effect on the surface of the plate.

[0089] Example 5

[0090] Based on Example 3, the composition of the green body material in this example is a mixture of powder with a residue of more than 85% after being sieved through a 60-mesh sieve and particles with a predetermined gradation and color, which can produce the concave-convex ceramic slab with a particle effect in the green body.

[0091] Example 6

[0092] Based on Example 3, this example uses either powder with a residue of 85% or more after passing through a 60-mesh sieve, or a mixture of powder with a residue of 85% or more after passing through a 60-mesh sieve and particles of a predetermined gradation and color, as the main material. In addition, powder of a different color from the main material is used as the line material and / or color area material. During the flat laying process, the predetermined color area and / or line material is applied simultaneously by a predetermined belt in a mechanical and digitally controlled digital fabric laying mechanism. First, the powder is applied once to fill the depressions on the lower mold in the mold cavity. Then, the layout material that forms the color area and lines is applied in the mold cavity to form an overall planar layout material. After subsequent processes, the concave-convex ceramic slab with color area and / or line effects in the blank can be produced.

[0093] Example 7

[0094] Based on Example 3, this example uses the production of a ceramic slab of a predetermined shape as an example. Similarly, raised or recessed areas of predetermined size, shape, height, or depth can be provided on the front or back of the slab to produce the pre-determined convex-concave ceramic slab. (See...) Figures 10-18As shown in the figure, 1 is the planar surface region of the board, and 2 is the raised or recessed surface region of the board.

[0095] Example 8

[0096] The difference between this embodiment and embodiment 3 lies in the flatness of the lower surface of the upper mold. In this embodiment, the predetermined position of the lower surface of the upper mold is a combination of a flat surface and small, conventional raised and recessed textures. The flat surface at the predetermined position is designed to facilitate the vertical upward suction of the blank later. Figure 20-22 As shown.

[0097] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for manufacturing a concave-convex ceramic slab formed by reverse-pressing in one piece, characterized in that, Includes the following steps: Prepare the raw materials needed to make the concave-convex ceramic slabs; The mold shape is designed in reverse according to the predetermined shape of the front and back of the concave-convex ceramic slab. The upper surface of the lower mold is a concave-convex shaped surface, and the concave-convex shaped surface and the concave-convex shaped surface of the concave-convex ceramic slab are a matching male and female matching shape design; the lower surface of the upper mold is a whole flat surface. A material spreading mechanism is used to lay the raw material flat inside the press mold cavity; A press is used to press the flat raw material in the press cavity into a blank through a pre-shaped mold; The blank is lifted vertically upwards and removed from the press; The blank is dried; The dried blank is fired to obtain a semi-finished product; The semi-finished product is cooled and its edges are cut and ground to obtain the concave-convex ceramic plate. The dimensions of the mold are designed using the following method: the dimensions of the concave-convex ceramic plate are enlarged by 1% to 3% to accommodate the edge grinding and cutting requirements, and the semi-finished product dimensions of the concave-convex ceramic plate after firing are designed. Then, the mold dimensions are designed based on the firing shrinkage rate of the ceramic plate body of 8.5% to 10.5%. The concave-convex ceramic slab has at least one concave or convex surface on its front or back side. The planar dimensions of the concave or convex surface are a width greater than or equal to 30 mm and a length greater than or equal to 100 mm. The minimum height difference between the concave and convex surfaces of the concave-convex ceramic slab is greater than or equal to 3 mm. From any cross-section of the central vertical axis of the concave-convex ceramic slab, the side of the convex surface near the central vertical axis (not passing through the central vertical axis) or the side of the concave surface away from the central vertical axis forms an angle of 0° < a ≤ 15° with the vertical axis; and the included angle a satisfies: tan a ≤ εL / [H(1+ε)]; where ε is the linear expansion coefficient, L is the distance from the projection of the apex of the slope onto the bottom surface to the vertical axis, and H is the thickness of the convex surface region.

2. The method for manufacturing concave-convex ceramic slabs by reverse-pressing integral dry pressing according to claim 1, characterized in that, The blank is vertically lifted and removed from the press by a robotic arm, and then flipped so that the concave and convex surfaces of the blank face upwards.

3. A type of concave-convex ceramic slab formed by reverse-pressing in one piece, characterized in that, The concave-convex ceramic slab has at least one concave or convex surface on its front or back side. The planar dimensions of the concave or convex surface are a width greater than or equal to 30 mm and a length greater than or equal to 100 mm. The minimum height difference between the concave and convex surfaces of the concave-convex ceramic slab is greater than or equal to 3 mm. From any cross section of the concave-convex ceramic slab with the central vertical axis, the side of the convex surface that does not pass through the central vertical axis forms an angle of 0° < a ≤ 15° with the vertical axis. Alternatively, from any cross-section of the concave-convex ceramic plate with the central vertical axis, the side of the concave region that is away from the central vertical axis, which does not pass through the central vertical axis, forms an angle of 0° < a ≤ 15° with the vertical axis; and the angle a satisfies: tan a ≤ εL / [H(1+ε)]; where ε is the coefficient of linear expansion, L is the distance from the projection of the apex of the slope onto the bottom surface to the vertical axis, and H is the thickness of the convex region. Viewed from any cross-section of the central vertical axis of the concave-convex ceramic slab, the side of the convex surface passing through the central vertical axis that is close to the central vertical axis forms an angle of 0° < b ≤ 75° with the vertical axis; or, viewed from any cross-section of the central vertical axis of the concave-convex ceramic slab, the side of the concave surface passing through the central vertical axis that is far from the central vertical axis forms an angle of 0° < b ≤ 75° with the vertical axis.

4. The concave-convex ceramic plate formed by reverse-pressing integral dry pressing according to claim 3, characterized in that, The concave-convex ceramic slab has at least one concave or convex surface on its front or back side. The planar dimensions of the concave or convex surface are a width greater than or equal to 50 mm and a length greater than or equal to 100 mm. The minimum height difference between the concave and convex surfaces of the concave-convex ceramic slab is greater than or equal to 5 mm.

5. The concave-convex ceramic plate formed by reverse-pressing integral dry pressing according to claim 3, characterized in that, The main shape of the concave-convex ceramic plate is any one of triangular, quadrilateral, circular, or elliptical. The convex or concave shape of the convex or concave surface of the convex ceramic plate is any one or a combination of triangle, quadrilateral, circle, and ellipse. The convex or concave surface of the front of the concave-convex ceramic plate is also provided with several small grooves or small convex strips, the width of the small grooves or small convex strips is 10mm~20mm, and the depth or height is 3mm~10mm.

Images