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CN-121974728-A - Preparation process of lead-free cadmium ceramic

CN121974728ACN 121974728 ACN121974728 ACN 121974728ACN-121974728-A

Abstract

The invention relates to a preparation process of lead-free cadmium ceramic, and belongs to the technical field of ceramic decoration. Aims at solving the problems of heavy metal harm, color stability and insufficient adhesive force caused by lead and cadmium in the existing ceramic stained paper decoration. The invention firstly prepares a lead-free and cadmium-free ceramic glaze based on silicate, wherein, environment-friendly metal oxides such as zinc oxide and cobalt oxide are added as a color former, then a digital printing technology is used for designing a high-precision stained paper pattern, then the pattern of the glaze is transferred onto ceramic decal paper through screen printing, the decal paper after printing stands and dries, the decal paper after drying is attached on the surface of a ceramic product to be decorated, and is burned and kept warm, so that the glaze is fused and adhered to form a compact decorative glaze layer, and proper ventilation is provided for the glaze layer in the heating process so as to discharge organic matters and heavy metal volatile matters in the glaze.

Inventors

  • ZHOU QIANWU

Assignees

  • 广东香泰瓷业有限公司

Dates

Publication Date
20260505
Application Date
20260306

Claims (10)

  1. 1. A preparation process of lead-free cadmium ceramic is characterized in that, The lead-free cadmium ceramic is prepared by mixing silicate serving as a base material and zinc oxide and cobalt oxide environment-friendly metal oxide serving as a color former to prepare glaze, transferring and printing the glaze onto a ceramic stained paper base material by adopting a screen printing technology, standing and drying the printed stained paper, attaching the stained paper to the surface of a ceramic blank, finally sintering and preserving heat to enable the glaze to be fused and attached to the surface of the ceramic to form a decorative layer, wherein ventilation is provided for the glaze layer in a heating stage so as to discharge volatile components.
  2. 2. The preparation process of the lead-free cadmium-free ceramic according to claim 1, which is characterized by comprising the following specific steps, S1, taking 50% -60% of silicon dioxide, 10% -15% of zinc oxide, 1% -2% of cobalt oxide, 5% -11% of boron oxide, 4% -7% of aluminum oxide, 5% -7% of calcium oxide, 2% -4% of sodium oxide, 1% of bismuth oxide and 6% -9% of ZrO 2 opacifying agent, putting the materials into a V-type mixer, mixing for 30 minutes, melting, directly pouring molten glass into cold water for quenching, so that the molten glass is burst into finely-divided frit, grinding the frit for 2 hours, ball-milling and sieving, and collecting glaze powder; S2, mixing an ethanol aqueous solution with a binder, stirring and dissolving in an 80 ℃ water bath to prepare transparent viscous ink-regulating oil, mixing base glaze powder with the ink-regulating oil, and grinding by a three-roller grinder until the granularity detected by a scraper fineness gauge is less than 5 mu m to prepare ceramic ink; S3, performing pattern design by using plane design software, aiming at the characteristic of deep color development of the leadless cobalt blue glaze, adjusting the dot density during color separation, selecting a 350-mesh polyester silk screen plate manufactured by photosensitive sun-curing after outputting a film, placing glaze ink on the silk screen plate for screen printing at blue parts of pattern openings corresponding to lotus lines, drying stained paper in multiple steps, and then carrying out decal; and S4, placing the porcelain cup with the stained paper in an electric kiln for firing to obtain the lead-free cadmium-free ceramic.
  3. 3. The process for preparing lead-free and cadmium-free ceramic according to claim 2, wherein, The melting described in step S1 is specifically performed at 1400 ℃ for 2 hours.
  4. 4. The process for preparing lead-free cadmium ceramic according to claim 2, wherein, The ball milling and sieving are carried out in the step S1, specifically, a proper amount of deionized water is added to ensure that the solid content of the slurry is 50 percent, then the slurry is ball milled for 36 hours, and the slurry is sieved by a 325-mesh sieve.
  5. 5. The process for preparing lead-free cadmium ceramic according to claim 2, wherein, The ethanol aqueous solution and the binder in the step S2 are mixed according to the mass ratio of 95:5, the ethanol aqueous solution and the binder are environment-friendly water-based resin, and the ethanol and the water are mixed according to the volume ratio of 1:9.
  6. 6. The process for preparing lead-free cadmium ceramic according to claim 2, wherein, And step S2, mixing the base glaze powder and the ink varnish according to the mass ratio of 7:3.
  7. 7. The process for preparing lead-free cadmium ceramic according to claim 2, wherein, And (3) screen printing, namely, scraping and printing a glaze pattern on the ceramic decal paper by using a scraper at 45 ℃, airing for 5 minutes at 60 ℃, and then repeatedly printing for one time according to the same process until the total thickness is 10-20 mu m.
  8. 8. The process for preparing lead-free cadmium ceramic according to claim 2, wherein, And step S3, namely, placing the dried materials in a 60-70 ℃ oven for drying for 10-15 minutes, and then drying for 5-10 minutes at 80-90 ℃.
  9. 9. The process for preparing lead-free cadmium ceramic according to claim 2, wherein, And (3) the decal in the step (S3) is specifically soaked in warm water for 15 seconds to soften the paper-based adhesive layer, the paper-based adhesive layer is attached to the outer surface of a cup with the height of Bai Ci, and the paper-based adhesive layer is left to stand and shade for 2 hours.
  10. 10. The process for preparing lead-free cadmium ceramic according to claim 2, wherein, And (3) firing, namely starting the kiln at room temperature to heat, slightly opening the ventilation valve from 30 ℃, heating at a speed of 5 ℃ per minute, burning the stained paper base when the temperature reaches 500 ℃, continuing heating and closing the valve, keeping the constant temperature for 20-30 minutes when the temperature reaches 830-850 ℃, and then closing the furnace to perform natural cooling.

Description

Preparation process of lead-free cadmium ceramic Technical Field The invention belongs to the technical field of ceramic decoration, and particularly relates to a preparation process of lead-free cadmium-free ceramic. Background Ceramic decal paper (decal paper) refers to a decorative material which is printed on a special paper base, can be transferred to the surface of ceramic, and is widely used for decorating ceramic ware. However, currently, ceramic decal pigments and auxiliaries on the market generally contain heavy metal components such as lead, cadmium and the like. In order to ensure bright color and glaze luster, the traditional ceramic overglaze color usually uses flux and pigment containing lead, so that the decorative pattern has enough brightness and bright color. Lead compounds such as lead oxide have the effects of reducing the melting temperature, increasing the glossiness and improving the color vividness in ceramic glaze, and are widely used in ceramic colored glaze from ancient times. However, heavy metals such as lead and cadmium belong to toxic and harmful substances, and in the use process of ceramic products such as ceramic tableware, wine set and the like contacted with food, the heavy metals are easily eroded and dissolved out due to contact with acidic or hot diet, and enter the food to cause harm to human health. Therefore, the leaching amount of lead and cadmium in ceramic products is strictly limited in various countries. However, the lead-containing overglaze decal process often has difficulty meeting these safety standards and does not meet the national relevant regulatory requirements. In order to meet the environmental protection requirements, lead-free pigments and low-lead substitutes are developed in recent years, but some problems still exist in practical production. For example, there have been attempts to use a low-lead pigment mixed with a lead-free pigment to reduce the lead-cadmium elution amount, but experiments have shown that the use of a low-lead pigment mixed with a lead-free pigment may rather destroy the stable color structure of the pigment, resulting in a higher lead-cadmium elution amount, and even when a lead-free pigment is used for decoration on a lead-containing glaze, lead-cadmium elution exceeding the standard may be caused. This means that the problem of heavy metal precipitation cannot be effectively solved by only partial replacement or mixed use, and that complete lead-free and cadmium-free needs to be realized from the source. Besides heavy metal harm, the existing ceramic decal decoration process has the technical defects of poor color stability, weak adhesive force, insufficient high temperature resistance and the like. Although the traditional lead-containing overglaze color is bright in color, part of the color is easy to fade and darken after being sintered at high temperature or used for a long time, and some lead-free alternative materials have new problems. The prior patent CN101050059A discloses a lead-free pigment lead-free and cadmium-free cover layer on ceramic glaze, which comprises main components consisting of SiO 2, sodium oxide and B 2O3, a viscosity regulator and a stabilizer, wherein the cover layer powder is melted first and then applied to a product to prepare the lead-free and cadmium-free cover layer, but the lead-free and cadmium-free cover layer has poor chemical stability and glossiness, has insufficient adaptability to different pigment colors, is easy to cause larger color difference and pattern distortion after firing certain easy-to-fade pigments, and has larger thermal expansion coefficient, so that the decorative pattern layer is easy to crack or spall on a ceramic surface after firing. These problems lead to reduced decorative durability and aesthetics of the product, limiting the popularization and application of lead-free and cadmium-free ceramic decals. Therefore, a new technical scheme is needed to overcome the defects, realize stable burning of the ceramic decal paper under the conditions of no lead and no cadmium, and simultaneously ensure the color effect and the service performance. Disclosure of Invention The invention provides a preparation process of lead-free cadmium ceramic, and aims to solve the problems of heavy metal damage, insufficient color stability and adhesion and the like caused by lead and cadmium in the existing ceramic stained paper decoration. The process disclosed by the invention comprehensively eliminates harmful substances such as lead, cadmium and the like from the aspects of glaze formula and manufacturing flow, introduces environmentally-friendly and safe substitution materials and optimized process parameters, and realizes the non-toxicity and high-performance adhesion of ceramic decorative patterns. The aim of the invention can be achieved by the following technical scheme: A preparation process of lead-free cadmium ceramic comprises the following technical scheme: S1, taking