A method for renovating old ceramic tile joints

Abstract

The application discloses a ceramic tile old beautiful joint renovation upgrading construction method, belongs to the technical field of building decoration engineering, aiming at the problems of old beautiful joint, such as oxidation yellowing, dirt hiding, aging and pulverization, adopting shovel-free process, including polishing or cleaning treatment on the surface of old beautiful joint, after cleaning and drying, directly coating ultraviolet light curing paint, and then rapidly curing a protective layer through ultraviolet light irradiation. The application does not need to shovel all old joints in the construction process, significantly improves the construction efficiency, reduces the risk of ceramic tile damage, adopts solvent-free light curing paint, is environment-friendly and non-polluting, the formed protective layer has excellent high-hardness wear resistance, waterproofness, mildew resistance and yellowing resistance, and realizes the overall upgrading and replacement of appearance and durability while repairing the surface defects of old beautiful joint. The application has remarkable practical value and popularization prospect due to low cost, simple construction and obvious effect.

Description

Technical Field

[0001] This invention relates to the field of building decoration and renovation engineering technology, and more specifically to a construction method for renovating and upgrading old tile grout. Background Technology

[0002] In interior and exterior building decoration, tiles are widely used after installation, and the joints are usually filled with grout sealant. Grout sealant not only prevents moisture and dirt from seeping into the gaps, avoiding mold and damage to the substrate, but also plays an important role in aesthetic decoration. Commonly used grout sealant materials include epoxy resin, hydrogenated epoxy resin, polyurea resin, and cement-based grout. These materials offer good sealing and aesthetic effects in the initial stages of construction.

[0003] However, with prolonged use and the influence of environmental factors (such as humidity, temperature changes, ultraviolet radiation, and corrosive cleaning agents), the original grout material often exhibits a series of aging and damage phenomena, mainly including: surface oxidation and yellowing, fading, aging and powdering, local cracking, hollowing, and even detachment, as well as dirt and blackening caused by stains. These defects not only seriously affect the overall decorative aesthetics but may also lead to the failure of the grout seal, allowing moisture to seep into the underlying layer of tiles, causing dampness and mold in the substrate, and even structural hazards such as tile hollowing and detachment.

[0004] The common approach to addressing the issue of old grout is currently the "removal-rework" method. Specifically, installers typically use a heat gun to heat the old grout material, softening it, and then use a specialized scraper or hook to completely remove it from the grout lines. After cleaning the surface, new grout material is then applied and further treatment is performed. While this method solves the problem, it has several drawbacks. The heating and removal process can easily damage the edges of the tiles, leading to chipping and scratches on the glaze. It also requires a high level of skill from the installers. Completely removing the old material is time-consuming and labor-intensive, generating a large amount of dust and waste, resulting in extensive subsequent cleaning and a long overall construction period. Material waste is significant, and labor costs are high. Furthermore, there may be potential problems with the bonding between the old and new substrates; the refilled grout may not perfectly match the original in terms of flatness and color consistency, often resulting in a decreased overall aesthetic appeal. Additionally, the removal process generates dust, and heating may release harmful gases, impacting the indoor environment and the health of the installers.

[0005] While some cleaning products exist on the market for stains on grout surfaces, they can only handle minor surface stains and are ineffective against aging issues such as yellowing, powdering, and cracking. Currently, in the field of building renovation, there is a lack of a standardized, efficient, and non-removable professional renovation method for aged grout that can simultaneously achieve aesthetic restoration and long-term performance improvement.

[0006] Therefore, there is an urgent need to develop an innovative construction process that can treat only the defective surface layer of the old grout while preserving the main structure of the old grout to the greatest extent, and then quickly and environmentally upgrade it by applying a high-performance protective layer, giving the grout a better durability and decorative effect, thus filling the technological gap. Summary of the Invention

[0007] In view of this, the present invention provides a construction method for renovating and upgrading old tile grout.

[0008] To achieve the above objectives, the present invention provides the following technical solution, comprising the following steps: S1. Pre-treat the old grout surface in the tile gaps to remove surface defects; S2. Clean the crevices after surface treatment to ensure they are dry, free of dust and oil. S3. Apply the UV-cured coating to the old grout surface after steps S1 and S2; S4. Use an ultraviolet light source to irradiate the applied photocurable coating to cure it and form a protective layer.

[0009] Preferably, in the above-mentioned construction method for renovating and upgrading old tile grout, in step S1, the surface treatment is mechanical grinding or chemical cleaning; the mechanical grinding is used to remove yellowing, powdering, dirt or uneven parts of the old grout surface; the chemical cleaning is used to clean the old grout surface.

[0010] Preferably, in the above-mentioned construction method for renovating and upgrading old tile grout, when mechanical grinding is used, the grinding depth is such that only the surface layer of the old grout is removed, exposing the stable underlying material.

[0011] Preferably, in the above-mentioned construction method for renovating and upgrading old tile grout, before step S3, step S2a is included: pasting a protective film; the protective film is a self-adhesive protective film, which is pasted along both sides of the tile grout to define the coating area.

[0012] Preferably, in the above-mentioned construction method for renovating and upgrading old tile grout, before step S3, step S2b is included: color change treatment; the color change treatment is to coat the surface of the old grout with a fast-drying pigment or a color-modified light-curing coating to cover the original color.

[0013] Preferably, in the above-mentioned construction method for renovating and upgrading old tile grout, the thickness of the self-adhesive protective film is 20 micrometers to 200 micrometers.

[0014] Preferably, in the above-mentioned construction method for renovating and upgrading old tile grout, in step S3, the coating specifically involves: applying the UV-cured coating to the grout area covered with the protective film, and smoothing the coating along the surface of the protective film with a scraper.

[0015] Preferably, in the above-mentioned construction method for renovating old tile grout, in step S4, the emission wavelength of the ultraviolet light source is 310 nanometers to 400 nanometers.

[0016] Preferably, in the above-mentioned construction method for renovating old tile grout, in step S4, the power of the ultraviolet light source is not less than 100 watts, the irradiation distance is 10 cm to 15 cm, and the irradiation time is 1 second to 30 seconds.

[0017] As can be seen from the above technical solution, compared with the prior art, this invention discloses a construction method for renovating old tile grout. By combining surface treatment without removal with ultraviolet curing coating technology, it provides an efficient, environmentally friendly, and durable solution for renovating old tile grout. This method only requires grinding or cleaning the surface defects of the old grout, without complete removal, greatly reducing the risk of damage to the tiles during construction and shortening the construction period. It uses solvent-free, zero-VOC UV-cured coatings, and the construction process is dust-free and odorless, making it green and environmentally friendly. The formed cured protective layer has excellent wear resistance, waterproof, mildew resistance, and anti-yellowing properties, not only repairing the surface defects of the original grout but also achieving a simultaneous upgrade in aesthetics and durability, filling a market gap and possessing significant practical value and promotional prospects. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] The construction method for efficient renovation of old tile grout and upgrading protection using UV-cured coating provided by this invention is based on a no-removal surface treatment + UV curing coating molding. It mainly includes four core steps, and color-changing treatment can be added between the core steps according to actual construction needs. At the same time, auxiliary procedures such as applying protective film can be added to take into account both standardized and personalized construction needs. It supports both original color renovation and repair, as well as grout color-changing renovation. The following is a detailed implementation method.

[0020] I. Core Construction Steps Surface treatment is the purpose of removing defects from the surface of the old grout, providing a stable, clean base with good adhesion for subsequent coatings. Depending on the aging state of the old grout, there are two methods: mechanical grinding and chemical cleaning. The contractor can choose according to their needs.

[0021] Mechanical grinding treatment is suitable for old grout with obvious yellowing, powdering, dirt, unevenness, cracking or peeling. It is applicable to grout of various materials (epoxy resin, polyurea, cement-based, etc.).

[0022] Handheld electric grinder, special grout grinding head (wire brush, diamond grinding disc, sandpaper disc) or manual grinding tools.

[0023] Move the sanding tool at a uniform speed along the direction of the tile grout lines to evenly remove the defective surface layer of the old grout. The sanding depth should be strictly controlled between 0.1mm and 0.5mm, removing only the deteriorated surface layer and exposing the intact and stable substrate underneath. Avoid excessive sanding that could damage the tile edges or destroy the underlying structure of the grout. After sanding, the surface of the old grout should have a uniformly rough surface without any smooth or shiny areas, thus improving the adhesion between the coating and the substrate.

[0024] Chemical cleaning treatment is suitable for old grout lines with only minor stains and discoloration, no powdering, cracking, hollowing, and basically intact structure.

[0025] Use neutral / mildly alkaline cleaners, special grout cleaners, or solvents such as alcohol.

[0026] Apply the cleaning agent evenly to the old grout surface and let it sit for 3-10 minutes. Use a stiff-bristled brush or scouring pad to scrub along the grout lines to remove surface stains. Thoroughly wipe the grout lines and surrounding tiles with clean water or a damp cloth to avoid chemical residue that could affect the adhesion of subsequent coatings.

[0027] Cleaning and drying are crucial steps that directly affect the adhesion between the UV-cured coating and the old grout. The application surface must be free of dust, oil, and moisture. Specific procedures are as follows: Dust removal: Use a high-powered vacuum cleaner with a fine nozzle to thoroughly remove polishing dust or cleaning residue from inside crevices, the surface, and the sides of tiles. Stain removal: Wipe the crevices with a clean, slightly damp cloth. If there are stubborn oil stains, you can apply a small amount of neutral detergent and wipe gently, then wipe clean with a dry cloth. Drying: Allow the construction area to air dry naturally, or use a hairdryer on the cool setting to dry it until the surface of the gaps is completely dry; you can check by touching it with your fingers or wiping it with a white paper towel. If there are no damp marks or dust falling off, it is considered qualified.

[0028] Coating application (divided into "no color change" and "color change" scenarios, with corresponding processes) The UV-curable coating used in this step is a high-solids-content (≥95%), solvent-free UV-curable resin coating. Its main components include acrylate oligomers, reactive diluents, photoinitiators, leveling agents, defoamers, and other additives. Coating tools can include a scraper, putty knife, a dedicated coating gun, or a brush. Two implementation methods are available depending on whether color modification is required: Renovation without color change (preserving the original grout's base color). Apply the coating directly to the cleaned and dried old grout substrate. For improved precision, apply a protective film to both sides of the grout line before applying the coating. Pour an appropriate amount of UV-cured paint into the gaps, and select a suitable scraper according to the width of the gaps; Use a scraper to scrape along the direction of the gap (or the direction guided by the protective film) at a 45° angle, applying moderate pressure to ensure that the paint fills the gap fully and makes full contact with the old grout base material; Clean excess paint from the scraper promptly, smoothing the coating to ensure a flat, smooth, and bubble-free grout surface.

[0029] Color change and renovation (changing the color of the grout, including two color change methods, implemented independently with equivalent results). After cleaning and drying the old grout base material, perform the color change treatment. Once the color-change layer meets the construction requirements, apply the UV-cured coating. Either color change method can be chosen based on construction needs and color effect requirements. The specific steps are as follows: Color change method 1: Apply quick-drying acrylic color paste to the substrate. Select a special fast-drying acrylic color paste with strong hiding power and fast drying speed, and mix it evenly according to the target color; Use a fine-bristled brush or a special grouting pen to apply the color paste evenly and thinly to the surface of the old grout base material, ensuring that the original grout color is completely covered without any exposed base material or brush marks. Let it stand to dry until the color paste is surface dry (usually 1-2 hours, adjust according to ambient temperature and humidity). Once the surface is no longer sticky or powdery, proceed with the subsequent UV-curing coating application.

[0030] Color change method 2: Add special colorant to UV-cured coating Add special colorant for tile grouting to solvent-free UV-curable coatings in proportion, and stir thoroughly with a stirring tool to ensure that the colorant and coating are mixed evenly, without particles or color difference, to formulate a colored UV-curable coating of the target color. If a protective film has been applied, directly apply the prepared colored UV-cured paint to the old grout base material using the "no color change renovation" application method, ensuring full filling and a smooth surface.

[0031] After coating, immediately irradiate with ultraviolet light to rapidly cross-link and cure the UV-curable coating to form a high-performance protective layer. The curing process parameters are exactly the same for both color-changing and non-color-changing scenarios. The specific operation is as follows: Handheld / push-type UV curing lamps and small-diameter UV point light source lamps (suitable for local repairs) require the light source to be matched with the paint photoinitiator, with an emission wavelength of 310nm-400nm (UVA band) and a lamp power of not less than 100W. Aim the UV lamp window at the seam after coating, keeping the distance between the lamp head and the coating surface at 10-15cm; move the lamp along the seam at a uniform speed of 5-10cm per second, and irradiate for 1-30 seconds at each spot, which can be dynamically adjusted according to the coating thickness and coating formula. Curing assessment: A simple test can be performed using the "finger touch method." Lightly touch the coating surface with your finger; if it is no longer sticky and feels hard to the touch, curing is complete. For cross-shaped gaps and localized repair areas, the irradiation time can be increased or repeated to ensure thorough curing. Protective film removal: If a protective film was applied during construction, gently peel it off before the coating cures, allowing the edges of the coating some time to level out and ensure that the edges of the grout coating are rounded and neat.

[0032] After curing, a comprehensive quality inspection of the renovated grout coating is conducted. The inspection standards are consistent for both color-change and non-color-change scenarios. Any minor defects are promptly repaired to ensure construction quality. The inspection contents are as follows: Appearance quality: Whether the coating is flat, smooth, and continuous; whether the color is uniform (in color-changing scenarios, it is necessary to confirm that the color tone is consistent with the target); whether there are defects such as bubbles, cracks, pinholes, and exposed substrate. Adhesion: On non-visually critical areas such as edges and corners, lightly scratch the coating with a fingernail to check for peeling or flaking. The passing standard is a cross-cut test (GB / T9286) grade of 0-1. Edge quality: Whether the junction between the coating and the tile is neat, without paint overflow, curling, or delamination; Basic performance: A simple test for water resistance is to drop a small amount of water onto the coating surface and observe whether it is hydrophobic and does not leak.

[0033] Repair guidelines: For defects such as uncured areas, small bubbles, and slight exposure of the substrate, apply UV-cured paint with a fine brush (or the corresponding color paint for color-changing scenes), and then cure again with UV light; for areas where paint has overflowed onto tiles, gently wipe and clean with a clean, damp cloth and a special adhesive remover.

[0034] II. Auxiliary procedures (select as needed, applicable to all renovation scenarios) Apply protective film To limit the area to be coated with paint, protect the tile glaze from contamination, and ensure neat and aesthetically pleasing edges of the grout coating, a protective film can be applied after cleaning and drying but before applying the paint. This is suitable for both non-color-changing and color-changing scenarios. Use self-adhesive protective film / masking tape with a thickness of 20 to 200 micrometers (preferably 50-150 micrometers) and a width selected according to the width of the tile gap and the required coating width (e.g., 3cm, 5cm). Align and apply the protective film precisely along both edges of the tile grout lines. Press it firmly with your fingers or a plastic scraper to ensure that the film adheres completely to the tile surface without any air bubbles. Pay special attention to the accuracy of the application at the cross-shaped grout lines. For crisscrossing tile grout lines, you can apply the film in two stages: first apply it in one direction, and after it has cured, apply the protective film in the other direction.

[0035] III. Implementation Examples for Different Renovation Scenarios Example 1: Color-Resistant Renovation - Repairing Severe Yellowing of Epoxy Resin Grout in Kitchen Surface treatment: Use an electric grinder with a 240-grit sandpaper head to grind away the yellowed surface layer to a depth of 0.3mm; Cleaning and drying: Vacuum clean the dust, wipe twice with a damp cloth, and dry with a hairdryer on the cool setting; Auxiliary step: Apply a 3cm wide and 100μm thick PE self-adhesive protective film; Coating application: Apply transparent solvent-free UV-cured coating by scraping, filling the gaps completely and smoothing the surface; UV curing: 365nm wavelength, 1000W power UV LED curing lamp, irradiation at a distance of 12cm and a speed of 8cm / s; Inspection and Repair: After removing the film, the coating is smooth and glossy, with an adhesion level of 0, no traces of yellowing repair, and the original base color of the grout is preserved.

[0036] Example 2: Color Change and Renovation (Method 1: Acrylic Color Paste) - Slightly Blackened Cement-Based Grout Should Be Changed to White Surface treatment: Use a special grout cleaner with a hard brush to scrub and remove black stains from the surface; Clean and dry: Wipe clean with water and let air dry naturally until there is no moisture. Color change treatment: Apply a thin layer of white quick-drying acrylic pigment, allow to dry for 1.5 hours; Coating application: Apply transparent UV-cured coating to the surface of the color-changing layer using a brush; UV curing: 385nm wavelength UV lamp, 10cm away, irradiate for 5 seconds to cure; Inspection and finishing: The coating is uniformly white with no exposed substrate, forming a hydrophobic protective layer that is easy to clean.

[0037] Example 3: Color Change and Renovation (Method 3: Paint with Colorant) - Local Wear and Tear in Polyurea Grout in Living Room to be Changed to Light Gray Surface treatment: Gently sand the worn areas by hand with 600-grit sandpaper to increase surface energy; Clean and dry: Wipe the polished area with alcohol wipes to remove grease and allow it to dry quickly; Coating preparation: Add light gray special color paste to transparent UV-cured coating and stir well; Coating application: Use a fine-tipped brush to precisely apply colored UV-cured coating to the worn repair area; UV curing: Curing with a 395nm wavelength small-aperture UV point light source lamp, irradiated for 3 seconds; Inspection and repair: The repaired area is light gray in color, with gloss and wear resistance consistent with the surrounding grout, and is seamlessly connected.

[0038] IV. Performance indicators of grout after renovation (meets requirements for both non-color change and color change scenarios) Tile grouting upgraded using the above methods, regardless of whether color change treatment is applied, meets the following excellent performance indicators according to laboratory simulation tests and long-term actual use tracking. Furthermore, the color change layer and the UV-cured protective layer are firmly bonded, with no fading or delamination: Adhesion: The cross-cut test (GB / T9286) achieves a grade of 0-1, indicating a tight bond with the old grout base material and color-changing layer; Hardness: The hardness of pencils (GB / T6739) can reach 3H-5H, which significantly improves wear resistance and resists daily friction and impact; Chemical resistance: Withstands wiping with common household chemicals (dishwashing liquid, vinegar, alcohol, laundry detergent) without corrosion or discoloration; Yellowing resistance: After 500 hours of UV aging test (GB / T23987), the color difference ΔE < 1.5, and there is no obvious yellowing after long-term light exposure; Anti-mold properties: After 28 days of cultivation in a humid chamber (GB / T1741), no mold growth was observed, making it suitable for humid environments such as bathrooms and kitchens; Environmental friendliness: There is no dust or harmful gas release during the construction process, and the VOC emission of the coating after curing is far below the stringent environmental protection standard limits such as DB11 / 1983-2022; Color change stability: The color change layer has good compatibility with UV-cured coatings, and there is no fading, powdering, or delamination after long-term use, with excellent color retention.

[0039] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0040] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A construction method for renovating and upgrading old tile grout, characterized in that, Includes the following steps: S1. Pre-treat the old grout surface in the tile gaps to remove surface defects; S2. Clean the crevices after surface treatment to ensure they are dry, free of dust and oil. S3. Apply the UV-cured coating to the old grout surface after steps S1 and S2; S4. Use an ultraviolet light source to irradiate the applied photocurable coating to cure it and form a protective layer.

2. The construction method for renovating and upgrading old tile grout according to claim 1, characterized in that, In step S1, the surface treatment is either mechanical grinding or chemical cleaning. The mechanical grinding is used to remove oxidation, yellowing, aging, powdering, dirt accumulation, or unevenness from the old grout surface. The chemical cleaning is used to clean the old grout surface.

3. The construction method for renovating and upgrading old tile grout according to claim 2, characterized in that, When mechanical sanding is used, the sanding depth is only to remove the surface layer of the old grout and expose the original underlying material.

4. The construction method for renovating and upgrading old tile grout according to claim 1, characterized in that, Before step S3, there is also step S2a: applying a protective film; the protective film is a self-adhesive protective film, which is applied along both sides of the tile grout to define the coating area.

5. The construction method for renovating and upgrading old tile grout according to claim 1, characterized in that, Before step S3, there is also step S2b: color change treatment; the color change treatment is to coat the old grout surface with a fast-drying pigment or a color-modified light-curing coating to cover the original color.

6. The construction method for renovating and upgrading old tile grout according to claim 4, characterized in that, The thickness of the self-adhesive protective film is 20 micrometers to 200 micrometers.

7. The construction method for renovating and upgrading old tile grout according to claim 4 or 5, characterized in that, In step S3, the coating process specifically involves: applying the UV-curable coating to the gap area covered with the protective film using a scraper, and then smoothing the coating along the surface of the protective film using a scraper.

8. The construction method for renovating and upgrading old tile grout according to claim 1, characterized in that, In step S4, the emission wavelength of the ultraviolet light source is 310 nanometers to 400 nanometers.

9. The construction method for renovating and upgrading old tile grout according to claim 1 or 8, characterized in that, In step S4, the power of the ultraviolet light source is not less than 100 watts, the irradiation distance is 10 cm to 15 cm, and the irradiation time is 1 second to 30 seconds.

10. The construction method for renovating and upgrading old tile grout according to claim 1, characterized in that, After step S4, step S5 is also included: testing the appearance quality, adhesion, color and waterproof performance of the cured protective layer.