Common Situations And Repair Techniques Of Scratches On The Surface Of Anti-static Terrazzo

Anti static terrazzo is widely used in places sensitive to static electricity such as electronic workshops, hospitals, laboratories, etc. due to its anti-static, wear-resistant, and easy to clean characteristics. Surface scratches not only affect aesthetics, but may also damage anti-static performance (such as damaging conductive layers). The following analysis will be conducted from two aspects: common situations and repair techniques:

1, Common situations of scratches on the surface of anti-static terrazzo
The causes and classification of scratches need to be combined with usage scenarios and material characteristics, mainly divided into the following categories:

1. Classify by scratch depth
Shallow scratches: only damage the anti-static coating of the terrazzo surface layer (such as epoxy anti-static layer or cement-based anti-static layer), without touching the aggregate layer or conductive layer (conductive fibers/conductive powder). Manifested as a slight whitening and small scratches on the surface, with no unevenness when touched by hand.
Cause: During daily cleaning, use a hard brush (such as a steel ball), sharp objects (such as keys, tools) for slight scratching, or long-term friction with dust (such as sand particles on the sole of the shoe).
Deep scratch: The scratch depth exceeds the surface layer, damaging the aggregate layer (such as quartz sand, marble debris) or conductive layer (conductive fiber breakage, conductive powder detachment). Manifested as obvious grooves, exposed aggregates, and a textured sensation when touched by hand. In severe cases, the conductive layer may break.
Causes: dragging of heavy objects (such as equipment handling), impact of sharp hard objects (such as falling metal tools), excessive friction of cleaning equipment (such as hard brush discs of floor scrubbers).
2. Classify by scratch location
Scratches in the middle area: located in the middle of the terrazzo floor, they are mostly randomly generated scratches during daily use. When repairing, it is necessary to consider both aesthetics and anti-static performance.
Edge scratches: Scratches caused by frequent collisions (such as carts or equipment movement) at the junctions with walls, equipment bases, door frames, etc., are easily overlooked but may damage the edge sealing (affecting the overall anti-static performance).
3. Classify by scratch morphology
Linear scratches: slender, continuous scratches (such as those left by dragging heavy objects), often caused by unidirectional force.
Spot/flake scratches: Local dense spot damage or small area flake peeling (such as surface layer peeling caused by improper cleaning after chemical corrosion).
2, Repair techniques for scratches on the surface of anti-static terrazzo
The repair process should follow the steps of "evaluating damage → cleaning treatment → selecting materials → precise repair → performance verification", with the core being to restore surface flatness and anti-static performance.

(1) Preparation before repair: evaluation and cleaning
Assess scratch depth:
Superficial scratches: Scratches should be lightly scraped with a fingernail, with no unevenness and only the surface layer turning white, indicating that the aggregate or conductive layer has not been damaged.
Deep scratch: The nail has obvious grooves when lightly scratched, or visible exposed aggregates or broken conductive fibers. Further confirmation is needed to confirm whether the conductive layer is intact (the resistance of the scratch area can be tested by a conductivity meter, and if the resistance increases abnormally, the conductive layer is damaged).
Cleaning treatment:
Use a soft bristled brush or vacuum cleaner to remove scratches and surrounding dust and sand particles, avoiding impurities from entering during repair.
Shallow scratches: Use a neutral cleaning agent (pH 7-8) dipped in a damp soft cloth to wipe and remove surface stains; Deep scratches: Use anhydrous ethanol or specialized terrazzo cleaner (non corrosive) to wipe to ensure that the repaired surface is clean and free of oil stains.
(2) Situation based repair techniques
1. Shallow scratch repair (only surface damage)
Objective: To restore the flatness and anti-static performance of the surface layer without the need to treat the conductive layer.
Material selection: Anti static terrazzo special repair paste (containing conductive powder/conductive fiber, matching with the original surface layer material), anti-static polishing wax.

Construction steps:

Fill scratches: Use a scraper to evenly fill the repair paste into the scratches, slightly above the surface (to avoid shrinkage and indentation), cover with plastic film (to prevent dust), and let it stand for 12-24 hours (to cure according to product instructions).
Polish flat: After curing, gently polish with 200-400 grit sandpaper (water mill) until it is flush with the original surface, avoiding excessive polishing and damaging the surface layer.
Polishing maintenance: Use anti-static polishing wax (containing conductive components) dipped in a soft cloth to wipe, restore luster and enhance anti-static performance. Avoid stepping on or getting wet within 24 hours after polishing.
2. Deep scratch repair (damaging aggregates or conductive layers)
Objective: To restore the flatness of the aggregate layer, reconnect the conductive layer, and ensure that the anti-static performance meets the standard.
Material selection: Anti static terrazzo repair mortar (including aggregates, conductive powder/fibers, curing agent), conductive adhesive (such as silver paste conductive adhesive), copper foil strip (used for conductive layer repair).
Construction steps:

Clean the damaged area: Use an angle grinder (with diamond grinding discs) to remove loose aggregates and surface layers around the scratch, forming a regular "V" groove (with a depth of 2-3mm beyond the scratch to ensure that the repair material is firmly bonded), and clean the dust inside the groove.
Repair the conductive layer (if damaged):
If the conductive fiber breaks: Use conductive adhesive (such as silver paste) to re bond the broken fiber, or lay a copper foil strip (10-15mm wide) to cover the scratched area. Connect the copper foil strip to the original conductive layer (such as ground copper foil) with conductive adhesive to ensure continuity of conductivity.
Testing conductivity: Use a conductivity meter to test the resistance of the repaired area, which should be consistent with the original ground resistance (usually 1 × 10 ⁴ -1 × 10 ⁶ Ω), otherwise the conductive material needs to be adjusted.
Fill the aggregate layer: Fill the "V" groove with anti-static repair mortar (mix aggregates, conductive powder, and curing agent in proportion), compact it with a scraper, slightly higher than the original surface (to avoid shrinkage), cover it with plastic film and let it stand for 24-48 hours to cure.
Polishing: After solidification, use 400-800 grit sandpaper (water mill) to gradually polish until it is consistent with the original surface flatness; Polish with anti-static polishing wax to restore luster.
3. Edge scratch repair (at the junction with the wall/equipment)
Characteristics: Narrow space, easily overlooked, requiring a balance between sealing and anti-static performance.
Repair techniques:

Cleaning the edges: Use a soft bristled brush to remove dust and debris from the edges. If scratches involve sealant on the wall/equipment, the old sealant should be removed first (cut along the gap with a utility knife).
Fill and repair: Treat the aggregate layer and conductive layer (if damaged) according to the deep scratch repair method, pay attention to the flatness of the edges and walls/equipment during repair, and avoid height differences.
Re sealing: After repair, fill the edge gaps with anti-static sealant (containing conductive components) to ensure sealing and anti-static performance (the sealant resistance should match the original ground).
(3) Maintenance and verification after repair
Maintenance requirements: Within 24-48 hours after repair, avoid stepping on, crushing with heavy objects, or getting wet (especially for deep scratch repairs), maintain ventilation in the environment (temperature 15-30 ℃, humidity ≤ 70%), and promote complete curing of the repair material.
Performance verification:
Appearance inspection: The repaired area should be consistent with the original surface color and gloss, without obvious color difference or unevenness.
Anti static test: Use a surface resistance tester (according to GB/T 1410-2006 standard) to test the resistance of the repaired area to ensure compliance with anti-static requirements (usually 1 × 10 ⁴ -1 × 10 ⁹ Ω, depending on the scenario).
Wear resistance test (optional): Use a wear tester (such as a Taber abrasion tester) to test the wear resistance of the repaired area, which should be equivalent to the original ground (to avoid scratching again in the short term).
summarize
Anti static terrazzo scratch repair requires "targeted measures": shallow scratches focus on surface repair and polishing, deep scratches require reconstruction of the aggregate layer and conductive layer, and edge scratches need to balance sealing and anti-static. The core is to choose anti-static repair materials that are compatible with the raw materials, and strictly verify the conductivity after repair to ensure that they meet the anti-static requirements of the usage scenario.