Grind tester

Introduction

A grind tester is an instrument used to measure the fineness of the grind of the pigments in the paints, the inks, and the other dispersions, by the determination of the size of the largest particles and the agglomerates, and it is used in the paint, the coating, the ink, and the many other industries for the quality control. The grind tester, also known as the Hegman gauge, consists of a steel block with a tapered groove, which is graduated with the scale, and the sample is placed at the deep end of the groove and drawn down with a scraper, and the point at which the particles first become visible in the film indicates the fineness of the grind, expressed in Hegman units or in micrometers; the grind tester is used for the measurement of the fineness of the grind of the pigments and the dispersions, for the quality control of the paints and the inks, for the assessment of the dispersion, for the process control, for the comparison of the batches, and for many other applications, and it is available in various ranges of the scale; the grind tester is a simple and a rapid instrument for the assessment of the dispersion quality, and it is an essential instrument in the paint and the coating industry. Grind testers are used in the paint and the coating industry, in the ink industry, in the pigment industry, in the laboratories, and for many other applications. With their fineness measurement, grind testers are essential for the dispersion quality control.

Grind Tester LGDT-T2010

Grind Tester features a measuring range of 0 to 200μm, allowing precise evaluation of particle fineness in a wide variety of samples. It detects minimum particle resolution range for ac...

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Standards

Complies with the above standards, but is not limited to them.

Features

1. Grind tester for measuring grind size, particle size distribution and grinding performance of materials.

2. Precision instrument for evaluating fineness of grind, dispersions and particle size in coatings, inks and pigments.

3. Suitable for paint, coating, ink, pigment, cosmetic, pharmaceutical, food and quality control laboratories.

4. Includes grind gauge (Hegman gauge), scraper, sample stage, measurement scale and operation manual.

5. Supports fineness of grind measurement for paints, coatings, inks, pigments, pastes and dispersions.

FAQ

Q1: What testing scenarios is this tester mainly applied to?

A: The grind tester (fineness of grind gauge, Hegman gauge) is used in paint and coating manufacturing, ink and pigment production, cosmetics, pharmaceuticals, food, and quality control laboratories to measure the fineness of grind (particle size distribution) of dispersions, pastes, and pigment suspensions, ensuring proper dispersion quality and consistent product performance. It supports paint and coating testing (fineness of grind for latex paints, industrial coatings, automotive paints, primers, topcoats - verify pigment dispersion (large particles/agglomerates cause defects: poor gloss, color variation, surface roughness, reduced hiding; measure Hegman fineness (0-8 scale) or micrometer particle size), ink and pigment (printing inks (offset, flexo, gravure), pigment dispersions, masterbatches - grind fineness affects print quality, color strength, gloss, and dispersion stability; measure particle size of pigment agglomerates), cosmetics (creams, lotions, foundations, lipsticks, mascaras - grind fineness affects texture, spreadability, color, and skin feel; ensure no large particles/grittiness), pharmaceuticals (ointments, creams, pastes, suspensions - particle size affects drug release, texture, and stability; regulatory requirements for topical formulations), food (chocolate, spreads, pastes, sauces, confectionery - fineness of grind affects texture, mouthfeel, and stability; chocolate conching monitoring), and quality control (incoming raw material inspection (pigment dispersion quality), in-process dispersion monitoring (during milling/grinding - determine when desired fineness is achieved, reducing over-processing time/energy), finished product specification verification, batch-to-batch consistency).

Q2: What standards does the tester comply with?

A: The grind tester follows relevant ISO, ASTM, DIN and GB/T standards including ISO 1524 (paints and varnishes - determination of fineness of grind), ASTM D1210 (standard test method for fineness of dispersion of pigment-vehicle systems by Hegman gauge), ASTM D333 (related), DIN 53203 (testing of pigments and extenders - determination of fineness of grind), and GB/T standards for fineness of grind. The hardware complies with applicable precision standards for grind gauges (typically +/- 5 micrometers accuracy for the groove depth). Calibration should use certified reference materials (standard pastes with known particle size) or certified depth gauges to verify groove depth accuracy. For regulated industries (pharmaceutical, food), follow applicable quality management (ISO 9001, GMP) and maintain calibration records.

Q3: What is the warranty period for the whole tester and key components?

A: The whole grind tester is covered by a 12-month warranty. The grind gauge (Hegman gauge with precision-machined groove), scraper, and housing are covered, while scraper (wear part - can be replaced), calibration standards, and cleaning supplies are consumables or accessories. Damage from improper use, scratching the gauge groove (using metal scraper incorrectly, abrasive samples - scratches affect accuracy; use only the provided scraper, clean carefully), dropping (precision gauge can be damaged by impact - affects groove flatness), corrosion (acidic/alkaline samples left on gauge - clean immediately after use), or unauthorized repair is excluded. Extended warranty may be available. Grind gauges are precision instruments - with proper care they last many years; scrapers are the main wear item.

Q4: Is this device difficult to operate? Is professional training required?

A: Operation requires trained laboratory personnel familiar with dispersion testing and proper grind gauge technique. We provide operation manuals and training. Proper instrument preparation (inspect gauge before use (groove should be clean, dry, free of scratches, residue, or corrosion; if scratched or worn, replace gauge - inaccurate readings), place gauge on flat, stable surface (bench - ensure gauge is level and stable), clean scraper (edge should be straight, clean, free of nicks; a damaged scraper edge causes inaccurate readings), sample preparation (ensure sample is homogeneous (stir/mix thoroughly before testing - pigment particles can settle; for viscous samples, warm slightly if specified; avoid introducing air bubbles (bubbles cause false readings), bring sample to test temperature (typically 23 +/- 2 degrees C per standard; temperature affects viscosity and particle behavior), sample application (place a small amount of sample (a few grams/drops) at the deep end of the groove (widest/deepest end - typically 0 or 100 micrometers depth; do not overfill (excess sample causes inaccurate readings; underfill causes dry spots), drawdown (hold scraper at right angle (90 degrees) to gauge surface, with firm, even pressure; draw sample smoothly from deep end to shallow end in one continuous motion (about 1-2 seconds; do not stop or go back - causes uneven film and inaccurate readings; do not press too hard (can flex gauge or scrape groove) or too light (leaves excess sample), reading (immediately after drawdown (within 5-10 seconds - before sample dries/settles), view the groove at an angle (oblique lighting - side lighting helps see particle peaks; look for the point where particles first appear (scratch marks, peaks, or "grit line") on the groove surface; read the scale at that point (Hegman units (0-8) or micrometers; the fineness of grind is the point where 3-5 particles or a continuous scratch line first appears; do not read isolated single particles (read the first significant cluster/scratch), repeat (take 2-3 readings for consistency (clean gauge between readings); report average or range; for QC, compare to specification (e.g., Hegman 7+ for topcoats, Hegman 5+ for primers), post-test (clean gauge immediately after use (before sample dries - use appropriate solvent (water for water-based, solvent for solvent-based) and soft cloth/lint-free wipe; do not use abrasive cleaners or metal brushes (scratch groove); dry thoroughly before storage; store gauge in protective case (avoid contact with hard objects that can scratch groove), maintenance (regular cleaning (after each use), groove inspection (check for scratches, wear, corrosion - replace if damaged), scraper inspection/replacement (when edge is nicked or worn), calibration verification (every 6-12 months with certified standard paste or depth gauge; if gauge is dropped or suspected damaged, recalibrate/replace), troubleshooting (inconsistent readings (sample not homogeneous, scraper damaged, technique inconsistent (speed/pressure), gauge dirty/scratched; re-mix sample, replace scraper, improve technique, clean/replace gauge), no particle line (sample too fine (beyond gauge range - use finer gauge), sample too coarse (all particles at deep end - use coarser gauge), sample too viscous (warm or reduce viscosity), particles settling (mix immediately before testing), gauge scratched (replace), bubbles in sample (degas or stir gently), and safety (some samples contain solvents (volatile, flammable, toxic) - use fume hood, wear PPE (gloves, safety glasses); clean up spills; dispose of solvent waste per regulations; do not use metal tools on gauge (scratch precision surface)) are important for accurate fineness of grind measurement.

Q5: What is the typical lead-time for order delivery?

A: Standard models require 7-30 working days. In-stock units can ship within 3-7 working days. Custom configurations or large built-to-order systems may require additional time, and we confirm the exact schedule before order confirmation.

Q6: Is regular calibration required? What is the recommended calibration cycle?

A: Calibration verification recommended every 6-12 months using certified standard paste (with known fineness/particle size traceable to national standards) or certified depth gauge (to verify groove depth at multiple points along the groove). If gauge is dropped, scratched, or suspected damaged, recalibrate or replace immediately. Routine inspection before each use (clean, check for scratches/wear, verify scraper edge). For regulated industries (pharmaceutical, food, ISO 17025 labs), follow applicable calibration schedules and maintain records (calibration certificates, inspection logs, standard paste lot numbers). Grind gauges are relatively stable (precision-machined stainless steel or glass), but scratches and wear from use can affect accuracy - regular inspection is key. If readings become inconsistent or gauge is visibly scratched, replace.

Q7: Are supporting consumables universal?

A: Scrapers (replacement - specific to gauge manufacturer (straight edge, stainless steel or plastic; some gauges use specific scraper design), certified standard pastes (for calibration - available from gauge manufacturers or reference material suppliers; specific particle size standards), cleaning supplies (solvents (water, alcohol, xylene), lint-free wipes/cloths, mild detergent), and storage cases are available from laboratory supply companies, though scrapers and calibration standards may be gauge-specific. Long-term consumable cost is minimal (occasional scraper replacement, calibration standard paste).

Q8: Can I customize parameters or supporting accessories?

A: Customization includes grind gauge type (single groove (standard Hegman gauge - one groove with scale), dual/triple groove (multiple grooves with different ranges on one gauge - convenient for wide range samples), North scale (Hegman 0-8, common in US), metric scale (0-100 micrometers, common in Europe/Asia), both scales (dual units on one gauge), groove range (0-25 micrometers (fine - for high-quality topcoats, inks), 0-50 micrometers (standard - general paints), 0-100 micrometers (coarse - for primers, adhesives, pastes), 0-150 micrometers (very coarse - for sealants, mastics)), gauge material (stainless steel (durable, corrosion-resistant, most common), glass (transparent, allows backlighting, but fragile), hardened steel (wear-resistant)), scraper type (stainless steel straight edge (standard), plastic (disposable, avoids scratching gauge), precision-ground edge), accessories (certified calibration paste, replacement scrapers, storage case, cleaning kit, magnifier (for reading fine particle lines), light source (oblique lighting for better visibility), digital vision system (camera + software for automated reading - advanced, reduces operator subjectivity), certifications (ISO 17025 calibration certificate, NIST-traceable), language and accessories. Additional scrapers, calibration standards, and accessories can be ordered separately.

Q9: Does the purchase include on-site installation and commissioning service?

A: Standard delivery includes the grind gauge, scraper, storage case (sometimes), calibration certificate (sometimes), and instruction manual. On-site installation is not required (manual instrument, no power/setup needed - just place on bench and use). On-site training is not included for standard orders but can be arranged at additional cost (for QC teams on proper technique and reading interpretation). Remote guidance is provided.

Q10: What types of samples are compatible with this equipment?

A: The grind tester measures fineness of grind for various paste/dispersion samples including paints and coatings (latex paints (interior/exterior), industrial coatings (epoxy, polyurethane, alkyd), automotive paints (basecoat, clearcoat, primer), marine coatings, wood coatings, powder coatings (as slurry), primers, sealants, adhesives - measure pigment dispersion quality; typical specification: topcoats Hegman 7+ (10 micrometers or finer), primers Hegman 5-6 (20-30 micrometers), sealants coarser), inks and pigments (offset printing inks, flexographic inks, gravure inks, screen printing inks, inkjet inks (filtered, very fine), pigment dispersions (color concentrates, masterbatches), carbon black dispersions, titanium dioxide slurries - inks require very fine grind (Hegman 8+ / <5 micrometers for high gloss/print quality), cosmetics (creams, lotions, moisturizers, foundations (liquid/powder), lipsticks, mascaras, eyeshadows, sunscreens, toothpaste - grind fineness affects texture and skin feel; foundations require fine grind for smooth application; lipsticks require fine pigment dispersion for color and texture), pharmaceuticals (ointments, creams, gels, pastes (topical drug products), suspensions (oral/topical), lipophilic formulations - particle size affects drug release, bioavailability, texture, and stability; regulatory requirements (FDA, EMA) for topical formulations; USP/EP may specify particle size limits), food (chocolate (conching/grinding monitoring - fineness affects texture and mouthfeel; typical <20-30 micrometers for smooth chocolate), peanut butter, spreads, sauces, pastes, confectionery, baby food - grind fineness affects texture and stability; food-grade equipment required), and other dispersions (pigment pastes, ceramic slurries, polishing compounds, dental materials, agricultural suspensions (pesticides, fertilizers) - any paste/viscous dispersion where particle size/agglomerate size affects quality). NOT compatible with: Low-viscosity liquids (free-flowing liquids do not form a proper film in the groove - use particle size analyzer (laser diffraction) instead), dry powders (grind gauge requires paste/viscous dispersion; for dry powders, use laser diffraction, sieve analysis, or microscopy), very coarse materials (>100-150 micrometers - beyond standard gauge range; use sieve analysis or optical methods), samples with large aggregates that scratch the gauge (if sample contains hard, large particles, use appropriate gauge or pre-filter), and samples that react with/corrode the gauge material (acidic/alkaline samples can damage stainless steel - use glass gauge or test quickly and clean immediately). IMPORTANT: Fineness of grind (FOG) fundamentals: (1) What it measures: The grind gauge (Hegman gauge) measures the largest particle/agglomerate size in a dispersion, NOT the average particle size. It detects oversize particles/agglomerates that indicate incomplete dispersion. A reading of Hegman 7 (12.5 micrometers) means the first significant particles appear at 12.5 micrometers depth - particles larger than 12.5 micrometers are present. It does not measure the full particle size distribution (for that, use laser diffraction or microscopy). (2) Hegman scale: The Hegman gauge (North American standard) uses a 0-8 scale where: Hegman 0 = 100 micrometers (coarse), Hegman 4 = 50 micrometers, Hegman 7 = 12.5 micrometers (fine), Hegman 8 = 0 micrometers (theoretical finest). Conversion: Hegman = 8 - (micrometers / 12.5). Metric gauges use direct micrometer scale (0-100, 0-50, 0-25). (3) How it works: The gauge has a precision-machined groove that tapers from deep (e.g., 100 micrometers) at one end to zero (flat) at the other, with a scale along the side. Sample is placed at the deep end and drawn down the groove with a scraper. At the deep end, all particles are submerged (below surface); as the groove becomes shallower, larger particles protrude above the surface, creating visible scratch marks/peaks. The point where particles first appear indicates the largest particle size present. (4) Reading technique: The "fineness of grind" is read at the point where 3-5 particles or a continuous scratch line first appears. Isolated single particles (1-2) are ignored (they may be contaminants or random large particles). Read within 5-10 seconds of drawdown (before sample dries or particles settle). Use oblique lighting (side light) to see particle peaks clearly. Some operators use a magnifier for fine gauges. (5) Interpretation: A finer grind (higher Hegman / lower micrometers) generally indicates: better pigment dispersion (more complete wetting/deagglomeration), better color development (higher tinting strength, more consistent color), better gloss (finer particles scatter less light, higher gloss), better surface smoothness (less orange peel/roughness), better weathering/durability (finer particles form more uniform film), but may require more milling time/energy (over-dispersion can reduce viscosity, increase gloss too much, or cause pigment re-agglomeration). Each product has an optimal grind specification (not always "the finer the better" - some products intentionally have coarser grind for texture (e.g., textured paints, hammerite finishes)). (6) Common errors: - Reading single particles instead of first significant cluster (causes falsely coarse readings). - Waiting too long to read (sample dries, particles settle - causes inaccurate readings). - Inconsistent scraper pressure/speed (causes variable film thickness, inconsistent readings). - Dirty/scratched gauge (causes false particle lines, inaccurate readings). - Sample not homogeneous (settled particles - causes falsely coarse readings; always mix immediately before testing). - Wrong gauge range (sample too fine/coarse for gauge - use appropriate range). - Temperature not controlled (viscosity changes with temperature, affects drawdown). (7) Quality control: In manufacturing, grind testing is used to: verify raw material quality (incoming pigment dispersion), monitor milling/dispersion process (determine endpoint - when desired fineness is reached, stop milling to save time/energy), verify finished product meets specification, ensure batch-to-batch consistency, troubleshoot quality issues (color variation, gloss problems, surface defects often trace to poor grind). (8) Alternative methods: For full particle size distribution: laser diffraction (ISO 13320), dynamic light scattering (DLS for nanoparticles), sieve analysis (for coarse dry powders), optical microscopy/image analysis, electron microscopy (SEM/TEM for nanoscale). The grind gauge is a quick, simple, low-cost QC tool for oversize particle detection, not a comprehensive particle size analyzer.