| HS Code | 740766 |
| Appearance | Milky white liquid |
| Solid Content | 55 ± 2% |
| Viscosity | 8,000–15,000 mPa·s at 20°C |
| Ph | 4.0–6.0 |
| Density | 1.05–1.10 g/cm³ |
| Particle Size | 0.5–2.0 μm |
| Glass Transition Temperature | Approximately 30°C |
| Minimum Film Forming Temperature | Approximately 10°C |
| Tensile Strength | ≥7 N/mm² on wood-to-wood bond |
| Elongation At Break | ≥300% |
| Storage Stability | 6 months in sealed container at 5–35°C |
As an accredited TH-620 PVAc Emulsion factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Supplied in 50 kg sealed plastic drums, ensuring safe storage and easy handling. |
| Container Loading (20′ FCL) | TH-620 PVAc Emulsion loaded in 20′ FCL, palletized drums/IBCs, secured, sealed, with proper labeling and ventilation. |
| Shipping | TH-620 PVAc Emulsion ships in sealed drums or IBC totes, protected from moisture and contamination. Non-hazardous under normal conditions, it requires no dangerous goods declaration. Keep containers upright, dry, and away from extreme heat or freezing. Standard ground or ocean freight is suitable, with prompt handling to maintain product stability. |
| Storage | Store TH-620 PVAc Emulsion in sealed original containers in a cool, dry, well-ventilated area away from direct sunlight, heat, and open flames. Recommended storage temperature is 5–35°C; do not freeze, as this damages the emulsion. Keep containers tightly closed to prevent skinning or contamination, and use within the product’s stated shelf life. |
| Shelf Life | Shelf life is 12 months from manufacture date when stored in original sealed containers, protected from frost and direct sunlight. |
When TH-620, a polyvinyl acetate homopolymer emulsion, is formulated into a cold-press wood lamination adhesive for furniture panel bonding, the wet blend is adjusted to a Brookfield RVT viscosity of 4,000–8,000 mPa·s at 20 °C using spindle #5 at 20 rpm, a range that stabilises transfer on two-roll coater equipment without generating excessive shear heat in circulating systems. The formulation is typically built around 68–78 wt% TH-620 as the primary binder, with 4–7 wt% dibenzoate or triacetin plasticiser, 0.3–1.0 wt% polyvinyl alcohol thickener, 0.1–0.3 wt% defoamer, and the balance water. Compliance for this downstream segment is anchored to EN 204:2016 classification D2 or D3 for non-structural interior wood adhesives, with shear strength measured according to EN 205:2016; North American laminate suppliers additionally specify ASTM D905-08(2021) block shear after 7-day conditioning at 23 °C and 50% RH. On continuous panel lamination lines, wet film thickness is controlled to 80–150 µm by a two-roll coater before the core and face veneer enter a cold press at 0.3–0.8 MPa for 20–40 min; high-frequency hot platen units operate at 90–110 °C for 2–5 min when cycle time reduction is required. Edge banding lines run at 10–30 m/min and require rapid fibre-tear development within the trimming zone to avoid adhesive squeeze-out onto cabinet door edges. Production-scale failure data indicates that viscosity drift above +10% at ambient humidity exceeding 65% RH reduces pick-up on the transfer roll and increases slinging on the return stroke; inline viscometers are therefore set to alarm before the upper control limit. Because the polymer backbone contains no urea-formaldehyde condensation chemistry, formaldehyde-scavenging additives are not required in this formulation. Terminal product types include veneer-faced MDF furniture panels, particleboard laminated shelving, and PVC-edge-banded kitchen cabinet doors.
On folder-gluers running at 150–250 m/min, the side-seam adhesive is applied through a disc or extrusion nozzle at 18–35 g/m² wet coat weight onto clay-coated board; the limiting failure mode is usually not cohesive film strength but delayed fibre-tear development after compression belts release. TH-620 is formulated at 50–65 wt% of the wet adhesive with 3–5 wt% plasticiser, 0.05–0.15 wt% defoamer, and water to a viscosity of 1,200–2,800 mPa·s at 20 °C measured by Brookfield RVT spindle #4 at 20 rpm. For cartons or paper sacks intended for dry, non-fatty food contact, the finished adhesive is maintained within indirect food-contact status under FDA 21 CFR 175.105, provided a functional barrier separates the adhesive layer from the food; EU supply additionally observes EC 1935/2004 and REACH Annex XVII restrictions on residual monomer and plasticiser migration. The production process on a high-speed folder-gluer positions the glue station before the folding section, followed by compression belts that deliver 0.2–0.5 MPa nip pressure for 1–3 s before final folding and stacking; hot air at 60–80 °C is used when line speed exceeds 200 m/min and the set time must fall below 5 s. Inline quality control measures fibre-tear on the side seam every 15–30 min, and production-scale experience records foam accumulation in recirculated troughs when defoamer concentration drops below 0.05 wt%; foam enters the nozzle and causes intermittent dry spots on the seam. Terminal product types include side-seam folding cartons for beverage multipacks, dry-food cartons, tissue boxes, and paper bag bottom seams.
Spiral tube winders apply TH-620 through a rubber pick-off roll running in an adhesive pan at 40–80 g/m² per ply; the adhesive is cut with water and defoamer to 600–1,500 mPa·s at 20 °C, using 65–80 wt% TH-620 as the main binder. Flat crush compliance is checked under ISO 11093-9:2019 after conditioning at 23 °C and 50% RH. The main out-of-round rejection pattern is adhesive migration into outer plies when viscosity falls below 600 mPa·s, causing asymmetric swelling at the mandrel-fit gauge. Terminal product types are film and foil cores, yarn carriers, and spiral postal tubes.
Where ready-mixed gypsum joint compound requires crack-bridging and improved sandability, TH-620 is introduced as a coalescing polymer modifier at 2–6 wt% on total wet compound solids, with the final system pH held at 7.5–8.5. The addition sequence is critical: the emulsion is added only after cellulose ether thickener has fully hydrated in the aqueous phase, because early addition produces colloidal flocculation that raises torque on positive displacement pumps and destabilises the thickener network. The production process uses a high-shear dissolver with a Cowles blade tip speed of 10–15 m/s and cooling water to keep batch temperature below 40 °C; dry gypsum, limestone filler and additives are dispersed first, followed by TH-620 in the letdown phase. Compliance for this segment is governed by ASTM C474-15 standard test methods for joint treatment materials, while EU-marketed compounds are classified under EN 13963:2014. The compound is applied by trowel or mechanical joint finisher at 1–3 mm wet thickness over paper-faced gypsum board, with drying time set by ventilation and substrate porosity. Storage of the finished compound must remain above 5 °C and below 40 °C; a freeze-thaw cycle destabilises the PVAc dispersion and creates grain in the skim coat. Operational boundaries include avoiding amine-based pH adjusters and maintaining pH below 9.5, since PVAc homopolymer undergoes progressive acetate hydrolysis under strongly alkaline conditions; wet-scrub resistance is lower than vinyl acetate-ethylene copolymers, restricting this binder to interior non-wet-service compounds. Terminal product types include ready-mixed jointing compound, skim coat, and patching plaster for drywall finishing.
In ready-to-use paste tile adhesive for interior wall applications, TH-620 is metered at 5–15 wt% of total wet formulation to modify open time, wet tack and deformation. The formulation is built on 35–45 wt% cement, 30–40 wt% fine sand, 0.3–0.6 wt% cellulose ether, 10–15 wt% water, and the balance TH-620 plus preservative and defoamer. Mixing is carried out in a low-shear planetary mixer rather than a high-shear dissolver to avoid air entrainment; the emulsion is charged after the cement and sand have been wetted out, and the final pH is limited to ≤9.5 because free calcium hydroxide in cement will otherwise hydrolyse acetate groups, raise viscosity, and produce acetic acid odour during storage. Compliance for this downstream segment is defined by EN 12004:2017 adhesive classification and ISO 13007-1:2014 terminology, with the formulation targeted at class D1 for normal-setting interior wall tile; exterior, submerged or heavy-traffic installations are outside the boundary for PVAc homopolymer modification. Published data specific to TH-620 in this high-pH cementitious configuration is limited; the stated pH and storage limits are derived from general PVAc homopolymer hydrolysis behaviour rather than a grade-specific accelerated aging study. At production scale, the main process conflict is viscosity rise during storage caused by cement hydration and acetate hydrolysis when the paste is stored above 30 °C; chilled storage below 25 °C and within a 6-month shelf life is specified. Open time on gypsum plaster and concrete substrates is checked under the classification protocol of EN 12004:2017, and slip resistance is assessed under EN 1308:2010 using a 100 g weight. Terminal product types include paste tile adhesive for ceramic wall tiles, glass mosaic adhesive for interior use, and renovation levelling paste.
The compliance matrix below records the batch-release standard designations and TH-620 addition ranges for the five scenarios described.
| Scenario | Standard designation | Test or classification target | TH-620 addition |
|---|---|---|---|
| Furniture lamination wood adhesive | EN 204:2016, EN 205:2016, ASTM D905-08(2021) | D2/D3 non-structural interior wood bond; block shear after 7-day conditioning | 68–78 wt% |
| Folding carton side-seam adhesive | FDA 21 CFR 175.105, EC 1935/2004 | Indirect food contact for dry, non-fatty packaging; fibre-tear at compression release | 50–65 wt%, 18–35 g/m² |
| Spiral paper tube winding adhesive | ISO 11093-9:2019 | Flat crush resistance after conditioning at 23 °C/50% RH | 65–80 wt%, 40–80 g/m² |
| Gypsum joint compound binder | ASTM C474-15, EN 13963:2014 | Joint compound crack resistance and shrinkage under interior use | 2–6 wt% on wet solids |
| Paste tile adhesive modifier | EN 12004:2017, ISO 13007-1:2014, EN 1308:2010 | D1 interior wall tile classification; slip resistance | 5–15 wt% |
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TH-620 PVAc emulsion is supplied as a white, non-plasticised aqueous dispersion of polyvinyl acetate homopolymer. The product is stabilised with a protective colloid system and is reported to be free of alkylphenol ethoxylates. Manufacturer batch certificates list non-volatile matter at 50 ± 2% when tested according to ISO 3251:2019, with Brookfield RVT viscosity measured at 20 rpm and 25 °C in the range 3,500–5,500 mPa·s. pH is given as 4.0–5.5. The mean particle diameter is reported between 1.0 and 2.0 µm by laser diffraction per ISO 13320:2020; this particle size distribution contributes to low foaming under low-shear mixing but requires adequate shear when the emulsion is compounded into pigmented coatings. Density at 20 °C is specified as 1.07–1.09 g/cm³ when measured by ISO 2811-1:2016. The product contains no added external plasticiser, and its minimum film-forming temperature is typically 16 °C under ISO 2115:2000. These baseline values place TH-620 in the medium-viscosity, medium-solids class of woodworking and packaging adhesive raw materials, but its differentiation from copolymer emulsions becomes apparent only when film mechanical properties and wet-service behaviour are examined.
Differences are measurable in film hardness, wet strength and creep resistance. Vinyl acetate-ethylene copolymers with equivalent solids content often show glass transition temperatures between 0 °C and 7 °C, whereas the TH-620 homopolymer backbone is assigned a glass transition temperature near 30 °C. That higher thermal transition increases lap-shear strength on beech at 23 ± 2 °C to a range of 8–10 N/mm² after 7 days of conditioning under ISO 6238. VAE dispersions of comparable non-volatile content typically fall below 6 N/mm² in the same joint geometry. Plasticised PVAc grades may match initial adhesion on absorbent substrates but show progressive loss of cohesive strength after ageing at 60 °C for 500 h, because benzoate plasticisers migrate toward the adhesive-substrate interphase. TH-620 does not contain migratory plasticiser, so the aged lap-shear retention is generally above 80% of the initial value. The trade-off is a reduction in low-temperature flexibility and a higher minimum film-forming temperature, which limits direct substitution in cold-room packaging lines without process heating.
Under application shear, TH-620 exhibits pseudoplastic behaviour typical of colloid-stabilised PVAc. A cone-and-plate measurement at 25 °C gives apparent viscosity of approximately 4,800 mPa·s at 1 s⁻¹, falling to 1,200–1,500 mPa·s at 100 s⁻¹. Production roller-coater data with a 40-line chromium-plated roller and doctor blade gap of 0.20 mm show transfer weights of 20–35 g/m² on high-pressure laminate. Mechanical shear stability, evaluated by circulating the emulsion through a gear pump at 1,500 rpm for 30 min, produces a viscosity increase of less than 10%; residue retained on a 100-mesh sieve remains below 0.05% by wet mass. These values support use in roller transfer and bead application, but air-spray systems with nozzle orifices below 0.3 mm may generate shear-induced coagulum. Batch-to-batch viscosity variation is controlled within ±500 mPa·s at the stated solids range. In a consecutive run of 12 IBC totes, mean viscosity was 4,200 mPa·s with standard deviation 180 mPa·s; no pump cavitation occurred when using a 2:1 ratio air-operated diaphragm pump with a 25 mm suction line.
| Parameter | Test method | Reported value |
|---|---|---|
| Non-volatile content | ISO 3251:2019 | 50 ± 2% |
| Brookfield viscosity | ISO 2555:2018, spindle 4, 20 rpm, 25 °C | 3,500–5,500 mPa·s |
| pH | ISO 976:2013 | 4.0–5.5 |
| Density | ISO 2811-1:2016, 20 °C | 1.07–1.09 g/cm³ |
| Minimum film-forming temperature | ISO 2115:2000 | 16 °C |
| Mean particle size | ISO 13320:2020 | 1.0–2.0 µm |
| Residual vinyl acetate monomer | Static headspace gas chromatography | < 0.1% |
Film formation proceeds by interdiffusion of polymer particles after water loss. At 23 °C and 50% RH, a 100 µm wet film becomes surface-dry in 20–30 min and develops full coalescence within 24 h. Residual water in the adhesive layer can delay adhesion build on non-porous substrates; open assembly time on PVC edge banding should not exceed 3 min unless the substrate is pre-warmed. If wet films are exposed to relative humidity above 70% during drying, the coalescence rate is limited by boundary-layer water vapour pressure and the dry film may remain hazy. This limitation is relevant for high-speed lamination where infra-red drying tunnel lengths below 2.5 m cannot remove sufficient water before pressing.
Formulation latitude is governed by the acidic pH range and protective colloid content. The emulsion can be compounded with calcium carbonate fillers up to 15–20 phr before viscosity rises above 15,000 mPa·s; however, fillers with BET surface area above 15 m²/g increase the thixotropic index and may reduce roller transfer uniformity. Crosslinking with polymeric diphenylmethane diisocyanate in an emulsion polymer isocyanate system is feasible only if the working pH is maintained below 6.0. Exposure to alkaline substrates above pH 8 accelerates hydrolysis of the vinyl acetate ester linkage, liberating acetic acid and reducing wet strength. For moisture-resistant assemblies, addition of 10–15% by weight of a water-dispersible isocyanate improves resistance to 4 h cold-water immersion; without crosslinker, the product is generally limited to dry-use conditions equivalent to EN 204 D1 or EN 204 D2. Foaming during high-speed mixing can be controlled with a defoamer at 0.2–0.5% on total wet weight, but siloxane defoamers above 0.8% may cause cratering in subsequent coating applications.
Accelerated ageing tests define the boundary between TH-620 and crosslinked PVAc grades. Lap-shear specimens prepared from beech with 150 g/m² application rate were conditioned for 7 days at 23 ± 2 °C and 50 ± 5% RH. Dry shear strength determined by ISO 6238 is 8–10 N/mm². After 4 h immersion in cold water at 23 °C and immediate testing, strength retention is typically 30–40%. After 24 h water immersion, unmodified films show visible whitening and a strength retention below 25%. This is a consequence of water uptake into the PVAc matrix and partial disruption of polymer-particle boundaries, not necessarily hydrolysis. Crosslinked EPI variants retain more than 60% of dry strength after the same soak. These data position TH-620 as a dry-use interior wood adhesive base when used without a reactive co-binder.
Thermal ageing at 60 °C for 500 h reveals no significant yellowing in the dry film, and tensile strength measured on free films according to ISO 527-3:2018 remains within 15% of the initial value. Elongation at break is typically 8–12% for the unplasticised homopolymer; this is lower than VAE copolymer films, which may exceed 300% elongation. The low elongation and higher modulus improve resistance to static creep in load-bearing wood joints but reduce suitability for flexible packaging and nonwoven lamination where elongation above 50% is required.
| Film property | TH-620 | VAE copolymer typical | Plasticised PVAc typical |
|---|---|---|---|
| Glass transition temperature | 30 °C | 0–7 °C | 12–18 °C |
| Minimum film-forming temperature | 16 °C | < 0 °C | < 5 °C |
| König pendulum hardness after 24 h | 80–100 s | 30–50 s | 40–60 s |
| Lap shear on beech after 7 days | 8–10 N/mm² | 5–7 N/mm² | 6–8 N/mm² |
| Elongation at break | 8–12% | > 300% | 50–150% |
As supplied, the emulsion is classified as non-flammable because the water content is above 45%. Residual vinyl acetate monomer is controlled below 0.1% by gas chromatography, aligning with many regional emissions criteria. The product is not intended for direct food contact unless the formulator demonstrates compliance under 21 CFR 175.105 or 21 CFR 176.180 for indirect food packaging adhesives. Because the polymer contains vinyl acetate units and protective colloid, it is generally not suitable for exterior marine or continuous water-soak service without additional crosslinking and hydrophobic modification. Storage requires protection from temperatures below 0 °C; freeze-thaw exposure can produce irreversible coagulation, and thawed material with visible grain should not be re-incorporated. This is a more severe limitation than for VAE dispersions that tolerate limited freeze-thaw cycling.
On a production line for laminated particleboard furniture, TH-620 is applied by roller at 60–80 g/m² to a 0.7 mm high-pressure laminate and pressed for 10–15 min at 1.2–1.5 N/mm² and 20 °C. The resulting bond develops sufficient handling strength within 2 h. Published data for this specific configuration is limited to supplier application bulletins; no independent third-party durability data are available.
