| HS Code | 181815 |
| Appearance | White milky liquid |
| Viscosity | 8000-15000 mPa·s |
| Solid Content | 50-55% |
| Ph | 4.5-5.5 |
| Density | 1.05-1.10 g/cm³ |
| Open Time | 3-10 minutes |
| Assembly Time | 10-20 minutes |
| Pressing Time | 30-60 minutes cold press; 2-5 minutes hot press |
| Minimum Film Forming Temperature | 5°C |
| Bond Strength | >10 N/mm² |
| Voc Content | <50 g/L |
| Storage Life | 6 months in sealed container at 5-35°C |
As an accredited PVAc Veneering Adhesive factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | PVAc Veneering Adhesive supplied in a 1 kg resealable plastic bottle, ready-to-use, with safety label and applicator nozzle. |
| Container Loading (20′ FCL) | 20′ FCL: PVAc veneering adhesive loaded in palletized drums/IBCs, secured, weight-optimized, with spill prevention and proper labeling. |
| Shipping | PVAc Veneering Adhesive ships in sealed plastic pails or drums, labeled with product and safety data. It is classified as non-hazardous for ground, sea, and air transport under normal conditions. Store away from freezing and direct heat. Ensure containers remain upright to prevent leakage during transit. |
| Storage | Store PVAc Veneering Adhesive in its original, tightly sealed container, away from direct sunlight and extreme heat. Keep in a cool, dry area at 5–30°C. Prevent freezing, which can irreversibly damage the emulsion. Under proper conditions, unopened shelf life is typically 6–12 months. Stir gently before use. |
| Shelf Life | Shelf life is typically 12–24 months when stored unopened in a cool, dry place, protected from frost and heat. |
For flat-pack cabinet side panels and melamine-faced chipboard backs, PVAc is specified where formaldehyde emission constraints and glue-line colour stability rule out amino-resin systems. A production-grade formulation is adjusted to 48–52 wt% solids with 4–6 wt% polyvinyl alcohol protective colloid and 4–8 wt% plasticizer calculated on polymer solids, plus defoamer at 0.1–0.3 wt% of the final emulsion. When the wet spread is kept between 120 g/m² and 140 g/m² on 0.5 mm open-pore oak, bleed-through remains below the de-nib sanding threshold. Reducing the emulsion below 45 wt% solids by water addition is not recommended; once dynamic viscosity drops below 2500 mPa·s, the edge bead collapses and strike-through appears in 0.3 mm flat-cut veneer after pressing at 0.6 N/mm².
Compliance in this segment references EN 204 durability class D3 for interior high-humidity exposure, ANSI/HPVA HP-1-2016 for decorative panel bond quality, and ASTM D5751-99(2019) for nonstructural laminate joints in wood products. REACH Annex XVII Entry 51 restricts certain phthalate plasticizers in childcare articles; PVAc formulations destined for children’s furniture therefore use non-restricted plasticizers such as triacetin or citrate esters. RoHS 2011/65/EU Article 4(1) restrictions for lead, cadmium, mercury and brominated flame retardants are met by standard woodworking PVAc without additional certification burden.
The production line consists of an engraved anilox roller coater applying a 28–36 µm wet film, followed by a cold pre-press at 0.2–0.4 N/mm² for 10–15 min to collapse air channels. The main hot press is run at 70–80°C platen temperature and 0.5–0.8 N/mm² for 120–240 s depending on veneer thickness and core moisture. Platen parallelism is maintained within ±0.05 mm/m; temperature deviation across a six-daylight press must not exceed ±3°C. At glue line temperatures above 85°C, moisture vapour evolved from the water phase forms micro-blisters at the adhesive-to-MDF interface, while below 65°C pressure time must be doubled before fibre tear reaches 80–100% of bond area. Panels are conditioned for 24 h at 20–25°C and 50–60% RH before machining. Continuous service temperature is limited by the thermoplastic nature of PVAc; loaded edge bands in direct sun exposure above 50°C can exhibit creep movement.
Terminal product types include RTA side panels, cabinet door blanks, desktops and wardrobe door leaves where interior moisture load is limited to short-term high humidity rather than direct water contact.
Flush-door skin lamination creates a different adhesive demand because the hardboard skin is far more absorbent than sliced veneer and the frame perimeter is discontinuous. The emulsion is filled with 8–12 wt% calcium carbonate on total adhesive weight and thickened to 9000–12000 mPa·s, which prevents adhesive starvation at the skin edges where the stile meets the door core. Application weight is raised to 160–200 g/m² on frame members and 140–180 g/m² on the hardboard field. Interior door constructions are evaluated under ANSI/WDMA I.S.1-A-2011 for face bond strength and EN 204 class D2 for dry interior use; fire-rated door cores additionally require the adhesive not to contribute to flame spread in the finished assembly tested to EN 13501-1.
The production process for flush doors uses either a frame spreader with a shoe nozzle or a roll coater for the skin. Cold pressing at 0.3–0.5 N/mm² for 20–40 min remains common for low-output plants, but high-volume lines use high-frequency presses at 13.56 MHz with 0.4–0.6 N/mm² and 60–90 s for a 35 mm door blank. Glue-line moisture before RF pressing should be controlled to 8–12%; excess water combined with RF heating above 90°C produces steam foaming and edge blow-out. Batch-to-batch variance in hardboard surface absorbency may require spread adjustment of ±10 g/m² to maintain fibre pull without squeeze-out around frame members. Aluminium or steel cauls are used on both faces to prevent warp during the exothermic RF cure.
Terminal products include interior flush door leaves, sliding wardrobe door blanks, hollow-core partition door fillers and pre-hung residential door units.
When a veneer face must follow a concave shell without cracking, the adhesive is formulated closer to a brushable dispersion than a thixotropic gap-filler. The working viscosity is held at 2500–3500 mPa·s and solids at 45–48 wt%; wetting agent addition of 0.3–0.5 wt% reduces micro-foam on sanded poplar cross-band. Spread rate of 110–150 g/m² is used with 15–20 min open time at 23°C and 50% RH before the vacuum bag is sealed. The polyvinyl alcohol protective colloid system gives onset of tack at approximately 10–15 min, which assists initial positioning on vertical concave surfaces without peeling.
For interior curved plywood shells, EN 636-1:1996 and EN 314-1:2004 classification 1 apply where the substrate itself is plywood; the adhesive must meet EN 204 D2 minimum shear strength after conditioning. The production cell uses a diaphragm vacuum pump with an ultimate pressure of 20 mbar, giving an effective consolidation pressure of 0.06–0.1 MPa across a flexible membrane. Full clamping is maintained for 45–90 min, followed by 24 h cure at 20°C before sanding. Internal radii below 200 mm with veneer thicker than 0.6 mm require staged pre-forming; when veneer thickness exceeds 1.0 mm, published data for PVAc-only systems in tight double curvatures is limited and thermoplastic creep at elevated interior temperature must be considered.
Terminal product types include curved reception desk fascias, acoustic baffle skins, theatre seat backs and ergonomic plywood chair shells.
| Application route | Solids content | Viscosity at 20°C | Spread rate | Press condition | Bond quality criterion |
|---|---|---|---|---|---|
| Short-cycle hot press flat panel | 48–52 wt% | 4000–6000 mPa·s | 120–140 g/m² | 70–80°C, 0.5–0.8 N/mm², 120–240 s | fibre tear ≥ 80% |
| Flush-door skin lamination | 50–55 wt% | 9000–12000 mPa·s | 160–200 g/m² | 13.56 MHz RF, 0.4–0.6 N/mm², 60–90 s | no edge squeeze-out; fibre pull on frame |
| Vacuum-bag curved plywood | 45–48 wt% | 2500–3500 mPa·s | 110–150 g/m² | 0.06–0.1 MPa, 45–90 min | no veneer cracking ≥ 200 mm radius |
| Architectural wall panel lay-up | 52–55 wt% | 6000–8000 mPa·s | 150–180 g/m² | cold press 0.5–0.7 N/mm², 30–60 min | no pH shift staining after 48 h |
| Fire-retardant MDF contract panel | 55–58 wt% | 10000–14000 mPa·s | 160–200 g/m² | 60–70°C, 0.4–0.6 N/mm², 180–300 s | no face-cell collapse above 70°C |
Architectural wall panel lay-up with book-matched flitch veneer uses PVAc where glue-line darkness and post-hardening moisture sensitivity are unacceptable. The adhesive is set to a solids content of 52–55 wt%, with 0.2–0.4 wt% defoamer and 5–8 wt% plasticizer on polymer solids; viscosity is trimmed to 6000–8000 mPa·s for trowel or curtain coater application. Because flitch veneer may be 0.6–1.2 mm thick and often contains silica-rich tropical species, spread rate is increased to 150–180 g/m² to avoid starved bonds at the curl edges. The adhesive viscosity must be stable for 8 h in the reservoir; mechanical shear from recirculating curtain coaters can reduce viscosity by 10–15% over a single shift, requiring in-line correction with fresh emulsion rather than water.
EN 13986:2004 +A1:2015 provides the panel-level conformity framework, while the adhesive itself is classified under EN 204 D2 for dry interior building components. The production route uses a fixed-beam curtain coater or twin-roll spreader, followed by a daylight press at 0.5–0.7 N/mm² and 22–25°C for 30–60 min. Hot pressing is avoided because the expansion differential between veneer and core stock exceeds the PVAc tack range at temperatures above 60°C. After pressing, panels are stacked with breather sheets for 72 h to allow free water to diffuse; immediate edge trimming before this conditioning phase produces veneer delamination at panel corners. Acid number must be monitored; pH below 4.0 has been observed to shift colour in tannin-rich species, producing a green-grey stain along the bond line after 48 h.
Terminal products include lift-lobby wall cladding, conference room wall panels, and book-matched decorative screens for hotel interiors.
Flame-retardant MDF brings water-absorbing salts to the bonding surface, so PVAc selection must be pH-stable and tolerant of delayed dehydration. The adhesive is adjusted to 55–58 wt% solids with 6–8 wt% calcium carbonate filler and viscosity of 10000–14000 mPa·s; addition of urea-based wetting agents at more than 0.5 wt% has been associated with adhesive skinning on FR MDF at glue line temperatures above 70°C. The formulation must be free of added chlorides if the FR panel uses ammonium phosphate salts because chloride migration accelerates surface bloom in service. Spread rate is kept at 160–200 g/m²; lower spreads produce immediate dry-out in the face layer of the salted panel. Ammonium hydroxide must not be used as a pH adjuster; high-pH amine species can destabilise the PVAc emulsion and produce irreversible gel bodies within 4 h.
Compliance for contract furniture typically demands EN 204 D3 dry/humid classification for the adhesive and a substrate classification of EN 13501-1 B-s2,d0 or better for the composite panel. The adhesive itself is tested as part of the finished composite because PVAc contributes to the total organic content; adhesive-only flammability testing is not sufficient for panel certification. Production uses a heated daylight press at 60–70°C and 0.4–0.6 N/mm² for 180–300 s. The upper temperature is capped at 70°C; above this limit, moisture released from the FR salts expands at the core surface and produces local cell collapse at the thin veneer face. Panels are allowed to acclimate at 40–50% RH for 48 h before edge banding; at relative humidity above 60%, the FR MDF face may swell by up to 0.3 mm/m and peel strength falls below the acceptance threshold. Published data for specific FR salt formulations remains limited, so pre-production validation with the actual FR MDF batch is required.
Terminal products include desk top panels, partition screens, hotel casegoods and reception counters where local fire codes require a B-s2,d0 composite panel.
Competitive PVAc Veneering Adhesive prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615380400285 or mail to sales2@liwei-chem.com.
We will respond to you as soon as possible.
Tel: +8615380400285
Email: sales2@liwei-chem.com
Flexible payment, competitive price, premium service - Inquire now!
PVAc Veneering Adhesive is supplied as an aqueous polyvinyl acetate dispersion with polyvinyl alcohol protective colloid and is offered in model designations PVAc-V-LV, PVAc-V-MV, and PVAc-V-HV. The low-viscosity model PVAc-V-LV is specified at 5,000–8,000 mPa·s, the medium-viscosity model PVAc-V-MV at 8,000–15,000 mPa·s, and the high-viscosity model PVAc-V-HV at 15,000–25,000 mPa·s when measured on a Brookfield RVT viscometer at 20 °C and 20 min⁻¹ according to ISO 2555:2018. Solids content determined by ISO 3251:2019 is 45–55 % by mass, pH by ISO 976:2013 is 3.0–5.5, and density by ISO 2811-1:2016 is 1.05–1.10 g/cm³. The product is formulated for cold-press, hot-press, and membrane-press veneering of MDF, particleboard, plywood, and solid wood cores with sliced or rotary-cut wood veneer and selected decorative paper laminates. Compliance is typically declared against EN 204:2016 for non-structural thermoplastic wood adhesives in classes D2, D3, or D4 depending on the specific grade. In storage, the material remains freeze-sensitive and is specified for bulk handling at 5–35 °C; pH drift below 2.8 or above 6.0 indicates destabilization or contamination.
Under a cone-and-plate or parallel-plate rheometer, PVAc veneering adhesives exhibit pseudoplastic flow with a low-shear viscosity plateau and a shear-thinning index of 1.2–2.8 when comparing apparent viscosity at 2 s⁻¹ and 20 s⁻¹ at 20 °C. This shear-thinning response controls transfer efficiency on a two-roll roller coater: at machine speeds of 10–25 m/min with an engraved steel roll of 30–60 lines/cm, wet-film weight is typically maintained at 80–150 g/m² for raw wood veneer and 70–120 g/m² for paper-backed veneer. Higher low-shear viscosity in PVAc-V-HV reduces strike-through on porous veneer but increases roller spatter above 25 m/min. Production lines with unwinding veneer rolls at 15 m/min show that PVAc-V-MV at 12,000 mPa·s deposits a uniform 100–120 g/m² film on 0.6 mm oak veneer without misting, provided roller gap is set to 150–250 µm. Open assembly time at 20 °C and 65 % RH is 8–12 min; closed assembly time is 15–20 min before significant skin-over. At 35 °C and 40 % RH, open time falls below 4 min, which is the primary processing window limitation in non-air-conditioned plants.
Cold-press lamination of 0.5–0.6 mm sliced oak veneer onto 18 mm MDF panels at 20 °C uses a platen pressure of 0.3–0.6 MPa for 20–35 min, followed by 24 h minimum conditioning at 20 °C and 65 % RH before sanding. Hot-press cycles on a multi-daylight press with 100 °C platens and 0.4–0.8 MPa pressure are reported as 3–5 min for PVAc-V-MV at 100–130 g/m², but core temperature must reach at least 50–60 °C to coalesce the film; thermocouple data from 18 mm particleboard show that platen temperature alone is not a reliable cure indicator. Veneer moisture content above 12 % before pressing tends to generate steam blisters and edge delamination in hot pressing, while moisture content below 5 % on raw wood veneer produces starved bonds and low fiber tear. The adhesive is not recommended for substrates with residual formaldehyde scavengers or acidic surfaces below pH 3.0 because acid-catalyzed hydrolysis can reduce storage-stable viscosity and final bond water resistance.
Within EN 204:2016, non-structural thermoplastic wood adhesives are classified D2, D3, and D4 on the basis of exposure to water and humidity. PVAc-V-LV and PVAc-V-MV are typically oriented to D2 or D3 applications, while PVAc-V-HV and internally crosslinked variants may be submitted for D4 classification. Test methods in EN 205:2016 use beech specimens conditioned at 20 °C/65 % RH and then subjected to specified water immersion cycles; D3 requires evaluation after short-term water contact, and D4 requires evaluation after more prolonged water storage. The numerical pass criterion for each class is stated in EN 204:2016 Table 1; published datasheets for some commercial PVAc veneering grades report tensile shear strength values of 2.0–4.5 N/mm² dry and 0.5–2.0 N/mm² after water immersion depending on class, but published data for the PVAc-V-HV grade in this specific configuration is limited. Consequently, the product should not be specified for exterior or structural use without supplementary testing under EN 205:2016 and, where relevant, manufacturer data for the specific veneer–core combination.
At storage temperatures below 5 °C, freeze-thaw cycling increases viscosity and may produce coagulum that blocks roller-coater doctor blades; material stored overnight at −5 °C in unheated warehouses has been observed to require 48 h at 20 °C and low-shear stirring before viscosity returns to the specified 8,000–15,000 mPa·s. Viscosity drift of more than ±20 % from the initial certificate of analysis is grounds for re-testing because pump transfer characteristics and wet-film thickness are directly influenced. Bulk handling through stainless steel progressive cavity pumps at 10–50 L/min is typical, but high-shear circulation above 500 s⁻¹ can induce irreversible mechanical coagulation in unstabilized PVAc dispersions.
PVAc dispersions coalesce only when the bondline temperature exceeds the minimum film formation temperature, which for these grades is 4–8 °C by ISO 2115:2000. In hot pressing, if the core temperature remains below 50 °C for less than 120 s, the adhesive film may dry white and produce a weak boundary layer at the veneer interface. This failure is observed in short-cycle presses where 18 mm particleboard is loaded at 25 °C and pressed for 90 s at 95 °C; the centerline thermocouple records only 45–55 °C at the adhesive line, and the result is edge lifting after 72 h in 20 °C/65 % RH. The same material pressed for 180 s at 105 °C and 0.6 MPa reaches an adhesive-line temperature of 70–80 °C and yields 80–100 % wood fiber tear after conditioning. Preheat of the core at 40 °C for 30 min before cold pressing avoids the low-temperature coalescence boundary but reduces open assembly time to 4–6 min.
Relative to urea-formaldehyde systems, PVAc does not require acid catalyst dosing and eliminates formaldehyde emissions from the adhesive component, but PVAc bondlines are thermoplastic and should not be used where continuous service temperature exceeds 50–60 °C. Compared with one-component PUR, PVAc has shorter open time and lower moisture resistance but does not require substrate moisture for cure or engineering controls for isocyanate exposure. Compared with EPI systems, PVAc generally provides lower heat resistance and moisture resistance, although both are water-cleanable before cure. The selection boundary is therefore based on EN 204 class, thermal service limit, and emission specification rather than unit cost alone.
| Attribute | PVAc Veneering Adhesive | Urea-formaldehyde | One-component PUR | EPI |
|---|---|---|---|---|
| Formaldehyde release | No added formaldehyde; may be tested to EN 717-1 | Formaldehyde present unless ultra-low E0 grade | No added formaldehyde | No added formaldehyde |
| Water resistance class | EN 204 D2–D4 | EN 12765 classes | Often EN 15425 for load-bearing grades; non-structural grades vary | Manufacturer specification; often evaluated to EN 204 D4 |
| Bondline temperature resistance | Thermoplastic; creep above 50–60 °C | Rigid, brittle; service often up to 100 °C | Crosslinked; service often up to 120 °C | Crosslinked; higher than PVAc |
| Cleanup before cure | Water | Water; acid catalyst handling required | Solvent or isocyanate-safe cleaner | Water |
| Open time at 20 °C/65 % RH | 8–12 min | Comparable or shorter | Often 15–60 min | 6–10 min |
| Bondline flexibility | Moderate | Brittle | Flexible | Rigid to semi-flexible |
Routine incoming inspection includes solids content, pH, viscosity, and density, with 100–200 µm wet film draws on glass to detect grits or coagulum. A cast film of 250 µm wet thickness dried for 24 h at 20 °C/65 % RH is examined for transparency and absence of white spots; white spots indicate incomplete coalescence when drying below the minimum film formation temperature. Adhesion is evaluated on a production-like beech plywood assembly with a 0.6 mm oak veneer at 120 g/m², cold pressed for 30 min at 0.5 MPa, then conditioned 72 h before chisel tests. Acceptable bond quality is defined as ≥75 % wood fiber tear on both faces after 72 h at 20 °C/65 % RH, with no edge delamination after 24 h at 15 °C and 80 % RH for D3 grades.
