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Anhui Liwei Chemical Co., Limited.

Covinax 625-78

    • Product Name: Covinax 625-78
    • Factroy Site: Lingwu, Yinchuan, Ningxia, China
    • Price Inquiry: sales2@liwei-chem.com
    • Manufacturer: Anhui Liwei Chemical Co., Limited.
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    Specifications
    HS Code 227426
    Product Name Covinax 625-78
    Active Ingredients Amoxicillin (as amoxicillin trihydrate) and Clavulanic acid (as potassium clavulanate)
    Strength 625 mg amoxicillin and 78 mg clavulanic acid per tablet
    Dosage Form Tablet
    Pharmacological Class Broad-spectrum penicillin combined with a beta-lactamase inhibitor
    Atcvet Code QJ01CR02
    Target Species Dogs
    Indications Treatment of bacterial infections in dogs caused by amoxicillin/clavulanic acid-susceptible organisms
    Route Of Administration Oral
    Adverse Reactions Gastrointestinal disturbances such as vomiting and diarrhoea; allergic hypersensitivity reactions
    Storage Conditions Store below 25°C in a dry place; keep in original packaging
    Manufacturer Le Vet B.V.

    As an accredited Covinax 625-78 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.

    Packing & Storage
    Packing Covinax 625-78 is supplied in 25 kg sealed drums with tamper-evident lids, hazard labeling, and secure documentation for safe handling.
    Container Loading (20′ FCL) The chemical Covinax 625-78 is loaded into a 20′ FCL on pallets, secured with dunnage, and properly labeled for safe transport.
    Shipping For shipping Covinax 625-78, use properly sealed, compatible containers with clear hazard labels. Follow the Safety Data Sheet and applicable dangerous goods regulations; avoid moisture, heat, and incompatible materials. If classified as hazardous, determine the UN number, packing group, and transport category from full chemical characterization.
    Storage Store Covinax 625-78 in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and moisture. Keep the container tightly sealed when not in use to prevent contamination or degradation. Avoid contact with incompatible materials such as strong oxidizers. Follow manufacturer guidelines and local regulations for safe handling and shelf-life management.
    Shelf Life Shelf life is typically 12 months from manufacture when stored unopened under recommended conditions; always verify label.
    Application of Covinax 625-78
    Covinax 625-78 is formulated into cold-set aqueous adhesives for case erecting, carton side-seaming, and tray forming on recycled and high-recycled-content board. On production lines that use timed-nozzle extruders, wheel-pot applicators, or stencil gluers at 60–120 cycles/min, the compounded adhesive is held at 20–35 °C and adjusted with process water to a Brookfield RVT viscosity of 800–1,500 mPa·s at 20 rpm and 25 °C. At these conditions, nozzle orifice diameters of 0.3–0.8 mm and application pressures of 0.2–0.5 MPa produce uniform bead placement without tailing or wheel slinging. Board porosity controls open time: for recycled linerboard with a Cobb60 water absorption value above 35 g/m² per TAPPI T 441, usable open time is commonly 1–2 s, whereas clay-coated board with Cobb60 below 20 g/m² may require 3–5 s compression dwell. Compression section pressure is kept at 0.05–0.2 MPa to avoid crushing flutes. The dry binder backbone in such formulations is often 100 parts of Covinax 625-78 plus 5–15 parts of rosin ester dispersion as tackifier, 0.5–2 parts of an associative polyurethane thickener, and 0.1–0.3 parts of mineral-oil-free defoamer; polyvinyl alcohol may be added at 1–3 parts to increase wet tack and fibre-tear development. If viscosity drops below 600 mPa·s, sling and misting are observed on wheel-pot equipment; if viscosity exceeds 2,500 mPa·s, stencil pattern transfer becomes incomplete and dried adhesive build-up appears on plate edges. Typical end articles include frozen-food cartons, beverage carrier trays, and lock-flap display trays. When the sealed package is intended for food, the compounded adhesive falls under FDA 21 CFR 175.105 as an adhesive used for incidental food contact; if the package surface itself is paper or paperboard, components must also be selected against 21 CFR 176.170(a)(5) for aqueous and fatty foods.

    Why does T-peel adhesion drop when laminated film-to-paper speeds exceed 120 m/min?

    The limiting factor is not dry bond strength but water transport into the paper sheet. At line speeds above 120 m/min, a roller-applied wet film of 25–35 µm has between 0.5 s and 1.0 s from transfer to nip; water cannot adequately wet clay-coated stock, and the adhesive dries as a disrupted film that fails at the coating interface instead of giving fibre tear. Covinax 625-78 is therefore let down to 50–60% solids and compounded with 2–5 dry parts of fully hydrolysed PVOH solution; final viscosity is adjusted to 400–800 mPa·s for roller or gravure application. Film pretreatment is controlled before nipping: corona-treated polyethylene or polypropylene must show wetting tension of at least 38 mN/m per ASTM D2578. Lower surface energy produces adhesive dewetting, silvering, and non-uniform coat-weight distribution across the web. Nip pressure is set at 0.2–0.5 MPa, and the laminated web is cured at 25–35 °C under moderate humidity before slitting. Cured bonds tested by ISO 11339:2018 T-peel method at 300 mm/min commonly show fibre-tear failure on uncoated paper and peel forces in the range of 150–300 N/m, depending on coat weight and paper direction. When the laminate is intended for food packaging, the film component must comply with 21 CFR 177.1520 for olefin polymers, and the adhesive must not penetrate through the paper to the food-contact surface unless the full structure is evaluated under 21 CFR 176.170. Failure modes on production lines include strike-through when viscosity is below 400 mPa·s, tunnelling when film tension is too low or corona treatment is below 36 mN/m, and delamination at high line speed when open time is less than the paper's water-uptake time.

    End-use scenarioStandard or regulationTest condition / clause
    Carton sealing for incidental food contactFDA 21 CFR 175.105Adhesive is separated from food by a functional barrier; components selected for low migration
    Paper and paperboard food-contact surfaceFDA 21 CFR 176.170(a)(5)Aqueous and fatty food types; extraction testing according to exposure conditions
    Film-to-paper lamination wetting tensionASTM D2578Corona-treated film target ≥ 38 mN/m before nip
    T-peel adhesion for flexible laminatesISO 11339:2018Peel rate 300 mm/min, specimen width 25 mm
    Wood adhesion classificationDIN EN 204/205D2 cold-water resistance when crosslinked; D1 dry interior
    Automotive trim volatile emissionsVDA 278Thermodesorption of VOC and FOG; values depend on assembled trim

    Profile Wrapping Adhesive Penetration Control on MDF and Particleboard Surfaces

    Profile wrapping and membrane pressing apply Covinax 625-78 to MDF or particleboard at 60–100 g/m² by roller coater or air-assisted spray. The PVC membrane is preheated to 70–90 °C, and the press or wrapping station operates at 0.2–0.5 MPa for 60–180 s. Filler addition is limited: 5–10 parts calcium carbonate per 100 parts dispersion improves film uniformity on coarse particleboard, but loadings above 15 parts produce visible telegraphing through thin PVC films. The adhesive is thickened with 0.1–0.5 parts of an alkali-swellable associative thickener so that the wet film does not soak into board with density below 650 kg/m³. For moisture resistance, 3–5 wt% of a water-emulsifiable aliphatic polyisocyanate crosslinker is added immediately before use; the resulting mixed adhesive has a pot life of 4–8 h at 25 °C and achieves DIN EN 204/205 D2 cold-water resistance at 2 h soaking. Uncured adhesive without crosslinker is generally limited to interior dry-service trim and is not recommended for continuous humidity above 65% RH. Production failure modes include spring-back of the membrane when press time is below 50 s, edge whitening of the PVC when oven temperature exceeds 95 °C, and irregular profile adhesion when the roller coater gap is not adjusted for board thickness variation greater than ±0.2 mm. The end products are cabinet door fronts, furniture edge profiles, and wrapped picture-frame mouldings.

    Perfect-bound stationery and case-bound book lines use Covinax 625-78 in cold side-gluing, endpaper tipping, and hinge reinforcement because the dispersion remains flexible at low temperatures and does not require heated application pots. The adhesive is thickened to 4,000–8,000 mPa·s with methylcellulose or a high-solids associative thickener to prevent penetration through open book paper and to maintain a convex film on the spine. On casing-in lines, nip pressures of 0.03–0.15 MPa and cover dwell below 5 s are sufficient for uncoated cover stock; for polypropylene-laminated covers, 2–5 dry parts of a carboxylated acrylic resin are added to raise interfacial adhesion. The end products are stapled or perfect-bound softcover books, laminated hardcover cases, and tear-out notepad blocks. If the bound product is a children's notebook or stationery article, compliance with REACH Annex XVII and EN 71-3 migration limits for heavy metals in the adhesive film is typically required; aqueous systems based on Covinax 625-78 can be formulated to meet these limits because plasticisers and heavy-metal stabilisers are not necessary.

    When polyester fabric is laminated to polyurethane foam in mattress and automotive trim lines

    Replacement of solvent-based polychloroprene with Covinax 625-78 in foam-to-fabric lamination changes wetting, drying, and pot-life control. Polyester fabric must have a surface energy above 40 mN/m; if not, the adhesive is modified with 0.3–0.8 parts of a non-ionic ethoxylated acetylenic diol surfactant, and the fabric may be pre-moistened to reduce hydrophobic dewetting. Typical compounded adhesive at 50–60% solids is applied by air-assisted spray or roll coater at 40–80 g/m² wet add-on. The lamination nip is held at 0.1–0.3 MPa; forced-air drying at 60–80 °C for 30–60 s is required before stacking. At relative humidity above 70%, pre-drying of the fabric and reduced line speed are necessary because residual moisture in the bond line causes foam collapse and delayed delamination under load. Bonded assemblies tested by ISO 11339:2018 at 300 mm/min normally show substrate failure in the foam if the adhesive film is fully coalesced; if peel failure occurs at the fabric-adhesive interface before full cure, curing time of 24–48 h at 20–25 °C is required before final judgement. When wash resistance or moist-heat performance is specified, 0.5–1.0 wt% of an aziridine crosslinker may be post-added; the pot life under continuous mixing is then 6–8 h, and the use of ammonia is discontinued because amine species deactivate the crosslinker. End uses include mattress border panels, automotive seat backings, and acoustic headliner laminates. For automotive interior trim, assembled parts are tested for VOC and FOG emissions under VDA 278; mattress applications may also be assessed under OEKO-TEX Standard 100 Annex 4 limits. Published controlled test data for Covinax 625-78 in this exact configuration is limited, so line-specific validation is performed on the actual foam and fabric lot before full production.

    Covinax 625-78 also serves as a saturated binder for cellulosic airlaid nonwovens used in absorbent wipes and tabletop mats. The dispersion is diluted to 8–12% solids for spray or foam application; curing at 120–130 °C for 2–3 min produces a crosslinkable film when combined with 1–2% of an ammonium zirconium carbonate catalyst. In this application, tensile strength of the nonwoven is measured by ISO 9073-3:1989; wet strength retention below 50% of dry tensile indicates insufficient curing or low crosslinker level.In heat-seal lidding applications, Covinax 625-78 is applied as a waterborne heat-seal coating on aluminium-lidding paper where the seal is activated at 120–140 °C and 0.2–0.4 MPa for 0.5–1.0 s. The dry coat weight is 4–8 g/m²; peel seal strength above 300 N/m on PET or PP cups is verified by ASTM F88/F88M-21. Compliance for dairy lidding requires 21 CFR 175.300 when the coating is separated from the food by foil.
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    Certification & Compliance
    More Introduction
    Covinax 625-78 is an aqueous surfactant-stabilized vinyl acrylic copolymer dispersion supplied for waterborne pressure-sensitive adhesive compounding. The product designation identifies a specific manufacturing variant within the Covinax range and is typically formulated into adhesives for coated paper labels, film facestocks, splicing tapes, and graphic mounting films. Manufacturer-published typical values place nonvolatile matter at 55.0 ± 1.0 wt%, pH at 4.5–5.5, Brookfield RVT viscosity at 1,000–2,500 mPa·s at 25°C, and glass transition temperature at −25°C. The anionic dispersion is delivered at acidic pH, requiring handling in stainless steel, high-density polyethylene, or epoxy-lined vessels; prolonged contact with carbon steel or unlined aluminium can generate destabilizing polyvalent metal ions.
    ParameterTypical published valueTest method
    Nonvolatile content55.0 ± 1.0 wt%ISO 3251
    pH4.5–5.5ASTM E70 / ISO 976
    Brookfield viscosity1,000–2,500 mPa·sISO 2555 / ASTM D2196
    Glass transition temperature−25°CASTM D3418
    Density1.05–1.10 g/cm³ASTM D1475
    Storage temperature5–35°CInternal stability protocol
    Because the product is film-forming at room temperature without external plasticizer, the minimum film formation temperature is below 20°C; however, drying kinetics on non-porous polyester and polypropylene facestocks remain slower than solventborne systems because water evaporation is limited by the wet-bulb depression in oven zones. The dispersion is suitable for compounding with rosin ester and hydrogenated hydrocarbon tackifier dispersions at pH above 4.0. High-acid tackifier dispersions should be added slowly under mild agitation to prevent shock-induced grit. Preservative packages must be checked for anionic compatibility; quaternary ammonium compounds and multivalent cationic wetting agents can reduce zeta potential and increase filtration pressure.

    When Direct Coating Replaces Solvent Casting on Silicone Release Liners

    In direct coating, the compounded adhesive is applied to a silicone-coated release liner, dried, and laminated to the facestock. This sequence differs from transfer coating, where the adhesive is first coated on the carrier. Covinax 625-78 requires re-wetting of the dried film surface when transfer lamination is selected; wet lamination before the final drying zone is preferred for high film clarity on clear polyester overlays. On a reverse gravure or comma coater equipped with a 150 µm wet gap, dry adhesive coat weights of 20–30 g/m² are typical for permanent paper labels. Lower coat weights below 15 g/m² are possible on polyester label facestocks, but continuous film formation depends on oven relative humidity and web temperature. Coating head residence time must be limited when the adhesive contains shear-thinning thickeners; prolonged recirculation through gear pumps can reduce Brookfield viscosity and shift wet-film thickness.

    Substrates with surface energy below 38 dyn/cm require in-line corona or atmospheric plasma treatment immediately before coating. Untreated polyethylene film permits de-wetting that appears as reticulated adhesive, which reduces peel adhesion by more than 30% under ASTM D3330/D3330M test conditions versus a properly treated substrate. Silicone release liners should be checked for extractable silicone migration; high-release premium liners may transfer silicone at drying temperatures above 100°C, producing low surface energy domains on the adhesive surface that reduce loop tack measured by ASTM D6195.

    What Limits Drying Capacity at 90°C in a Three-Zone Air Impingement Oven?

    Drying of an aqueous acrylic dispersion is not governed by solvent evaporation alone; it also involves coalescence of polymer particles and removal of water trapped within the capillary structure of coated paper. A three-zone air impingement oven configured with nozzle velocity of 15–25 m/s and zone temperatures of 70°C, 85°C, and 95°C can dry a 24 g/m² wet film on a 50 µm polyester carrier at line speeds from 40 to 70 m/min, depending on web tension and exhaust dew point. Residual moisture above 2.0 wt% in the dried adhesive is a critical defect threshold: microfoam becomes entrapped when the web exits the oven and is laminated with a hot nip. Moisture content should be verified at the reel edge and centre with a Karl Fischer or near-infrared gauge, not inferred from surface tack alone. Published data for this specific three-zone configuration is limited; the values given are production-scale reference ranges rather than universal limits.

    When line speed exceeds the drying capacity, the dry film develops a skin layer while the core remains water-laden. Later release of moisture at the film interface creates blisters and tunnelling on clear facestocks. Increasing oven air temperature above 100°C is not a reliable remedy because the polymer surface can crosslink or yellow in the presence of residual amine stabilizers; conversely, air dew point above 15°C suppresses the water vapour partial-pressure gradient and causes adhesive haze in thick film sections. Process windows for this dispersion are therefore defined by residual moisture, not solely by oven exit web temperature.

    Rheology modification of Covinax 625-78 follows waterborne adhesive practice. Alkali-swellable acrylic thickeners are added as pre-neutralized dispersions at 2–4 wt% active; associative urethane thickeners can be used when high-shear viscosity must be maintained through slot-die lips. The emulsion tolerates pH adjustment with ammonia or sodium bicarbonate, but pH excursions above 8.5 increase residual odor and may reduce crosslinker pot life. Polyfunctional aziridines, when used, are blended after pH adjustment and must be monitored for gel time under ASTM D2471; the addition of aziridine at 0.2–0.5 wt% on adhesive solids raises shear resistance but shortens usable coating life to 8–24 h at 25°C. Combining Covinax 625-78 with amine-functional adhesion promoters interrupts the crosslinking mechanism and may retain water sensitivity; such combinations should be excluded unless a separate surface primer is applied.

    Shear Adhesion Failure Time, Tackifier Dispersions, and Brookfield Rheology

    Static shear adhesion of a compounded Covinax 625-78 film is commonly measured by ASTM D3654/D3654M using a 25 mm × 25 mm bond area and a 1 kg applied mass at 70°C or 23°C. The unreinforced polymer typically exhibits cohesive-failure times below 10 h at 70°C; adding a hydrogenated hydrocarbon tackifier dispersion at 10–20 wt% on polymer solids increases room-temperature shear holding to more than 24 h for paper label constructions. Higher tackifier loadings, above 25 wt%, can depress shear performance and increase adhesive transfer to stainless steel panels after 24 h dwell. The optimum tackifier grade must be selected by differential scanning calorimetry and loop tack rather than by solids cost alone; a low-molecular-weight rosin ester with acid number above 12 may require pH buffering to avoid local coagulation in the acidic emulsion.

    Brookfield rheology after formulation is shear-thinning but Newtonian in the low-shear range. Typical coating formulations are adjusted to 2,500–4,500 mPa·s at 20 rpm for comma coating, and 800–1,500 mPa·s at 1,000 s⁻¹ for slot-die application. Viscosity drift after 24 h of recirculation should not exceed ±10%; larger drift indicates particle destabilization or associative thickener incompatibility. Filtration through a 250 µm bag before the coating head is sufficient for most gravure and comma operations; slot-die lines require two-stage filtration at 150 µm and 75 µm because die lips above 1.5 m width are sensitive to microgel deposits.

    Differences from solventborne acrylic and hot-melt systems become most visible in converting equipment and substrate tolerance. Solvent acrylic pressure-sensitive adhesive can be applied directly to untreated films and dries at high line speeds because the solvent wetting envelope is broader and the heat load per gram of dry adhesive is lower; however, it requires explosion-proof coaters, regenerative thermal oxidizers, and VOC controls under Directive 2010/75/EU and EPA Method 24. Hot-melt styrenic block copolymer pressure-sensitive adhesives require slot-die application at 150–180°C and achieve immediate adhesion without drying, but they have lower heat resistance and higher viscosity at point of application, and they cannot be cleaned with water. Covinax 625-78 is positioned between these systems: it requires a drying oven and surface treatment but avoids hot-melt thermal degradation and solvent emission controls. Compared with other waterborne vinyl acrylic dispersions, the higher hydrophobicity of the 625-78 variant reduces water whitening after 24 h immersion; however, published immersion data for this specific configuration is limited, and all formulations intended for moisture exposure must be crosslinked. Regulatory documentation for Covinax 625-78 is supplied with each batch. The dispersion is manufactured under a quality system that supports REACH registration and EU Ecolabel criteria for water-based adhesives; relevant test data include ASTM D3960 volatile organic compound content, ASTM D1490 for nonvolatile matter, and ASTM D2196 for Brookfield viscosity. Food-contact suitability is not intrinsic to the polymer and must be confirmed on the finished adhesive under FDA 21 CFR 175.105 or 176.170 conditions relevant to the intended substrate and additive package. The product is not recommended for use in potable-water contact laminates or biomedical skin adhesion without additional toxicological qualification. Stability at shelf storage is generally 12 months in unopened containers held at 5–35°C; repeated freeze-thaw cycling is not tolerated, and containers must not be exposed to temperatures below 0°C because particle-size growth will increase viscosity and reduce coating uniformity. Outdoor weathering and UV resistance are functions of the formulated adhesive and facestock laminate. The dispersion itself is not ultraviolet-stabilized; prolonged UV exposure can reduce peel adhesion and cause edge yellowing if aromatic tackifiers are used. For window-film and outdoor graphic applications, a hindered amine-light-stabilized overlaminate or UV absorber package should be qualified under ASTM G154 or ISO 4892-3, and adhesion retention should be monitored under ASTM D3330 after accelerated weathering. The 625-78 polymer can be compounded with light-stable aliphatic tackifier dispersions to delay yellowing, but the wet-out of such tackifiers on low-energy facestocks may require additional nonionic wetting agent at 0.1–0.3 wt% on total formulation.