| HS Code | 362949 |
| Brand | Kuraray |
| Product Code | SPGO56-11 |
| Product Form | PVA binder staple fiber |
| Fiber Composition | Polyvinyl alcohol (PVA) |
| Fiber Length | 11 mm |
| Fiber Linear Density | 0.56 dtex |
| Fiber Color | White |
| Fiber Density | 1.26 g/cm³ |
| Fibrillation Characteristic | Readily fibrillated in water to create bridging fibrils |
| Bonding Characteristic | Hydrates in hot-water wet-laid process and bonds upon drying/curing |
| Thermal Characteristic | Softening behavior suitable for glass paper binder applications |
| Dispersibility | Disperses well in aqueous papermaking slurry |
| Glass Fiber Compatibility | Designed for effective cohesion with glass fibers in glass paper formation |
As an accredited Kuraray SPGO56-11-PVA Binder Fiber for Glass Paper factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Packaged in sealed, moisture-proof 25 kg bags to protect Kuraray SPGO56-11 PVA Binder Fiber for Glass Paper. |
| Container Loading (20′ FCL) | One 20′ FCL of Kuraray SPGO56-11 PVA Binder Fiber, palletized and secured, for use in glass paper manufacturing. |
| Shipping | Shipped as sealed, moisture-protected packages on pallets to preserve fiber integrity. Keep dry and avoid crushing during transit. Standard freight handling applies, with no special hazardous material requirements for this PVA binder fiber. Store in a cool, ventilated area away from direct sunlight. |
| Storage | Store in a cool, dry, well-ventilated area, away from direct sunlight, heat sources, and open flames. Keep the original sealed container intact to prevent moisture absorption and contamination. Maintain moderate humidity to avoid clumping or degradation. Ensure compatibility with local fire and chemical storage regulations. Use first-in, first-out inventory rotation. |
| Shelf Life | Store in original, dry packaging away from humidity. Shelf life is typically two years from manufacture. |
In dry-type transformer interlayer insulation, glass paper is used as a dielectric barrier and resin-holding interleaf between conductor windings. The wet-laid production of this glass paper is more strongly constrained by slitting edge integrity than by tensile strength alone. On an inclined-wire former running a furnish of 0.02–0.08 wt% glass microfibre and silane-sized chopped strand, Kuraray SPGO56-11 is metered as a dry fibre into the stock preparation chest before the headbox; binder addition below 8 wt% of dry furnish produces edge fibrillation during winder acceleration beyond 300 m/min, while addition above 15 wt% creates an organic-rich surface layer after through-air drying at 180–210 °C that resists subsequent epoxy impregnation and lowers dielectric performance after conditioning. Compliance testing for this application is structured around IEC 60243-1:2013 for electric strength and IEC 60085:2007 for thermal class documentation. The downstream process continues with two-roll calendering at 120–180 N/mm to a finished caliper of 0.15–0.35 mm, resin impregnation in a horizontal treater, B-staging, and die-cutting into layer insulation, slot liners, and phase barrier sheets for dry-type transformers. Field records from high-humidity plants indicate that the calendered sheet must enter the resin treater at 0.5–1.2% moisture; higher residual moisture in SPGO56-11-bonded paper causes bubble formation in the resin bath and coating skip on the backup roll.
The primary process conflict in CEM-3 glass paper production is the trade-off between wet-web tensile before impregnation and epoxy wet-out after vertical treater passage. SPGO56-11 is added at 6–10 wt% of dry solids in this application, with a practical upper inspection window of 12 wt% for qualification. When the binder fibre content moves above 12 wt%, epoxy wet-out time in low-viscosity brominated epoxy resin at 25 °C is observed to increase by 18–30 s in vertical tracer units, and post-press cross-sections show an increase in resin-starved interstices around the binder fibre junctions. Below 6 wt%, the dry glass paper fails to survive immersion in the treater at web tensions above 1.2 kN/m, and web breaks occur at the coating head. Compliance is assessed under IPC-4101 base-material specifications for CEM-3 composite laminate, with heat resistance checked by 288 °C solder float and flammability classified under UL 94 V-0. Downstream processing comprises wet-laid sheet formation on a Fourdrinier wire, through-air drying, pre-drying at 105–120 °C for 20–40 min when ambient relative humidity exceeds 60%, resin impregnation in a vertical epoxy treater with zone temperatures of 120 °C, 140 °C, and 160 °C, then layup with copper foil and press cure at 160–175 °C and 2.5–4.0 MPa. The terminal product is CEM-3 copper-clad laminate for printed circuit boards, used in appliance control modules, motor drives, and low-cost electronics requiring punchable laminates with moderate electrical properties. Because the binder fibre does not melt at normal CEM-3 press temperatures, it remains as a structural interposer during resin flow and prevents glass fibre washout at the sheet edges; this is the reason the grade is retained even where the resin system would alone supply final laminate strength.
Unlike electrical-grade glass paper, a surfacing veil for vinyl ester or unsaturated polyester corrosion liners is designed to wet out rapidly and disappear visually into the resin-rich layer. SPGO56-11 is used at a lower addition ratio of 5–8 wt% in this application; above 8 wt%, the binder fibre can remain as an undissolved white network in the cured resin, causing a defect known locally as “veil tracking” in filament-wound and hand-lay-up laminates. The governing material standard is ISO 3374:2000 for mass per unit area and binder content of glass-fibre mats, with compatibility testing conducted in styrene and vinyl ester resin baths at 20–25 °C for 120 s. Production of the veil on a dilute wet-laid former is followed by through-air drying at 150–180 °C and winding on 76 mm inner-diameter cores. Downstream, the veil is applied directly onto the gel coat or over the chop strand mat in FRP pipe, tank, and duct fabrication; the layup is then consolidated with serrated rollers and cured at ambient temperature or with post-cure at 80 °C. Terminal product types include filament-wound FRP piping for chemical plants, acid storage tanks, scrubber shells, and corrosion-resistant duct sections. The operational boundary in this sector is that SPGO56-11 should not be combined with amine-based additives in the gel coat because residual alkaline functionality can interfere with cobalt-promoted MEKP cure at the veil interface, producing a sticky interlayer after ambient moulding.
At the wet end of a HEPA/ULPA glass-fibre filter line, the binder system must survive rotary pleating without embrittlement and must not create a coarse fibre network that disturbs the submicrometre glass microfibre web. SPGO56-11 is metered at 5–10 wt% of the dry furnish; the lower bound is set by pleat retention after creping on a rotary pleater operating at 120–180 pleats/m, while the upper bound is imposed by air permeability loss measured across the formed sheet at 200 Pa differential pressure. Compliance follows EN 1822-1:2019 for HEPA and ULPA filter element classification and ISO 29463-1:2017 for terminology and classification of high-efficiency particulate air filters. The production sequence includes stock dispersion in deionized water with conductivity ≤ 10 µS/cm, inclined-wire formation, through-air drying at 160–190 °C, electrostatic-free winding, and subsequent pleating and potting into frames with polyurethane or ceramic adhesive. Terminal products are HEPA and ULPA filter elements for cleanrooms, biosafety cabinets, and hospital isolation suites. Published data for SPGO56-11 specifically in ULPA-grade webs with basis weights below 50 g/m² is limited; filter media producers typically qualify binder fibre lots by comparing strip tensile index after pleating and dust loading capacity under ISO 16890-1. Storage of the dried glass paper at relative humidity above 60% is known to produce soft pleat edges because the PVA binder absorbs moisture and loses dimensional stiffness before pleating; sealed moisture-barrier wrapping is therefore required for export shipments.
The lamination of glass paper to open-cell acoustic foam or mineral wool in automotive dash mats places an upper boundary on organic binder content because the facing is sealed behind an interior panel and contributes to cabin VOC emissions. SPGO56-11 addition in this sector is typically 10–18 wt%; below 10 wt%, the bond between the glass paper and a polyester acoustic mat fails during steam-jet de-molding at 120–140 °C, and above 18 wt%, hot-nip lamination on a belt press at 160–190 °C can cause the binder fibre to exude and deposit on the chrome-surfaced nip rolls, creating brown spots on the facing. Emission compliance is assessed under VDA 278:2011 for automotive interior VOC and fogging behaviour, with supplementary indoor-air testing under ISO 16000-3:2011; acoustic performance is tested under ISO 11654:1997 for weighted sound absorption coefficient. The downstream process includes wet-laid web formation, hot calender densification to 0.8–1.5 mm, inline slitting, adhesive coating, and belt-press lamination to a moulded acoustic substrate; die-cutting then yields dashboard insulators, under-hood absorption panels, and industrial duct liner facings. The operational boundary is that the glass paper facing must be conditioned to ≤ 0.5% moisture before hot-nip lamination to avoid steam blister delamination, a defect that appears only after the vehicle has experienced its first thermal cycle.
Competitive Kuraray SPGO56-11-PVA Binder Fiber for Glass Paper prices that fit your budget—flexible terms and customized quotes for every order.
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Kuraray SPGO56-11 is a polyvinyl alcohol (PVA) homopolymer staple binder fibre supplied for the wet-laid manufacture of glass paper and related inorganic-fibre nonwovens. The grade designation places the aqueous dissolution/softening onset at approximately 56 °C; the fibre remains discrete during furnish dispersion and then softens, dissolves, and forms bond points at glass fibre intersections when the wet web is heated in the dryer section. In glass paper furnishes, SPGO56-11 is normally added at 4–12 wt% of the dry furnish, with the optimum determined by target basis weight, air permeability, and tensile index. Published data for this specific configuration is limited; lot-specific values for fibre linear density, cut length, dissolution curve, and tensile properties should therefore be read from the certificate of analysis. Product-characterization methods relevant to the product envelope include ISO 1973/ASTM D1577 for linear density, ISO 6989/ASTM D5103 for staple length, ISO 5079/ASTM D3822 for dry tenacity and elongation, ASTM D2654 for moisture regain, ISO 3451 for ash content, and ISO 3071 for aqueous extract pH.
| Property | Reference method | Value / note |
|---|---|---|
| Fibre linear density | ISO 1973/ASTM D1577 | PVA binder fibre class commonly 1.1–2.2 dtex; SPGO56-11 lot certificate required |
| Cut length | ISO 6989/ASTM D5103 | Glass paper grades commonly 3–6 mm; lot-dependent |
| Dry tenacity | ISO 5079/ASTM D3822 | PVA staple fibres commonly 6–10 cN/dtex; SPGO56-11-specific data limited |
| Dry elongation at break | ISO 5079/ASTM D3822 | Commonly 15–25% for non-high-modulus PVA staple fibre |
| Aqueous dissolution onset | Controlled heating of 1% aqueous slurry at 1 °C/min | Grade designation indicates approximately 56 °C |
| Ash content | ISO 3451 | Typically below 0.5 wt% for glass paper binder grades; confirm by lot |
Wet-laid glass paper requires a furnish that inhibits glass microfiber agglomeration before sheet formation. SPGO56-11 is introduced into the pulper after glass fibre dispersion, and the stock is diluted to a headbox consistency of 0.01–0.05 wt%. The forming fabric on an inclined wire or cylinder mould delivers basis weights between 20 g/m² and 120 g/m² in commercial glass paper grades, measured by ISO 536. Vacuum dewatering is maintained below 0.3 bar differential pressure to avoid binder-fibre loss through the wire; binder retention in the sheet is typically verified by loss on ignition at 525 °C according to ISO 2144 or TAPPI T 413, with the residual ash representing glass fibre. The wet web enters the dryer at a moisture content of 60–70 wt%. During the initial drying zone, the sheet temperature must be brought above 56 °C while free moisture is still present; otherwise the PVA fibre cannot flow into glass fibre intersections and the sheet remains delaminated.
Binder distribution is controlled more by fibre dispersion than by resin diffusion. On production-scale inclined-wire formers, binder-rich streaks are a documented failure mode when the approach-flow velocity falls below the threshold needed to prevent fibre re-flocculation; a minimum stock velocity of 0.3 m/s in the headbox approach pipe is commonly maintained. A forming fabric with a mesh count of 30–40 wires/cm improves retention of 4–6 mm PVA staple fibre but increases drainage resistance; the jet-to-wire speed ratio is typically held at 0.95–1.0 to minimise orientation anisotropy. When the forming section is operated with vacuum suction above 0.4 bar, PVA fibre loss increases and the retained binder content in the sheet can fall below the intended value by 1–2 wt%.
The stock preparation line for glass paper typically uses a low-shear pulper fitted with a rotor speed below 300 rpm; high-shear dispersion above 500 rpm can break PVA staple fibres and generate fines that pass through the forming wire. After pulping, the stock is passed through a vibrating screen with slot width 0.3–0.5 mm to remove undispersed fibre bundles. This screening step is critical because PVA fibres that have been wetted but not dispersed can survive the fan pump and appear as translucent defects in the final sheet. The approach flow system is operated at total pressure below 2.5 bar to prevent shear-induced flocculation; retention is adjusted with a nonionic or weakly cationic flocculant at 0.005–0.02 wt% on dry furnish.
Powdered PVA binders require either dry blending with glass fibre or pre-dissolution in hot water before the headbox. Pre-dissolved PVA at 4% solids typically produces solution viscosities in the range 50–200 mPa·s at 25 °C depending on molecular weight; introducing this solution into a headbox at 0.01–0.05 wt% stock consistency can raise approach-system viscosity and disturb fibre dispersion. SPGO56-11 avoids that viscosity contribution because the PVA remains particulate until the dryer, where the sheet is already formed. In thermoset-bonded glass paper, phenolic resin cure at 130–180 °C produces a crosslinked bond network with wet strength retention often above 50%. By contrast, the PVA binder fibre forms a thermoplastic bond point that re-softens under high humidity. Dry tensile index of PVA-bonded glass paper at 8 wt% binder addition is commonly reported in the range 10–30 N·m/g under ISO 1924-3; after 24 h immersion, wet tensile index declines to 2–8 N·m/g unless a crosslinking agent is co-added. These ranges are for PVA binder fibres as a class; published data for SPGO56-11 specifically is limited. Formaldehyde emission is not intrinsic to PVA, and formaldehyde content in the bonded sheet can be assessed by ISO 14184-1 if regulatory testing is required.
| Binder system | Activation condition | Bond type | Wet strength retention | Formaldehyde |
|---|---|---|---|---|
| SPGO56-11 PVA binder fibre | ~56 °C dissolution/softening | Thermoplastic | Low unless crosslinked | Not a formaldehyde-based system |
| Powdered PVA | Pre-dissolution at 80–95 °C | Thermoplastic film | Low unless crosslinked | Not formaldehyde-based |
| Phenolic resin | 130–180 °C cure | Thermoset | Higher | Requires emission control |
| Acrylic latex | Film formation at 20–100 °C | Thermoplastic or crosslinked | Moderate | Possible from some grades |
Addition above 12 wt% creates a property cliff-edge. The binder phase can fill interfibre voids, increase sheet density, and reduce air permeability. For 30 g/m² glass paper, air permeability measured under ISO 5636-3 may fall from approximately 500 mL/min to below 200 mL/min as binder addition increases from 8 wt% to 15 wt%; these values are indicative and not grade-specific to SPGO56-11. At addition levels above 12 wt%, dissolved PVA may migrate to the paper surface during drying and form a continuous skin. That skin restricts water vapour transmission in the later dryer zones and can cause reel blocking on drum dryers. The corrective action is to reduce initial dryer surface temperature to 80–90 °C and increase drying dwell time by 20–30% so that water escapes before the binder film seals the surface. If the same formulation is run on a through-air dryer, air temperature should be kept at 110–120 °C until the sheet moisture content falls below 10 wt%; higher air temperatures can set the surface skin before the core bonds.
In a production-scale inclined wire line, binder addition above 12 wt% also increases felt contamination risk after wet pressing. At press linear loads above 60 kN/m, PVA that has softened during the early dryer stages can be squeezed into the felt, where it dries and reduces felt permeability. Felt cleaning cycles under permeability monitoring based on ISO 5636-3 typically require more frequent chemical wash cycles when the binder content exceeds 12 wt%. A second cliff-edge appears in thin sheets below 25 g/m². The low number of glass fibre intersections limits the number of available bond points, so binder addition above 10 wt% increases stiffness without proportional tensile improvement. Bending stiffness measured by ISO 2493-1 may increase by 30–50% when binder addition is raised from 8 wt% to 15 wt% in thin glass paper; the gain in tensile index is smaller.
The processing window is narrow. Dissolution begins at 56 °C, but if the web reaches this temperature too early, binder migration to the sheet surface increases. If the web remains below 56 °C until the moisture content drops below 5 wt%, the fibre cannot dissolve and bonding is incomplete. In multi-drum dryer sections, a staged surface-temperature profile of 80 °C, 100 °C, and 120 °C across the first three cylinders is common for grades below 80 g/m². Final sheet moisture content of 1–3 wt%, measured after conditioning under ISO 287, prevents bond-point embrittlement. Decomposition of PVA in air begins above 200 °C, so dryer surface temperatures above 180 °C should be avoided even in the final drying zones. In through-air dryers, the supply air temperature may be set at 110–130 °C because the sheet temperature remains near the wet-bulb temperature until free water is removed.
If the furnish contains cationic retention aid residues, the dissolution temperature of PVA can be affected only mildly; however, borate ions introduced from recycled water or from pigments can crosslink the 1,3-diol units of PVA and shift the observed dissolution onset upward beyond the dryer capability. Strong mineral acids promote PVA hydrolysis and discolouration. Therefore, the wet-end pH is normally maintained between 6.0 and 7.5, measured by ISO 6588, and recycled white water is monitored for boron. These operational boundaries should be confirmed by pilot-scale trials on the intended machine configuration.
PVA fibre absorbs atmospheric moisture. Storage at relative humidity above 60% increases fibre moisture content and can shift the observed dissolution onset downward because water plasticises the PVA phase. Fibre conditioned at 23 °C and 65% RH according to ISO 139 may reach an equilibrium moisture regain of 4–5 wt%; above 7 wt% moisture, the fibre bundles become tacky and do not disperse uniformly in the pulper. Pre-drying at 50–60 °C for 2 h in a through-circulation tray dryer is recommended when the incoming fibre moisture exceeds 7 wt%. Damp fibre fed into the pulper produces binder-rich aggregates in the formed sheet; these aggregates are visible as translucent spots after drying and cannot be redispersed once the web has passed through the press section.
In addition, SPGO56-11 should not be premixed with powdered boric acid, borax, or strong mineral acids. Borate ions crosslink the 1,3-diol structure of PVA and raise the dissolution onset above typical glass paper dryer temperatures, leaving undissolved fibre bundles in the final sheet. If boron levels in the white water exceed 5 mg/L, determined by inductively coupled plasma optical emission spectrometry, the dissolution temperature should be re-verified with a controlled heating test because the grade designation assumes a borate-free aqueous environment.
For sheet certification, dry tensile index is determined by ISO 1924-3, air permeability by ISO 5636-3, and ash content by ISO 2144 or TAPPI T 413. A target air permeability of 200–800 mL/min for 30–60 g/m² glass paper is common; actual specifications are end-use-dependent. Binder distribution in the finished sheet can be assessed by examining a 10 µm cross-section under 200× transmitted light microscopy; a surface skin layer thicker than 10 µm indicates binder migration from excessive initial dryer temperature or over-addition. Because published data for SPGO56-11 in specific glass paper constructions is limited, pilot-scale verification on the intended machine configuration is required before production commitment.
