Sodium Silicate in the Paper & Packaging Industries

Applications of sodium silicate in paper and packaging: how “water glass” can change your line’s quality, speed, and economics

When sheet brightness fluctuates, downtime rises, and costs keep squeezing, you don’t always need risky, high-impact changes. A multi-functional additive like sodium silicate can help “steady the rhythm” of your line: cleaner deinking, more economical bleaching, stronger bonding, and more uniform coating.  Bavand Chemical Company is one of the sodium silicate manufacturers in Iran , by offering a wide range of grades (controlled moduli, 35–40% solids) and pilot support, makes reliable implementation on the production line much easier.

Applications of Sodium Silicate in the Paper Industry

What is sodium silicate, and why is it multi-functional?

Sodium silicate—whether as solid sodium silicate (flakes/powder) or liquid sodium silicate (aqueous solution)—is essentially an alkaline SiO₂/Na₂O system with an adjustable silica modulus.

• Higher modulus → a more stable silica network, both in liquid sodium silicate and in solutions prepared by dissolving solid sodium silicate in water.
• Lower modulus → higher alkalinity and reactivity, especially in concentrated liquid solutions.

That’s why liquid sodium silicate and solutions made from solid sodium silicate can act as a pH buffer, a dispersant, a peroxide stabilizer, and also a component in adhesive/coating formulations.

 Bavand Chemical supplies both solid and liquid forms of sodium silicate in grades with low interfering metals (controlled Fe/Cu) to preserve H₂O₂ stability during bleaching processes.

Key, practical applications

In each application below, we highlight roles and expected outcomes to make implementation clearer.

1) Deinking & peroxide bleaching of recycled pulp (Deinking & Peroxide Bleaching)

• Main roles: Alkalinity buffering (stable pH 10–11), stabilizing H₂O₂ against metal ions, dispersing ink to prevent re-deposition.
• Expected result: Higher brightness, optimized peroxide consumption, reduced foam and secondary contamination.
• Formulation notes: Start with 0.5–3% (based on dry pulp); recommended modulus 3.0–3.4.

 Bavand Chemical implementation suggestion: Use silicate together with a low-dose chelant and inject after alkali addition to maximize peroxide efficiency.

2) Stickies & pitch control (Stickies/Pitch Control)

• Problem: Latex/adhesive deposits on wire/felts/press → spots, roll breaks, sudden downtime.
• Silicate role: Controlled alkalinity + active dispersion → breaks down/emulsifies contaminants and reduces surface tack.
• Practical benefit: Cleaner machine, less scrap, improved sheet uniformity.

Practical note: Accurate dosing and conductivity monitoring prevent silica gel formation;  Bavand Chemical’s technical team calibrates injection points.

3) Starch & silicate adhesives (Starch & Silicate Adhesives)

• Corrugating: Adjusts set time and viscosity, improves wettability, increases dry/wet bond strength.
• Pure silicate adhesives (tubes/bags/fiber drums): Stable mineral bonding, VOC-free, repulpable.
• Starting guideline: 5–15% of 35–40% silicate solution in starch formulations (depending on rheology/temperature).
• Technical warning: Too much dosage → brittleness; balance with a low-dose plasticizer/latex.

 Bavand Chemical service: Laboratory tuning of the adhesive formulation based on local starch and your line conditions.

4) Coating & pigment dispersion (Coating/Dispersion)

• Roles: Disperses kaolin/calcium carbonate, improves coating uniformity, stabilizes suspensions.
• Target performance: Smoother surface, controlled opacity, mineral bonding after drying.
• Starting dose: 0.1–1% relative to pigment; monitor pH/EC.

Note: To avoid conductivity increase/gel risk, mixing temperature and order of addition should follow  Bavand Chemical instructions.

5) Water & effluent (Water & Effluent)

• Function: pH balancing, supports coagulation/flocculation, reduces FOG.
• Caution: Excess dosage → silica gel/precipitation; monitor soluble silica.

 Bavand Chemical approach: Continuous dosing design and online soluble-silica monitoring to maintain stable water quality.

Advantages

• ✅ Multi-purpose and economical: One material, several key functions → fewer additives and simpler control.
• ✅ Process and quality stability: Strong pH buffering → less variability in brightness/adhesion/foam and more predictable production.
• ✅ Improved bonding and strength: In adhesives, shorter set time, stronger bonding, potentially better ECT/RCT.
• ✅ Recycling- and environment-friendly: VOC-free; silicate adhesives are repulpable.
• ✅ Synergistic with peroxide: Greater H₂O₂ stability → cleaner bleaching and lower cost.
• ✅ Controls troublesome contaminants: Less stickies/pitch → cleaner machine and fewer stoppages.

If you aim to simultaneously improve brightness, machine cleanliness, interlayer bond strength, and coating uniformity, sodium silicate is a precise, scalable, and economical choice and with  Bavand Chemical’s stable supply and technical services, results come faster.

Compact application table (Use–Benefit–Risk–Dose)

Choosing the right grade and key parameters

• Silica modulus (SiO₂/Na₂O): Deinking/peroxide 3.0–3.4; adhesive/coating 2.2–3.2.
• Solution solids: Industrial 35–40% for stable dosing.
• Low interfering metals: Lower Fe/Cu → better H₂O₂ stability.
• Viscosity/pumpability: For continuous injection and uniform mixing.
• Documentation: SDS, CoA, TDS + batch traceability.

 Bavand Chemical provides CoA for each batch and advice on selecting the right modulus for each application.

Professional line implementation

• Mother tank with gentle agitation and a closed lid (prevents CO₂ pickup and gel formation).
• Continuous injection after alkali/peroxide addition using accurate flowmeters.
• Online monitoring: pH, conductivity, alkalinity, residual H₂O₂, soluble silica.
• Do/Don’t:
• Do: Dilute with soft/DM water; use a chelant during bleaching.
• Don’t: Mix directly with strong multivalent cations; operate at high temperatures (gel risk).

 Bavand Chemical’s team documents the dosing layout, dilution scenario, and optimal conductivity limits for your line.

Target unit: Corrugated carton production

Challenges: Long adhesive set time, delamination on the evening shift, high starch consumption, reduced ECT under humidity.
Solution: Redesign the starch adhesive with 10% of 38% silicate solution (modulus 3.1), set pH 10.8, adjust gelatinization temperature, add a low-dose plasticizer (per  Bavand Chemical’s recommended instructions).
6-week results:

• ↓ 7–9% starch consumption (direct savings)
• ↑ 3–5% line speed (shorter set time)
• ↑ 4–6% dry ECT and ↑ 3–5% wet ECT
• ↓ Delamination on the evening shift

With a targeted formula change aligned with  Bavand Chemical’s guidelines, multiple benefits were achieved at once: better economics + higher strength + smoother production rhythm.

Safety, environment, and storage notes

• Alkaline and corrosive: Alkali-resistant gloves, goggles/face shield, apron required.
• Skin/eye contact: Prolonged rinsing with water; refer to occupational health.
• Leaks/spills: Contain, dilute, controlled neutralization (with a weak acid).
• Storage & compatibility: Use compatible tanks; avoid contact with aluminum/zinc.
• Environmental: VOC-free; monitor soluble silica in effluent management.

Safety documents (SDS) and transport guidelines are available from  Bavand Chemical.

Purchasing checklist

• Modulus, solids content, low interfering metals in the CoA.
• Supplier reliability (lead time/capacity) and technical support (pilot/optimization).
• Automated dosing equipment, pH/EC sensors, operator training.
• Full documentation: SDS, TDS, CoA, batch traceability.

 Bavand Chemical provides industrial samples, in-line pilot trials, and scheduled operator training.

Final summary

By smartly implementing key applications and leveraging the standout advantages of sodium silicate from cleaner deinking to stronger bonding and more uniform coating—you can stabilize quality, reduce stoppages, and control costs.  Bavand Chemical’s support in grade selection, formulation, and monitoring makes the path faster and more reliable.

For specialized consultation, consumption/dosage estimation, and export price inquiry for  Bavand Chemical liquid or powdered sodium silicate, fill out the order form on the website or contact our sales department.