Paper bio-dry-strength agents

01Overview and value chain

Markers: [EC: EU PPWR / Effluent Guidelines | OECD: Industrial biotechnology | Regulator: EPA (USA), REACH (EU)]

Paper bio-dry-strength agents are wet-end and surface additives of biological origin — modified starches, carboxymethyl cellulose and other cellulosic polymers, refining enzymes and biopolymer resins — dosed at 0.5–2% on dry fiber to rebuild the hydrogen-bond network that gives paper its tensile, burst and short-span compressive strength. They are the structural answer to two pressures on the industry at once: the collapse of fresh-fiber quality as recycled content rises toward 100% in containerboard and tissue, and the regulatory and brand-driven drive to replace fossil, non-biodegradable polyacrylamide (PAM) dry-strength resins. A well-tuned bio-starch program lifts tensile and short-span compressive strength by 20–40% and lets a mill raise filler or recycled-fiber loading by 5–15 percentage points without losing runnability, while enzymatic refining pre-treatment cuts refining energy by 15–30%.

Key directions of paper bio-dry-strength agents:

1. Cationic & thermally modified starch (Cationic/Thermally Modified Starch): the dominant bio-based DSA, cooked and dosed at the wet end or size press to add 20–40% tensile on recycled liner.
2. Cellulosic polymers & nanocellulose (Cellulosic Polymers/Nanocellulose): CMC, micro- and nano-fibrillated cellulose that form bond-bridges between fibers, raising Scott-bond and surface strength and enabling higher filler loadings.
3. Enzyme-assisted refining & strength (Enzyme-Assisted Refining): cellulase and amylase treatments that cut refining energy 15–30% while preserving fiber length, often layered with a starch program.
4. Biopolymer & biomass-balanced resins (Biopolymer/Biomass-Balanced Resins): chitosan, guar, alginate and biomass-balanced strength resins that displace fossil PAM and are fully compatible with the paper-recycling loop.

Sectoral value chain

[starch/biomass] ──> [modification] ──> [wet-end dosing] ──> [sheet forming]
                          │                                         │
                  (cook / enzyme)                           (press + dry)
                          │                                         │
                          ▼                                         ▼
[strength-tested paper] <─── [strength development] <───── [recycle loop]

Value chain levels

Cross-cutting technologies of the sector:

• Jet-cook & on-site starch preparation (Jet-Cook Starch Prep): continuous starch cooking for stable wet-end viscosity.
• Enzymatic refining control (Enzymatic Refining Control): cellulase dosing tuned to freeness targets.
• Real-time wet-end sensors (Real-Time Wet-End Sensors): charge, retention and strength feedback for closed-loop DSA dosing.

02US

The US concentrates strength-chemistry innovation in the large recycled-containerboard and tissue sectors, where bio-based starch programs are the default route to strength on 100% recycled furnish.

recycled containerboard, tissue strength, enzymatic refining

• Solenis BioBond & Dry Strength Program: renewable starch-based strength programs documented to raise containerboard quality on low-grade recycled furnish.
• Buckman Smarter Strength: enzyme-plus-digital program layering Ackumen ECHOWISE Pro real-time sensing with targeted enzymatic and starch dosing.
• Effluent Guidelines & TSCA: EPA regulation of wet-end chemical discharges drives the shift away from residual acrylamide monomer toward starch and biopolymer DSAs.

03CN

China is both the largest paper and board producer and the fastest-growing market for bio-based strength additives, with domestic biomass-chemistry players supplying modified starch and furan/biomass-platform strength resins to the recycled-packaging sector.

recycled packaging, biomass-platform chemistry, domestic supply

• Shandong Shengquan Group: biomass-platform supplier (listed SSE: 605589) producing biomass-based paper additives alongside its furfural and phenolic-resin lines.
• Market growth: Chinese market analyses list biomass and modified-starch dry-strength agents among the fastest-growing wet-end segments through 2032.
• MARA & GB standards: national standard framework for food-contact and industrial starch additives frames the modification chemistry permitted in paper-contact grades.

04EU

The EU leads on the regulatory pull — recyclability and fiber-based packaging substitution — that makes bio-based strength chemistry a strategic input for corrugated and containerboard.

recyclability mandate, biomass-balanced chemistry, starch supply

• Kemira FennoBond™ & biomass-balanced additives: Finnish chemistry house whose FennoBond dry-strength line (777E for tissue) sits alongside biomass-balanced wet- and dry-strength additives that cut fossil carbon in the strength program.
• Roquette STABILYS® thermally modified starch: dedicated paper-bioindustry starch portfolio for industrial strength applications.
• EU PPWR & REACH: the Packaging & Packaging Waste Regulation’s recyclability requirements and REACH chemical registration are the twin drivers displacing fossil PAM with starch and biopolymer DSAs.

05Leading companies and research institutes

06Tech stack and innovations

The bio-dry-strength stack is built on starch chemistry, enzymatic fiber conditioning and closed-loop wet-end control.

1. Cationic & thermally modified starch (Cationic/Thermally Modified Starch):
   • cooked at 90–95 °C and dosed at 0.5–2% on dry fiber to add 20–40% tensile.
   • case: Roquette STABILYS® A040 thermally modified starch for industrial paper-bioindustry strength.
2. Enzyme-assisted refining & strength (Enzyme-Assisted Refining):
   • cellulase and amylase treatment cuts refining energy 15–30% at target freeness.
   • case: Buckman Smarter Strength layering Ackumen ECHOWISE Pro sensing with targeted enzymes.
3. Biomass-balanced & biopolymer resins (Biomass-Balanced/Biopolymer Resins):
   • biomass-balanced and renewable-carbon strength resins displace fossil PAM.
   • case: Kemira FennoBond™ 777E and biomass-balanced strength additives; Solenis BioBond renewable starch program.

07Value chains and production pipelines

Industrial pipeline of a bio dry-strength program (TAPPI T 494 / ISO 1924)

┌───────────────────────────┐      ┌───────────────────────────┐
│ 1. Starch/biomass feed    │ ───> │ 2. Modification & cooking │
└───────────────────────────┘      └───────────────────────────┘
                                                  │
                                                  ▼
┌───────────────────────────┐      ┌───────────────────────────┐
│ 4. Sheet forming & press  │ <─── │ 3. Wet-end dosing         │
└───────────────────────────┘      └───────────────────────────┘
               │
               ▼
┌───────────────────────────┐      ┌───────────────────────────┐
│ 5. Drying & strength dev  │ ───> │ 6. Strength QC & effluent │
└───────────────────────────┘      └───────────────────────────┘

Stage 1: Starch/biomass feed

Corn, potato or tapioca starch and cellulosic side-streams are received as the bio-based feedstock for the strength additive.

Stage 2: Modification & cooking

Native starch is cationized or thermally modified (e.g. STABILYS® A040), or cellulosic polymer is refined to CMC/NFC, then jet-cooked to a stable wet-end viscosity.

Stage 3: Wet-end dosing

The bio-DSA is dosed at 0.5–2% on dry fiber to the stock, often with a refining enzyme, under real-time charge and retention sensing.

Stage 4: Sheet forming & press

The treated furnish is formed on a fourdrinier or former and wet-pressed; the modified starch is retained on the fibers to build the bonding network.

Stage 5: Drying & strength development

The web passes the drying cylinders and, where used, the size press for surface starch, developing the tensile, burst and short-span compressive strength.

Stage 6: Strength QC & effluent

Tensile (TAPPI T 494 / ISO 1924) and Scott-bond are verified, and the lower residual-acrylamide effluent is managed under EPA Effluent Guidelines and REACH.