Foam Agents CTR-ISF-C / CTR-ISF-D / CTR-ISF-P — CENTOR Underground System Solutions

TBM Soil Conditioning · EPB Shield

IS Series Foam Agents

CTR-ISF-C · CTR-ISF-D · CTR-ISF-P

Three formulations of soil conditioning foam agent for EPB (Earth Pressure Balance) shield TBMs. Mixed and foamed through the machine's foaming device before injection into the cutterhead excavation chamber, where they condition the excavated soil to improve its flow characteristics through the screw conveyor and earth chamber.

All IS Series variants create temporary cohesion in the excavated material, reduce water permeability at the face, provide an air cushion to compensate for abrupt pressure changes, and improve overall muck rheology. The three variants differ in solid content and active chemistry to suit different ground types — from standard sandy clay through dispersive soils to cohesive or mixed-face conditions.

CTR-ISF-C — At a Glance

AppearanceColourless to pale yellow liquid

Density1.01–1.03 g/cm³

Solid Content13.5–15.1%

pH7.0–9.0

Mix Ratio1.5–5%

Expansion8–25×

Biodeg.>80% in 28 days

1.5–5%

Mixture Ratio

8–25×

Expansion Rate

30–120%

Injection Rate

* Usage parameters shown for CTR-ISF-C Standard. Consult our engineering team for CTR-ISF-D / CTR-ISF-P application parameters.

Variant Comparison

CTR-ISF-C vs CTR-ISF-D vs CTR-ISF-P

Property	CTR-ISF-CStandard	CTR-ISF-DDispersed	CTR-ISF-PPolymer
Appearance	Colourless to pale yellow transparent liquid	Colourless to pale yellow transparent liquid	Colourless to pale yellow transparent liquid
Density (g/cm³)	1.01–1.03	1.02–1.05	1.01–1.03
Solid Content	13.5–15.1%	19.4–21.4%	13.5–15.1%
pH	7.0–9.0	7.0–9.0	7.0–9.0
Solubility	Completely water soluble	Completely water soluble	Completely water soluble
Biodegradation (28 days)	>80%	—	—
Mix Ratio	1.5–5%	Contact us	Contact us
Expansion Rate	8–25×	Contact us	Contact us
Injection Rate	30–120%	Contact us	Contact us
Packaging	200 kg drum / 1,000 kg IBC	1,000 kg IBC	1,000 kg IBC
Ground Suitability	Wet to sandy clay	Dispersive soils	Cohesive / mixed face
Key Enhancement	Standard formulation	Higher solid content	Polymer-enhanced
GHS Hazard	H302 · H315 · H318 — see safety section	—	—

Variants

Individual Formulations

CTR-ISF-C

Standard Formulation

The standard soil conditioning foam for TBM use. Designed for wet to sandy clay soils, it creates temporary cohesion and reduces water permeability, providing an air cushion to compensate for face pressure changes. Suitable for the widest range of ground conditions.

Density1.01–1.03 g/cm³

Solid Content13.5–15.1%

pH7.0–9.0

Mix Ratio1.5–5%

Expansion8–25×

Injection Rate30–120%

StandardBiodegradable >80%Wet to sandy clayGHS H302/H315/H318

CTR-ISF-D

Dispersed — Higher Solids

A dispersed-type formulation with significantly higher solid content (19.4–21.4%) compared to CTR-ISF-C. Engineered for dispersive soil conditions where a more concentrated active chemistry is required to achieve stable foam conditioning in high-permeability or granular ground.

Density1.02–1.05 g/cm³

Solid Content19.4–21.4%

pH7.0–9.0

SolubilityCompletely water soluble

Packaging1,000 kg IBC

Dispersive soilsHigh solid contentWater soluble

CTR-ISF-P

Polymer-Enhanced

A polymer-enhanced formulation for cohesive or mixed-face ground conditions. The polymer additive system improves foam structure stability and soil integration performance, making it effective in sticky clays and mixed-face environments where standard foam may be less effective.

Density1.01–1.03 g/cm³

Solid Content13.5–15.1%

pH7.0–9.0

SolubilityCompletely water soluble

Packaging1,000 kg IBC

Polymer-enhancedCohesive / mixed faceWater soluble

Performance — All Variants

Key Benefits

Reduces clay adhesion & muck cake on cutterhead — foam injection prevents buildup of sticky material on disc cutters and scraper tools, reducing cleaning interventions and clogging risk.

Improves soil rheology — conditioned muck flows more uniformly through the screw conveyor, reducing torque peaks and equipment wear during extraction.

Reduces face permeability — air-entrained foam reduces the hydraulic conductivity of the excavated face, preventing groundwater inflow and improving face support stability.

Prevents soil consolidation — temporary cohesion created by foam prevents granular soils from consolidating in the earth chamber, avoiding plug formation and drive interruptions.

Improves face stability & EPB pressure control — foam compressibility provides buffering against sudden pressure changes at the face, improving EPB pressure regulation during ring building.

Non-toxic to environment (CTR-ISF-D & CTR-ISF-P) — biodegradable active agents minimise environmental impact. CTR-ISF-C is water soluble and biodegradable (>80% in 28 days) — handle with appropriate PPE.

Logistics

Packaging & Storage

Packaging Options

CTR-ISF-C: 200 kg drum or 1,000 kg IBC
CTR-ISF-D: 1,000 kg IBC
CTR-ISF-P: 1,000 kg IBC

Storage Conditions

Store at 5°C–35°C (CTR-ISF-C) or ambient (CTR-ISF-D / CTR-ISF-P)
Keep dry, away from direct sunlight
12-month shelf life from manufacture date (CTR-ISF-C)
Not regulated for transport (all variants)

CTR-ISF-C Safety Information

⚠ GHS Hazard Classification — CTR-ISF-C Only

CTR-ISF-C carries GHS hazard classifications.
Read before use.

CTR-ISF-C (Standard Foam Agent) is classified under the GHS system. CTR-ISF-D and CTR-ISF-P do not carry these classifications. All personnel handling CTR-ISF-C must read the full Safety Data Sheet and wear appropriate personal protective equipment before use.

DANGER

Hazard Statements (CTR-ISF-C)

H302 — Harmful if swallowed
H315 — Causes skin irritation
H318 — Causes serious eye damage

Required PPE — CTR-ISF-C

Safety goggles / face shield (eye protection)
Chemical-resistant gloves (hand protection)
Respiratory protection in enclosed spaces
Chemical-resistant protective clothing

Transport classification: CTR-ISF-C is not regulated for transport under ADR, IATA, or IMDG — no hazmat shipping requirements apply.

IS Series Foam Agents

IS Series Foam Agents

CTR-ISF-C vs CTR-ISF-D vs CTR-ISF-P

Individual Formulations

Key Benefits

Packaging & Storage

Related Products

Request Technical Guidance on Foam Selection