The terms a plant engineer actually uses.

Working definitions, not textbook ones. We write them the way the people on shift talk about them.

BMA

Hydrolyzed protein set retarder, originally a Bayer trademark. Adsorbs onto growing dihydrate crystals; particularly effective with kettle-calcined stucco.

BNS

β-Naphthalene sulfonate. Polycondensate dispersant, electrostatic mechanism, lower cost than PCE.

Bound water

The 6.2 wt% of structural water held within the CaSO₄·2H₂O crystal, released only on calcination.

bwoc

By weight of cement — or in board service, by weight of stucco. Standard dosage convention.

Calcination

Thermal conversion of gypsum (CaSO₄·2H₂O) to hemihydrate (CaSO₄·½H₂O) and/or anhydrite, typically at 120–180 °C in a kettle or flash calciner.

DensGlass

Georgia-Pacific's paperless gypsum board family with fiberglass mat facing instead of paper.

Dihydrate

CaSO₄·2H₂O. The set form of gypsum, also the raw quarry mineral.

Edge dam

The lateral barrier at the forming station that constrains slurry to the board width.

FIBC

Flexible intermediate bulk container. The 1,000 kg 'big bag' used for dry chemical shipments.

Flash zone

First section of the board kiln, where high-temperature gas evaporates free water rapidly.

Fluidity cone

Truncated cone (typically ASTM C472 inspired) used to measure slurry spread as a flow proxy.

FSI

Foam Stability Index — internal Nordgyp lab method for characterizing foam half-life and density.

Hemihydrate

CaSO₄·½H₂O. The calcined intermediate that rehydrates to dihydrate when stucco is mixed with water.

Lignosulfonate

Wood-pulping by-product, used as a low-cost dispersant. Acts as a mild retarder; watch dosage on fire-rated boards.

PCE

Polycarboxylate ether. Comb-polymer dispersant with carboxylate backbone and PEG side chains; steric mechanism.

PMHS

Poly(methylhydrogensiloxane). The reactive silicone used in hydrophobic board cores; releases H₂ on grafting.

Set time

Time from end of mixing to a defined hardness threshold (Vicat needle penetration), conventionally split into initial and final set.

STMP

Sodium trimetaphosphate. Crosslinking agent for non-migratory starches in the gypsum core.

Stucco

Industry term for calcined gypsum, predominantly hemihydrate with controlled anhydrite content.

Type X

Fire-rated gypsum board per ASTM C1396, typically with chopped glass fiber and vermiculite for high-temperature core integrity.

VHI

Very High Inhibition (against water absorption). Type H per EN 520, < 5% absorption per ASTM C473.

Vicat

Penetration test apparatus used to determine initial and final set of cementitious materials, adapted for gypsum.