Polyurethane technical glossary

Technical glossary

Bilingual definitions of every term used across the portal — chemistry, process, regulatory and market.

2K / 3K / 4K 2K / 3K / 4K Process: Notation for number of reactive components in the system (2 components, 3 components, etc.).
Aftermixer Aftermixer Equipment: Mixing head accessory that generates back-pressure to improve mixing in high-density systems.
Back pressure Contrapressão Process: Pressão gerada no cabeçote para otimizar mistura.
Blowing agent Agente de expansão Chemistry: Substance that generates gas during foaming, either physical or chemical.
Bubble / blister Bolha Process: Surface defect of trapped air.
Bulk tank Tanque bulk Equipment: Larger-volume storage reservoir.
Carousel Carrossel Equipment: System similar to race track, with molds in circuit.
Casting / pouring Casting / vazamento Process: Deposition of reactive system into an open mold.
Catalyst Catalisador Chemistry: Substance that accelerates the reaction.
Cavity Cavidade Equipment: Internal space of the mold where the material solidifies.
Chain extender Extensor de cadeia Chemistry: Low-weight di-hydroxy or di-amine that modifies polymer structure.
Clamp / press Prensa / clamp Equipment: Device that applies closing force to the mold.
Class A surface Superfície classe A Equipment: High visual quality automotive finish.
Closed-loop control Malha fechada Equipment: Control with feedback and automatic parameter adjustment.
Conveyor Transportador Equipment: In-line continuous handling system.
Cooling channels Canais de refrigeração Equipment: Ducts embedded in the mold for circulation of water or oil for thermal control.
Core Macho Equipment: Mold part that forms internal cavities of the part.
Cream time Tempo de creme Process: Time to visible onset of reaction (mixture becoming opaque).
Day tank Tanque de alimentação Equipment: Operational component reservoir, fed from bulk storage.
Demold time Tempo de desmoldagem Process: Minimum time to remove the part from the mold without deformation.
Double-belt lamination Laminação dupla esteira Process: Continuous process to manufacture sandwich panels.
Draft angle Ângulo de saída Equipment: Wall inclination to allow demolding.
Electroformed nickel shell Níquel eletroformado Equipment: Thin-shell mold obtained by electrodeposition over a master pattern.
Exotherm Exotermia Process: Heat released by polymerization reaction.
Flame retardant(FR) Retardante de chama Chemistry: Additive to reduce flammability.
Flash Rebarba Process: Material extruded along the parting line.
Frothing Frothing Process: Pre-expansion of the reactive system with soluble gas before contact with the substrate.
Gasketing / FIPFG(FIPFG) Gasketing Process: Robotized application of *in-situ* foamed gaskets in electrical, automotive and other components.
Gate Ponto de injeção Equipment: Opening through which the reactive system enters the cavity.
Gating system Sistema de injeção Equipment: Set of runners and gates that direct the flow to the mold.
Gear pump Bomba de engrenagem Equipment: Positive-displacement pump used at low pressure.
Gel time Tempo de gel Process: Time until mixture reaches gel viscosity.
Heat exchanger Trocador de calor Equipment: Device for component temperature control.
High-pressure metering machine Dosadora de alta pressão Equipment: Machine that pumps components at 100–250 bar for impingement mixing.
Hot spot Ponto quente Process: Zone of localized overheating in part or mold.
Impeller Impelidor Equipment: Rotating element inside the mixing chamber of low-pressure mixing heads. Homogenizes streams by mechanical action at 6,000–21,000 rpm.
Impingement mixing head Cabeçote de impingement Equipment: High-pressure mixing head where mixing occurs by collision of reactive streams.
Insert Inserto Equipment: Pre-positioned component that becomes embedded in the molded part.
Isocyanate Isocianato Chemistry: Reactive component with NCO group.
L-head mixing head Cabeçote L-head Equipment: Impingement mixing head geometry where streams enter at opposite angles (180°) into an L-shaped chamber with the outlet channel.
Lance-type piston pump Bomba de pistão tipo lança Equipment: Specialized variant for RRIM with abrasive fillers.
Long fiber injection(LFI) Injeção de fibra longa Process: Open-mold process with chopped fiber wetted by the reactive system at the mixing head outlet.
Low-pressure metering machine Dosadora de baixa pressão Equipment: Machine with gear pumps and mechanical mixing head.
Methylene diphenyl diisocyanate(MDI) Difenilmetano diisocianato Chemistry: Aromatic isocyanate of majority use in rigid PU and RIM.
Mix ratio Razão de mistura Process: Proportion between reactive components (volumetric or by mass).
Mixing head Cabeçote de mistura Equipment: Device where streams meet for homogenization before delivery to the mold.
Mold Molde Equipment: Tool that gives shape to the part during cure.
Mold carrier Carregador de molde Equipment: Structure that supports and moves the mold during the cycle.
Mold release agent Agente desmoldante Equipment: Product applied to the mold surface to facilitate demolding.
MQ mixing head(MQ) Cabeçote MQ Equipment: Family of self-cleaning mixing heads originally developed by Hennecke. Geometry derived from L-head with refined control features.
Multi-component mixing head Cabeçote multicomponente Equipment: Mixing head that receives 3 or more reactive streams. Used for integrated pigmentation or systems with additional reactive components.
Open-loop control Malha aberta Equipment: Control without automatic measurement feedback.
Parting line Linha de partição Equipment: Line where the two halves of the mold meet.
Piston pump Bomba de pistão Equipment: Positive-displacement pump for high pressure.
Polyol Poliol Chemistry: Reactive component with hydroxyl groups (OH), reacts with isocyanate.
Polyurea Poliuréia Chemistry: Polymer obtained by reaction of isocyanate with amine.
Prepolymer Pré-polímero Chemistry: Partially reacted intermediate used in two-step systems.
Programmable logic controller(CLP / PLC) Controlador lógico programável Equipment: Automated process control unit.
Pultrusion Pultrusão Process: Continuous process to manufacture fiber-reinforced profiles.
Purge Purga Process: Cleaning of the mixing chamber or lines, with solvent or mechanically.
Quasi-prepolymer Quasi-prepolímero Chemistry: Prepolymer with high free NCO content (16–32%).
Race track Race track Equipment: Closed circuit of molds passing through fixed operation stations.
Reaction injection molding(RIM) Moldagem por injeção por reação Process: Discontinuous process in which reactive liquid components are mixed by high-pressure impingement and injected into a closed mold, polymerizing in seconds.
Recirculation Recirculação Process: Continuous flow of components through the mixing head between shots.
Reinforced reaction injection molding(RRIM) Moldagem por injeção por reação reforçada Process: Variant of RIM with particulate filler (short fiber, mineral) suspended in one of the components.
Rise time Tempo de crescimento Process: Total foam expansion time.
Rotary table Mesa rotativa Equipment: System of indexed stations rotating around a central axis.
Self-cleaning mixing head Cabeçote autolimpante Equipment: Mixing head with internal cleaning piston that eliminates solvent between shots.
Short shot Short shot Process: Incomplete cavity filling.
Shot Disparo Process: One injection cycle.
Shot weight Peso do disparo Process: Total mass delivered in a shot.
Sink mark Marca de rechupe Process: Surface depression from contraction during cure.
Slabstock Slabstock Process: Continuous production of block foam on a conveyor belt.
Solvent purge Purga por solvente Equipment: Cleaning method in which solvent (traditionally methylene chloride or modern CFC-free systems) is injected into the mixing head between shots to remove residues.
Splash Splash Process: Splash of reactive mixture on mold internal surface, causing defect.
Splay Estrias Process: Surface marks caused by moisture or contamination.
Spray Spray Process: Gun application, used for skins, coatings and *in-situ* insulation.
Spray gun Pistola de spray Equipment: Portable mixing head for atomization application.
Structural reaction injection molding(SRIM) Moldagem por injeção por reação estrutural Process: Variant of RIM with pre-positioned continuous fiber reinforcement in the mold.
Surfactant Surfactante Chemistry: Additive that stabilizes foam during formation.
Tack-free time Tempo de toque seco Process: Time until surface is not tacky to touch.
Throughput / flow rate Vazão Process: Mass of material delivered per unit of time.
Toluene diisocyanate(TDI) Tolueno diisocianato Chemistry: Aromatic isocyanate used mainly in flexible foams.
Tooling Ferramental Equipment: Combined set of mold + accessories + thermal exchange system + demolding system.
Variable frequency drive(VFD) Variador de frequência Equipment: Rotation control device for pump motors.
Vent Respiro Equipment: Opening that allows air displaced by the material to escape.
Venting Ventilação do molde Equipment: Design and execution of vents.
Vertical foaming Espumação vertical Process: Slabstock variant with vertical expansion, producing round or rectangular cross-section blocks.
Void Vazio Process: Internal air or gas pocket in the part.
Water purge Purga por água Equipment: Modern cleaning method in low-pressure mixing heads using water instead of solvent. Reduces VOC emissions and simplifies disposal.
Weld line / knit line Linha de emenda Process: Visible line where flow fronts meet.