- Machine DirectionMachine Direction:The panel orientation that corresponds with the direction that the product moved through the machine that manufactured or machined it. Also referred to as the parallel direction.
- Mat-formed PBMat-formed PB:A particleboard in which the coated (blended) particles are formed into a mat before being hot pressed.
- MelamineMelamine:A laminate that derives its name from the melamine resin system used to saturate the paper laminate and adhere it to the substrate.
- MFMF:Melamine Formaldehyde. Thermosetting resin with exterior capabilities commonly used as a saturating resin for paper laminates.
- MHDMHD:Manufactured (Mobile) Home Decking. A particleboard product designed for use as a single-layer floor system in the construction of mobile (manufactured) homes.
- Model Building CodesModel Building Codes:Building code developed by a regional federation of building officials. Model codes in the United States are the Uniform Building Code (UBC) published by the International Conference of Building Officials (ICBO); Standard Building Code (SBC) published by the Southern Building Code Congress International (SBCCI); Basic Building Code (BBC) published by the Building Officials and Code Administrators International (BOCA); and National Building Code (NBC) published by the American Insurance Association.
- Modulus of Elasticity (MOE)Modulus of Elasticity (MOE):A measure of the board's resistance to deflection or sagging when loaded as a simple beam. Value stated in pounds per square inch (psi).
- Modulus of Rupture (MOR)Modulus of Rupture (MOR):An index of the maximum breaking strength of the board when loaded as a simple beam. Value stated in pounds per square inch (psi).
- Moisture Content (MC)Moisture Content (MC):The amount of water in wood, generally expressed as a percentage of dry weight.
- Mottling EffectMottling Effect:An irregular appearance in an area or entire surface of a finished board due to heavy application of finishing material, poor drying or incompatible solvents. Also known as “Orange Peel”.
- MUFMUF:Melamine Urea Formaldehyde. UF resin fortified with melamine. See MF, UF.
- NPANPA:National Particleboard Association
- OpacityOpacity:As applied to a filled board surface, refers to the degree of coverage of filler that masks the board surface. Higher opacity denotes more complete masking.
- OverlayOverlay:A thin layer of paper, plastic, film, metal foil, or other material bonded to one or both faces of a panel.
- Particleboard PressParticleboard Press:Hot press that consolidates the particleboard mat into a board and cures the resin binder under heat and pressure.
- Particleboard PrepressParticleboard Prepress:A cold press following the former that helps consolidate the particleboard mat prior to the hot press. Always seen in caulless systems.
- PBIPBI:Industrial grade particleboard. A particleboard product manufactured primarily for use in industrial applications such as furniture and cabinet manufacturing. Usually an ANSI A208.1 type M-2 or M-3 grade.
- PBUPBU:Particleboard underlayment. A particleboard product manufactured for interior use as the smooth surface layer under finish floor coverings in double-layer floor construction.
- Perforator TestPerforator Test:A formaldehyde test developed in Europe as a plant quality-control test. It extracts free formaldehyde from particleboard with toluene. (European test No. EN120).
- Phenol Formaldehyde (PF)Phenol Formaldehyde (PF):A water-resistant thermosetting resin system commonly used to bond softwood plywood, oriented strand board (OSB), and exterior particleboard (ANSI A208.1 “Exterior”).
- PitsPits:Tiny voids on the board surface between fines or flakes.
- PlatenPlaten:A part of a press consisting of a rigid metal plate, usually heated, for exerting pressure on the mat.
- Poor AdhesionPoor Adhesion:A condition that develops when a finish or laminate is applied over a filler and sufficient adhesion does not occur.
- PrecurePrecure:Curing of a resin before pressing. It can also refer to incomplete sanding of a pressed board. Manifested as soft, crumbly panel surfaces.
- Prefinished PanelPrefinished Panel:Panels having factory-applied, decorative or protective coatings.
- Primary MarksPrimary Marks:Occasional deep scratches or marks that feel rough on finish-sanded board. Caused by the primary coarse grit sanding heads, leaving scratch patterns that are not totally removed by finish sanding heads.
- PSFPSF:Pounds per square foot. Measure of loads distributed over each square foot of board surface.
- PSIPSI:Pounds per square inch. Measure of loads distributed over each square inch of board surface.