Insulation Technology Glossary
131 technical terms from the world of electrical insulation materials, processing methods and standards.
Aramid Paper
Aramid paper is an electrical insulating paper made of meta-aramid to IEC 60819-3-3 which, as Nomex 410, is UL-rated for 220 °C and withstands 18 to 34 kV/mm sh...
Armature Insulation
Insulating parts in electrical machines that reliably separate winding wire, iron core and commutator from each other.
Battery Insulation
Insulation system for protecting battery cells and modules from short circuits, overheating and mechanical damage.
Bent Parts
Components manufactured by precision bending processes from materials such as metal, films and laminates.
Breakdown Voltage
Breakdown voltage is the reverse voltage at which a diode or another semiconductor suddenly conducts heavily, from a few volts for Zener diodes to more than 1,0...
Bridge Die Cutter
Specialised die-cutting machine with a movable bridge for the precise manufacture of formed parts from insulating materials.
Busbar Insulation
Electrical insulation of busbars in the high-voltage system, as a wrap, coating or converted insulation part made of polyimide or PET.
Cable Insulation
Cable insulation is the non-conductive layer around an electrical conductor that confines the current to the conductor and prevents a breakdown to the surroundi...
Capacitor Insulation
Capacitor insulation is the electrical separation in and around a capacitor, from the dielectric with typically 100,000 MΩ·µF for PP film to the insulation of c...
Commission Warehouse
A commission warehouse is the store of a commission agent who sells the principal's goods in his own name for the principal's account under sections 383 ff. of ...
Composite Materials
Materials made of two or more constituents that remain distinguishable in the finished material and together achieve properties none of the constituents has on ...
Consignment Warehouse
Inventory method in which the supplier remains the owner of the goods until the customer consumes or sells them.
Contract Slitting
Service in which a specialised converter cuts roll material to exact widths and lengths on behalf of the customer.
Converting Processes
Further processing of web-form materials through cutting, stamping, laminating and forming into ready-to-use products.
Copper Foil
Thin metallic material with high electrical and thermal conductivity, used in EMC shielding and printed circuit board manufacturing.
Copper vs Aluminium Windings
For the same resistance an aluminium winding needs 1.63 times the cross-section of a copper winding, weighs half as much and its metal costs around a tenth; dis...
Corona Discharge
Electrical discharge in the air around a conductor that starts at around 30 kV/cm at the conductor surface without breaking down, and erodes organic insulating ...
Creepage Distance
Shortest path along the surface of an insulating material between two conductive parts, 2.0 to 4.0 mm long at 400 V and pollution degree 2 according to IEC 6066...
Cross-section Reduction
Reduction of the conductor cross-section, which increases electrical resistance and can lead to unwanted heating.
Deflection Curves
Description of the deflection of a component under load, relevant for calculating the load-bearing capacity of insulating parts.
Dielectric Losses
Energy that an insulating material converts into heat in an alternating field through delayed polarisation, measured as the dissipation factor tan δ, around 0.0...
Dielectric Strength
Dielectric strength is the electric field strength in kV/mm at which an insulating medium becomes conductive; air withstands around 3 kV/mm across a 1 cm gap, S...
DIN 8580
DIN 8580 divides all manufacturing processes into six main groups: primary forming, forming, separating, joining, coating and changing material properties, orde...
DIN ISO 2768
Standard for general tolerances for linear and angular dimensions as well as form and position without individual tolerance indication.
DMD Laminate
Three-layer insulating material made from polyester nonwoven, polyester film and nonwoven with high dielectric strength for motors and transformers.
Electric Field Strength
Physical quantity describing the force on an electric charge within an electric field, measured in V/m.
Electric Motor Winding
The functional heart of an electric motor: current-carrying conductors with a matched insulation system of slot insulation, layer insulation and turn insulation...
Electric Strength
Electric strength is the maximum field strength in kV/mm a solid insulating material withstands without breakdown to IEC 60243, 303 kV/mm for 25 µm Kapton HN an...
Electrical Conductivity
Electrical conductivity states how well a material conducts current. It is expressed in S/m, is the reciprocal of resistivity and ranges from 57 MS/m for copper...
Electrical Insulating Films
Electrical insulating films are thin plastic films that separate live parts, from PET in class B (130 °C) to polyimide in class R (220 °C).
Electrical Insulators
Components made from non-conductive material that separate live parts. GOBA supplies the device-side version as an insulating part, not the overhead-line insula...
Electrical Transformer
Electrical machine for transforming alternating voltages through electromagnetic induction, with an insulation system of cellulose or aramid paper and insulatin...
Electrically Insulating Coatings
Applied layers that reliably prevent the flow of electrical energy between components.
Electrically Insulating Plastics
Electrically insulating plastics are polymers with a volume resistivity above 10¹¹ Ω·cm that differ by orders of magnitude in dielectric strength, permittivity,...
EMC Shielding
Measures to reduce electromagnetic interference between electrical and electronic systems by means of shielding materials.
Field Coil Insulation
Multilayer insulation for field coils in DC machines and generators, separating the winding from the pole core and housing.
Film Extrusion
Continuous process that melts plastic granulate and forms it into blown, cast or biaxially oriented film, with BOPP stretched about 4.5 times lengthwise and 9 t...
Film Sustainability
Ecological assessment of plastic films across their entire life cycle: raw materials, production, service life, recyclability and disposal.
Filter Nonwoven
Porous sheet filter medium for separating particles from gases or liquids, made from synthetic or natural fibres.
Foam Tape
Self-adhesive construction element based on foamed polymers for sealing, damping and insulation in industrial applications.
Form Coils
Prefabricated, precisely shaped windings for electrical machines with high precision and reproducible quality.
Forming Technology
Forming technology covers the manufacturing processes that give a solid body a new shape through plastic deformation without changing its mass or material cohes...
Hairpin Stator
Stator technology with U-shaped copper conductors (hairpins) for electric motors with higher fill factor and better heat dissipation.
Hairpin Winding
Hairpin winding is a stator winding made of rectangular, U-shaped copper conductors that are inserted axially into the slots and welded, filling around 70 to 75...
High-temperature Insulation
Electrical insulating materials for continuous temperatures above class B (130 °C): PEN, PPS, aramid paper, polyimide, PEEK, PTFE and mica, ordered by thermal c...
High-voltage Insulation
Insulation system for electric motor windings with specific requirements for efficiency, dielectric withstand strength and long-term stability.
High-Voltage Insulation
High-voltage insulation is the electrical separation of conductors above 1 kV AC by air, gas, oil or solid insulation, from porcelain insulators on overhead lin...
HOSTAPHAN
HOSTAPHAN is the biaxially oriented PET film from Mitsubishi Polyester Film in Wiesbaden that insulates as RN and WN in thermal class B up to 130 °C and withsta...
Hydraulic Lifting Device
Systems for precise and safe handling of heavy loads using pressurised fluid in industrial manufacturing.
IEC 60085
International standard for the thermal classification of electrical insulation systems with thermal classes Y (90 °C) to S (240 °C).
Insulating Film Cutting
Precision cutting of electrical insulating films into defined geometries for motor and industrial applications.
Insulating Material
Insulating material is a substance with very low electrical conductivity that separates live parts and keeps current on its intended path.
Insulating Paper
Insulating paper is a flat electrical insulating material of cellulose or aramid fibres, alone or laminated with film, that separates winding and core in motors...
Insulation Parts to Drawing
Production of custom insulation parts from a drawing, from the required specifications and achievable tolerances to scaling from prototype to series.
Insulation Properties
The full set of material properties that determine a material's ability to prevent the flow of electrical energy or heat.
Insulation Resin
Liquid or pasty material for the electrical, mechanical and thermal protection of windings and assemblies in electrical engineering.
Insulation Resistance
Electrical resistance of an insulating material, indicating how well it prevents current flow between conductors, measured in megohms.
Insulation Sleeving
Tubular insulation for conductors, windings and connections, in variants such as silicone, glass fibre, silicone-coated glass fibre and PTFE for high temperatur...
ISO 9001
International standard for quality management systems, defining requirements for processes, documentation and continuous improvement.
Joining Technology
Methods for creating permanent or detachable connections between components through bonding, welding, riveting or mechanical joints.
Joule's Law
Joule's law describes the heat that current generates in a resistance: Q = I² · R · t, and for copper at 0.0175 Ω·mm²/m it rises by 0.4 % per kelvin.
Kanban Storage
In kanban storage an empty bin with a fixed quantity triggers replenishment; the number of bins equals daily consumption times lead time plus a 10 to 20% safety...
Kapton
Kapton is DuPont's registered trademark for polyimide film, usable continuously up to 240 °C and reaching 303 kV/mm dielectric strength at 25 µm thickness.
Kiss-Cut
Partial stamping process in which only the face material is cut through without damaging the underlying carrier liner.
Knife Shaft
Rotating shaft with rotating cutting blades for precise longitudinal slitting of films, papers and nonwovens.
Laminate Composites
Multilayer materials made from films, papers and resin systems, joined by lamination or bonding into high-performance insulating materials.
Laminating Film
A laminating film is bonded across its full surface to paper, board, metal or an insulating material, usually 12 to 30 µm thin in print finishing and, as lamina...
Layer Insulation
Insulating layer between winding layers in electric motors and transformers that prevents voltage flashover between layers.
Make or Buy for Insulation Parts
The sourcing decision whether a company produces stamped and cut insulation parts in-house or awards them to a contract manufacturer. Cost comparison, selection...
Material Thickness
Distance between the two surfaces of a material, determining stability, flexibility and electrical insulation capability.
Matrix Stripping
Process step after die cutting in which the waste matrix is stripped from the web to expose the finished parts.
Mica Tape
Mica tape is a flexible insulating tape of mica paper on glass fabric or film, 0.06 to 0.26 mm thick, that forms the main insulation of high-voltage windings an...
Micanite
Micanite is a composite of at least 90 % mica and at most 10 % binder that insulates continuously up to 500 °C with muscovite and 700 °C with phlogopite and wit...
Minimum Bending Radius
Smallest permissible curvature a material can take when bent without breaking or losing its properties.
Molded Parts
Insulating parts with defined geometry, produced by stamping, bending or forming, for installation in electrical machines.
Multilayer Insulation Materials
Insulating materials made from several stacked insulating layers for increased dielectric withstand strength and mechanical load capacity.
Mylar
Brand name of Mylar Specialty Films (formerly DuPont Teijin Films) for biaxially oriented polyester film (BOPET), distinguished from the sister brand Hostaphan.
NMN Laminate
Three-layer laminate of Nomex, polyester film and Nomex for motor and transformer insulation, with a high thermal class and good form stability.
Nomex
Nomex is the aramid paper developed by DuPont and a brand of Arclin since 2026, available as grade 410 from 50 to 760 µm, insulation class H (180 °C), listed by...
Nonwoven
Sheet structure of fibres bonded without weaving or knitting under ISO 9092, used in insulation laminates as a resin-carrier layer.
Partial Discharge
Localised electrical discharge within an insulation system without full breakdown, causing gradual ageing of the insulating material.
Partial Stamping
Chipless cutting process using punch and die, in which films and insulating materials are only partially stamped through.
Phase Insulation
Insulating separation of the winding phases in the stator, usually as a stamped and folded part made of Nomex, DMD or NMN.
Polyester Film
Polyester film is biaxially oriented PET film (BOPET) made from polyethylene terephthalate, used in electrical insulation as thermal class B with a continuous r...
Polyethylene
Most produced plastic in the world with good electrical insulation properties, available as HDPE, LDPE, LLDPE, UHMWPE and PE-X.
Polyimide
Polyimide is a class of aromatic high-performance polymers with no melting point that withstands 220 to 240 °C continuously as a film and reaches around 300 kV/...
Polypropylene Films
Polypropylene films are films made from semi-crystalline polypropylene, as CPP or biaxially oriented BOPP, with a very low dissipation factor and a continuous s...
Polystyrene Film
Film made from the amorphous thermoplastic polystyrene (GPPS, HIPS, OPS), usable continuously only up to 70 °C, with a dissipation factor of 0.9 × 10⁻⁴ at 50 Hz...
Pressboard
Technical material made from compressed cellulose fibres with good electrical insulation properties and high mechanical strength.
PTFE Film
Fluoropolymer film with very high temperature and chemical resistance and good dielectric properties, distinguished from PET and polyimide.
PV Backsheet
Rear protective and insulating layer of photovoltaic modules, providing weather protection and electrical insulation.
PVC Film Alternative
Film materials such as PET, PP, PE or polyimide that replace polyvinyl chloride in technical applications for regulatory, thermal or environmental reasons.
R-PET and A-PET
Two variants of polyethylene terephthalate: R-PET made from recycled material and A-PET as an amorphous variant with high transparency and formability.
Recycled Content
Percentage share of recycled material in a product, an important indicator for sustainability and resource efficiency.
Rewind Slitting
Manufacturing process for splitting wide material rolls into narrower rolls with precise longitudinal or cross cuts.
Roll Slitting
Precision process for longitudinally dividing web-form materials such as films, paper or fabric into defined widths.
Rotary Die Cutting
High-productivity stamping process with rotating cylinders that continuously produces formed parts from roll material.
Sealing Technology
Controlling the leakage or ingress of liquids, gases or solids at connection points using suitable sealing materials.
Separator Films
Functional separating film for isolating components, layers or media in batteries and industrial processes.
Series Production of Insulation Parts
Constant, process-capable production of insulation parts in series, with the processes, logistics concepts such as Kanban and consignment, and traceability.
Sheet Insulation Materials
Large-area, flexible insulating materials in film, paper or nonwoven form for electrical insulation in the electrical industry.
Slot Closure Wedges
Wedge-shaped insulating parts inserted into the open side of the stator slot to mechanically fix the winding.
Slot Insulation
Insulation of stator slots in electric motors and generators: protects windings from mechanical damage and electrical breakdown.
Slot Liner Covers
Insulating cover elements in electric motors that protect and fix winding heads in the slot area.
Stamped Parts
Components produced by precision stamping processes from films, papers and insulating laminates for industrial applications.
Stamped Parts for the Electrical Industry
Stamped insulation parts for motors, transformers and switchgear, with the typical materials, requirements and industries of the electrical sector.
Stator Insulation
The stator insulation system of slot, layer, turn and phase insulation, with materials, thermal classes and the difference between conventional and hairpin wind...
Surface Leakage Current
Unwanted current flow across the surface of an insulating material, caused by contamination, moisture or ageing.
Surface Protection Film
Temporary protective solution for sensitive component surfaces during manufacturing, transport and assembly.
Surface Resistance
Surface resistance is the resistance along the surface of a material, measured in ohms and stated as surface resistivity in ohms per square, from 10¹⁷ Ω/sq for ...
Tensile Strength
Maximum tensile stress a material reaches before it fails, measured in MPa or N/mm² according to ISO 6892, ISO 527 or ISO 1924, depending on the material class.
Thermal Classes of Insulation
Classification of electrical insulating materials by their maximum continuous operating temperature according to IEC 60085 into classes Y, A, E, B, F, H and C.
Thermal Conductivity
Material property indicating how well a material conducts heat, measured in W/(m·K).
Thermal Insulation
Layer or component that slows heat flow between areas of different temperature, sized via λ and R = d/λ, from pipe insulation to thin layers inside devices.
Thermal Insulation in Battery Systems
Materials and barriers against thermal runaway and heat transfer in battery systems, with a combined electrical and thermal function.
Thermoplastics
Thermoplastics are polymers whose molecular chains are held together by physical forces alone, so they soften under heat and can be reshaped repeatedly.
Thermosets
Polymers whose molecular chains crosslink covalently into a dense network during curing and can neither be melted nor reshaped afterwards, from paper laminate t...
Through-Cut
Cutting process in which all material layers, including the carrier liner, are completely severed.
Tracking Resistance
Resistance of an insulating material to tracking, measured as the CTI according to IEC 60112, with material groups and reference to the pollution degree.
Transformerboard
Compressed cellulose material for transformer insulation, oil-resistant and mechanically strong, distinguished from pressboard.
Triflexil
Flexible insulating laminate made of Nomex and polyester film in thermal class F (155 °C) for motors and transformers.
Trivoltherm
Flexible sheet insulation material with excellent electrical and thermal insulation properties for demanding applications.
Turn Insulation
First and most important insulation layer in an electric motor: separates individual conductor turns and prevents short circuits between wires.
Viledon
Filter nonwovens by Freudenberg for air and liquid filtration in industry, building services and paint technology.
Voltage Breakdown
A voltage breakdown is the collapse of insulation at the breakdown voltage, around 30 kV per centimetre in air and never below 330 V.
Vulcanised Fibre
Vulcanised fibre is a laminated material of pure cellulose without resin that, at about 1.2 g/cm³, withstands 7.7 to 15.7 kV/mm depending on thickness, lasts 80...
Web Edge Guiding
System for precise guiding of web-form materials during slitting and winding processes to prevent misalignment.
White Goods
White goods is the trade term for major electrical household appliances such as washing machines, dryers, dishwashers, refrigerators and cookers, whose motors, ...
Winding Shaft
Component for the controlled winding and unwinding of web-form materials in slitting and converting equipment.
Withstand Voltage
Dielectric withstand voltage is the test voltage a part, appliance or cable withstands without breakdown, for example 1,000 V for 1 s in the routine test to EN ...