Glossary

Commonly used terminology

Browse through our explanations of commonly used terminology in the adhesive tape and tape converting industry. For a specific term use the search or filter options.

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A
Acetate cloth

A type of backing used in electrical insulation tapes. This backing offers excellent absorption of electrical insulation resins and varnishes. View acetate cloth tapes here.

Abrasion resistance

The ability of a tape to withstand rubbing and friction and still function satisfactorily.

Accelerated ageing

When the deterioration of a tape from natural ageing is accelerated and simulated in the laboratory.

Accelerated weathering

An aspect of accelerated ageing; a tape is placed in a chamber and exposed to ultraviolet light, heat, and water whereby the effect of exposure to outdoor conditions on a tape can be measured.

Acetate film

A transparent film which is used for various reasons as a tape backing. Its primary characteristic is that it is more moisture resistant than cellophane.

AccuPlace

Automated pick and place equipment for placement of difficult to handle adhesive components. Find out more here.

Acrylic polymer

A synthetic polymer with excellent ageing characteristics that can be used either as a single component adhesive or a coating or saturate, depending upon composition.

Acrylic/acrylate

Synthetic polymer with excellent ageing characteristics that can be used as a component adhesive.

Adhesion

Adhesion is the interaction that develops between two dissimilar bodies when they are in contact. At the molecular level, adhesion is based on physical and in some cases chemical bonding. The strength of adhesion depends on the type of adhesive. Pressure sensitive adhesives build up adhesion under light pressure. The ultimate bonding strength is reached after 24-72 hours. Read our tips on getting the optimum adhesion from your adhesive tape. 

Adhesion build-up

An increase in the peel adhesion value of a pressure-sensitive tape after it has been allowed to adhere to the applied surface.

Adhesion to backing

The bond produced to the backing of the same tape or another tape backing.

Adhesion to skin

A study to determine the degree of adhesion to skin of medical tapes or adhesives for up to 96 hours. Additionally, the amount of residue remaining on the skin after the material removal is assessed. For more information go to our device attachment to skin and wound care pages.

Adhesive

Adhesives are polymer materials that are used to join dissimilar materials. Adhesives may be classified in many ways, e.g. by mode of application and setting, chemical composition, cost, and suitability for various adherents and end products. The term “pressure sensitive adhesive” (PSA) is used to describe adhesives that are permanently tacky in dry form at room temperature. The most common pressure sensitive adhesives are acrylics, natural rubber/resin, and synthetic rubber/thermoplastic rubber.

Adhesive failure

Adhesive failure describes the separation of adhesive either from backing or from the substrate. The other basic failure mechanism of an adhesive bond is “cohesive failure” which refers to a fracture in the middle of the bulk adhesive. Learn more in our guide to using adhesive tapes.

Adhesive residue

Adhesive which is pulled away from the tape and remains on the surface to which the tape was applied.

Adhesive transfer

The transfer of adhesive from its normal position on the tape to the surface to which the tape was attached, either during unwind or removal.

Ageing resistance

Ageing resistance is the degree of reliable performance of the tape over time, under certain conditions. Depending on the adhesive system being used, adhesive tapes are often usable for permanent applications. This permanence is reflected by the resistance of the adhesive against ozone (O3), oxygen (O2), UV light, temperature, humidity, water and different kinds of chemicals. Generally acrylic adhesives are much better suited to withstand these environmental influences than rubber adhesives and can maintain their permanent, reliable functionality over many years.

Anchorage

The specific adhesion of a pressure sensitive adhesive to a face material or an anchor coat.

B
Bisco™

Bisco™ is a high performance silicone foam offering characteristics such as high resistance to temperature extremes, UV and ozone, high resilience to mechanical fatigue and excellent compression-set and creep resistance. See our foam and rubber page here for more information.

Blocking

An undesired adhesion between touching layers of material, usually due to extreme conditions of pressure, temperature, or humidity.

Breaking load

The force required to break a unit width of tape under prescribed conditions.

Bursting strength

The ability of a tape to resist damage when a force is applied evenly and perpendicularly to the surface of a tape.

Backing

Materials which “carry” the adhesive. The backing also reinforces the adhesive tape and improves handling and processing properties. Most commonly used backing types are film backings (e.g. PET, PP, PVC, PE), paper based backings (e.g. non-woven, tissue), foam backings (e.g. PU, PE and PVC foams).

A specialty adhesive tape type is a transfer tape which has no backing. The adhesive is directly coated on the liner.

Backside

The uncoated side or side opposite the adhesive coating. For a double coated tape, the side in contact with the liner after unwinding.

Backsize

A material applied to the backside of a tape to provide a release surface or heat seal property.

C
Composite film

A polyester film backing used in electrical insulation tapes. View composite film tapes here.

Converting

The operation of changing a jumbo roll of adhesive tape into a finished product by slitting, short roll winding and die-cutting. Parafix has over 45 years experience as a tape converting specialist; read more about our converting capabilities here.

Core

The inner cylinder of cardboard or plastic on which the tape is wound.

Corona resistance

The ability of an elastomeric adhesive, coating, or sealer acting as an insulator to withstand the effects of high voltage discharge. Indications of failure appear as surface cracks.

Corona treatment

This is the method to modify the surface of a substrate to provide better anchorage of the adhesive. Corona treatment is an atmospheric plasma treatment. It is applied to non polar/low energy surfaces to facilitate the anchorage of the adhesive.

Creep

The slow movement of the adhesive or backing under shear stress.

Crepe paper

Paper which has small regular folds in it giving it a higher stretch than a flat back paper of the same weight.

Cross-linking

The development of a three dimensional structure within an adhesive to improve cohesive strength, temperature, oil or solvent resistance.

Cure

To alter the properties of an adhesive by chemical reaction, which may be condensation, polymerisation, or vulcanisation. Usually accomplished by the action of heat and catalysts, alone or in combination, with or without pressure.

Curling

The tendency of a tape to curl back on itself when unwound from the roll and allowed to hang from the roll.

CAD

Stands for Computer Aided Design. It is the use of computer programmes to produce 2D or 3D graphical representations of physical objects.  These programmes enable the user to perform calculations and analyse component design variants for determining an optimum shape and size for the final output. This minimises the requirement for tooling and physical prototypes at your component design stage. Parafix offer this capability in house, learn more here.

Caliper

Thickness of a tape, backing, or adhesive, usually measured in mils (1/1000 of an inch).

Carrier

The base material onto which a pressure sensitive adhesive is applied, on both faces, to produce a double-sided tape.

Cellophane film

A thin transparent film manufactured from wood pulp.

Clean room

A clean room is an environment with a controlled level of dust and other contaminants. Parafix has a class 7 clean room; compliant with BS EN ISO 14644-1, for the manufacturing of automotive, electrical and healthcare components. Learn more here.

Closed side (adhesive)

The surface of the adhesive on a double sided tape, which normally remains in contact with the release liner on unwinding.

Closed side (liner)

Is the surface of a release liner, which normally remains in contact with the adhesive on unwinding.

Coated cloth

Fabric with a rubber or plastic back coating. Examples are insulation tapes (including glass cloth and acetate cloth) and medical tapes (nonwovens). Browse our range of single sided cloth tapes here. 

Coating weight 

The amount of a solution applied to a sheet in the tape making process. The units are usually grains per 24 square inches.

Cohesion

Cohesion describes the inner strength of the adhesive. It mainly determines the holding power (shear resistance) of the tape.

Cohesive failure

Cohesive failure leaves adhesive residue on both the PSA tape backing and the laminated surface, showing that the adhesive broke internally. Use an easy check with your finger: it sticks on both the substrate and the tape.

Cold flow

The tendency of a pressure-sensitive adhesive to act like a heavy viscous liquid over periods of time. Such phenomena as oozing and increases in adhesion are the result of this characteristic.

Colour

Usually describes the colour of a tape when looking at the backing, regardless of the colour of the adhesive.

Colour stability

The ability of a tape to retain its original colour, particularly when exposed to light.

Conditioning

The process of subjecting material to specific temperatures and relative humidity conditions for a stipulated period of time.

Conformability

The backing of an adhesive tape influences its ability to adhere to curved, rough or irregular surfaces. Conformable backings increase the contact area of adhesive and substrate. Foam backings are inherently conformable and can therefore compensate for surface irregularities between the two bonding substrates.

D
Dead stretch

The increase of length of a piece of tape after it has been stretched without breaking and allowed to recover.

Delamination

Where the liner separates from the tape.

Dielectric strength

The measure of the maximum voltage stress that a single layer of tape can withstand before dielectric failure occurs, the test being carried out under prescribed conditions.

Dimensional stability

Correlates with humidity of liners. Dimensional stability prevents the liner from showing an irregular surface or dimensional change due to absorption of moisture. Dimensionally stable liners are mainly:

  • PE coated paper liners
  • Film liners
Double coated

See double-sided tape.

Double faced

See double-sided tape.

Double sided tape

Comprised of a backing material coated with adhesive on both sides. Usually one adhesive layer is covered with a release liner (closed side) in order to wind the PSA tape in roll form. In double sided tape production the backing is often pre-treated with a primer to enable a maximum anchorage between backing and adhesive.

View our range of double sided materials here.

Dual Lock™

Dual Lock™ is a 3M™ reclosable fastening system that is up to 12 times stronger than regular hook and loop systems. They offer temporary and invisible fastening for various applications, such as those within point of sale, signage and transportation.

Dwell

The length of time a tape sample is allowed to remain in contact with any specific testing surface before the test begins.

E
Elastic memory

A tendency of some tape backings to return to their original length after being elongated.

Elasticity

The extensible property of adhesive films or adhesive interfaces to contract and expand in such a manner as to overcome the differential contraction and expansion rates that the bonded adherends may exhibit.

Elastomer

An elastic, polymeric substance, such as natural or synthetic rubber.

Electrical strength

The voltage at which breakdown of the tape occurs under the prescribed conditions of test, divided by the distance apart of the two electrodes between which the voltage is applied.

Electrolytic corrosion factor

A measure of the tape’s corrosive effect on an electrical conductor, particularly copper. This is particularly important in the selection of tapes for electrical insulation.

Elongation at break

The amount a tape has stretched lengthwise at the point of breaking. It is expressed as a percentage of the original unstretched length.

EMI/RFI shielding

Where electro-magnetic interference and radio frequency interference is shielded in electronic devices. This can be achieved using various materials, including copper and aluminium tapes. Learn more here.

Easy unwind treatment

See release coating.

Edge curl

The peeling back or lifting of the outer edge of a tape after application.

F
Foam

These are materials containing small holes (cells) distributed throughout the entire body. They can be either closed cell or open cell. Most common foams are:

  • AC foam
  • Ethylene-vinylacetate-foam (EVA)
  • Polyurethane-foam (PU)
  • Polyethylene-foam (PE)

Browse our foam materials here.

Faceside

The side of the backing on which the adhesive is coated. For a double-coated tape; the side first exposed after unwinding.

Face stock 

Any paper, film, fabric, laminate, or foil material suitable for converting into pressure sensitive material stock. In the finished construction this web is bonded to the adhesive layer and becomes the functional part of the tape construction.

Fall-off

When a tape pulls completely from the surface to which it is applied and drops off.

Fatigue 

A weakness resulting from stress created by repeated flexing or impact force upon the adhesive-adherend interface.

Filaments

Thin, longitudinal threads of glass, polyester, nylon, or other high strength materials. View our filament reinforced tapes here.

Film

Uniform, homogeneous, plastic webs. Learn more on our single sided film tape and medical grade film pages.

Fish eyes

Relatively small deformations (pockmarks) in the adhesive caused by the entrapment of air between layers in the roll. These are not an indication of a quality defect.

Flagging

A peeling away from the surface or tape backing of the end of a length of tape, particularly in a spiral wrap application.

Flame resistance

This is the ability of a tape to withstand exposure to flame. Fireproof materials will not burn even when exposed to flame. Flame-resistant (fire-retardant, self-extinguishing) materials will burn when exposed to flame, but will not sustain the burn after the flame is removed.

Flame treatment

Method for modifying the surface of a substrate to provide better anchorage of an adhesive to a non polar backing by flame.

Flatback

A term used to describe a smooth paper backing for a tape to distinguish it from crepe paper backings.

Flexibility

The ability of a tape to be freely bent or flexed during application, particularly applicable in low temperature use.

Fluting

The distortion of a roll of tape such that the layers no longer form a circle.

G
Gapping

An opening between layers within a roll.

Glass cloth tape

A high strength tape offering insulation and protection against high temperatures and/or flame. They also provide solvent and abrasion resistance. View our glass cloth insulating tapes here. We also offer acetate cloth tapes.

Glass transition temperature

The glass transition temperature (TG) is the temperature at which the adhesive becomes brittle. It is important that the application temperature is distinctly above the TG of the adhesive (e.g. resealable bags that are stored in the fridge or freezer as it can prevent a safe reclosure of the bag). Learn more about storing your adhesive tape here. 

Gloss

The measure of the reflectiveness of a tape backing, generally expressed by such terms as glossy, low gloss, dull, etc. A more specific definition is on the Gardner scale which measures absorption of light reflected from a beam with a stated angle of incidence.

Guillotining

Converting equipment commonly used to laminate and sheet adhesive materials. Learn more here.

H
Hand tearability

Property of tapes which allows manual cutting or tearing without the use of additional equipment such as knife, scissors or dispenser. Both liner and backing must be tearable.

Hard adhesive

A term usually used to characterise highly cohesive adhesive tapes. Advantages (compared to soft adhesives) include:

  • Higher holding power
  • Withstands higher sustained loads
  • Good temperature resistance
  • Less edge picking
  • Improved die- cuttability

Disadvantages include:

  • Low initial tack and adhesion;requires higher contact pressure
  • Not suited for rough surfaces
Heat activated adhesive

A type of adhesive that is rendered tacky by application of heat and forms a bond on cooling. Browse our heat activated films here.

Heat resistance

The ability of a tape to withstand a specified temperature under well defined conditions.

Heat seal

An adhesive film intended to be reactivated by the application of physical or chemical changes caused by exposure to high temperatures.

High liner release

When the tape release from the liner is difficult, or above the expected result.

High-speed unwind

Unwinding or dispensing of tapes at a relatively high speed, usually over 15 metres per minute.

Holding power (shear adhesion, shear resistance)

The ability of the adhesive to resist forces applied in the same plane as the tape.

Hot melt pressure-sensitive adhesive

A pressure sensitive adhesive applied to the backing in a hot molten form, which cools to form a conventional pressure sensitive adhesive.      

Humidity resistance

Moisture or even humidity can affect the performance of an adhesive, especially if applied under wet or very humid conditions. In this instance, the adhesive absorbs the humidity, which leads to reduced adhesion performance. This effect occurs especially with water-based acrylics, which should not be used under those conditions. In general an adhesive tape is humidity resistant when it resists contact with humid air or even water without negative effects on the adhesion properties.  Humidity can also damage paper liners and lead to ‘bubbles’ on the surface of the tape. All acrylics have a good humidity resistance and filmic liners are more dimensionally stable than paper ones. Read our guide on the correct storage of your adhesive tape. 

HVAC

Stands for ‘heating, ventilation and air conditioning’.

Hygroscopic 

A tendency of some materials to readily absorb moisture from the atmosphere.

I
IP rating

The IP in “IP rating” stands for “Ingress Protection”. The IP rating refers to the robustness of a product to ingress of moisture and dust. Any enclosure should have an IP rating that classifies the design relative to application needs. 

Insulation resistance

The ability of tape to prevent the flow of electrical current across its surface of the backing. Electrical insulation materials can be viewed here. 

Interleave

See release liner.

Interliner

See release liner.

Impact resistance (shock resistance)

The ability of a tape to resist sudden impacts, pulls, or shocks as may sometimes be encountered by packages in transit or portable devices. Our range of foam tapes and VHB tapes are ideal for impact absorption.  

Insulating tape

Tapes which are used for electrical insulation. For more information, visit our electrical insulation tapes page.

J
Jumbo

A large roll of tape or backing which is wound up as the material emerges from the coater or treatment. It is later converted.

K
Kapton®

Kapton® is the brand name for a polyimide film produced by DuPont. Browse our non-adhesive electrical insulation materials here.

Kiss cut

A type of die-cutting where the cutter is adjusted to only cut the material and leave the liner or backing untouched.

Kraft

A sulphate wood pulp paper.

Key

The bond between the adhesive and the carrier or backing.

Key coat

See prime coat.

Key failure

Failure of an adhesive bond such that separation is at the interface of adhesive and carrier or backing.

L
LAB

Low adhesion backsize.

Label stock

Pressure sensitive materials which are usually printed, frequently die cut, furnished in roll or sheet form with an interleave, and intended for use as labels.

Laminate, lamination

A combination of two or more materials, which function as one backing on web. Learn more about laminating here.

Lap joint

A joint made by lapping one material over another to provide a mated area that can be joined with an adhesive.

Laser cutting

Utilising laser technology to cut material. Often used to cut small and complicated geometries and to produce samples without tooling. Learn about our laser cutting capabilities here.

Latent stain

A stain in a surface to which tape has been applied, which does not become noticeable until sometime after the tape is removed, usually after the surface has been exposed to sunlight or heat.

Lifting

A situation where a section of tape has pulled away from the surface to which it has been applied, even though no outside stress is applied.

Liner

Anti-adhesive material which covers the adhesive on a double sided tape and prevents the adhesive from sticking to itself. The liner is used as a protection aid during handling, processing and storage. Most commonly used liner types are:

  • Paper liners (e.g. glassine paper, PE-coated paper, clay-coated paper)
  • Film liners (e.g. PP, PET, PE)

Silicone is used as a release system to avoid adhesion between liner material and adhesive.

Low release liner

The tape release from the liner is easy, or below the expected result.

M
Memory

The ability of a fibre or tape to return to its original form after being stressed or elongated.

Metal foil

Thin flexible sheets of metal, such as aluminium, copper and lead used as tape backings because of their inherent properties such as weather resistance, electrical conductivity and reflectivity. Browse our single sided foil tapes here.

Migration

The molecular movement over a long period of time of an ingredient from one surface to another when both are in contact. Migration may occur between tape components and the surface to which applied. Some plastic films (e.g. PVC) contain plasticisers which are apt to migrate into the tape adhesive, causing the adhesive to soften. Other ingredients like foaming, vulcanisation, age-resistant agents used for flexible seals migrate into the tape and can compromise the bond.

MSI

One thousand square inches.

MVTR 

The moisture vapour transmission rate; a measure of the rate of water vapour transmission through a pressure sensitive product usually measured in grams/square meter/24 hours.

Melinex™

The brand name for a polyester film made by DuPont. Browse non-adhesive insulation materials here.

N
Natural rubber

Component of adhesives, not inherently self-adhesive. Resins, so called “tackifiers” need to be added to achieve self adhesive properties.

Nomex®

Nomex® is the brand name for an inherently flame-resistant aramid fibre that is manufactured by DuPont. For more information visit our non-adhesive insulation materials page or view our full range of insulation tapes here.

Non-polar substrates

Critical surfaces to adhere to due to low surface energy. The lower the surface energy the lower the molecular attraction to the adhesive (adhesion). Typical materials are polyolefins such as PP and PE, but also PS, EVA and many powder painted surfaces. By surface pretreatment (e.g. corona treatment) the polarity can be modified to achieve higher surface energy and improved adhesion. Use of primers will also act as adhesion promoters.

Non-woven

Paper and polymer fibre based backing material for adhesive tapes.

O
Occlusive

To prevent moisture from passing through.

Off-core

Layers of tape are in correct alignment, but tape is displaced sideways on core.

Offsetting

The movement of a component of a tape, usually the adhesive, from its backing; this transfer may occur during unwinding of tape, or on removal of the tape from a substrate.

Oozing

A ‘squeezing out’ of the adhesive at the edge of the tape, caused by “cold flow” of a soft adhesive.

Opacity, opaqueness

The ability of a tape to prevent the transmission of light.

Open side (adhesive)

The surface of the adhesive on a double sided tape which is exposed on normal unwinding or separation.

Open side (liner)

The surface of a release liner which is exposed on normal unwinding or separation.

Optically clear tape

Is a tape with a transparent, film-free isotropic adhesive, formulated specifically for electronic displays, that allows accurate colour and full display brightness while providing a long lasting, high strength bond. Browse optically clear tapes here.

Outgassing

The chemical ingredients evaporating from adhesives (e.g. monomer residues, solvents, etc.), especially under elevated temperature conditions. Often a concern in the automotive, aerospace and electronics industries, where chemical residues could affect electric circuits, for example. Browse low outgassing tapes here.

P
Polyurethane (PU)

Polyurethane (PU) is a versatile material resistant to moisture, bacteria, chemicals and abrasion. It can be used for medical purposes as a breathable backing for wound dressing and device fixation, and as foam or rubber for a range of applications for gasketing, sealing, gap filling and cushioning.

Pressure-sensitive tape

A term used to describe a category of tape coated on one or both faces with a pressure sensitive adhesive. It is permanently tacky at room temperature and requires no activation by water, solvent or heat to adhere to a variety of surfaces upon contact. In some cases the adhesive may be further cured by heating after application. The bond strength may be increased by pressure and/or time.

Prime coat

A coating on the adhesive side of the backing, which serves as a bonding agent between adhesive and backing.

Primer

A coating applied to a surface (e.g. backing or a substrate) to prepare it for the application of an adhesive, improving bond performance between backing and adhesive or between tape and substrate. Learn more about surface preparation here.

Printability

The ability of a tape to accept and hold a printed legend and especially to resist offsetting of the print when unwound from a roll.

PTFE tape

PTFE stands for Polytetrafluoroethylene and is a high-temperature tape used in applications requiring consistent performance and minimum shrinkage across a wide range of temperatures. They are extremely resistant to chemicals and have high arc resistance. Browse PTFE tapes here.

PVC

Polar substrate which is easy to adhere to. Often used as a backing available in varying degrees of hardness. Suitable for electrical insulation and cable harnessing applications.

Peel adhesion

The force required to peel a strip of tape from a substrate at a specified angle and speed.

Permanent adhesive

An adhesive that has been designed to remain permanently in position under the specified service conditions.

Permeable

To allow gasses or moisture to pass through.

Pinholes

Very small defects in a tape, which may permit the passage of light, electricity or water vapour, the minute holes may be in the backing and/or the adhesive.

Plasticisation 

The softening of an adhesive when exposed to migrating plasticisers or oils.

Plasticised plyvinylchloride

A tough durable plastic film having excellent resistance to oils, chemicals and many solvents. It has excellent abrasion resistance. It can also be coloured. Its high stretch is due to the addition of a plasticiser.

Plasticiser resistance

The ability of an adhesive tape to maintain its properties under influence of plasticisers. In contact with plasticisers (e.g. a component of foam materials or soft PVC) the adhesive performance of adhesive tapes can be affected, especially with rubber based adhesives. Adhesive tapes with a film backing sometimes perform better since the film layer acts as a barrier against migration of plasticisers. Important for applications on EPDM or soft PVC profiles for instance.

Polar substrates

Uncritical surfaces to adhere to due to high surface energy. On these substrates the high molecular attraction between adhesive and substrate leads to increased adhesion. Most common materials are PET, PC, PVC, ABS, steel, aluminium, glass etc.

Polycoated

Covered with a layer of polyethylene film, usually applied as a liquid on paper for adhesive liner use.

Polyester (PET)

A strong non-stretchable film, having good resistance to moisture, solvents, oils, caustics and many other chemicals.

Polyethylene (PE)

A tough, stretchy film having very good low temperature characteristics.

Polyimide

A strong film with electrical, thermal, chemical and mechanical properties, which can withstand extreme temperatures and demanding environments. Browse polyimide products here.

Polymer

A large molecule built up of repetitive smaller chemical units, commonly used in adhesive compounding.

Polyolefin

A general term used to cover a family of resins such as polyethylene and polypropylene.

Polypropylene (PP)

A cousin of polyethylene, with similar properties, but stronger and having a higher temperature resistance.

Polyvinyl chloride (PVC)

A usually thin transparent film with excellent resistance to acids, water and organic solvents. Usually formulated with a migratable plasticiser to make it flexible.

Poron™

Poron™ is a high performance polyurethane foam offering characteristics such as excellent compression-set resistance, low outgassing, non-fogging, is flame retardant, non-corrosive to metal and will not become brittle and crumble. For more information see our foam and rubber page here.

Porosity

Permeability of a surface (tape backing) to a liquid or gas or a measure of percentage void space within a material such as foam.

Pre-release

The unwanted separation of a tape from its release liner during unwinding.

Pressure sensitive adhesive (PSA)

A type of adhesive, which is permanently tacky at room temperature and when applied to a variety of surfaces, forms an immediate bond. The bond strength may be increased by pressure and/or time. Browse tapes here.

Pattern coated 

A term that refers to the width and spacing arrangement of strips of adhesive laid down parallel to machine direction and across the width of pressure sensitive stock during its production.

Peaking

Large singular upheavals in the outer layers of a roll of tape.

Q
Quick stick

Initial Adhesion (wet grab) – the property of a pressure sensitive adhesive which allows it to adhere to a surface under very light pressure. It is determined by the ability of the adhesive to quickly wet the surface contacted.

R
Reinforcement

A material which strengthens the backing and/or the adhesive.

Release coating

A coating applied to the backing on the side opposite the adhesive, which provides ease of unwind and prevents delamination or tearing, or to a film or paper to produce a release liner.

Release force

Force needed to remove the liner from the covered adhesive layer of a double sided adhesive tape. The release force can be adjusted by release agents, such as silicones.

Release liner

A removable material which protects the adhesive face or faces.

Removal

The act of pulling tape away from the substrate.

Removable adhesive

An adhesive that has been designed to allow subsequent removal without damaging or contaminating the substrate under specified conditions. An example is protection films which offer temporary protection from potential scratching, marring, chipping, UV damage and dirt during manufacture, packing, storage, shipping and installation. 

Resistance

The ability of a tape to resist exposure to varying conditions such as acids, oils and solvents, after application and to perform satisfactorily.

Repositioning

Short term repositioning can be important to correct the first mounting of a substrate. It depends on the initial adhesion level, the cohesion of the adhesive and the backing type. This is important e.g for mounting of displays or front panels.

Residue free removability

Relevant when bonded materials have to be separated after the life cycle of the product (e.g. some shelf-edge labelling).

Reversibility

Property which allows repeated bonding of two substrates. Tapes with different adhesion levels on each side are specially suited for bag sealing.

Rewinding

The operation of winding the webstock from the reel onto a core to produce rolls of the desired width, diameter, and tension.

S
Shear adhesion

The ability of a tape to resist the static forces applied in the same plane as the backing, usually on a vertical test panel.

Shear resistance

Shear resistance is measured as a force required to pull the pressure sensitive material parallel to the surface to which it was affixed under specific conditions. The shear resistance of PSAs may be measured statically or dynamically. Static shear test methods use a constant load of longer test times. Dynamic shear tests measure the cohesion of the sample in a tensile tester under increasing load (force).

Shock resistance

Shock resistance is a suddenly applied force on an adhesive bond. Under normal conditions (room temperature) the shock resistance of tapes is significantly higher. PSA tapes with a foam backing have an incorporated buffer system and therefore absorb shock much better than film tapes. Additionally, high coating weights and flexible backings of high quality film tapes can take over part of this buffer function.

Shrinkage

Reduction of any dimension of a tape.

Single faced

A tape to which a pressure sensitive adhesive is applied to only one side of the backing. Browse single sided tapes here.

Slick surface

A tape offering characteristics such as reduced friction, anti-stick, easy release, sound management, squeak and rattle prevention, noise reduction, chemical resistance and barrier, high strength and abrasion resistance.

Slivering

When the tape tears or breaks into small pieces, either on unwind or on removal from a surface.

Soft adhesive

Contrary to hard adhesives, soft adhesives flow easier into rough and textured surfaces and substrates.

Advantages (compared to hard adhesives)include:

  • Good wetting – adhesive flows into rough, uneven substrates
  • High initial tack (immediate bond)

Disadvantages:

  • Lower temperature resistance
  • lower shear resistance (holding power)
Softener resistance

See plasticiser resistance.

Solvents

Direct contact with solvents should be avoided, because they can penetrate into the adhesive and reduce the functionality of the tape. Therefore the substrate should be dry before the tape is applied. All acrylics, especially pure acrylics, have a good resistance to solvents contrary to rubber based adhesives.

Splitting

See delamination.

Stain resistance

The ability of a tape to be applied to a substrate without discolouring the substrate.

Stiffness

The measure of a tape’s flexibility and conformability.

Storage stability

The ability of a tape to retain a specified level of its original properties after defined conditions and length of time of storage.

Subsequent adhesion

The force required to remove a unit width of pressure sensitive tape from a standard panel after it has been in contact with a release liner for a given period of time. This must be compared with the adhesion of the same tape that has not been in contact with the release liner to determine the degree of loss of adhesion.

Substrate

The surface to which a pressure sensitive tape is applied.

Surface energy (surface wetting ability)

The measure of surface tension in dynes. The lower the surface energy of a substrate, the more difficult it becomes for an adhesive or coating to wet out that surface.

Synthetic rubbers

Specific type of adhesive.

Saturation (impregnation)

Adding materials (saturant) to the backing for improvement of physical properties.

Self-seal 

An adhesive joint that is accomplished by coating both adherend surfaces and bringing them under pressure e.g. an elastomeric adhesive (cohesive) used on envelope flaps, box closures, etc, whereby the adhesive film will bond only to itself.

T
Tear resistance

The force required to propagate a tear in a tape in a given direction after the tear has been initiated.

Telescoping

A sideways sliding of the tape layers, one over another, such that the roll looks like a funnel or a telescope, usually occurring over a period of time.

Temperature resistance

Ability of a double sided tape to remain unaffected (adhesion, cohesion) when exposed to higher temperatures. We distinguish between ‘short term’ temperature resistance (seconds to minutes) and ‘long term’ temperature resistance (hours to years).

Tensile strength

The force required to break a piece of tape by pulling opposite ends of the piece.

Thermoplastic rubber adhesive

Specific type of adhesive; it softens on heating and reverts to original state when cooled. This process may be repeated.

Thermosetting

Adhesive becomes firmer on heating and remains so on cooling. Thermosetting of adhesive improves solvent resistance and increases softening temperature.    

Thickness (caliper, gauge)

The perpendicular distance from one surface of either a tape, backing or adhesive to the other, usually expressed in mils, thousandths of an inch or millimetres. This is usually measured under controlled slight pressure with a special gauge.

Tie coat

See prime coat.

Transfer tape

PSA tape without backing reinforcement. The adhesive is directly coated on to the release liner. Browse transfer tapes here.

Transparency

The ability of a tape to allow the transmission of light. A tape is rated as transparent if 10 point type can be easily read when the tape is applied directly over it.

Tack

Tack describes the contact behaviour of the adhesive to the substrate under a minimum of time and pressure. Also referred to as ‘wet-grab’ and ‘quick-stick’.

Tape conversion

See converting.

U
Ultimate adhesion

The maximum adhesion available from a pressure sensitive adhesive, determined from the force necessary to remove a strip of tape from a surface after an extended period of time.

Unwinding force

Force required to unwind a double sided adhesive tape. The unwinding force is a result of the interaction between adhesive and release liner. A low and constant unwinding force is an important property for the processing of an adhesive tape.

V
VOC

VOC stands for Volatile Organic Compound. These are organic chemicals that easily evaporate at room temperature. They enter the surrounding air from every day products such as paint, wood products and plastics.

VHB™

VHB™ stands for Very High Bond and is a tape produced by 3M™. VHB™ tapes are high-strength and a proven alternative to screws, rivets, welds and other mechanical fasteners. This high-strength bonding tape permanently adheres one substrate to another while spreading the stress load across the entire length of the joint. Learn more here.

Vinyl

An abbreviation applied indiscriminately to both PVC and UPVC. Browse vinyl tapes here.

Void

A bare uncoated area on either the adhesive or release coated side of the tape.

W
Water vapor transmission rate (WVTR)

The weight of water vapour allowed through a controlled area of tape within a specified time period and under controlled conditions.

Web

The long, continuous sheet of material which is drawn through the processes of making tape.

Wet grab

See tack.

Wrinkles

Small ridges or furrows formed on the surface of a roll of tape and often resulting in jagged edges on the slit roll.

Wet out

Wet out describes the flow or spread of adhesive over a substrate. High surface energy substrates encourage good wet out which assures greater surface contact.

Washboard effect

A condition when a surface has a definite corrugated or ridged surface.

Water absorption

The measure of the amount of water which will be soaked up by a tape under stated conditions and be retained by it.

Water dispersible

A tape where the adhesive will dissolve completely under the proper chemical environment and the backing will break up into extremely small pieces.

Water penetration rate (WPR)

The weight of water transmitted through a controlled area of tape under a specified time and conditions.

Weather resistance

The ability of a material (tape or adhesive) after application to resist exposure to such conditions as UV light and humidity. Generally acrylic adhesive tapes display good weathering resistance.

X
X/Y axis plotter

A two directional plotter that can produce parts without the need for tooling. Learn more here.

XYZ-axis tape

A pressure sensitive adhesive tape with isotropic electrical conductivity through the thickness of the tape (the Z-axis) and through the plane of the adhesive (X, Y planes). Ideal for EMI/RFI shielding and gasket attachment to metal surfaces. Browse electrically conductive tapes here.

Y
Yield

A yield is a quantity achievable from an input role of material.

Z
Z-axis tape

A pressure sensitive adhesive tape with isotropic electrical conductivity through the thickness of the tape (the Z-axis); used for attaching grounded EMI/RFI shielding and interconnecting silver ink/polyester flex circuits. Browse electrically conductive tapes here.

Zone coated

Often required in automotive and medical applications, the adhesive is applied to a controlled area of the backing in zones or stripes. Learn more about custom presentation options here.