Adhesive tapes: an overviewJohn Moot
What are adhesive tapes?
Adhesive tapes are a combination of a material and an adhesive film and are used to join or bond objects together rather than using fasteners, screws or welding.
The use of adhesive tapes instead of mechanical fasteners makes it possible to simplify manufacturing processes.
In addition, adhesive tapes can protect surfaces so that the surface is not damaged when fasteners or screws are used. Adhesive tapes are also used to provide electrical insulation, dissipate heat or seal against media.
Adhesive tapes are good solutions for automated product manufacturing, while liquid adhesives are messy and time-consuming because they must be sprayed or rolled onto the surface before bonding.
What are adhesive tapes made of?
Adhesive tapes consist of a material called a carrier material (e.g. paper, plastic film, fabric, foam), coated with an adhesive and covered with a release liner if required.
The adhesive-coated carrier is then wound into a jumbo roll. The jumbo roll is then cut into narrow strips to produce several small rolls or short rolls. Each roll and its composition is unique and can be tailored to specific applications for a variety of adhesive solutions.
How are adhesive tapes applied?
Adhesive tapes can be pressure sensitive, thermally activated or even require moisture to function. In many cases the tape is used in roll form, but often die-cuts are also made from tape.
Most popular types of adhesive tapes:
Pressure sensitive adhesives
Pressure-sensitive adhesives (PSAs) are tacky in dry form at room temperature. They adhere firmly to a variety of surfaces and require only the use of a finger or hand or a pressure tool. PSAs do not require water, solvent or heat activation to adhere to materials such as paper, plastic, glass, wood, cement and metal. The recommended adhesion pressure is 14.5 – 29 psi =^ 10 – 20 N/cm². The temperature during application should be moderate, somewhere between 15º C and 35º C. Lower temperatures could result in insufficient “wetting” or “coverage” of the adhesive on the substrate. Very high temperatures can cause the tape to stretch during application, which could create additional stress in the final application.
Heat activated adhesive
Heat-activated adhesive tape is normally tack-free until activated by a heat source. Heat-activated tape requires time to bond at elevated temperatures of 80˚C or higher. Heat-activated adhesive allows aggressive bonding to difficult surfaces such as rubber, EPDM, PU and PVC-based plastics. It can be produced with different carriers suitable for a variety of applications.
Water activated adhesive
Water-activated adhesive tape, gummed paper tape or rubberized tape is a starch or bone glue based adhesive that is applied to a kraft paper backing. When moistened, this coating becomes sticky. Water-activated adhesive tape is inexpensive and is used to close and seal cartons. Dr. Dietrich Müller GmbH does not offer this adhesive tape, but uses it to close cartons.
What types of adhesives are used for adhesive tapes?
Choosing the right adhesive for a project requires a good understanding of the application and the substrate or carrier used. The following adhesives are primarily used in the applications Dr. Dietrich Müller GmbH serves:
- Acrylic adhesives offer excellent resistance to environmental influences and cure faster than other adhesives.
- Epoxy resins exhibit high strength and low shrinkage during curing and are known for their toughness and resistance to chemical and environmental damage.
- Rubber-based adhesives offer highly flexible bonds and are usually based on butadiene-styrene, butyl, polyisobutylene or nitrile compounds.
- Silicone adhesives (polysiloxane) and sealants have high flexibility and are resistant to very high temperatures.
- Polyurethane and isocyanate adhesives offer greater flexibility, impact strength, resistance and durability.
What materials are used for the carrier of the adhesive tapes?
Adhesive tapes and films differ in terms of the carrier or backing material. The most common carrier/support materials used by Dr. Dietrich Mueller GmbH are listed here:
- Paper: Paper adhesive tape products have a paper carrier. This can also be creped. The tapes are also called crepe adhesive tapes.
- Fabric: A fabric carrier often contains a woven fabric or fabric layer for reinforcement, for additional strength and heat resistance. Synthetic and glass fabrics are used here.
- Felt and fleece: Felt or fleece tapes are often applied to substrates to avoid scratches.
- Foam: Adhesive-coated foam backing tape contains an adhesive that is protected by a liner. Foam is often used for sealing, weather stripping and assembly.
- Rubber: a rubber liner can be used to make a conformable rubber electrical insulation and sealing tape. There are also self-welding variants.
- Metal foil: aluminum, aluminum-reinforced and leaded carrier materials resist flames, extreme temperatures and high humidity. Metal tapes are generally intended to seal joints and seams against moisture or steam. Aluminum foil is laminated to paper or plastic films to achieve greater strength. Copper foil is used in the manufacture of multilayer printed circuit boards (PCB).
- Plastic foils: In general, there are two categories of plastics: Thermoplastics and thermosets. Plastic foil products contain one or more plastic layers. They consist of a plastic film, which can be clear, colored, printed or unprinted. They can be single or multilayer and can be combined with materials such as paper and/or aluminum. Dr. Dietrich Müller GmbH processes in particular polyester films, polyimide films and PVC films.
- PET/Polyester: Polyethylene teraphthalate (PET)/Polyester products use a PET or polyester carrier in the form of a film or laminate. Mylar or hostaphane is often used as the carrier material.
- Polyimide: Polyimide adhesive tape consists of a polyimide film and a heat-resistant silicone adhesive or an acrylic adhesive. Polyimide films are useful substrates for the manufacture of flexible circuit materials. Polyimide film retains its excellent physical, mechanical, chemical and electrical properties over a wide range.
- PVC/Vinyl: Polyvinyl chloride (PVC)/vinyl products use a vinyl or PVC carrier to resist wear, weather and abrasion.
- Silicone: Silicone is an excellent product for gaskets, insulators, press pads and stamped parts. Many types of silicone carriers can be used to meet different requirements. These include fabric reinforcements in particular.
- Acrylic Films: Acrylic films are plastic or thermoplastic resin films manufactured using polymethyl methacrylate (PMMA) or polymethyl-2-methylpropanoate. Acrylic films have excellent clarity and are UV stable.
- Glass/Fiberglass: Fiberglass composite material or a layer of glass provides exceptional stability in harsh environments by resisting shrinkage, decay or burning.
- Filament: Filament tape, usually referred to as strapping tape, consists of thousands of filaments (usually glass fiber) woven into yarns and embedded in the adhesive. It is a strong and versatile material that allows the user to bundle similar or odd shaped items for shipping or storage. There are also filament tapes that are reinforced with a polyester film.
- Fluoropolymer/PTFE/PVDF: Polytetrafluoroethylene (PTFE) is an insoluble compound with a high degree of chemical resistance and a low coefficient of friction. Fluoropolymer films, layers or coatings consist of plastics such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF). Fluoropolymer is often used in applications that require superior chemical resistance, good dielectric properties, and water and dirt repellency. It is also used in applications where the conveyed material must not adhere to the belt, fabric or laminate.
- Transfer adhesive tape: Transfer adhesive tape consists of a thin adhesive film without backing and can be transferred to most dry surfaces as a peelable adhesive layer. Transfer tapes often use a peelable protective film to improve handling and application of the tape.
- Double sided tapes: Double sided tapes consist of carrier materials coated on both sides. Each side can have a different adhesive strength. The masking films are made of either paper, film or silicone.
Punched parts from adhesive tape
Dr. Dietrich Müller GmbH uses all adhesive tapes to produce die-cut or shaped die-cut parts or adhesive parts that are used in a variety of applications. Die-cut parts made of adhesive tape can be supplied on a roll, as a die-cut part on a roll, die-cut parts as individual parts or as a magazine-loaded die-cut part.
There are also many options for quantities. Punched parts can be produced in small series or in large series as mass punched parts.