010.sealing tapes
TRANSCRIPT
Presented by Shrikant Athavale
For PG Students , SIES Nerul
On 13-11-2010
There are Many Types of
Adhesive Tapes
We can broadly Categories them in to
two major groups.
• Tapes with Pressure Sensitive Adhesive
• Tapes with Non Pressure Sensitive Adhesive , or in other words , Tapes with remoisten able Adhesive
Introduction :
PSA Tapes were first introduced about 150 years ago. Initially medical tape and dressing was developed and a U.S. Patent was issued in 1846.
PSA’s are widely used since the 19 th century. Industrial Tapes were introduced between the 1920 ,s and 1930,s .
Hot Melt adhesives were introduced in the 1940,s .
PSA Tapes are used for many different Applications.
These tapes are aggressively and permanently tacky at room temperatureand will adhere to a variety of surfaces with just finger or hand pressure.
They require no activation with water, solvents or heat.
PSA Tape consists of mainly two components, the Adhesive and the backing.The manufacturing process for both the backing material and the adhesive system must be carefully controlled and the two materials must be correctly matched in order to meet the demanding conditionsencountered in critical uses.
PSA Tapes provide only an easy way to apply the flexible backing. The Name itself suggests the application of little pressure by hand the Tape can be applied or removed with equal ease.
PSA Tapes provide a convenient and fast means of application that would be difficult to meet by other methods by hand.
The function of Pressure Sensitive Adhesive , is to provide instant adhesion on application without activation, easily removable or replaceable.
The adhesive will have sufficient strength so that the coated layer does not break up.
The adhesive bonding and de bonding involves certain amount of energy.
The PSA forms a film having good elasticity and have to possess properties like,
Tack , Peel and Shear
( the property which makes the product to stick quickly )
( the property responsible for resistance to remove or peel off from the applied surface )
and
( the property which decides the holding power of the product) .
Since all these properties are essential a balance of all these has to be worked out while designing a PSA.
( the property which makes the product to stick quick )
Tack is the Wet ability of PSA is nothing but to form a bond in a short time , with little pressure . hence the adhesive needs to have good flow.
( the property responsible for resistance to remove or peel off from the applied surface )
PEEL is the force required to peel off the PSA from the applied surface The following have an impact on the peel strength of a PSA.
( the property which decides the holding power of the product) .
Shear is the holding power of PSA is nothing but the resistance to shear stress.
Today we are going to discuss more about sealing and Packaging Tapes .
The sealing applications are many
Box or carton sealing
Acoustic or Duct sealing
Gap sealing
Various types of tapes are used for such application
Box or carton sealing tapes are mainly based on Film , paper or woven fabric
Gap sealing tapes are based on foams
And
Duct sealing tapes are based on metal foil, reinforced metal foil, plastic reinforced with woven fabric
PSA Tapes mainly consist of two main components , the carrier / backing material and the Adhesive.
Generally Tapes are produced by coating a carrier ( or backing material ) , such as plastic films , fabrics, paper or foil , with a adhesive , which is normally in liquid form.
These adhesives contain solvents , such as water, or organic chemicals such as toluene, ethyl acetate etc.
The solvent is evaporated with help of hot air impregnation , so that a dry adhesive film is formed , above the backing material with a firm bond .
In some cases the back-side of the tape is coated for non adhesive or release properties, which helps to have easy unwind property , with no adhesive transfer.
The Backing material
The backing material is the most important component of PSA Tapes .
The backing or carrier provided the necessary strength and body to tape product.
The backing has to be sufficiently strong .
The backing needs to have reasonably good tensile strength , elongation , conformability, moderate heat resistance , chemical resistance, abrasion resistance etc.
The various backing materials that are common in use are shown above.
The backing materials need a primer coat or chemical or physical , surface preparation / treatment before adhesive coating.
Surface Treatment
Plastics Films are widely used in Packaging applications such as Self Adhesive Tapes, Laminates, Printing etc.
As we know all these films are chemically inert and have very low surface energy. The below mentioned table gives an idea about the surface tension of various polymers.
19Poly Tetra Fluro Ethylene PTFE5
33Polystyrene PS4
27Poly iso butylene PIB3
32Poly Propylene PP2
31Poly Ethylene PE1
Surface Tension ofHomopolymer in Dynes/Cm2
PolymerSr.No.
Inner Paper Core
Silicone Paper Adhesive
The Backing MaterialAlu Foil / FSK / Alu Glass / Foam
Single Side Adhesive Tapes
Double Side Adhesive Tapes
Inner Paper Core
Silicone Paper
Adhesive Foam
PSA Tapes mainly consist of three main components , the carrier / backing material , the Adhesive , and the release paper
Generally Tapes are produced by coating a carrier ( or backing material ) , such as plastic films , fabrics, paper or foil with a adhesive , which is normally in liquid form.
The Adhesive Coated and Silicone coated Jumbo Rolls are then need to be converted into Log Rolls of required Lengths , and then they are , either Slit or Sliced into the required widths .
This process is known as
Rewinding
and
Slicing
Packaging tapes
Custom Printed Packaging Tape
Carton sealing tape printed with your company name. The low cost way to advertise your business and products. Ensures repeat orders Your company telephone number is always on hand Tapes are boldly printed in the colours of your choice Available in polypropylene or vinyl
2. Tapes with Non Pressure Sensitive Adhesive , or in other words , Tapes with remoisten able Adhesive
KSK Tape
Box sealed with KSK Tape
The Postal Stamp
Gummed Kraft Sealing
Features:
b) Applications: light packaging by coating Kraft paper with water - soluble adhesive
c) Can be overlapped
d) Suitable for printing and can be written on
e) No need to remove the tape from cardboard boxes before recycling
f) Kraft gummed tape made using recycled paper is also available
Acoustic or Duct sealing
Such as
Alu Glass TapeAlu . Foil Tape
FSK Tape
Foam Tape
Aluminium Foil Tapes
Moisture and chemically resistant - helps seal and protect many sensitive assemblies and surfaces Thermally conductive - maximizes efficiency when heating or cooling by increasing the transmission over a broader area Heat and light reflective - helps protect plastic components from heat warp age. Can help to improve visibility by magnifying light sources Flame resistant - helps protect parts from flame damage Outdoor performance - resists UV degradation and provides long lasting service
Applications
Heating and ventilation - duct sealing and air conditioning Glass & Glazing - edge sealing of double glazed sealed units - mirror backing. Building and construction - vapour barrier and thermal isolation and insulation Telecommunications - insulation and co-axial shielding
•Useful for outdoor & indoor applications of AC & hot-air ducting ,solar applications
•Die-cut applications in electrical industry
•Moisture and vapour barrier
•Prevents radiation
•Heat resistant
•Air-craft paint stripping
Insulation
on door panels to weatherproof the switchgear enclosed.to provide accustic damping.Thermal Insulation in Air Conditioning , Pollution Control and Mechanical applications
Ideal for thermal insulation, accoustic damping and weather stripping and almost all applications requiring heat or accoustic insulation.
Common application are in the Air conditioning industry to prevent heat loss from open gaps, crevices etc.Glassware Industry to provide a soft base for the glass panel to rest on or against to make safe for childeren.
Available in white and black colour in thicknesses from 1.00 mm to 25 mm. This is EVA foam tape with a greater structural strength, useful where larger gaps need to be filled. It also has a lower mass and higher air content improving its thermal insulation properties. Ideal for door panel gasketing and for packaging expensive equipment.
