Monday 9 May 2011

Adhesive products

Adhesive products



An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials. Adhesives cure (harden) by evaporating a solvent (these are most adhesives that cure at room temperature) or by exposing them to an elevated temperature.

Adhesion is any attraction process between dissimilar molecular species that can potentially bring them in "direct contact’’ By contrast cohesion takes place between similar molecules.

A self-adhesive stamp is a postage stamp with a pressure sensitive adhesive that does not require moistening in order to adhere to paper. They are usually issued on a removable backing paper

Gaffer tape, gaffer's tape, gaff tape or gaffa tape is a strong, tough, cotton cloth pressure sensitive tape that adheres strongly but can be removed cleanly. It is used on theater, film and television productions as well as live performances and any other kind of stage work. The tape is often referred to as a production expendable because it is discarded after the production process is complete.

Blu-Tack is a versatile, reusable putty-like pressure-sensitive adhesive, commonly used to attach papers to walls or other surfaces. The original version of the product was blue, but many colours are now available. Blu-Tack can leave an oily stain on paper materials if attached for a long period of time.
Pressure sensitive adhesive (PSA, self adhesive, self stick adhesive) is adhesive which forms a bond when pressure is applied to marry the adhesive with the adherend. No solvent, water, or heat is needed to activate the adhesive. It is used in pressure sensitive tapeslabels, note pads, automobile trim, and a wide variety of other products.
As the name "pressure sensitive" indicates, the degree of bond is influenced by the amount of pressure which is used to apply the adhesive to the surface.
Surface factors such as smoothness, surface energy, removal of contaminants, etc. are also important to proper bonding.
PSAs are usually designed to form a bond and hold properly at room temperatures. PSAs typically reduce or lose their tack at cold temperatures and reduce their shear holding ability at high temperatures; specialty adhesives are made to function at high or low temperatures. It is important to choose an adhesive formulation which is designed for its intended use conditions.
Pressure sensitive adhesives are manufactured with either a liquid carrier or in 100% solid form. Articles such as tapes and labels are made from liquid PSAs by coating the adhesive on a support and evaporating the organic solvent or water carrier, usually in a hot air dryer. The dry adhesive may be further heated to initiate a cross-linking reaction and increase molecular weight. 100% solid PSAs may be low viscosity polymers that are coated and then reacted with radiation to increase molecular weight and form the adhesive (radiation cured PSA); or they may be high viscosity materials that are heated to reduce viscosity enough to allow coating, and then cooled to their final form (hot melt PSA, HMPSA).

 

Contact adhesive
Contact adhesives are used in strong bonds with high shear-resistance like laminates, such as bonding Formica to a wooden counter, and infootwear, as in attaching outsoles to uppers.
Natural rubber and polychloroprene (Neoprene) are commonly used contact adhesives. Both of these elastomers undergo strain crystallization
Contact adhesives must be applied to both surfaces and allowed some time to dry before the two surfaces are pushed together. Some contact adhesives require as long as 24 hours to dry before the surfaces are to be held together. Once the surfaces are pushed together, the bond forms very quickly. It is usually not necessary to apply pressure for a long time, so there is less need for clamps.
Hot adhesive
Hot adhesives, also known as hot melt adhesives, are simply thermoplastics applied in molten form (in the 65-180 C range) which solidify on cooling to form strong bonds between a wide range of materials. These adhesives are popular for crafts because of their ease of use and the wide range of common materials they can join. A glue gun (shown at right) is one method of applying hot adhesives. The glue gun melts the solid adhesive then allows the liquid to pass through its barrel onto the material, where it solidifies.
Thermoplastic glue may have been invented around 1940 by Procter & Gamble as a solution to water-based adhesives commonly used in packaging at that time failing in humid climates, causing packages to open and become damaged.

Drying adhesives

There are two types of adhesives that harden by drying: solvent based adhesives and polymer dispersion adhesives, also known as emulsion adhesives.
Solvent based adhesives are a mixture of ingredients (typically polymers) dissolved in a solvent. White glue, contact adhesives and rubber cements are members of the drying adhesive family. As the solvent evaporates, the adhesive hardens. Depending on the chemical composition of the adhesive, they will adhere to different materials to greater or lesser degrees.
Polymer dispersion adhesives are milky-white dispersions often based on polyvinyl acetate (PVA). Used extensively in the woodworking and packaging industries. Also used with fabrics and fabric-based components, and in engineered products such as loudspeaker cones.

Reactive adhesives

Multi-part adhesives

Multi-part adhesives harden by mixing two or more components which chemically react. This reaction causes polymers to cross-link into acrylics, urethanes, and epoxies.[citation needed]

One-part adhesives

One-part adhesives harden via a chemical reaction with an external energy source, such as radiationheat, and moisture
Ultraviolet (UV) light curing adhesives, also known as light curing materials (LCM), have become popular within the manufacturing sector due to their rapid curing time and strong bond strength. Light curing adhesives can cure in as little as a second and many formulations can bond dissimilar substrates (materials) and withstand harsh temperatures. These qualities make UV curing adhesives essential to the manufacturing of items in many industrial markets such as electronics, telecommunications, medical, aerospace, glass, and optical. Unlike traditional adhesives, UV light curing adhesives not only bond materials together but they can also be used to seal and coat products. They are generally acrylic based.
Heat curing adhesives consist of a pre-made mixture of two or more components. When heat is applied the components react and cross-link. This type of adhesive includes epoxies, urethanes, and polyimides.
Moisture curing adhesives cure when they react with moisture present on the substrate surface or in the air. This type of adhesive includes cyanoacrylates and urethanes.

Natural adhesives

Natural adhesives are made from organic sources such as vegetable matter, starch (dextrin), natural resins or from animals e.g. casein oranimal glue. They are often referred to as bioadhesives. One example is a simple paste made by cooking flour in water. Animal glues are traditionally used in bookbinding, wood joining, and many other areas but now are largely replaced by synthetic glues. Casein’s are mainly used in glass bottle labelling. Starch based adhesives are used in corrugated board production and paper sack production, paper tube winding, wall paper adhesives. Another form of natural adhesive is blood albumen (made from protein component of blood), which is used in the plywood industry. Animal glue remains the preferred glue of the luthier. Casein based glues are made by precipitating casein from milkprotein using the acetic acid from vinegar. This forms curds, which are neutralized with a base, such as sodium bicarbonate (baking soda), to cause them to unclump and become a thicker plastic-like substance.

Synthetic adhesives

Synthetic adhesives are based on elastomersthermoplasticsemulsions, and thermosets. Examples of thermosetting adhesives are: epoxy,polyurethanecyanoacrylate and acrylic polymers.
Mechanism in adhesion
Adhesion, the attachment between adhesive and substrate may occur either by mechanical means, in which the adhesive works its way into small pores of the substrate, or by one of several chemical mechanisms. The strength of adhesion depends on many factors, including the means by which it occurs.
In some cases an actual chemical bond occurs between adhesive and substrate. In others electrostatic forces, as in static electricity, hold the substances together. A third mechanism involves the van der Waals forces that develop between molecules. A fourth means involves the moisture-aided diffusion of the glue into the substrate, followed by hardening.

Electrostatic adhesion

Some conducting materials may pass electrons to form a difference in electrical charge at the join. This results in a structure similar to a capacitor and creates an attractive electrostatic force between the materials.

Diffusive adhesion

Some materials may merge at the joint by diffusion. This may occur when the molecules of both materials are mobile and soluble in each other. This would be particularly effective with polymer chains where one end of the molecule diffuses into the other material. It is also the mechanism involved in sintering. When metal or ceramic powders are pressed together and heated, atoms diffuse from one particle to the next. This joins the particles into one.
History of adhesive
The oldest known adhesive, dated to approximately 200,000 BC, is from spear stone flakes glued to a wood with birch-bark-tar, which was found in central Italy. The use of compound glues to haft stone spears into wood dates back to round 70,000 BC. Evidence for this has been found in Sibudu Cave, South Africa and the compound glues used were made from plant gum and red ochre. The Tyrolean Iceman had weapons fixed together with the aid of glue.
6000-year-old ceramics show evidence of adhesives based upon animal glues made by rendering animal products such as horse teeth. During the times of Babylonia, tar-like glue was used for gluing statues. The Egyptians made much use of animal glues to adhere furniture, ivory, and papyrus. The Mongols also used adhesives to make their short bows, and the Native Americans of the eastern United States used a mixture of spruce gum and fat as adhesives to fashion waterproof seams in their birchbark canoes.
In medieval Europe, egg whites were used as glue to decorate parchments with gold leaf. The first actual glue factory was founded in Holland in the early 1700s. In the 1750s, the English introduced fish glue. As the modern world evolved, several other patented materials, such as bones, starch, fish, and casein, were introduced as alternative materials for glue manufacture. Modern glues have improved flexibility, toughness, curing rate, and chemical resistance.
In the late 1800s in Switzerland, casein was first used as a wood glue. Today, it is seen to be used to glue grocery bags

Adhesive market in India
Pidilite Industries Limited has become synonymous to adhesives and bonding agents. The company proudly owns the punch line Building bonds what with most of its offerings becoming eponymous to the product family they belong to. Remember fevicol, feviquick, M-Seal, Dr. Fixit just to name a few. It takes a lot to earn such a tag, from projecting the right image in all forms of public attention a la? media to making products which live up to the expectations that have been conjured.

 


Fevicol in India
The Fevicol story began in 1959, when the Parekh Group floated Pidilite Industries to capitalize on the potential market for synthetic resin adhesives, or "white glue" in India. The primary application of white glue was in woodworking, with secondary applications in upholstery, flooring, and footwear. Being a synthetic resin adhesive, the product’s ease of application worked as a unique selling proposition for the brand; this was at a time when unwieldy natural adhesives (which needed to be melted before use) were the norm in the wood furniture making industry.
Pidilite Industries decided to leverage the Fevicol brand’s success and popularity by launching a version suitable for the retail market. The first product line extension, a 30-gram collapsible tube, was introduced in the early 1970’s. Subsequently the company rolled out a spate of uniquely packaged Fevicol products, available for school students as well as professional and educational institutions. The introduction of various packaging formats helped transition the brand from the image of an industrial product to an all-purpose glue.
Few of the adhesive products in the Indian market are:
Brand and the brief description of the products are listed below-
Dr. Fixit Silicone Sealant (Adhesives & Sealants)
Multi Purpose Silicone Sealant.
Dr. Fixit Silicon Sealant comes in 2 variants:
General Purpose - Acetic Cure Silicon Sealant for windows.
Metal and Glazing purpose - Neutral Cure Silicon Sealant.
Applications:
  • Glass and Ceramics.
  • Metal and painted surfaces.
  • Non oil wood.
  • Sealing aluminum/ glass window frame joints, fixing glass into aluminum frames.
  • Bathroom fittings, Plastic and Tiles.
Features & Benefits
  • Fast curing silicone sealant.
  • Very strong adhesion.
  • High elasticity.

Fevicol 998 Fw (Adhesives & Sealants)

Used for bonding soles made of neolite rubber / leather / microcellular rubber to uppers made of leather, rubber, synthetic fabrics, etc. in manufacturing quality footwear.
Features & Benefits
  • Excellent bonding strength for high stress shoes & sandals.
  • Does not contain benzene.
  • Consistent quality.

Fevicol Foamfix (Adhesives & Sealants)

Synthetic rubber adhesive.

introducing fevicol foamfix with faster bonding to your expectation. Specially for making superior quality sofa, chair, mattresses etc.
Applications:
  • Foam / rubber foam to foam.
  • Upholstery ( rexine to foam / rubber foam ), wood / plywood to foam / rubber foam / rexine.
  • Metal to foam / rubber foam.
Features & benefits
  • Free from benzene - non hazardous to health.
  • Soft on foam, keeps foam shape intact.
  • Faster bonding.
  • Excellent spreadability.
  • Mild smell.
  • economical in long run

Fevicol Mr (Adhesives & Sealants)

  • Used for art & craft activities.
  • Used in activities like collage making, bread crafting, papier-mâché & other craft techniques.
  • Bonding/sticking paper, cardboard, thermocole, fabrics, wood, plywood, etc.

Features and benefits
  • Synthetic white adhesive.
  • Ready to use.
  • Strong bonding.
  • Simple and convenient to use.
  • Convenient pack sizes to meet different quantity requirements.

Fevicol Pl 222 (Adhesives & Sealants)

Used for bonding soles made of PVC, polyurethane, TPR, EVA to leather, synthetic fabric uppers in manufacturing quality footwear.
Features & Benefits
  • Excellent bonding strength to withstand high stress conditions.
  • Consistent & superior quality.

Fevigum (Adhesives & Sealants)

  • Used for sticking paper to paper.
Features and Benefits
  • Excellent paper to paper bonding.
  • Available in different fragrances and colors.
  • Attractive packaging.
  • Easy dispensing Packing made simple and convenient to use especially by children.

Fevistik (Adhesives & Sealants)

  • Used for bonding most plastics, rubber, ceramic, metal and porous materials like wood, leather.
  • Used for repairing broken plastic parts, joining footwear, leather articles, making ‘O` rings.
  • Bonding/sticking paper, cardboard, thermocole, fabrics, wood, plywood, etc.
Features & Benefits
  • Bonds in an instant.
  • Withstands temperature from -40°c to 90°c.
  • Clog resistant nozzle, preventing wastage.

M-seal (Adhesives & Sealants)

Used for sealing, joining, repairing and insulating ferrous and non-ferrous metals, glass, asbestos, concrete, ceramics, etc.
Used for sealing leakage in flush tank, wash basin pipes, radiators, etc. For joining chipped parts of ceramic, metal patterns, for repairing and insulating cable terminal entry into switch boxes, transformers, etc.
Can be used as a craft medium (especially m-seal white) for making decorative artifacts, murals etc.
Features and benefits
  • mouldable into different shapes.
  • Cures to hard mass for long lasting sea.
  • Can be shaped, drilled, filed, sanded, painted upon so as to suit the type of surface applied on.
  • Withstands temperature upto 120°c.
  • Available in different variants.
  • M-seal general purpose.
  • M-seal phataphat (for faster curing).
  • M-seal white (for a white finish).

Pv Seal (Adhesives & Sealants)

  • Used for joining and plugging leakage in rigid PVC pipe joints. 
  • For joining telecom cables, PVC drainage pipes, for industrial pipelines.
Features & Benefits
  • Specially formulated PVC solvent cement.
  • Viscous liquid form does not drip down in vertical pipe joints.
  • Withstands temperature from -30°C to 90°C.

1 comment:

  1. I am glad to meet this site, would it be okay if I ask question? Adhesives & Glues-Manufacturers Thank you so much and more power!

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