Release agent
Encyclopedia
A release agent is a chemical used to get a slip effect. It can provide a solution in processes involving mold release, die-cast
release, plastic
release, and tire
and web
release.
construction industry, form release agents prevent the adhesion of freshly placed concrete to the forming surface, usually plywood
, overlaid plywood, steel
or aluminum. In this application, there are two types of release agents available: barrier and reactive.
Barrier release agents prevent adhesion
by the development of a physical film
or barrier
between the forming surface and the concrete.
Reactive release agents are chemically active and work by the process of a chemical reaction
between the release agent and the free limes available in fresh concrete. A soapy film is created which prevents adhesion. Because it is a chemically reactive process, there is generally little to no residue or unreacted product left on the forming surface or concrete which provides for a cleaner process.
Water based release agents is a result of more focus on health, environment and safety issues. This has resulted in development of new technologies in this area have focused largely on water based formulations and the movement has been away from petroleum or solvent based products.
from a cooking container after baking
or roasting
. Traditionally fat
or flour
have been used, but in industrial food processing other chemicals might be used. The application is called bakery release.
In bakery paper or greaseproof paper
release agents like catalyst cured silicone
release coatings may be used.
release agents are used to get slip effect of the paper from the processing equipment. A release agent may be applied on the process rolls (like the yankee cylinder) or in the paper coating.
Some paper
types are made with release coatings:
and casting
that aids in the separation of a mould from the material being moulded and reduces imperfections in the moulded surface.
Die casting
Die casting is a metal casting process that is characterized by forcing molten metal under high pressure into a mold cavity. The mold cavity is created using two hardened tool steel dies which have been machined into shape and work similarly to an injection mold during the process...
release, plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
release, and tire
Tire
A tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...
and web
Web (manufacturing)
A web is a long, thin, and flexible material. Common webs include foil, metal, paper, textile, plastic, and wire. Common processes carried out on webs include coating, plating, and laminating....
release.
Concrete
In the concreteConcrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
construction industry, form release agents prevent the adhesion of freshly placed concrete to the forming surface, usually plywood
Plywood
Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...
, overlaid plywood, steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
or aluminum. In this application, there are two types of release agents available: barrier and reactive.
Barrier release agents prevent adhesion
Adhesion
Adhesion is any attraction process between dissimilar molecular species that can potentially bring them in close contact. By contrast, cohesion takes place between similar molecules....
by the development of a physical film
Film
A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects...
or barrier
Barrier
A barrier or barricade is a physical structure which blocks or impedes something.Barrier may also refer to:-Physical barriers:* Automatic full barriers, which serve to block roads at railway crossings...
between the forming surface and the concrete.
Reactive release agents are chemically active and work by the process of a chemical reaction
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...
between the release agent and the free limes available in fresh concrete. A soapy film is created which prevents adhesion. Because it is a chemically reactive process, there is generally little to no residue or unreacted product left on the forming surface or concrete which provides for a cleaner process.
Water based release agents is a result of more focus on health, environment and safety issues. This has resulted in development of new technologies in this area have focused largely on water based formulations and the movement has been away from petroleum or solvent based products.
Food processing
Release agents are used to aid in the separation of foodFood
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
from a cooking container after baking
Baking
Baking is the technique of prolonged cooking of food by dry heat acting by convection, and not by radiation, normally in an oven, but also in hot ashes, or on hot stones. It is primarily used for the preparation of bread, cakes, pastries and pies, tarts, quiches, cookies and crackers. Such items...
or roasting
Roasting
Roasting is a cooking method that uses dry heat, whether an open flame, oven, or other heat source. Roasting usually causes caramelization or Maillard browning of the surface of the food, which is considered by some as a flavor enhancement. Roasting uses more indirect, diffused heat , and is...
. Traditionally fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
or flour
Flour
Flour is a powder which is made by grinding cereal grains, other seeds or roots . It is the main ingredient of bread, which is a staple food for many cultures, making the availability of adequate supplies of flour a major economic and political issue at various times throughout history...
have been used, but in industrial food processing other chemicals might be used. The application is called bakery release.
In bakery paper or greaseproof paper
Greaseproof paper
Greaseproof paper is paper that is impermeable to oil or grease and is normally used in cooking or food packaging. Normally greaseproof paper is produced by refining the paper stock and thus create a sheet with very low porosity. This sheet is supercalendered to further improve the density...
release agents like catalyst cured silicone
Silicone
Silicones are inert, synthetic compounds with a variety of forms and uses. Typically heat-resistant and rubber-like, they are used in sealants, adhesives, lubricants, medical applications , cookware, and insulation....
release coatings may be used.
Paper
In industrial papermakingPapermaking
Papermaking is the process of making paper, a substance which is used universally today for writing and packaging.In papermaking a dilute suspension of fibres in water is drained through a screen, so that a mat of randomly interwoven fibres is laid down. Water is removed from this mat of fibres by...
release agents are used to get slip effect of the paper from the processing equipment. A release agent may be applied on the process rolls (like the yankee cylinder) or in the paper coating.
Some paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
types are made with release coatings:
- Release linerRelease linerA Release liner is a paper or plastic based carrier web material, which is coated on one or two sides with a release agent, which provides a release effect against any type of a sticky material such as an adhesive or a mastic. Release liner are available in different colors, with or without...
s for pressure sensitive adhesive laminates and tapes - Casting papers
- General industrial release papers
- Food-grade release and packaging papers
Plastics
Release agents, also known as de-moulding agent, form oil, parting agent or form releaser, is a substance used in mouldingMolding (process)
Molding or moulding is the process of manufacturing by shaping pliable raw material using a rigid frame or model called a pattern....
and casting
Casting
In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process...
that aids in the separation of a mould from the material being moulded and reduces imperfections in the moulded surface.