Talalay Process
Encyclopedia
The Talalay process is a method of producing molded pieces of natural latex
foam rubber
. A natural liquid latex rubber base is introduced to a closed mold that has been vacuumed of air. The mold is then frozen to stabilize the cell structure. Carbon dioxide
gas is introduced and the mold is heated to cure the rubber. The result is marketed as a healthier alternative to petroleum
-based foams since petroleum-based foams give off volatile organic compounds as they age. In the marketing of products such as beds that include natural latex foams created with the Talalay process, these products are sometimes characterised as 'organic
' or as completely natural. However this claim may not be completely true since unspecified curing agents are used in the Talalay process and ammonia
is commonly used to stabilize liquid rubber.
Leon, Joseph and Ansil Talalay developed the “Talalay” process at various commercial entities. B.F. Goodrich in Shelton CT, Dunlopillo in Harrigot UK, and Radium LLC in Maastricht, NL, made this process commercially practical in the late 1940s. This process utilizes a closed mold with pre-vacuum, followed by freezing to maintain uniform bubble geometry. Carbon Dioxide (CO2) is flooded through the frozen, open foam matrix to form carbonic acid (CO2+H2O-> H2CO3). Much like the addition of Na2SiF6 in the Dunlop process, the carbonic acid lowers the pH
, thereby causing gellation. In the next process step, vulcanization locks the foam into a uniform bubble distribution.
The first Talalay production plants were built in England, Canada and the US. The Talalay process is an elaborate process that yields very controlled densities and product “feel”. The formulation uses many of the same base components as the Dunlop formulation, but without gellation reagents.
After the foamer aeration step, the compound is distributed into an opened mold in a precise volume and pattern. The Talalay type mold is designed to be closed and sealed with pressure provided by press hydraulics. After closing the mold, a vacuum is applied to the interior, thereby causing the air matrix bubbles to “inflate” and fill out the mold form4.
While being supported by the vacuum, the mold and foam mass temperature is reduced to -20F (-28C) and frozen in place. Because the resultant foam matrix is open, carbon dioxide can be pushed through the structure, thereby forming carbonic acid that moves the pH from above 10 to 7. The reduction in alkalinity triggers the foam to gel in place and hold its shape. The mold temperature can then be incrementally raised to the vulcanization temperature of 230F (115C) for a measured amount of time. At this point, the foam form can be de-molded and sent to a washing step. Typical molding cycles are 60 minutes. After washing, the foam form is introduced into the vulcanizer stage to complete the cross-linking process. The final step is the drying process where residual moisture is driven off.
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
foam rubber
Foam rubber
Foam rubber refers to rubber that has been manufactured with a foaming agent to create an air-filled matrix structure. Commercial foam rubbers are generally either polyurethane foam or natural foam rubber latex. Latex foam rubber, used in mattresses, is well-known for its endurance.-See also:*...
. A natural liquid latex rubber base is introduced to a closed mold that has been vacuumed of air. The mold is then frozen to stabilize the cell structure. Carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
gas is introduced and the mold is heated to cure the rubber. The result is marketed as a healthier alternative to petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
-based foams since petroleum-based foams give off volatile organic compounds as they age. In the marketing of products such as beds that include natural latex foams created with the Talalay process, these products are sometimes characterised as 'organic
Organic movement
The organic movement broadly refers to the organizations and individuals involved worldwide in the promotion of organic farming, which is a more sustainable mode of agriculture...
' or as completely natural. However this claim may not be completely true since unspecified curing agents are used in the Talalay process and ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
is commonly used to stabilize liquid rubber.
Leon, Joseph and Ansil Talalay developed the “Talalay” process at various commercial entities. B.F. Goodrich in Shelton CT, Dunlopillo in Harrigot UK, and Radium LLC in Maastricht, NL, made this process commercially practical in the late 1940s. This process utilizes a closed mold with pre-vacuum, followed by freezing to maintain uniform bubble geometry. Carbon Dioxide (CO2) is flooded through the frozen, open foam matrix to form carbonic acid (CO2+H2O-> H2CO3). Much like the addition of Na2SiF6 in the Dunlop process, the carbonic acid lowers the pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
, thereby causing gellation. In the next process step, vulcanization locks the foam into a uniform bubble distribution.
The first Talalay production plants were built in England, Canada and the US. The Talalay process is an elaborate process that yields very controlled densities and product “feel”. The formulation uses many of the same base components as the Dunlop formulation, but without gellation reagents.
After the foamer aeration step, the compound is distributed into an opened mold in a precise volume and pattern. The Talalay type mold is designed to be closed and sealed with pressure provided by press hydraulics. After closing the mold, a vacuum is applied to the interior, thereby causing the air matrix bubbles to “inflate” and fill out the mold form4.
While being supported by the vacuum, the mold and foam mass temperature is reduced to -20F (-28C) and frozen in place. Because the resultant foam matrix is open, carbon dioxide can be pushed through the structure, thereby forming carbonic acid that moves the pH from above 10 to 7. The reduction in alkalinity triggers the foam to gel in place and hold its shape. The mold temperature can then be incrementally raised to the vulcanization temperature of 230F (115C) for a measured amount of time. At this point, the foam form can be de-molded and sent to a washing step. Typical molding cycles are 60 minutes. After washing, the foam form is introduced into the vulcanizer stage to complete the cross-linking process. The final step is the drying process where residual moisture is driven off.