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| Ultrachemical Product Information - Return to Products List
Material Description: Penreco Candle Gels are manufactured from a specially selected and processed mineral oil. They are gelled with copolymers that give them a clear rubbery texture. Candle gels contain no crystalline components. They undergo no true first order transitions as they are heated from room temperature to over 212°F (100°C). Unlike waxes that go through melting transitions at specific temperatures, Versagels™ simply decrease in viscosity as they are heated. The viscosity of candle gels can only be measured at elevated temperatures. Even at high temperatures their rheology is not simple. They are described as "visco elastic" to reflect their rubbery and viscous properties. The accompanying figure shows a typical plot of viscosity on a log scale versus temperature. The data were generated using a Brookfield Thermosel viscometer. It is obvious that the viscosity increases rapidly at low temperatures, especially below 212°F (100°C). Since there are no transitions involved in heating Versagel C™ the total amount of heat required to raise the temperature can be calculated strictly from the specific heat. A typical specific heat for Penreco Candle Gels is 0.454 BTU/lb - °F. To heat a drum of 360 net pounds from 60°F (15°C) to 212°F (100°C) would require approximately 24,840 BTU's, (26,180 KJ). Handling and Storage: It is obvious that Penreco Candle Gels must be heated in order to make them fluid enough to incorporate dyes, fragrances and any other ingredients desirable in the final product. Generally, the additives will tend to decrease the viscosity. The first obstacle is to remove the gels from the drums. Penreco drums are 20/18 gauge steel and they have 2 inch and 3/4 inch bungs on their tops. The entire lid can be removed by unbolting a retainer ring that holds the lid in place. There are many ways to heat drums. Several companies, listed below, sell equipment to heat 5 gallon drums of adhesives, cable fillers, etc. This same equipment may be used for handling candle gels. Another approach is to use flexible heating belts that are made to fit around a 55-gallon drum. As many as three belts can be strapped to a single drum. Trials at Penreco showed that a drum with three heat belts could easily melt the contents of a full drum of Versagel™ C MP candle gel in less than 24-hours. Manufactures of drum heating belts are listed below. Positive displacement pumps can be used to move liquid candle gels from drums to the filling equipment. It may be necessary to heat trace pumps, as well as input and output lines to maintain a fluid state. Insulation on lines will help maintain a constant temperature and reduce operating costs. A list of pump manufactures is shown below. Penreco candle gels are also available in heated and insulated tank trucks. These trucks can deliver as much as 44,000 lbs of liquid candle gel. Of course these quantities will require an investment in heated storage tanks and other equipment. Caution: Use protective clothing, gloves, and face shield when working with hot materials. See MSDS.
*FOR Versagel™ C-LP, MP, HP respectively Stability: Penreco Candle Gels are very stable materials. However, prolonged heating can eventually cause them to develop a yellow color and odor. This is caused by auto oxidation of some of the hydrocarbons in the gels. It is difficult to predict when auto oxidation will begin because it depends on a number of factors. The most important are time and temperature. Continuous heating of Versagel™ Candle Gels above 110°C (230°F) is not recommended. However, a few days at that temperature will not cause a problem. The material can be held for a week at 100°C (212°F) or for a longer period of time at lower temperatures. As mentioned above there are other factors that can effect oxidative stability. Obviously, reducing oxygen exposure would reduce the possibility of the material degrading. Replacing the air above the surface of hot candle gel with an inert gas such as nitrogen would permit longer heating at higher temperatures. Unfortunately inert gas systems are expensive to install and maintain. Oxidation can occur quickly when thin films of candle gel are exposed to hot surfaces. This can happen when the level of a storage tank drops but the walls are still heated. It can also occur in piping after the material has been drained of the bulk of the material but a residual remains. If heat tracing remains on, the residual may quickly oxidize. A small amount of oxidized material can cause an odor in a large volume of candle gel the next time that line is used. It is important, therefore, to discontinue heating surfaces that do not contain bulk quantities of candle gel. Penreco staff members are available to help in any way that we can. You can reach our sales, shipping, and technical departments at Karns City, PA by calling 1-800-245-3952 for any assistance.
*The list of manufacturers provided is not intended to be a comprehensive list of all manufacturers of the type of equipment list. Penreco does not in any way endorse or recommend that equipment be purchased from any of the listed manufacturers. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
