Soap Barring

Framing. The framed bar process is by far the oldest and the most straightforward process utilized in the production of bar soaps. The wet base soap is pumped into a heated, agitated vessel commonly referred to as a cmtcher. The minor ingredients used in soap bars such as fragrance or preservative are added to the wet soap in the cmtcher or injected in-line after reduction of product stream temperature. The hot mixture is then pumped into molds and allowed to cool. 

Milling not only provides intimate mixing, but also eliminates variation in ribbon thickness and cmshes lumpy materials, eg, overdried soap, which might impact finished bar texture. Milling is also used for the formation of the proper bar soap crystalline phase, which plays a critical role in both the performance properties of the soap bar and the handling characteristics of the in-process soap. For example, too hot a milling temperature can create sticky soap that is difficult to process further. 

Bar Soap Additives. There are a variety of additives that may be formulated into soap bars to provide additional consumer benefits or modify the performance of the products. 

Anionic surfactants are the most commonly used class of surfactant. Anionic surfactants include sulfates such as sodium alkylsulfate and the homologous ethoxylated versions and sulfonates, eg, sodium alkylglycerol ether sulfonate and sodium cocoyl isethionate. Nonionic surfactants are commonly used at low levels ( 1 2%) to reduce soap scum formation of the product, especially in hard water. These nonionic surfactants are usually ethoxylated fatty materials, such as H0CH2CH20(CH2CH20) R. These are commonly based on triglycerides or fatty alcohols. Amphoteric surfactants, such as cocamidopropyl betaine and cocoamphoacetate, are more recent surfactants in the bar soap area and are typically used at low levels (<2%) as secondary surfactants. These materials can have a dramatic impact on both the lathering and mildness of products (26). 

Table 2. Primary Manufacturers of Bar Soaps, Liquid Handsoaps, and Body Washes...

There are a variety of analytical methods commonly used for the characterization of neat soap and bar soaps. Many of these methods have been pubUshed as official methods by the American Oil Chemists Society (29). Additionally, many analysts choose United States Pharmacopoeia (USP), British Pharmacopoeia (BP), or Pood Chemical Codex (FCC) methods. These methods tend to be colorimetric, potentiometric, or titrametric procedures. However, a variety of instmmental techniques are also frequendy utilized, eg, gas chromatography, high performance Hquid chromatography, nuclear magnetic resonance spectroscopy, infrared spectroscopy, and mass spectrometry. 

In the soap, perfume, and flavor industries benzyl alcohol is primarily used in the form of its aUphatic esters. Benzyl benzoate [120-51-4] finds widespread use as a fragrance diluent. Benzyl alcohol is frequently employed in bar soap fragrances at 30—40 wt % of the fragrance. Benzyl alcohol is commercially available in five grades (Table 2). 

Because of factors of low cost, stabUity, and odor quaUty, PEA is ideaUy suited for use in bar soap fragrances where its use can be up to 30—50% of the fragrance. 

Stangen-blei, n. bar lead, -eiaen, n. bar iron, rod iron, -gold, n, ingot gold, -kali, n. potash in sticks, stick potash, -kitt, m. stick cement, -kupfer, n, bar copper, rod copper, -lack, m. stick-lac. -schwefel, m. roll sulfur, stick sulfur, cane brimstone, -seife, /. bar soap, -silber, n, ingot silver, -spat, m, columnar barite, -stahl, m. bar steel rod steel, -stein, m. pycnite (columnar topaz), -tabak, m. roll tobacco, -wachs, n. stick wax, stick polish, -zinn, n, bar tin. 

Commercial bar soaps contain sodium tallowate, sodium cocoate, sodium palmate, and similar ingredients, all of which are the results of reacting solid fats—tallow, coconut oil, and palm kernel oil, respectively—with lye. 

Sodium isethionate is an amphoteric detergent used in detergent bar soaps. It makes a dense lather in addition to the lather made by the soap. It is nondrying and mild on the skin. It works equally well in soft or hard water. It is also an antistatic agent in shampoos. 

Syndet bar soaps were developed for sensitive skin. Their pH value usually is around 5-6, far less than that of the normal soaps (pH 9-10), which is the reason for the latter causing dermal fissures with people who need frequent washing of their hands. The manufacture of syndet bar soaps requires special attention to methodology. A typical raw material composition of a syndet bar soap is as follows ... 

Koch and Kligman s [70] assessment of syndet bar soaps will be discussed in Sec. VI. To repeat their conclusion, the syndet bar soap containing a sulfo-succinate elicited the weakest skin reaction. 

Use about equal parts of soap and oil. If bar soap is used, slice it into small chips. If both gasoline and fuel oil are available, use both in equal parts. 

Atmospheric flash drying, in bar soap manufacture, 22 750-751 Atmospheric fluorine, detection of,... 

Barrier type aerosol system, 1 784-785 Bar soap, 22 727-728, 748-752. See also Soap bar entries... 

Casting, 70 12. See also Castings aluminum alloys, 2 333-334 in bar soap manufacture, 22 748, 749-750... 

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