Heavy-duty liquid detergents (HDLDs) were introduced into the laundry market many years after the introduction of powder detergents

 The liquid crystalline phase is in the form of spherical lamellar bilayers or droplets. Contain layers of surfactant and water.

 A lamellar droplet is held together by an intrinsic balance of various inter- and intradroplet forces.  A stable structured liquid is achieved when the inter-and intralamellar forces are manipulated in such a way that phase separation is minimized or avoided.

 Structured liquids have the ability to suspend undissolved and insoluble solids. The unstructured clear liquids, by their very nature, don’t permit the use of insoluble materials.

* The length of the carbon chain strongly influence the ease of formulation and performance of the surfactant. A longer allyl chain  Increases the hydrophobocity of the molecule,  Lowers the critical micelle concentration (CMC)  And usually, provides better soil removal characteristic

2. Alcohol ethoxylated  nonionic surfactant  The high aqueous solubility of alcohol ethoxylates makes them a useful ingredient in unstructured liquids.  Excessive use of nonionic surfactants cause phase separation of HDLD.  Studies have shown that product containig:  LAS + alcohol ethoxylates  lower the CMC  provide improvements in the detergency.

3. Alkyl ether sulfates (AEOS)  anionic surfactants. 4. Alkyl sulfates  anionic surfactants 5. Polyhydroxy fatty acid amides (Glucamides) 6. Methyl ester sulfonates  anionic surfactants. 7. Other surfactants :  Soap is now used only as minor ingredient in HDLDs to provide foam control.  A variety of other surfactants are also used primarily for specialty applications. They include amine oxides, amphoterics, and betains.

Builder classes : a. organic b. Inorganic

2) Defoamers Used to minimize excessive foaming. 3) Hydrotropes It is sometimes necessary to use hydrotopes to sulubilize all ingredients in an unstructured liquids. 4) Minors A number of ingredients, although used in small amounts serve very important roles. Preservatives are needed to inhibit the growth of microorganisms in aqueous products.