Immersion dyeing

Alternative procedures are paddle dyeing for sensitive skins in an open vessel, and immersion dyeing, in which the leather passes through a dye solution and is subsequently squeezed by a roller. Spraying and roller machines have mostly replaced other techniques such as traditional brush dyeing, which colors the surface only. 

Immersion Dyeing , Pro Chemical Dye, http //www.prochemical.com/directions/VatDyesIm-mersion.htm, 2003. 

It has been used as a bird repellant and is the parent compound of the anthraquinone vat dyes in which the dyeing is carried out by immersion in the reduced vat solution followed by air oxidation to the original insoluble compound. 

The direct microscopic count determines the number of viable and dead microorganisms ia a milk sample. A small amount (0.01 mL) of milk is spread over a 1.0 cm area on a microscope sHde and allowed to dry. After staining with an appropriate dye, usually methylene blue, the sHde is examined with the aid of a microscope (oil immersion lens). The number of bacterial cells and clumps of cells per microscopic field is determined and, by appropriate calculations, is expressed as the number of organisms per milliliter of sample. 

Zeta Potential. When a textile is immersed in water a negative charge is developed on its surface. This is caked the 2eta potential. This happens even with ionic fibers in neutral dyebaths. Negatively charged dyes therefore are coulombicaUy repeUed. 

Isotherms. When a fibei is immersed, in a dyebath, dye moves fiom the external phase into the fibei. Initially the late is quick but with time this slows and eventually an equiUbrium is reached between the concentration of dye in the fiber and the concentration of dye in the dyebath. For a given initial dyebath concentration of a dye under given dyebath conditions, eg, temperature, pH, and conductivity, there is an equiUbrium concentration of dye in fiber, Dj and dye in the dyebath external solution, D. Three models describe this relationship simple partition isotherm, Freundhch isotherm, and Langmuir isotherm. 

Taucherkolben, m. (Mach.) plunger. Tauch-farbe, /. dipping color, -ftlrbimg, /. dip dyeing dip coloring, -filter, n. immersion... 

Tests for quality of sealing of anodic coatings have become internationally standardised. They include dye spot tests with prior acid treatment of the surface (ISO 2143 1981 and BS 6161 Part 5 1982), measurement of admittance or impedance (ISO 2931 1983 and BS 6161 Part 6 1984), or measurement of weight loss after acid immersion (ISO 3210 1983 and BS 6161 Part 3 1984, and ISO 2932 1981 and BS 6161 Part 4 1981). Of these the chromic-phosphoric acid immersion test (ISO 3210) has become the generally accepted reference test. 

Ampoules that have been sealed by fusion must be tested to ensure that a hermetic seal was obtained. The leaker test is performed by immersing the ampoules in a dye solution, such as 1% methylene blue, and applying at least 25 in. (64 cm) of vacuum for a minimum of 15 minutes. The vacuum on the tank is then released as rapidly as possible to put maximum stress on weak seals. Next, the ampoules are washed. Defective ampoules will contain blue solution. 

Among some of the test procedures that may be used for monitoring package integrity over time are dye immersion testing using either pressure or vacuum,... 

The natural dye was extracted by immersion of fresh Morns nigra (black mulberry) in ethanol for several hours. The pure violet dye extract, a blend of p-carotene and Morus nigra, and a composite blend of chlorophyll A and B, carminic acid, trans-P-carotene, and Morus nigra extracts (hereafter called Mix) were deposited on Ti02. 

---