Stain stick

You may have noticed that stains stick to some fabrics more than other fabrics. Also, different processes are used to remove different stains. This illustrates the principles used in chromatography. Chromatography separates components of a mixture based on how quickly molecules dissolved in a mobile phase solvent move along a solid phase. 

The next improvement was to use a strip of cellulose acetate, which is transparent (Figures 27-7 and 27-8). This was proposed by J. Kohn in 1957 (Biochem J., 65, 9). It is more homogeneous than paper and gives sharper resolution, and few stains stick to it, so the background is reduced. In addition, much shorter running times are needed. It is brittle when dry, but quite pliable and stronger than paper when wet. 

TREATING STAINS. Attack spills and smudges immediately. Use a solid stain stick or spot-treating liquid and carefully follow package directions because all fabrics and all stains are unique. 

Currently, the bottled prewash products on the store shelves do not vary much. The major producers have their products in a trigger spray, stain stick, or a container with a scrub brush on top. Aerosol products, once a familiar item on store shelves, are a rare sight. The chlorofluorocarbons (CFCs) which are the propellant found in aerosol products have been banned due to their effect on the ozone layer. Other propellants that may be on the market are flammable and hazardous. 

The next prewash product is the stick which is a solid surfactant product that can be placed in a push-up tube or, more commonly, in a screw-up tube. Stain sticks have grown in popularity with the consumer for a variety of reasons ... 

When choosing a surfactant for a stain stick, having the following characteristics in the surfactant will aid in making a better product ... 

Viscosity % Solids Appearance/color Density or specific gravity pH—5% in 50/50 IPA/water Softening point for stain sticks... 

One significant development in recent years has been the widespread treatment of clothing fabrics to give a measure of water and stain resistance. Mention may also be made of the expression Teflon-coated (Teflon is the DuPont trade name for PTFE) to describe a person, usually a politician, to whom no dirt (i.e. scandal) sticks, a reflection of the non-stick characteristics of the polymer ... 

Basic materials such as lime or magnesium oxide increase the hardening rate of novolak-hexa compositions and are sometimes referred to as accelerators. They also function as neutralising agents for free phenols and other acidic bodies which cause sticking to, and staining of, moulds and compounding equipment. Such basic substances also act as hardeners for resol-based compositions. 

Tape >System of Analysis. A tape system which is used widely for analysis in the Pediatric Laboratory is a system whose principle was developed by the author. A reagent is placed on a paper tape. The paper is covered with a membrane, such as cellophane, cellulose nitrate or cellulose acetate, porous to low molecular weight substances. Finally, the serum is placed above the porous membrane, so that diffusion of the components of serum take place and a stain is produced on the paper (60). This principle has been incorporated for example, with glucose oxidase, in the conmercially available Dextro-Sticks. In addition, a similar principle is being applied by some for the analysis of components in urine (Ames Co., South Bend, Indiana). 

PVF films are appreciated for weatherability, good chemical and staining resistance good non-stick properties, easy-to-clean properties low permeability good behaviour at low temperature good electrical insulating properties even in hot and wet environments fire resistance (but beware of toxic fumes). 

Silver nitrate, which is a caustic agent, is available as a stick or pen in combination with potassium nitrate and is suitable for the removal of warts on the hands and feet. It should be used with caution and patients are advised to protect the surrounding skin, as it can cause chemical burns. It can also cause staining of skin and fabric. 

Uses Removal of granulation tissue warts prophylaxis in bums Action Caustic antiseptic astringent Dose Adults Peds. Apply to moist surface 2-3 x wk for several wk or until effect Caution [C, ] Contra Do not use on broken skin Disp Topical impregnated applicator sticks, soln ophth topical ointment SE May stain tissue black, usually resolves local irritation, methemoglobinemia EMS None OD Unlikely... 

Using the eyedropper, spread one drop of the ferric chloride solution over the entire surface of one end of the sample stick. A stain will develop immediately. Use the other end as untreated control. Cut the stick in half and compare stained end and control end side by side. Record the color, intensity, and distribution of the stain that appears within the first 30 s ... 

DuPont registered the Teflon trademark in 1945 and released Its first Teflon products a year later. Since then the non-stick coating has become a household staple on kitchen cookware, in baking sprays, and as a stain repellantfor fabrics and textiles. 

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