A perforation is a small hole in a thin material or web. There is usually more than one perforation in an organized fashion, where all of the holes collectively are called a perforation. The process of creating perforations is called perforating, which involves puncturing the workpiece with a tool. Perforations are usually used to allow easy separation of two sections of the material, such as allowing paper to be torn easily along the line. Packaging with perforations in paperboard or plastic film is easy for consumers to open. Other purposes include filtrating fluids, sound deadening, allowing light or fluids to pass through, and to create an aesthetic design.Various applications include plastic films to allow the packages to breathe, medical films, micro perforated plate and sound and vapor barriers. Processes
Pins and needles
Rotary pinned perforation rollers are precision tools that can be used to perforate a wide variety of materials. The pins or needles can be used cold or heated. Cold perforation tools include needle punches. There are a handful of manufacturers that specialize in hot and cold needle perforation tooling and equipment. In materials that have elasticity this can result in a "volcano" hole that is preferred in many applications. Pinned rollers can be made from a variety of materials, including plastic, steel, and aluminum. In more brittle films, cold perforation can cause slitting rather than creating a round hole, which can jeopardize the materials integrity under pressure. The solution to this is often heating the pin; i.e. hot pin perforation.
Chlorothiazide, sold under the brand name Diuril among others, is an organic compound used as a diuretic and as an antihypertensive.It is used both within the hospital setting or for personal use to manage excess fluid associated with congestive heart failure. Most often taken in pill form, it is usually taken orally once or twice a day. In the ICU setting, chlorothiazide is given to diurese a patient in addition to furosemide (Lasix). Working in a separate mechanism from furosemide and absorbed enterically as a reconstituted suspension administered through a nasogastric tube (NG tube), the two drugs potentiate one another. It was patented in 1956 and approved for medical use in 1958. It is on the World Health Organizations List of Essential Medicines. Indications
Large amount of excess fluid including:
Heart failure
Peripheral edema
Hypertension

Contraindications
Anuria
Allergies to sulfa drugs

Side effects
Nausea / Vomiting
Headache
Dizziness
Excess urine production
Dehydration
Hypoelectrolytemia (esp. hypokalemia / hypomagnesia)

History
The research team of Merck Sharp and Dohme Research Laboratories of Beyer, Sprague, Baer, and Novello created a new series of medications, the thiazide diuretics, which includes chlorothiazide. They won an Albert Lasker Special Award in 1975 for this work.The structure has been determined by X-ray crystallography. See also
Hydrochlorothiazide


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