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Tearing (simulated)
Tearing is the act of breaking apart a material by force, without the aid of a cutting tool. A tear in a piece of paper, fabric, or some other similar object may be the result of the intentional effort with one's bare hands, or be accidental. Unlike a cut, which is generally on a straight or patterned line controlled by a tool such as scissors, a tear is generally uneven and, for the most part, unplanned. An exception is a tear along a perforated line, as found on a roll of toilet paper or paper towels, which has been previously partially cut, so the effort of tearing will probably produce a straight line. Materials vary in their susceptibility to tearing. Some materials may be quite resistant to tearing when they are in their full form, but when a small cut or tear is made, the material becomes compromised, and the effort needed to continue tearing along that line becomes less. Materials can be characterized by standard test methods to measure their tear resistance. There are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mending The Tears LACMA 54
The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure, and supporting utilities in industrial, business, and residential installations. Over time, this has come to include multiple wordings that describe various cost-effective practices to keep equipment operational; these activities occur either before or after a failure. Definitions Maintenance functions can defined as maintenance, repair and overhaul (MRO), and MRO is also used for maintenance, repair and operations. Over time, the terminology of maintenance and MRO has begun to become standardized. The United States Department of Defense uses the following definitions:Federal Standard 1037C and from MIL-STD-188 and from the Department of Defense Dictionary of Military and Associated Terms * Any activity—such as tests, measurements, replacements, adjustments, and repairs—intended to retain or restore a func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cutting Tool
In the context of machining, a cutting tool or cutter is typically a hardened metal tool that is used to cut, shape, and remove material from a workpiece by means of machining tools as well as abrasive tools by way of shear deformation. The majority of these tools are designed exclusively for metals. There are several different types of single edge cutting tools that are made from a variety of hardened metal alloys that are ground to a specific shape in order to perform a specific part of the turning process resulting in a finished machined part. Single edge cutting tools are used mainly in the turning operations performed by a lathe in which they vary in size as well as alloy composition depending on the size and the type of material being turned. These cutting tools are held stationary by what is known as a tool post which is what manipulates the tools to cut the material into the desired shape. Single edge cutting tools are also the means of cutting material performed by metal s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paper
Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed on the surface, followed by pressing and drying. Although paper was originally made in single sheets by hand, almost all is now made on large machines—some making reels 10 metres wide, running at 2,000 metres per minute and up to 600,000 tonnes a year. It is a versatile material with many uses, including printing, painting, graphics, signage, design, packaging, decorating, writing, and cleaning. It may also be used as filter paper, wallpaper, book endpaper, conservation paper, laminated worktops, toilet tissue, or currency and security paper, or in a number of industrial and construction processes. The papermaking process developed in east Asia, probably China, at least as early as 105 CE, by the Han court eunuch Cai Lun, although the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fabric
Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the only manufacturing method, and many other methods were later developed to form textile structures based on their intended use. Knitting and non-woven are other popular types of fabric manufacturing. In the contemporary world, textiles satisfy the material needs for versatile applications, from simple daily clothing to bulletproof jackets, spacesuits, and doctor's gowns. Textiles are divided into two groups: Domestic purposes onsumer textilesand technical textiles. In consumer textiles, aesthetics and comfort are the most important factors, but in technical textiles, functional properties are the priority. Geotextiles, industrial textiles, medical textiles, and many other areas are examples of technical textiles, whereas clothing and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cutting
Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force. Implements commonly used for wikt:cut, cutting are the knife and saw, or in medicine and science the scalpel and microtome. However, any sufficiently sharp object is capable of cutting if it has a hardness sufficiently larger than the object being cut, and if it is applied with sufficient force. Even liquids can be used to cut things when applied with sufficient force (see water jet cutter). Cutting is a compression (physical), compressive and shearing (physics), shearing phenomenon, and occurs only when the total stress (physics), stress generated by the cutting implement exceeds the ultimate Strength of materials, strength of the material of the object being cut. The simplest applicable equation is: \text = or \tau=\frac The stress generated by a cutting implement is directly proportional to the force with which it is applied, and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scissors
Scissors are hand-operated shearing tools. A pair of scissors consists of a pair of metal blades pivoted so that the sharpened edges slide against each other when the handles (bows) opposite to the pivot are closed. Scissors are used for cutting various thin materials, such as paper, cardboard, metal foil, cloth, rope, and wire. A large variety of scissors and shears all exist for specialized purposes. Hair-cutting shears and kitchen shears are functionally equivalent to scissors, but the larger implements tend to be called shears. Hair-cutting shears have specific blade angles ideal for cutting hair. Using the incorrect type of scissors to cut hair will result in increased damage or split ends, or both, by breaking the hair. Kitchen shears, also known as kitchen scissors, are intended for cutting and trimming foods such as meats. Inexpensive, mass-produced modern scissors are often designed ergonomically with composite thermoplastic and rubber handles. Terminology The noun ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perforation
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toilet Paper
Toilet paper (sometimes called toilet tissue or bathroom tissue) is a tissue paper product primarily used to clean the anus and surrounding anal region of feces after defecation, and to clean the perineal area and external genitalia of urine after urination or other bodily fluid releases. It also acts as a layer of protection for the hands during these processes. It is usually supplied as a long strip of perforated paper wrapped around a paperboard core for storage in a dispenser near a toilet. The bundle is known as a toilet roll, or loo roll or bog roll in Britain. There are other uses for toilet paper, as it is a readily available household product. It can be used like facial tissue for blowing the nose or wiping the eyes. Some women may use the paper to absorb the bloody discharge that comes out of the vagina during menstruation. It can be used to wipe off sweat or absorb it. Toilet paper can be used in cleaning like a less abrasive paper towel. As a prank, toile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paper Towel
A paper towel is an absorbent, disposable towel made from paper. In Britain, paper towels for kitchen use are also known as kitchen rolls, kitchen paper, or kitchen towels. For home use, paper towels are usually sold in a roll of perforated sheets, but some are sold in stacks of pre-cut and pre-folded layers for use in paper-towel dispensers. Unlike cloth towels, paper towels are disposable and intended to be used only once. Paper towels absorb water because they are loosely woven, which enables water to travel between the fibers, even against gravity ( capillary effect). They have similar purposes to conventional towels, such as drying hands, wiping windows and other surfaces, dusting, and cleaning up spills. Paper towel dispensers are commonly used in toilet facilities shared by many people, as they are often considered more hygienic than hot-air hand dryers or shared cloth towels. History In 1907, the Scott Paper Company of Philadelphia, Pennsylvania, introduced paper tiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test Method
A test method is a method for a test in science or engineering, such as a physical test, chemical test, or statistical test. It is a definitive procedure that produces a test result. In order to ensure accurate and relevant test results, a test method should be "explicit, unambiguous, and experimentally feasible.", as well as effective and reproducible. A test can be considered an observation or experiment that determines one or more characteristics of a given sample, product, process, or service. The purpose of testing involves a prior determination of expected observation and a comparison of that expectation to what one actually observes. The results of testing can be qualitative (yes/no), quantitative (a measured value), or categorical and can be derived from personal observation or the output of a precision measuring instrument. Usually the test result is the dependent variable, the measured response based on the particular conditions of the test or the level of the independ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tear Resistance
Tear resistance (or tear strength) is a measure of how well a material can withstand the effects of tearing. It is a useful engineering measurement for a wide variety of materials by many different test methods. Discussion For example, with rubber, tear resistance measures how the test specimen resists the growth of any cuts when under tension, it is usually measured in kN/ m.Tear Resistance., , 15 June 2012 Tear resistance can be measured by the ''ASTM D 412'' method (the same used to measure tensile strength, modulus and elongation). ASTM D 624 can be used to measure the resistance to the formation of a tear (tear initiation) and the resistance to the expansion of a tear (tear propagation). Regardless of which of these two is being measured, the sample is held between two holders and a uniform pulling force applied until the aforementioned deformation occurs. Tear resistance is then calculated by dividing the force applied by the thickness of the material. Materials with low ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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