MANDREL– a usually tapered or cylindrical axle, spindle, or arbor inserted into a hole in a piece of work to support it during machining.
a metal bar that serves as a core around which material (such as metal) may be cast, molded, forged, bent, or otherwise shaped.
Mandrel, cylinder, usually steel, used to support a partly machined workpiece while it is being finished, or as a core around which parts may be bent or other material forged or molded.
Mandrel bending is a method of rotary draw bending, in which – the mandrel, a solid mandrel shaft with up to five segmented, donut shaped, balls that are just slightly smaller than the ID of the pipe/tube that is being bent – is inserted into the pipe/tube to provide internal support during bending.
MARCHING MODULUS– A marching modulus during vulcametry is a problem often observed in silica-filled S-SBR/BR tire tread compounds. A typical example is given in Figure 1, in which a plateau torque or a marching modulus may be obtained for one and the same compound formulation but different mixing conditions.
MASTERBATCH – Masterbatch is a concentrated mixture of pigments and/or additives encapsulated during a heat process into a carrier resin which is then cooled and cut into a granular shape. Masterbatch allows the processor to color raw polymer economically during the plastics process.
Typically, a masterbatch is available in either a liquid or pellet form and is comprised of a concentrated mixture of pigments, dyes and/or additives to color plastic products. Masterbatch is used in place of fully colored compounded materials largely referred to as pre-color.
MASTICATE– Mastication, the process by which the viscosity of natural rubber is reduced to a suitable level, is an important step in the mixing process. Rubber polymers such as Natural Rubber (NR) require mastication to reduce their viscosity/elasticity and to even out variations between different polymer lots.
Introduction. Rubber mixing process (RMP) is one of the determinations of physical and chemical properties of vulcanized rubber. RMP starts from rubber mastication and then followed by rubber chemicals and/or filler mixing into rubber.
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MATRIX – Matrix molding or matrix transfer molding is a technique often used during molding. The person doing the assembly will first create the rigid outer shell or flask, then introduce the softer and more fluid molding material between the shell and the prototype.
There are 5 types of plastic moulding that is considered to be the most effective and most popular. These 5 types are extrusion moulding, compression moulding, blow moulding, injection moulding and rotational moulding.
MECHANICAL PROPERTIES– Mechanical properties are physical properties that a material exhibits upon the application of forces. Examples of mechanical properties are the modulus of elasticity, tensile strength, elongation, hardness and fatigue limit.
What are the main mechanical properties?
MECHANICAL RUBBER GOODS– Mechanical rubber goods are used worldwide in a large number of applications. They are distinguished by high durability, flexibility and moldability. … They allow easy demolding of rubber parts, reduce soiling of the mold surface and ensure the dimensional accuracy of the molded rubber part.
The rubber goods in common use are air cushions, mackintoshes, hot water bottles, ice caps, ice collars rubber tubes, catheters, rectal tubes, gloves and rubber beds. The nurses should make all efforts to prolong the life of the rubber goods.
The process of sterilization which is used in Rubber Industry is Dry Air Sterilization. Dry Air Sterilization is the safest way to sterilize the products and the best testing equipment through which dry sterilization can be performed is Laboratory Hot Air Oven.
MICROMETER – A micrometer is a measuring instrument that can make extraordinarily precise measurements. Most micrometers are designed to measure within one one-thousandth of an inch! That’s a close fit. Exact measurements like this are necessary when even the smallest of space between objects can cause problems or difficulties.
Least count error: A metre ruler may have graduations at 1 mm division scale spacing or interval. A Vernier scale on a caliper may have a least count of 0.1 mm while a micrometer may have a least count of 0.01 mm.
Micrometer, in full micrometer caliper, instrument for making precise linear measurements of dimensions such as diameters, thicknesses, and lengths of solid bodies; it consists of a C-shaped frame with a movable jaw operated by an integral screw.
MICRON– A “micron” is an abbreviated term for “micrometer”, or a millionth of a meter (1/1,000,000 meters). This is about . 00004 inches. For Size comparison, a human red blood cell is about 5 microns across.
How many micron in 1 um? The answer is 1. We assume you are converting between micron and micrometre. You can view more details on each measurement unit: micron or um The SI base unit for length is the metre.
Micrometre, also called micron, metric unit of measure for length equal to 0.001 mm, or about 0.000039 inch. Its symbol is μm.
MIGRATION– Migration of compounding ingredients is an important factor in the overall properties and performance of rubber articles containing a number of layers for example, a tire, a hose or a conveyor belt. In certain cases, migration of compounding ingredients before, during and after vulcanization in rubber compounds can be of benefit. For example, waxes and p-phenylenediamines antiozonants rely heavily on the migration mechanism to provide optimum protection of rubber products during service against degradation by ozone. In addition, the dispersion of compounding ingredients such as oil, curatives, and antidegradants can be enhanced by diffusion within rubber. In other cases, however, diffusion across a rubber-to-rubber interface can be detrimental to performance. Diffusion will change the distribution of materials which in turn may result in changes in mechanical properties, loss in adhesion or antidegradant protection, and staining of light-colored products. Thus, a better understanding of the migration of chemical additives in rubber could provide the desired distribution of ingredients for obtaining the optimum compound performance.
MILL – A ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals, ceramic raw materials and paints. Ball mills rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium.
A mill is a device that breaks solid materials into smaller pieces by grinding, crushing, or cutting. Such comminution is an important unit operation in many processes. There are many different types of mills and many types of materials processed in them.
Any mixing process that utilizes the kinetic energy of relative fluid motion. The archetype of mechanical mixing is the instability of a vertically sheared flow.
Particles in a solution are mixed together evenly. … This makes the solution look like one substance. Particles in a mechanical mixture are not mixed evenly. The particles stay together in groups.
MILL SHRINKAGE- Shrinkage is a change in dimensions across the length and width of the fabric after washing, usage, and when exposed to the relaxing of fabrics. Mainly shrinkage is of two types. One is minus shrinkage and the other is plus shrinkage. Skew (twisting of the vertical grains) is also observed along with shrinkage.
Inventory shrinkage is the term used to describe the loss of inventory. … The term shrinkage is also used by manufacturers when referring to the loss of raw materials during a production process.
MODULUS – The moduli of rubber samples are typically expressed as the stress needed to strain a rubber sample for 25%, 50%, 100%, 200% and 300%. This is reported as Modulus 25%, Modulus 50% etc. The higher these percentages are, the stiffer the material is.
The most common method of determining the density of a rubber material is to weigh a test piece in air and water. Weighing in air provides the actual weight and weighing in water provides the volume. The density is then calculated by dividing the weight by the volume.
Rubber and elastomers are tested using various tension, compression, and adhesion tests. These tests are similar to those performed on other materials, but the key difference is in the control of the environment.
MODULUS OF ELASTICITY – modulus of elasticity and is defined as: The mechanical property of a material to withstand the compression or the elongation with respect to its length. … Young’s modulus describes the relationship between stress (force per unit area) and strain (proportional deformation in an object.
Young’s modulus is a measure of the ability of a material to withstand changes in length when under lengthwise tension or compression. Sometimes referred to as the modulus of elasticity, Young’s modulus is equal to the longitudinal stress divided by the strain.
It describes the relative stiffness of a material, which is measured by the slope of elastic of a stress and strain graph. It is calculated by the ratio of stress value to its corresponding strain value.
MOLD LUBRICATION – The main function of a self-lubricating mold component is to guide and control movement. Such a mold is typically made of aluminum bronze, an excellent bearing material, with embedded graphite plugs. … Graphite doesn’t evaporate and is relatively inert, so the lubrication it imparts is essentially permanent.
A lubricant is a substance which introduced to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. For example – motor oil, friction modifier, friction additive, gel, silicons, flourocarbons, ect.
Definition. Lubricant is a substance which is used to control (more often to reduce) friction and wear of the surfaces in a contact of the bodies in relative motion . Depending on its nature, lubricants are also used to eliminate heat and wear debris, supply additives into the contact, transmit power, protect, seal.
MOLD SHRINKAGE– Mold shrinkage is the phenomenon where the volume of the molten plastic filled inside the cavity of a mold is shrinking at the time as being cooled and solidifying.
Shrinkage (casting), size reduction of liquid metal as it solidifies. Shrinkage (concrete), size reduction of concrete as it sets and ages. Shrinkage (fabric), size reduction of fabric when washed with water or hot water.
Understanding how shrinkage happens in retail stores is the first step in reducing and preventing it.
MONOMER – A molecule that is a building block for larger molecules (polymers). For example, an amino acid acts as the building blocks for proteins.
A monomer is a molecule that forms the basic unit for polymers, which are the building blocks of proteins. Monomers bind to other monomers to form repeating chain molecules through a process known as polymerization. Monomers may be either natural or synthetic in origin.
A monomer is the smallest individual unit that can combine with other monomers to form polymers. A polymer is a large molecule that is composed of many repeating monomers bonded together. Monomers are joined together through a process called polymerization to form polymers.
MOONEY SCORCH – For a rubber specimen tested in a Mooney viscometer, the time elapsing after the minimum torque has been reached for torque to increase by five “Mooney units”.
Mooney viscosity is a property for elastomers and rubbers and defined as the shearing torque resisting rotation of a rotor disk embedded in rubber or elastomer within a cylindrical cavity. it is measured by using Mooney viscometer and calculated from the torque on the rotating disc of the machine.
(chemical engineering) In rubber manufacture, the time during which a rubber compound can be worked at a given temperature before curing begins.
Main entry – A main haulage road. Where the coal has cleats, main entries are driven at right angles to the face cleats.
Main fan – A mechanical ventilator installed at the surface; operates by either exhausting or blowing to induce airflow through the mine roadways and workings.
Manhole – A safety hole constructed in the side of a gangway, tunnel, or slope in which miner can be safe from passing locomotives and car. Also called a refuge hole.
Man trip – A carrier of mine personnel, by rail or rubber tire, to and from the work area.
Manager – The official in charge of a mine, surface and underground.
Manway – An entry used exclusively for personnel to travel form the shaft bottom or drift mouth to the working section; it is always on the intake air side in gassy mines. Also, a small passage at one side or both sides of a breast, used as a traveling way for the miner, and sometimes, as an airway, or chute, or both.
Measured coal resources – Coal for which estimates of the rank, quality, and quantity have been computed from sample analyses and measurements from closely spaced and geologically well-known sample sites, such as outcrops, trenches, mine workings, and drill holes. The points of observation and measurement are so closely spaced and the thickness and extent of coals are so well defined that the tonnage is judged to be accurate within 20 percent of true tonnage. Although the spacing of the points of observation necessary to demonstrate continuity of the coal differs from region to region according to the character of the coal beds, the points of observation are no greater than ½ mile apart. Measured coal is projected to extend as a ¼-mile wide belt from the outcrop or points of observation or measurement.
Medium-Volatile Bituminous Coal – A non-binding bituminous coal with 69-78% fixed carbon and 22-31% volatile matter.
Meta-Anthracite Coal – A non-binding anthracite coal that has 98% or more fixed carbon, and 2% or less volatile matter.
Meridian -– A surveying term that establishes a line of reference. The bearing is used to designate direction. The bearing of a line is the acute horizontal angle between the meridian and the line. Azimuths are angles measured clockwise from any meridian.
Meta-Anthracite Coal – A non-binding anthracite coal that has 98% or more fixed carbon, and 2% or less volatile matter.
Methane – A potentially explosive gas formed naturally from the decay of vegetative matter, similar to that which formed coal. Methane, which is the principal component of natural gas, is frequently encountered in underground coal mining operations and is kept within safe limits through the use of extensive mine ventilation systems.
Methane monitor – An electronic instrument often mounted on a piece of mining equipment, that detects and measures the methane content of mine air.
Mine development – The term employed to designate the operations involved in preparing a mine for ore extraction. These operations include tunneling, sinking, cross-cutting, drifting, and raising.
Mine mouth electric plant – A coal burning electric-generating plant built near a coal mine.
Miner – One who is engaged in the business or occupation of extracting ore, coal, precious substances, or other natural materials from the earth’s crust.
Mineral – An inorganic compound occurring naturally in the earth’s crust, with a distinctive set of physical properties, and a definite chemical composition.
Mining Engineer – A person qualified by education, training, and experience in mining engineering. A trained engineer with knowledge of the science, economics, and arts of mineral location, extraction, concentration and sale, and the administrative and financial problems of practical importance in connection with the profitable conduct of mining.
Misfire – The complete or partial failure of a blasting charge to explode as planned.
MSHA – Mine Safety and Health Administration; the federal agency which regulates coal mine health and safety.
Mud cap – A charge of high explosive fired in contact with the surface of a rock after being covered with a quantity of wet mud, wet earth, or sand, without any borehole being used. Also termed adobe, dobie, and sandblast (illegal in coal mining).
Mouth – The opening at the surface of any passage into a mine.