 | This article may be confusing or unclear to readers. In particular, it is probably a poor translation from the German.(February 2017) |
A mechanical powder press is a machine press designed to compress powders, commonly used in the production of technical ceramics.
The function principles of the mechanic press machines differ in how to ensure the upper punch–main movement by cams, spindles-and friction drives, eccentric, knuckle-joints or by the round table principle, independent if the die-or lower punch movement is realized by cams- or eccentric systems or other mechanically or hydraulically combined systems. The executions of auxiliary movements are also not decisive for a term-classification. These auxiliary movements can also base on pneumatic and hydraulic principles. In comparison to hydraulic press machines the maximum compaction forces of mechanical powder presses are limited and are placed in the range >/= 5000 kN. For the requirements of wet-and dry pressing techniques in the field of Technical Ceramics cams-, eccentric-, knuckle joint- as well as round table presses have proved and tested, whereas cam-presses especially used for wet-press-techniques of pourable materials. The range of compaction force of mechanical presses for products of the Technical Ceramics is < 2500 kN, what is caused from the less density of the ceramic materials. Normally the upper punch-, lower punch- and die systems of mechanical presses don’t work on base of multi-subdivided punches.
Adaptable cam-executions, which can be made suitable individually to the concerned products, will meet especially the requirements of wet-press-technique of pourable compounds, while applications of eccentric-, knuckle-joint and round table presses are particularly related on the dry-press-technique of compounds with gliding characteristics. The sinusoidal movement of eccentric presses offers advantages especially for bigger strokes < 100 strokes per minute and the distorted sinusoidal movement of the knuckle joint is especially used for products, which need a longer time for deairing in the phase of compaction and a longer time for decompression after the bottom dead centre. For this kind of compaction technology the strokes are limited < 35 strokes per minute, but in contrast to that the compaction speed of round table presses for small and simple shaped products are especially high and quantities < 30,000 pcs per minute can be realized.
The unit of product–technology–press machine / tooling is characterizing the context between the ceramic compaction technology and the design principles of the mechanical presses. Distinctions of the die- withdrawal- and the ejection technology of the uniaxial dry- and wet-press- technique in the technical ceramics influence the approachable quality of the compactions in depending on the geometric shape of the products and in depending on the selected type of press. Because the achievement of a speed-proportional compaction relation with pure mechanical presses is very difficult to realize and high mechanical investments are necessary, more and more combined mechanic-hydraulic function principles on base of subdivided punches will win a higher signification, because the requirements of the high-accuracy-pressing can be met better. The design principles of particularly mechanical powder presses, explained in a dissertation of Dr.B.Froherz offer some base confrontation of advantages and disadvantages related to technology and presses especially for tool designers.
A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain, and brick.
A tablet is a pharmaceutical oral dosage form or solid unit dosage form. Tablets may be defined as the solid unit dosage form of medicament or medicaments with suitable excipients. It comprises a mixture of active substances and excipients, usually in powder form, pressed or compacted from a powder into a solid dose.
Sintering or frittage is the process of compacting and forming a solid mass of material by heat or pressure without melting it to the point of liquefaction.
Powder metallurgy (PM) is a term covering a wide range of ways in which materials or components are made from metal powders. PM processes can avoid, or greatly reduce, the need to use metal removal processes, thereby drastically reducing yield losses in manufacture and often resulting in lower costs.
A ball mill is a type of grinder used to grind or blend materials for use in mineral dressing processes, paints, pyrotechnics, ceramics, and selective laser sintering. It works on the principle of impact and attrition: size reduction is done by impact as the balls drop from near the top of the shell.
Many ceramic materials, both glassy and crystalline, have found use as optically transparent materials in various forms from bulk solid-state components to high surface area forms such as thin films, coatings, and fibers. Such devices have found widespread use for various applications in the electro-optical field including: optical fibers for guided lightwave transmission, optical switches, laser amplifiers and lenses, hosts for solid-state lasers and optical window materials for gas lasers, and infrared (IR) heat seeking devices for missile guidance systems and IR night vision.
A punch press is a type of machine press used to cut holes in material. It can be small and manually operated and hold one simple die set, or be very large, CNC operated, with a multi-station turret and hold a much larger and complex die set.
Spark plasma sintering (SPS), also known as field assisted sintering technique (FAST) or pulsed electric current sintering (PECS), or Plasma Pressure Compaction (P2C) is a sintering technique.
Ceramic forming techniques are ways of forming ceramics, which are used to make everything from tableware such as teapots to engineering ceramics such as computer parts. Pottery techniques include the potter's wheel, slip casting and many others.
Axial engines are a type of reciprocating engine with pistons arranged around an output shaft with their axes parallel to the shaft. Barrel refers to the cylindrical shape of the cylinder group whilst the Z-crank alludes to the shape of the crankshaft.
Ceramic engineering is the science and technology of creating objects from inorganic, non-metallic materials. This is done either by the action of heat, or at lower temperatures using precipitation reactions from high-purity chemical solutions. The term includes the purification of raw materials, the study and production of the chemical compounds concerned, their formation into components and the study of their structure, composition and properties.
The following outline is provided as an overview of and topical guide to machines:
Custom-fit means personalized with regard to shape and size. A customized product would imply the modification of some of its characteristics according to the customers requirements such as with a custom car. However, when fit is added to the term, customization could give the idea of both the geometric characteristics of the body and the individual customer requirements, e.g., the steering wheel of the Formula 1 driver Fernando Alonso.
Bioceramics and bioglasses are ceramic materials that are biocompatible. Bioceramics are an important subset of biomaterials. Bioceramics range in biocompatibility from the ceramic oxides, which are inert in the body, to the other extreme of resorbable materials, which are eventually replaced by the body after they have assisted repair. Bioceramics are used in many types of medical procedures. Bioceramics are typically used as rigid materials in surgical implants, though some bioceramics are flexible. The ceramic materials used are not the same as porcelain type ceramic materials. Rather, bioceramics are closely related to either the body's own materials or are extremely durable metal oxides.
Hot pressing is a high-pressure, low-strain-rate powder metallurgy process for forming of a powder or powder compact at a temperature high enough to induce sintering and creep processes. This is achieved by the simultaneous application of heat and pressure.
Tableting is a method of pressing medicine or candy into tablets. Confectionery manufacture shares many similarities with pharmaceutical production.
Carbon nanotube metal matrix composites (CNT-MMC) are an emerging class of new materials that mix carbon nanotubes into metals and metal alloys to take advantage of the high tensile strength and electrical conductivity of carbon nanotube materials.
Compaction of ceramic powders is a forming technique for ceramics in which granular ceramic materials are made cohesive through mechanical densification, either by hot or cold pressing. The resulting green part must later be sintered in a kiln. The compaction process permits an efficient production of parts to close tolerances with low drying shrinkage. It can be used for parts ranging widely in size and shape, and for both technical and nontechnical ceramics.
Ultra-high-temperature ceramics (UHTCs) are a class of refractory ceramics that offer excellent stability at temperatures exceeding 2000 °C being investigated as possible thermal protection system (TPS) materials, coatings for materials subjected to high temperatures, and bulk materials for heating elements. Broadly speaking, UHTCs are borides, carbides, nitrides, and oxides of early transition metals. Current efforts have focused on heavy, early transition metal borides such as hafnium diboride (HfB2) and zirconium diboride (ZrB2); additional UHTCs under investigation for TPS applications include hafnium nitride (HfN), zirconium nitride (ZrN), titanium carbide (TiC), titanium nitride (TiN), thorium dioxide (ThO2), tantalum carbide (TaC) and their associated composites.
Gyratory equipment, used in mechanical screening and sieving is based on a circular motion of the machine. Unlike other methods, gyratory screen operates in a gentler manner and is more suited to handle fragile things, enabling it to produce finer products. This method is applicable for both wet and dry screening.