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Injection Molding Of Liquid Silicone Rubber
Injection molding of liquid silicone rubber (LSR) is a process to produce pliable, durable parts in high volume. Liquid silicone rubber is a high purity platinum cured silicone with low compression set, good stability and ability to resist extreme temperatures of heat and cold ideally suitable for production of parts, where high quality is required. Due to the thermosetting nature of the material, liquid silicone injection molding requires special treatment, such as intensive distributive mixing, while maintaining the material at a low temperature before it is pushed into the heated cavity and vulcanized. Chemically, silicone rubber is a family of thermoset elastomers that have a backbone of alternating silicon and oxygen atoms and methyl or vinyl side groups. Silicone rubbers constitute about 30% of the silicone family, making them the largest group of that family. Silicone rubbers maintain their mechanical properties over a wide range of temperatures and the presence of me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Silicone Rubber
Silicone rubber is an elastomer (rubber-like material) composed of silicone—itself a polymer—containing silicon together with carbon, hydrogen, and oxygen. Silicone rubbers are widely used in industry, and there are multiple formulations. Silicone rubbers are often one- or two-part polymers, and may contain fillers to improve properties or reduce cost. Silicone rubber is generally non-reactive, stable, and resistant to extreme environments and temperatures from while still maintaining its useful properties. Due to these properties and its ease of manufacturing and shaping, silicone rubber can be found in a wide variety of products, including voltage line insulators; automotive applications; cooking, baking, and food storage products; apparel such as undergarments, sportswear, and footwear; electronics; medical devices and implants; and in home repair and hardware, in products such as silicone sealants. Curing In its uncured state, silicone rubber is a highly adhesive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulcanization
Vulcanization (British: Vulcanisation) is a range of processes for hardening rubbers. The term originally referred exclusively to the treatment of natural rubber with sulfur, which remains the most common practice. It has also grown to include the hardening of other (synthetic) rubbers via various means. Examples include silicone rubber via room temperature vulcanizing and chloroprene rubber (neoprene) using metal oxides. Vulcanization can be defined as the curing of elastomers, with the terms 'vulcanization' and 'curing' sometimes used interchangeably in this context. It works by forming cross-links between sections of polymer chain which results in increased rigidity and durability, as well as other changes in the mechanical and electrical properties of the material. Vulcanization, in common with the curing of other thermosetting polymers, is generally irreversible. The word vulcanization is derived from Vulcan, the Roman god of fire and forge. History Rubber—latex� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubber
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, and Indonesia are three of the leading rubber producers. Types of polyisoprene that are used as natural rubbers are classified as elastomers. Currently, rubber is harvested mainly in the form of the latex from the rubber tree (''Hevea brasiliensis'') or others. The latex is a sticky, milky and white colloid drawn off by making incisions in the bark and collecting the fluid in vessels in a process called "tapping". The latex then is refined into the rubber that is ready for commercial processing. In major areas, latex is allowed to coagulate in the collection cup. The coagulated lumps are collected and processed into dry forms for sale. Natural rubber is used extensively in many applications and products, either alone or in combination ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastics Industry
The plastics industry manufactures polymer materials—commonly called plastics—and offers services in plastics important to a range of industries, including packaging, building and construction, electronics, aerospace, and transportation. It is part of the chemical industry. In addition, as mineral oil is the major constituent of plastics, it therefore forms part of the petrochemical industry. Besides plastics production, plastics engineering is an important part of the industrial sector. The latter field is dominated by engineering plastic as raw material because of its better mechanical and thermal properties than the more widely used commodity plastics. Companies Markets According to PlasticsEurope, the top three markets for plastics are packaging, building and construction, and automotive. Production Plastics production has been growing globally. The numbers include thermoplastics and polyurethanes, as well as thermosets, adhesives, coatings and sealants and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastomers
An elastomer is a polymer with viscoelasticity (i.e. both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus and high failure strain compared with other materials. The term, a portmanteau of ''elastic polymer'', is often used interchangeably with rubber, although the latter is preferred when referring to vulcanisates. Each of the monomers which link to form the polymer is usually a compound of several elements among carbon, hydrogen, oxygen and silicon. Elastomers are amorphous polymers maintained above their glass transition temperature, so that considerable molecular reconformation is feasible without breaking of covalent bonds. At ambient temperatures, such rubbers are thus relatively compliant ( E ≈ 3 M Pa) and deformable. Their primary uses are for seals, adhesives and molded flexible parts. Application areas for different types of rubber are manifold and cover segments as diverse as tires, soles for shoes, and dam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runner (casting)
In metalworking and jewelry making, casting is a process in which a liquid metal is delivered into a mold (usually by a crucible) that contains a negative impression (i.e., a three-dimensional negative image) of the intended shape. The metal is poured into the mold through a hollow channel called a sprue. The metal and mold are then cooled, and the metal part (the ''casting'') is extracted. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods. Casting processes have been known for thousands of years, and have been widely used for sculpture (especially in bronze), jewelry in precious metals, and weapons and tools. Highly engineered castings are found in 90 percent of durable goods, including cars, trucks, aerospace, trains, mining and construction equipment, oil wells, appliances, pipes, hydrants, wind turbines, nuclear plants, medical devices, defense products, toys, and more. Traditional techniques include lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sprue (manufacturing)
A sprue is the vertical passage through which liquid material is introduced into a mold and it is a large diameter channel through which the material enters the mold. It connects the pouring basin to the runner. In many cases it controls the flow of material into the mold. During casting or molding, the material in the sprue will solidify and need to be removed from the finished part. It is usually tapered downwards to minimize turbulence and formation of air bubbles. Casting In casting, a sprue is the passage through which a molten material is introduced into a mold, and the term also refers to the excess material which solidifies in the sprue passage. Function Sprues can serve as filters, as heat sinks, and as feeders. Bronze, in particular, has a high shrinkage rate as it is cooling. A sprue is tapered with its bigger end at the top to receive the liquid metal, the smaller end is connected to the runner. Sprue design The design of the sprue gating and runner is also essen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transfer Molding
Transfer molding ( BrE: transfer moulding) is a manufacturing process in which casting material is forced into a mold. Transfer molding is different from compression molding in that the mold is enclosed rather than open to the fill plunger resulting in higher dimensional tolerances and less environmental impact. Compared to injection molding, transfer molding uses higher pressures to uniformly fill the mold cavity. This allows thicker reinforcing fiber matrices to be more completely saturated by resin. Furthermore, unlike injection molding the transfer mold casting material may start the process as a solid. This can reduce equipment costs and time dependency. The transfer process may have a slower fill rate than an equivalent injection molding process. Process The mold interior surfaces may be gel-coated. If desired, the mold is first pre-loaded with a reinforcing fiber matrix or preform. Fiber content of a transfer molded composite can be as high as 60% by volume. The fil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Platinum is a member of the platinum group of elements and group 10 of the periodic table of elements. It has six naturally occurring isotopes. It is one of the rarer elements in Earth's crust, with an average abundance of approximately 5 μg/kg. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa, which accounts for ~80% of the world production. Because of its scarcity in Earth's crust, only a few hundred tonnes are produced annually, and given its important uses, it is highly valuable and is a major precious metal commodity. Platinum is one of the least reactive metals. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalyst
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry of all kinds. Estimates are that 90% of all commercially produced chemical products involve catalysts at some sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metering Pump
A metering pump moves a precise volume of liquid in a specified time period providing an accurate volumetric flow rate. Delivery of fluids in precise adjustable flow rates is sometimes called metering. The term "metering pump" is based on the application or use rather than the exact kind of pump used, although a couple types of pumps are far more suitable than most other types of pumps. Although metering pumps can pump water, they are often used to pump chemicals, solutions, or other liquids. Many metering pumps are rated to be able to pump into a high discharge pressure. They are typically made to meter at flow rates which are practically constant (when averaged over time) within a wide range of discharge (outlet) pressure. Manufacturers provide each of their models of metering pumps with a maximum discharge pressure rating against which each model is guaranteed to be able to pump against. An engineer, designer, or user should ensure that the pressure and temperature rating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubbers
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, and Indonesia are three of the leading rubber producers. Types of polyisoprene that are used as natural rubbers are classified as elastomers. Currently, rubber is harvested mainly in the form of the latex from the rubber tree (''Hevea brasiliensis'') or others. The latex is a sticky, milky and white colloid drawn off by making incisions in the bark and collecting the fluid in vessels in a process called "tapping". The latex then is refined into the rubber that is ready for commercial processing. In major areas, latex is allowed to coagulate in the collection cup. The coagulated lumps are collected and processed into dry forms for sale. Natural rubber is used extensively in many applications and products, either alone or in combination with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
