Epoxy granite, also known as synthetic granite, [1] is a polymer matrix composite and is a mixture of epoxy and granite commonly used as an alternative material for machine tool bases. Epoxy granite is used instead of cast iron and steel for improved vibration damping, longer tool life, and lower assembly cost, and thus better properties for stabilizing and housing machines. [2] [3]
Machine tools and other high-precision machines rely upon high stiffness, long-term stability, and excellent damping characteristics of the base material for their static and dynamic performance. The most widely used materials for these structures are cast iron, welded steel fabrications, and natural granite. Due to the lack of long-term stability and very poor damping properties, steel fabricated structures are seldom used where high precision is required. Good-quality cast iron that is stress-relieved and annealed will give the structure dimensional stability, and can be cast into complex shapes, but needs an expensive machining process to form precision surfaces after casting. Natural granite has a higher damping capacity than cast iron, but similarly to cast iron can be labor-intensive and expensive to machine and finish. The traditional market for epoxy granite is to replace iron and steel in these applications. [4]
Precision granite castings are produced by mixing granite aggregates (which are crushed, washed, and dried) with an epoxy resin system at ambient temperature (i.e., cold curing process). Quartz aggregate filler can also be used in the composition. Vibratory compaction during the molding process tightly packs the aggregate together. Mechanical and thermo-mechanical properties can be improved further if fiber is used as well as the granite. [5] [6] Other resins in addition to the epoxy may also be used instead of fibers to improve properties such as water absorption. [7] If porosity is controlled, damping effects can be improved further. [8] Threaded inserts, steel plates, and coolant pipes can be cast-in during the casting process. To achieve an even higher degree of versatility, linear rails, ground slide-ways, and motor mounts can be replicated or grouted-in, therefore eliminating the need for any post-cast machining.
Epoxy resins and granite, specifically waste granite dust, may be used in other applications such as floor coatings. Waste granite filings are produced in the mining industry, and the low density means this can be easily dispersed by winds and thus distributed in the environment. Research is being done on innovative solutions such as using waste granite powders in epoxy resins and designing binders for coatings based on this. [9]
The vibration damping of epoxy granite is often claimed to be superior to that of steel or cast iron [10] It is also well known that iron and steel and alloys corrode or rust, whereas epoxy is often used to prevent corrosion. So, the corrosion and general chemical resistance of epoxy granite to most common solvents, acids, alkalis, and cutting fluids is superior to steel and alloys and does not require constant painting. [11] Epoxy granite material has an internal damping factor up to ten times better than cast iron, up to three times better than natural granite, and up to thirty times better than steel fabricated structure. [12] The method of casting compared to steel allows easier inclusion of inserts etc. and thus reduced machining of the finished casting and reduced assembly time by incorporating multiple components into one casting. [13] Polymer cast resins use very little energy to produce, and the casting process is done at room temperature. [14]
Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also collectively called epoxy. The IUPAC name for an epoxide group is an oxirane.
Thermal analysis is a branch of materials science where the properties of materials are studied as they change with temperature. Several methods are commonly used – these are distinguished from one another by the property which is measured:
In materials science, a thermosetting polymer, often called a thermoset, is a polymer that is obtained by irreversibly hardening ("curing") a soft solid or viscous liquid prepolymer (resin). Curing is induced by heat or suitable radiation and may be promoted by high pressure or mixing with a catalyst. Heat is not necessarily applied externally, and is often generated by the reaction of the resin with a curing agent. Curing results in chemical reactions that create extensive cross-linking between polymer chains to produce an infusible and insoluble polymer network.
Fibre-reinforced plastic is a composite material made of a polymer matrix reinforced with fibres. The fibres are usually glass, carbon, aramid, or basalt. Rarely, other fibres such as paper, wood, boron, or asbestos have been used. The polymer is usually an epoxy, vinyl ester, or polyester thermosetting plastic, though phenol formaldehyde resins are still in use.
Pre-preg is a composite material made from "pre-impregnated" fibers and a partially cured polymer matrix, such as epoxy or phenolic resin, or even thermoplastic mixed with liquid rubbers or resins. The fibers often take the form of a weave and the matrix is used to bond them together and to other components during manufacture. The thermoset matrix is only partially cured to allow easy handling; this B-Stage material requires cold storage to prevent complete curing. B-Stage pre-preg is always stored in cooled areas since heat accelerates complete polymerization. Hence, composite structures built of pre-pregs will mostly require an oven or autoclave to cure. The main idea behind a pre-preg material is the use of anisotropic mechanical properties along the fibers, while the polymer matrix provides filling properties, keeping the fibers in a single system.
A coating is a covering that is applied to the surface of an object, usually referred to as the substrate. The purpose of applying the coating may be decorative, functional, or both. Coatings may be applied as liquids, gases or solids e.g. Powder coatings.
Microstructure is the very small scale structure of a material, defined as the structure of a prepared surface of material as revealed by an optical microscope above 25× magnification. The microstructure of a material can strongly influence physical properties such as strength, toughness, ductility, hardness, corrosion resistance, high/low temperature behaviour or wear resistance. These properties in turn govern the application of these materials in industrial practice.
Vinyl ester resin, or often just vinyl ester, is a resin produced by the esterification of an epoxy resin with acrylic or methacrylic acids. The "vinyl" groups refer to these ester substituents, which are prone to polymerize and thus an inhibitor is usually added. The diester product is then dissolved in a reactive solvent, such as styrene, to approximately 35–45 percent content by weight. Polymerization is initiated by free radicals, which are generated by UV-irradiation or peroxides.
Pultrusion is a continuous process for manufacture of fibre-reinforced plastics with constant cross-section. The term is a portmanteau word, combining "pull" and "extrusion". As opposed to extrusion, which pushes the material, pultrusion pulls the material.
Polymer concrete, also known as Epoxy Granite, is a type of concrete that uses a polymer to replace lime-type cements as a binder. In some cases the polymer is used in addition to Portland cement to form Polymer Cement Concrete (PCC) or Polymer Modified Concrete (PMC). Polymers in concrete have been overseen by Committee 548 of the American Concrete Institute since 1971.
Aminoethylpiperazine (AEP) is a derivative of piperazine. This ethyleneamine contains three nitrogen atoms; one primary, one secondary and one tertiary. It is a corrosive organic liquid and can cause second or third degree burns. Aminoethylpiperazine can also cause pulmonary edema as a result of inhalation. It is REACH and TSCA registered.
Polymer engineering is generally an engineering field that designs, analyses, and modifies polymer materials. Polymer engineering covers aspects of the petrochemical industry, polymerization, structure and characterization of polymers, properties of polymers, compounding and processing of polymers and description of major polymers, structure property relations and applications.
A thermoset polymer matrix is a synthetic polymer reinforcement where polymers act as binder or matrix to secure in place incorporated particulates, fibres or other reinforcements. They were first developed for structural applications, such as glass-reinforced plastic radar domes on aircraft and graphite-epoxy payload bay doors on the Space Shuttle.
Carbon fiber-reinforced polymers, carbon-fibre-reinforced polymers, carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic, also known as carbon fiber, carbon composite, or just carbon, are extremely strong and light fiber-reinforced plastics that contain carbon fibers. CFRPs can be expensive to produce, but are commonly used wherever high strength-to-weight ratio and stiffness (rigidity) are required, such as aerospace, superstructures of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications.
In polymer chemistry, the term prepolymer or pre-polymer, refers to a monomer or system of monomers that have been reacted to an intermediate-molecular mass state. This material is capable of further polymerization by reactive groups to a fully cured, high-molecular-mass state. As such, mixtures of reactive polymers with un-reacted monomers may also be referred to as pre-polymers. The term "pre-polymer" and "polymer precursor" may be interchanged.
In materials science, a polymer matrix composite (PMC) is a composite material composed of a variety of short or continuous fibers bound together by a matrix of organic polymers. PMCs are designed to transfer loads between fibers of a matrix. Some of the advantages with PMCs include their light weight, high resistance to abrasion and corrosion, and high stiffness and strength along the direction of their reinforcements.
Neopentyl glycol diglycidyl ether (NPGDGE) is an organic chemical in the glycidyl ether family. It is aliphatic and a colorless liquid. It has the formula C11H20O4 and the CAS registry number of 17557-23-2. It has two oxirane groups per molecule. Its principle use is in modifying epoxy resins.
1,4-Butanediol diglycidyl ether (B14DODGE) is an organic chemical in the glycidyl ether family. It is aliphatic and a colorless liquid. It has two epoxide (oxirane) groups per molecule. Its main use is in modifying epoxy resins especially viscosity reduction.
1,6-Hexanediol diglycidyl ether is an organic chemical in the glycidyl ether family. It is an aliphatic compound that is a colorless liquid. It has two epoxide (oxirane) groups per molecule. Its main use is in modifying epoxy resins especially viscosity reduction whilst flexibilizing. It is REACH registered.
Castor oil glycidyl ether is a liquid organic chemical in the glycidyl ether family. It is sometimes called castor oil triglycidyl ether. It has the theoretical formula C66H116O12 and the CAS number 14228-73-0. The IUPAC name is 2,3-bis[12-(oxiran-2-ylmethoxy)octadec-9-enoyloxy]propyl 12-(oxiran-2-ylmethoxy)octadec-9-enoate. A key use is acting as a modifier for epoxy resins as a reactive diluent that adds flexibility and improved mechanical properties.