http://www.runyvmat.com/As the industry leader in phosphine ligands and catalysts for homogeneous catalysis, Solvay offers a range of phosphorus compounds used in a breadth of applications and markets. Our scalable phosphorus chemistry meets the unique requirements of reactions that are crucial to several manufacturing processes across markets and applications, including petrochemicals, life sciences, flavors and fragrances, agrochemicals, fine chemicals, and plastics and other polymers. And do you what is Phosphine Ligands? Phosphines are a three-valent phosphorus compound and act as a "soft" σ-donating ligand with an unshared electron pair. This gives solubilization and stabilization to organometallic complexes by forming complexes with various transition metal species including latter-period transition metals and others, and is also used for controlling the reactivity and selectivity of the transition metal promoted reactions. Electron density and bulkiness of phosphine ligands are greatly related to the reactivity of their forming metal complexes. Generally, the phosphine ligands with high electron density increase the reactivity of oxidative addition from a metal center, and their bulkiness improves the reductive elimination. For example, trialkylphosphines especially tert-butyl or cyclohexyl group substituted phosphines show the highest electron density while the electron density of triarylphosphines and phosphite are sequentially decreasing. On the other hand, as an index of the bulkiness of phosphine ligands, that of monodentate phosphine ligands shows the cone angle (θ) while bidentate phosphine ligands show the bite angle (ω). As the angle of the phosphine ligands is wider, their steric effect is greater and they are regarded as more bulky phosphine ligands. A monodentate phosphine ligand of tri(o-tolyl)phosphine, and bidentate phosphine ligands of 1,1'-bis(diphenylphosphino)ferrocene and Xantphos are known as representative bulky phosphine ligands. There are many different kinds of Phosphine Ligands, such as Chiral Phosphine Ligands, Chelated Phosphine Ligands, Biaryl Phosphine Ligand, Trisubstituted Phosphine Ligands and Other Phosphine Ligands. Homogeneous catalysis is an efficient alternative to its heterogeneous counterpart, and enables access to certain molecules that are not accessible through heterogeneous catalysis. Our high-performance phosphine ligands provide endless customization opportunities for catalytic processes. Phosphorus chemistry offers substantial diversity of structure, tunability and thermal stability, which leads to its use in many essential industries and an abundance of applications. A majority of Solvay's phosphorus technologies are available in liquid or solution form, which facilitates ease of handling and safe product stewardship. Solids are available if preferred. Produced via industry-recognized manufacturing processes, our phosphine ligands and catalysts can be manufactured at any scale. Solvay offers expertise and manufacturing wherewithal at any phase of the value chain, but specializes in developing ligand solutions from the initial R&D stage all the way to industrial-scale production and distribution. Except for Phosphine Ligands, there are also many other material Intermediate and Function Materials like Catalyst including Homogeneous Catalyst and Olefin Copolymerization Catalyst. posted an update 1년, 7개월전
http://www.tzdegree.com/Injection molding is an important industrial method. It is little bit similar to die casting but the difference is in raw material used. In die casting we use metals which require extremely high temperature for melting but injection molding is mainly done on glasses, elastomers and most commonly thermoplastic and thermosetting polymers but this technique is widely used for fabrication of thermoplastic materials. This process is done by heating of raw material and injecting them into the mold cavity by applying pressure at a specific temperature without any change in their chemical composition.
Main parts of Injection Molding Machine:
The main parts of the Injection molding machine are material hopper, barrel, an injection ram/ rotating screw type plunger, heating device (heater), movable pattern, ejectors, and a mold inside mold cavity.
Generally injection molding machines works in horizontal manner. Injection molding machine consists of a barrel (cylindrical pipe). A hopper is located at one end of the barrel. A hydraulic ram or rotating screw runs by electric motor used of providing force is located inside the barrel. A heating element (heater) is attached to the barrel circumstantially used for melt the molding material comes down from the hopper.
On the other side of barrel a mold cavity attached. Mold is located inside the mold cavity and a movable pattern is used in whole manufacturing. Mold is generally made up of copper, aluminum and tool steels. The life cycle for different material molds are different. This can be selected as per requirement.
Working of injection molding similar to extrusion and it works like an injection as name suggest. Molding material/ raw material pour into the hopper by feeding device. After that molding material goes down under the action of gravity into the cylinder (barrel). A circumferential heater which is located on the barrel is used to melt the material. When powder form of molding material goes dawn into the barrel from hopper it starts melting and a hydraulic ram or rotating screw pushes the material forward into the mold by applying some pressure. Molten plastic material is injected into a closed mold attached on the other side of barrel; in this split mold is used. Molding material goes forward continuously by the rotating screw. Pressure applies by the hydraulic system. Injection pressure is generally 100-150 MPa. After injection, pressure is applied for some time or locked at same position with some force.
After the whole process is done the parts manufactured is cooled sufficiently. Then mould is open and some ejectors are used for proper removal of the part without damage. After removing the part mold is closed again. This process is very fast and automatically repeated. Here complex shape parts can be easily manufactured. Production capacity of injection molding is 12-16 thousand parts per cycle.
The process of injection moulding has today evolved to a high technical level. Major technical advances are not to be expected. Areas of interest to moulding machine designers and engineers include process control and quality assurance where inroads are still to be made as technology progresses.
Injection molding is used for making complex shape parts of various sizes having less wall thickness.
Typical parts like cup, containers, toys, plumbing fittings, electrical components, telephones receivers, bottle caps, automotive parts and components.
Except for Injection Molding Machine, many other machine uses the process of moldinng, such as Blow Molding Machine, Automatic Blow Molding Machine, Semi Automatic Blow Molding Machine, Extrusion Molding Machine, Jerrycan Blow Molding Machine, Drum Extrusion Blow Molding Machine, Preform Injection Machine, Cap Injection Molding Machine, etc.