Injection molding.

Injection molding is a process in which molten polymer is forced under high pressure into the mold cavity through an opening called sprue.
In this process the pelletized material is put into the cylinder through a Hopper, from where charge passes into the heating chamber where it melts and then it passes into the mold cavity through the nozzle where the polymer attains its shape.
The cylinder is provided with a screw which is also called receprocating screw since it not only rotates but also moves forward and backward according to the polymer molding step.
The characteristics of this process is that the time cycle of this process is very small.
This process is highly productive and polymer of accurate shape and size are formed.(Check out Extrusion molding also)
This process is generally used for thermoplastics.
The thermoplastics used in injection molding process are polypropylene (PP), polycarbonate (PC), acrylonitrile butadiene styrene (ABS) and nylon-6 (N6) etc.

Injection molding.

Comments

Difference between organic and inorganic polymers.

Difference between organic and inorganic polymers. Definition Organic polymers are the polymers that essentially contain carbon atom in the backbone. Inorganic polymers are the polymers that have no carbon atom in the backbone. Structure Most organic polymers have simple structures. Almost all inorganic polymers are highly branched and have complex structures. Electrical Conductivity In most of the aqueous solutions, organic polymers are typically poor conductors of electricity and heat. Inorganic polymers in aqueous solutions are good conductors of electricity, this is because they have high ability to ionise and this makes them better conductors. Flammability Organic polymers are flammable whereas inorganic polymers are nonflammable. Effect on nature Organic polymers are environmental friendly as these are biodegradable. Inorganic polymers are not environmental friendly as these are non biodegradable. Examples Organic polymers include polysaccharide...

Monomers.

Monomers. A monomer is a molecule that can be reacted together with other monomer molecules to form a larger polymer chain. Some monomers are given below with their polymers . Tetrafluoroethene ; Tetrafluoroethene is the monomer of Teflon . Teflon and its monomer. Acrylonitrile (vinyl cyanide); Acrylonitrile is the monomer of Polyacrylonitrile . Polyacrylonitrile and its monomer. Isoprene; Isoprene is the monomer of Polyisoprene (natural rubber). Polyisoprene and its monomer. Chloroprene; Chloroprene is the monomer of Neoprene . Neoprene and its monomer. Vinyl chloride; Vinyl chloride is the monomer of Poly(vinyl chloride) . Polyvinyl chloride and its monomer. Vinyl acetate; Vinyl acetate is the monomer of Poly(vinyl acetate). Poly(vinyl acetate) and its monomer. Propylene; Propylene is the monomer of Polypropylene . Polypropylene and its monomer. Styrene; Styrene is the monomer of Polystyrene . Polystyrene and i...

Determination of molecular weight of polymers by viscosity method.

Determination of molecular weight of polymers by viscosity method. It is a simple method for determining the molecular weight of polymers. Addition of polymers in the solvent increases the viscosity of the solvent, due to introduction of inhomogeneities by the polymers. If η₀ is the viscosity of the solvent and η is the viscosity of the solution at the same temperature, then the relative viscosity is given by Relative viscosity. Specific viscosity: It is defined as the relative increase in viscosity and is given as Specific viscosity. Reduced viscosity: It is defined as the relative increase in viscosity per unit concentration (C) of polymer and is given as Reduced viscosity. Intrinsic viscosity: The reduced viscosity is dependent on concentration (C). If a graph is plotted between reduced viscosity vs concentration then the extraplotation value when C=0 is called intrinsic viscosity. Intrinsic viscosity. Graph of reduced vi...

Polymers

Search This Blog