Molding can be defined as the process of manufacturing by giving a particular shape to a liquid or a pliable raw material using a rigid frame called a mould.
A mould is a hollow box which is made from a pattern. While working a mould is filled with raw material like plastic ,glass, metal etc. The liquid cools down into the mould and gets harder adopting its shape.
TYPES OF MOLDING
• Injection molding
• Foam molding
• Extrusion molding
• Compression molding
• Blow molding
• Matrix molding
• Plastic molding Vacuum plus assist molding
It is a process for giving a particular image to a pliable raw material by injecting into a mould. It can be performed with a host of materials, including metals, glasses and thermosetting and thermoplastic polymers. For getting the required shape the material is first heated, mixed and injected into a mold cavity where it cools and get harder. Usually the products are made by engineers but the moulds are made by a mould maker from metals like steel or aluminum. Today it is widely being used for manufacturing entire body panels of cars.
Injection molding is a high production method of producing a wide variety of thermoplastic parts into shapes ranging from fairly simple to white complex.
Injection mould cavities are fed with melted plastic material which is forced under high pressure with the help of a sprue which feeds a runner system then through a gate into the cavity. The material is then cooled to the point that the material is solid and eject this solidified material out of the cavity.
It requires a screw type plunger to inject molten plastic material into a mold cavity. This solidifies into a shape in the mould. It is used to process both thermoplastic and thermosetting polymers. Thermoplastic have characteristics which make them highly suitable for injection molding, like the property of being recycled. this property helps them to be used everywhere they also helps the property of being soften and even flow from heating. If a thermosetting polymer is not ejected from the injection barrel in a timely manner, chemical cross linking may occur causing screw and check values to seize and potentially damaging the injection molding machine.
In injection molding a high pressure of raw material is being injected into a mould with a high pressure. Molds can be of single cavity or multiple cavity. Molds are generally made of tool steels ,but stainless steel and aluminum molds are suitable for certain application. Aluminum tools typically are parts with narrow dimensional tolerance.
When thermoplastic are molded raw material is fed through a hopper into a heated barrel with reciprocating screw. While injecting into the barrel the thermal energy increases and Vander Val of forces which resist higher thermal energy states. it reduces versatility which enable the polymer to flow with...