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√ As the plastic industry developed a second type plunger machine appeared. known as two stage plunger. √ This type of equipment involved two plunger units set on top of other the one to plasticize the material and feed it to another cylinder that consist of a chamber to heat the plastic material by conduction and plunger that operates as a shooting plunger and push the plasticize material into the mould. Advantages    • Faster than conventional machine (single plunger) .  • No Pressure loss encountered in compacting the granules.   • Allows larger parts with more projected area. Disadvantage :  • Extra construction for pre plasticizing so cost is more.

ADDlTlVE - A substance added to a plastic compound to alter its characteristics. Examples are plasticizers, and flame retardants. ALLOY - A combination of 2 or more plastics which form a new plastic.  AMORPHOUS - A plastic material in which the molecular structure is random and becomes mobile over a wide temperature range. ANNEAL ~ To heat a moulded part up to a temperature just below its melting point and slowly cooling it back; down to room temperature. This relieves moulded stresses. ANlSOTROPlC SHRlNKAGE - S hrinkage that occurs more in one direction (usually the direction of flow; reinforced materials shrink more across the direction of flow) than another. AUTOMATIC OPERATlON -The term used to define the mode in which a moulding machine is operating when there is no need for an operator to start each cycle. BARREL - A metallic cylinder in which the injection screw (or plunger) resides in the moulding machine . Also called CYLINDER. BLEND - A m

1. Intense industry competition often results in low profit margins. 2. Mould costs are high. 3. Moulding machinery and auxiliary equipment costs are high. 4. Lack of knowledge about the fundamentals of the process causes problems. 5. Lack of knowledge about the long term properties of the materials may result in long-term failures.

1. The Screw type Injection Moulding Machine consists of a hopper, a reciprocating screw and barrel assembly, and an injection nozzle. 2. This system confines and transports the plastic as it progresses through the feeding, compressing, degassing, melting, injection and packing stages. 3. A single screw injection Moulding machine for themoplastic showing the plasticizing screw,al a barrel band heaters to heat the barrel, a stationary platen, and a movable platen.

1. The plunger type injection moulding machine is available horizontal or vertical type and operated pneumatically or hydraulically.The clamping and Injection may be Semi or automatic. 2. In a semi Automatic type the clamping cylinder & the Injection cylinders are operated by levers which is connected the pneumatic or hydraulic cylinders. In Automatic type, the cylinders are actuated automatically to a set timers.

1. The cost of the machines is increased depending on their functions and Size . 2. The simplest Injection Moulding machine is a hand injection moulding machine With a very low cost . 3. The simplest mode of injection moulding machine may be considered as hand operated mode, which is an apt equipment to underStand the interaction of major operating parameters . 4. The machine consists of Barrel, Plunger, Band Heaters along with energy regulator, Rack & Pinion system for injecting the material by the plunger, a torpedo and nozzle.  5. The clamping is done manually on a working table. The machine is fitted on the working table. Heating is set manually .  6. The capacity of . the machine is available from 0.5 Oz to 2 Oz. Once heating is achieved the production starts manually. 7. The quality of the product is completely depend upon the skill of the operaton .The heating set point is achieved by heat & trial method. 8. Although Temperature contr

• A  toggle  is  mechanically  device  to  amplify  force. • In  a  moulding  machine,  which  consists  of  two  bars joined,  together  end  to  end  with  a  pivot  . • The  end  of one  bar  is  attached  to  a  stationary  platen, and  the  other  end  of  a  second  bar  is  attached  to  the movable  platen. • When the  mould  is open,  the  toggle  is  in  the  shape  of  a  V. • When pressure  is  applied  to  the  pivot,  the  two  bars  form a  straight  line.

PE is made up from Ethylene monomers. PE is divided into different class according to their density. Different types of PE are as below: ( Polymers )                   ( Density ) LDPE               0.910 -0.940 (g/cc) LLDPE             0.915 -0.925 (g/cc) MDPE              0.926 -0.940 (g/cc) HDPE               0.941 -0.959 (g/cc) VLDPE             0.880 -0.915 (g/cc) UHMWPE        0.930 -0.935 (g/cc) Properties of PE: √ Very low cost √  Excellent chemical resistance √  Very good processability. √  High impact strength at low temperature. √ Excellent electrical insulating properties . √ Very low water absorption √ Can be transparent in thin film form . Limitations of PE: √ Low strength, stiffness and maximum service temperature . √ Highly flammable . √ High-frequency welding and joining impossible . √ Poor abrasion resistance. Processing of PE: • For Injection Molding Process: √ Melt temperature: 160-260°C. √ Post mold shrinkage lies

1. Hand Injection Moulding Machine  (Vertical) . (Click Here) 2. Plunger Type Injection Moulding Machine (vertical & Horizontal). (Click Here) 3. Screw Type Injection Moulding Machine. (Click Here) 4. Plunger - Plunger Injection Moulding Machine. 5. Screw - Plunger Injection Moulding Machine.

√ The function of the torpedo is to help the material for proper melting and crate back pressure for help in mixing. Torpedo used Vartical Hand Injection Machine .

1. A devices made of two dissimilar metals which are used to measure the temperature of a heated area such as the barrel or nozzle. 2. It sends a signal to controller which then turns off or  on to control the temperature of that area.

1. Parts can be produced at high production rates.  2.Large volume production is possible. 3.Relatively low labour cost per unit is obtainable.  4. Part require little or no finishing.  5. Many different surface, colours, and finishes are available.  6. Good decorations is possible.  7. For many shapes this process is the most economical way to fabricate.  8. Process permits the manufacture of very small parts which are almost impossible to fabricate in quantities by other methods. 9. Close dimensional tolerances can be maintained.  10. Parts can be moulded with metallic and non-metallic inserts.

√ Advantages - { injection Blow Moulding } 1. Accurate shaping of the neck. 2. A High level of dimensional accuracy. 3. Mini weight tolerance. 4. The highest quality surface finish. 5. Production absolutely free from waste. 6. Crystal clear containers for pharmaceutical  application. 7. Finished bottle without weld line and scrap. 8. Secondary /finishing operation can be avoided. 9. Multi-cavities can be operated. √ Disadvantages -{ injection Blow Moulding } 1. The preform design generally establish the core rod length & diameter. 2. The process is more expensive than extrusion blow moulding. 3. Compromise between preform wall thickness and blow up ratio. 4. The ratio of the maximum wall thickness to minimum wall thickness across a preform cross-section should be less than 1.5 to prevent weld lines. 5. Preform thickness greater than 6 mm is unstable during blowing since the thick section cannot be properly conditioned. 6. The technique is not suitable

√ General Rules for Safety&Precaution  ,Fitter tools,  Introduction of polymers & Fundamental Termininology of polymers PDF files- (Download)