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The name of the machine tool is lathe. Its feature is used to turn fully automatic mechanical products. we have daily maintenance tasks like Check water line pressure gauges, check air pressure, clean chip filter, weekly maintenance like inspect all filters, check colant levels, top up oil levels, maintenance twice a year like inspect spindle bearing, inspect drive we need to do these things to make sure the machine works for a long time

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Good affternoon, my name Quang, today I will talk about some common problems for plastic injection moulding. From my point of view, there are 3 typical problems of plastic injection moudling. They are: Short shot,Void and sink mark. The reason for short shot is not enough plastic in the shot; the fill speed and pressure is low. To solve this problems, we have the following solutions: increase fill speed, plastic and mould temperature. About Void, there are two main reasons for this phenomenon: Fisrt: the injection pressure is low,second the gate is too small.When faced this problem,we can increase gate size and the injection pressure to force more materials into the mold. Final, sink mark. There are two reasons for this phenomenon. Fisrt, the internal stress is too high. Second, the part has low surface rigidity. There are 2 ways to avoid these causes: Increase holding pressure and holding time and the next one is reduce mould temperature

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As you can see in the figure, this is a plastic extrusion moulding process. There are six steps in this process. First, we move the polymer pellets from the hopper to the cylinder. Second, an electric motor turns the screw in the extrusion moulder. Beside that, the cord polymer pellets move along the cylinder. Next, heaters warm the polymer pellets to turn them into a liquid. Then, the warm, soft molten polymer moves along the cylinder. Finally, the machine pushes the molten polymer out into the mould.

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Plastic is a synthetic material that uses polymers as a main ingredient. Plastic is able  to be moulded or shaped to any forms. Plastic has been choosen for making many items Because it is versatile, lightweight, durable, cheap and safe. As I know, There are 7 types of plastic with different uses and features including: PET, HDPE, PVC, LDPE, PP, PS, and OTHER PLASTIC. The first one is PET. It is strong and recycable. We use PET to make food and drink packaging. Next is HDPE, it hard and resistant to heat. This plastic use for grocery bags, milk jugs and also in shampoo bottles too. Finally, LDPE, it really cheap and easy to produce and can be use in plastic bags or dispensing bottles. There are still a few types of plastic that haven't been mentioned, today I'm only talk about some of the commonly plastics.

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The check valve is made of cast iron

The first step is casting.In this step, hot liquid material is poured in to a container and cooled to make correct shape.Next, in this stage, materials are turned on a machine called a lathe.part of materials is removed to make the correct shape. The lathe is then drilling, this step means that hole are made using a drill.After drilling , the next step is paiting, a surface is covered with paint. And the next step is punching, this step means that holes are punched in a material.Finally, inspector will inspect product carfully to make sure the quality before selling it.

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NX is a form of industrial arts that involves using a computer to create technical designs. It was released for the first time in 1973. The software is simple, useful and powerful. NX is used in aerospace, automotive companies.
NX can use to create drawings, 2-D or 3-D models . Not only that, it's also used to edit data, link data from various services and finally, this software is used for collecting multiple design elements into a single feature. Before NX, designers were farced to draw everything by hand, it's time-consuming. But now, NX is designed faster and more flexible. Also, it create a very high level of control and reduced the companies mistakes and maximize productivity. Beside, NX has also cons like: lake ease of use, required professional training before using and focused more on the layout of icons.

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Cad is a form of Industrial arts that involves using a computer to create technical designs. Unlike Cad, manual drafting is the practice of creating drawings by hand with pencil or ink on media such as paper or polyester film using drafting equipment. Both Cad and manual drafting are used to create preliminary design and layouts. But designing and changing models with cad are faster and easier than using traditional drafting. Unlike cad, manual drafting required to have designing skill and explanation skill. Cad has high accuracy in representation whereas, the opposite true that for hand drafting. Manual drafting is more time consuming than CAD because drafter has to start from the beginning to make changes.

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There are two kinds of drives: belt drive and chain drive. Both belt drive and chain drive and chain are used for transmitting motion and power. BD is made of rubber and plastic while CD is made of metal with a number of links. CD different from BD because it cause noise and vibration. Slippage occurs in BD no such slippage in CD.BD has low efficiency. Unlike BD, CD has a higher. Belt tension of BD is affected bu atmospheric condition and temperature, CD is different from BD as it isn't. BD requires minimum maintenance frequent re-tension, whereas CD requires regular lubricated. Finally , BD used in flour mills, coolant pump and lubricant AC, Cam,,,CD used in bicycle and motorcycles.

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Gear is a rotating circular component of machine with teeth, which mash with another toothed part to transmit torque. There are four common types of gears: Helical gear, worm gear, Rack and pinion gears, and bevel gears. Firstly, Helical gear are used in high speed application, large power transmission and control noise. It have their teeth cut in spiral shape. Secondly, worm has just one continuous tooth and worm pair with a worm gear which use to reduce speed. Next, Rack and pinion which used for converting and rotational motion into linear motion. They are consists of a circular gear(the pinion) engaging a linear gear( the rack). Finally, bevel gears are used in transmit rotational power through shafts an angle, normally 90 degrees.

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There are two kinds of bearing: Rolling contact bearing and journal bearing. Firstly, Rolling contact bearing consist of 3 main parts. The first part is the function which support load for machine. Then, the component of rolling contact bearings are rollers, inner race and outer race. The function of inner race is rotates with the shaft and outer race is used to remain parts, there are 3 types: ball bearing uses spherical roller to support radial, straight roller bearing uses a cylindrical roller to support radial motion and thrust roller bearing are used to support thrust motion using barred- shaped roller.
Secondly, Journal Bearing is a bearing that uses lubricated sleeve and has no rolling part.

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Coupling is a component which connect two shafts together to transmit power. As far as I know, there are two types of coupling including: Rigid coupling and flexible coupling. Actually, rigid coupling can accommodate a slight misalignment between shafts while a rigid coupling can not tolerate any such misalignment. Rigid coupling is simple, inexpensive and transmit power than flexible coupling which can reduce shock and vibration but a rigid coupling cannot. Also, example of rigid coupling are sleeve-style coupling, muff coupling and clamp coupling,...Example of flexible coupling are beam coupling and bushed in flexible coupling.

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Writing:
Just like other forms of academic writing, a presentation can be divided into 3 parts: Introduction, Body and Conclusion. Dring the opening of your presentation, attract the audience's attention and built their interest is the most important, then you should clearly presented the topic and purpose will help the listeners focus on and easily follow the main ideals. Next, During the presentation, u should combine gesture with eye contact and facial expression. Also, u should stay relaxed, confident and present enough the main of content. And don't forget to smile when standing in front of the audiences. Finally, in the conclusion of presentation, u should restate sum up the main of content and interact with audiences with small question of the speech. And u shouldn't forget to say Thank for your listening.