Podcast
Questions and Answers
What is meant by the term 'ductility' in the context of material properties?
What is meant by the term 'ductility' in the context of material properties?
Which process involves the use of molds to shape softened plastics?
Which process involves the use of molds to shape softened plastics?
What happens to the wall thickness of a material during the blow molding process?
What happens to the wall thickness of a material during the blow molding process?
In which state is plastic material considered solid and ready for machining?
In which state is plastic material considered solid and ready for machining?
Signup and view all the answers
What occurs during the extrusion blowing process?
What occurs during the extrusion blowing process?
Signup and view all the answers
What is the role of air in the blow molding process?
What is the role of air in the blow molding process?
Signup and view all the answers
What is indicated by the term 'breaking strain'?
What is indicated by the term 'breaking strain'?
Signup and view all the answers
Which process involves creating a preform before shaping it with blowing?
Which process involves creating a preform before shaping it with blowing?
Signup and view all the answers
What initial process occurs during thermoforming?
What initial process occurs during thermoforming?
Signup and view all the answers
Which materials are commonly used in thermoforming?
Which materials are commonly used in thermoforming?
Signup and view all the answers
What is the purpose of plug-assisted forming?
What is the purpose of plug-assisted forming?
Signup and view all the answers
What occurs during the hot rolling process of metals?
What occurs during the hot rolling process of metals?
Signup and view all the answers
Which product is typically produced through thermoforming?
Which product is typically produced through thermoforming?
Signup and view all the answers
What is the main purpose of using vacuum forming in thermoforming techniques?
What is the main purpose of using vacuum forming in thermoforming techniques?
Signup and view all the answers
In the process of blown film, what happens to the tube after extrusion?
In the process of blown film, what happens to the tube after extrusion?
Signup and view all the answers
What is a key consideration when softening plastic in thermoforming?
What is a key consideration when softening plastic in thermoforming?
Signup and view all the answers
What is the main feature of direct extrusion?
What is the main feature of direct extrusion?
Signup and view all the answers
What distinguishes indirect extrusion from other extrusion methods?
What distinguishes indirect extrusion from other extrusion methods?
Signup and view all the answers
Which process can produce components with superior strength and toughness?
Which process can produce components with superior strength and toughness?
Signup and view all the answers
What is a characteristic of cold forging?
What is a characteristic of cold forging?
Signup and view all the answers
In which forging process does the form of the workpiece remain undefined?
In which forging process does the form of the workpiece remain undefined?
Signup and view all the answers
What primarily differentiates hot forging from cold forging?
What primarily differentiates hot forging from cold forging?
Signup and view all the answers
What is a common application of metal drawing?
What is a common application of metal drawing?
Signup and view all the answers
What happens to the material during bending/folding?
What happens to the material during bending/folding?
Signup and view all the answers
Study Notes
Transforming Materials
- Plastically modify solid shapes, maintaining material consistency. This can be done through cold, semi-warm, or hot transformations.
- Transformability depends on the material's ability to deform without losing cohesion. The amount of deformation a material can undergo before losing cohesion is called ductility.
- Breaking strain: The amount of strain a material can withstand before coherence is lost.
- Processing plastics: Plastic materials can be in glass, softened, or viscous states; these states determine the molding processes they can be used in.
- Blow Molding: A process where a hollow form is transformed by blowing. This stretches the shape and reduces wall thickness post-blowing.
- Extrusion Blowing: An extrusion machine continuously extrudes a tube which is pinched off and pressed. Air is blown into the tube while it's in the mold, and the mold moves to avoid collision.
- Free Form Blowing: Extrusion machine produces tubes; two molds are placed around the extruded pipe to pinch it off. Air is then blown into the pipe, which is stretched and shaped while in the molds. The molds move to avoid collisions.
Injection Blow Molding
- A preform is made through injection molding, before blowing the wall thickness which is nearly constant.
- The preformed sleeve is blown into shape using compressed air in a mold.
- Step 1: Injection molding. Step 2: Blow molding. Step 3: Ejection.
Blown Film (Plastic)
- An extruder with vertical extrusion creates a thin-walled tube which is inflated into a large balloon.
- The tube is rolled up by guide rollers into a thin film/carrier bags. A thin tubular film is generated.
- The film can be perforated as needed.
- Thermoforming: Sheet material heated into the rubber phase, and then transformed on a mold. Free form process.
Thermoforming
- Heated plastic is pulled against a mold using vacuum to shape the plastic.
- Plug-assisted forming provides pressure to improve the plastic's shape.
Metal Transforming
- Solid metal transforming is done by rolling processes where the workpiece is rolled between pairs of rollers.
- Hot rolling involves thickness reduction, recrystallization, and internal stress relief.
- Cold rolling impacts dimensional accuracy and finishing.
- Extrusion: Material is pressed through a die using a ram. This process can create rods, tubes, and profiles. Process is semi-continuous with extruded material moving in a similar direction to the ram.
- Direct extrusion: Extruded material and ram move in the same direction.
- Indirect extrusion: Extruded material and the ram move in opposite directions,
- Hollow extrusion: A forming process to create hollow profiles.
- Metal drawing: A process to reduce the cross-section of a rod, wire, or tube.
Forging
- Forging: A process that uses compressive forces to shape a workpiece making it stronger. The workpiece is heated first, to a red temperature.
- Hot forging: Relatively low process forces, high accuracy and surface quality.
- Cold forging: High process forces, good dimensional accuracy.
- Open die forging: Billet takes the shape of the die and doesn't require extensive manipulation in the manufacturing process.
- Closed die forging: An open form that is used to create a product
- Bending/Folding: Forming process where material stretches on one side and compresses on the other due to tension from bending moment or forces. A neutral layer experiences no tension or compression.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the various methods of plastic material transformation in this quiz. Learn about ductility, breaking strain, and different molding processes like blow molding and extrusion. Test your understanding of how materials can be plastically modified while maintaining their integrity.
