Chapter 3D Thermoforming

Question 1

What is thermoforming?

Answer 1

Thermoforming is the process of transforming a plastic sheet into a 3D shape using heat, vacuum, and pressure.

Question 2

What type of plastic is used in thermoforming?

Answer 2

Thermoplastics are used because they can be softened and reshaped while retaining the new shape after cooling.

Question 3

What are the forces required for thermoforming?

Answer 3

Mechanical, air, or vacuum pressure.

Question 4

What are some advantages and problem of thermoforming?

Answer 4

Low tooling cost, ability to produce large surface area parts economically, and good dimensional accuracy.
- But thinning can be problem in some part design.

Question 5

How does thermoforming differ from thermoset processing?

Answer 5

Thermoforming uses thermoplastics, which can be reshaped and recycled, whereas thermoset materials cannot be reformed once cured.

Question 6

What is an advantage and disadvantage of thermoset composite processing?

Answer 6

Advantages
- Fibers are easy to wet, leading to less void and porosity.
- Much easier
- Less heat and pressure
- Simple low cost tooling equipment.
Dis
- Production low due to long cure time.
- Cannot reform
- Recycling is an issue.

Question 7

What is an advantage and disadvantage of thermoplastic composite processing?

Answer 7

Advantage
- Short process cycle time, making it suitable for high-volume production.
- Can reshaped and reform
- Easy to recycle
Dis
- Requires heavy and strong tooling
- Not easy to process, sometimes need special equipment to apply heat and pressure.

Question 8

What are nanomaterials?

Answer 8

Materials that have at least one dimension within the nanoscale range (≤100nm).

Question 9

What factors influence the properties of nanomaterials?

Answer 9

Size, shape, and surface structure of the nanoparticles.

Question 10

What is a polymer nanocomposite?

Answer 10

A combination of polymers and nanomaterials where at least one phase remains in the nanometer range.

Question 11

How do polymer nanocomposites differ from traditional composites?

Answer 11

They exhibit huge interfacial interactions at the surfaces between nanomaterials and polymer matrices, leading to superior performance.

Question 12

What are some examples of nanomaterials used in polymer nanocomposites?

Answer 12

Carbon nanotubes (CNT), graphene, nanosilica, metal oxides, and nanoclays.

Question 13

Ultrafine size can give problems?

Answer 13

• Have tendency to aggregates and form bulk materials bcs have high surface energy & reactive
• Lost the attributes
• Property might be lower than composite