Plastic

Question 1

Injection mold

Answer 1

for creating plastic parts in large volumes

• It involves injecting molten plastic into a mold cavity shaped like the desired product
• Once the plastic cools and solidifies the product is ejected.

:automobiles, packaging materials, and consumer goods

Question 2

blow molding

Answer 2

a plastic manufacturing process that creates hollow objects.

• the extrusion of a molten tube, which is then placed between mold halves.
• Compressed air expands in the plastic to match the mold’s shape.
• After cooling and solidification, the mold opens, and there is the product
• 2 or more molds
• air comes through the other side

: containers, gas tanks, electrical enclosures

Question 3

Appreciate the timeline of events in the process of inventing different plastics.

Answer 3

1907: the first synthetic plastic, introduced polyethylene, PVC, nylon, polyester, and PET.

1950s: the emergence of polypropylene. In response to environmental concerns

1980s: brought biodegradable plastics, and ongoing efforts focus on using recycled plastics today

Question 4

where most current plastics come from

Answer 4

are derived from crude oil or natural gas, with ethylene as a key building block. Efforts to create sustainable alternatives include bio-based plastics and increased recycling.

Question 5

brief history in the development of different types of plastic

Answer 5

Today, there’s a push for recycled plastics to tackle environmental concerns. The history reflects a journey from Bakelite’s invention to ongoing efforts for sustainable plastic solutions.

Question 6

Thermoplastics plastics

Answer 6

a linear or branched structure with non-cross-linked molecular chains

• They soften when heated, allowing for molding and reshaping. Upon cooling, they solidify, retaining the new shape.

-This process can be repeated without significant degradation, making them recyclable

: polyethylene and PVC,

Question 7

Thermosetting plastics

Answer 7

form a three-dimensional network structure due to irreversible cross-linking during the curing process. Once molded and set, they don’t soften upon reheating. While they offer

:phenolic resins and epoxy

Question 8

the importance and methods of recycling plastics

Answer 8

Recycling plastics is essential for environmental sustainability, reducing the need for new materials and lowering energy consumption.

mechanical recycling: which melts and reshapes plastic

chemical recycling: breaking it down for reuse.

This contributes to a circular economy, emphasizing the importance of responsible waste management to minimize the environmental impact of plastic waste.