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(a) A polymer manufacturing process is shown below - Leaving Cert Engineering - Question 6 - 2010
Question 6
(a) A polymer manufacturing process is shown below. (i) Name the process and describe the principle of operation; (ii) Identify one component produced by this proc... show full transcript
Worked Solution & Example Answer:(a) A polymer manufacturing process is shown below - Leaving Cert Engineering - Question 6 - 2010
Step 1
Name the process and describe the principle of operation;
Answer
The process is called Calendering. This operation involves producing continuous lengths of sheets in thermoplastics by passing the material through a series of heated rollers. As the material moves between the rollers, it is gradually thinned to the desired thickness. The resulting sheets can either be cut or rolled for further use.
Step 2
Step 3
Differentiation between thermoplastics and thermosetting plastics:
Answer
Thermoplastics are characterized by secondary bonding (weak van der Waals forces) and can have a linear or branched internal structure. They generally have a low melting point and can be reshaped multiple times without losing significant strength.
In contrast, thermosetting plastics are defined by primary bonding (strong covalent bonds) with a cross-linked internal structure. They have a high melting point and cannot be reformed after curing, making them stiff and less flexible.
Step 4
Explain any three of the following in relation to polymers:
Answer
(i) Stabiliser: Stabilizers are additives used in polymers to prevent degradation from environmental factors such as ultra-violet light and other environmental conditions.
(ii) Glass transition temperature: This temperature describes the transition of a solid amorphous polymer into a rubbery state. It is influenced by factors like temperature and the molecular structure of the polymer.
(iii) Condensation polymerisation: This process involves the reaction between two monomers, eliminating a small molecule like water as a by-product. It creates strong primary bonds and results in structures like cross-linked polymers, exemplified by phenol formaldehyde.