Question

3. Mention the advantages and disadvantages of thermoplastic.
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Answer 1

Answer:

Advantages of Thermosets

The use of thermoset plastics has a number of advantages. Unlike thermoplastics, they retain their strength and shape even when heated. This makes thermosetting plastics well-suited to the production of permanent components and large, solid shapes. Additionally, these components have excellent strength attributes (although they are brittle), and will not lose significant strength when exposed to higher operating temperatures.

Thermosets plastics have gained in popularity among manufacturers, who have switched to their use as a lower cost replacement for metal components.

The benefits that thermoset plastics can offer over their metal counterparts include:

Available molded-in tolerances

Choice of color and surface finishes

High strength-to-weight ratio and performance

Outstanding dielectric strength

Low thermal conductivity and microwave transparency

Resistance to corrosion effects and water

Lower tooling/set-up costs

Reduced production costs over fabrication using metals

There are certain disadvantages to the use of thermosets whereas the material properties are not as developed as those of thermoplastics.

The low initial viscosity of materials results in flash and the need for secondary operations. Also, low tensile strength and ductility tend to result in parts that require designs with thick walls. The compounds used in thermosets are reactive systems, which can impact the useful shelf life. Batch processes may exhibit greater variation and less consistency from lot-to-lot. High levels of some filler in the materials may result in excessive tool wear. The product quality is dependent upon the degree of crosslinking established during the molding cycle.2

Table 1: Pros and Cons of Thermoset Materials

Thermoset Pros2

Thermoset Cons2

More Resistant against high temperature

Cannot be recycled.

Hard and rigid

Much more difficult to surface finish.

Excellent aesthetics finishes

Cannot be remolded or reshaped.

High mechanical property

Poor thermal conductivity for housing replacements.

Cost-effective

The rigidity of the material can result in product failure when used in high in vibration applications.

Excellent dimensional stability