Question

....... is the disadvantage of plastics used in food packaging.

• A. Easy colouring
• B. No rusting
• C. Good water resistance
• D. Tendency to creep

Hint:

Creep behavior in polymers is highly temperature-dependent and increases significantly near or above the glass transition temperature (\(T_g\)) of the polymer.
For structural or load-bearing applications, polymers with higher crystallinity or those reinforced with mineral fillers are selected to resist creep.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Plastics are synthetic or semi-synthetic polymers that have revolutionized the food packaging sector due to their versatility, low cost, and ease of processing.
Despite their extensive benefits, polymers possess certain inherent mechanical and thermodymic drawbacks that must be maged.

Step 2: Detailed Explation:
Many characteristics of plastics are highly advantageous for food distribution and storage.
For example, they are easy to color, which is highly beneficial for product branding and light protection.
They are completely immune to chemical rusting, unlike metal-based packaging materials.
They also offer good water resistance, protecting dry foods from exterl humidity.
However, plastics are viscoelastic materials, meaning they exhibit both viscous and elastic characteristics when subjected to mechanical stress.
A major engineering disadvantage of plastics is their tendency to creep.
Creep is defined as the slow, progressive, and permanent deformation of a material under a constant mechanical load over an extended period.
This is particularly problematic when plastic crates or heavy plastic bottles are stacked in warehouses, where the sustained load can lead to package distortion, collapse, or loss of structural integrity.
This physical limitation is not shared by rigid packaging materials such as metal or glass.

Step 3: Fil Answer:
The correct option is (D).