Question 31 (Textile Engineering & Fibre Science)
Consider the following assertion [a] and reason [r] and choose the most appropriate answer.
[a] The apparent blend ratio of polyester / viscose fabric would increase as a result of drying
[r] The moisture content of viscose is significantly higher than that of polyester
| (A) | [a] is right [r] is wrong |
| (B) | [a] is right [r] is right |
| (C) | [a] is wrong [r] is wrong |
| (D) | [a] is wrong [r] is right |
[Show Answer]
Option B
Frequently Asked Questions | FAQs
What is a polyester viscose blend?
A polyester viscose blend, often referred to as simply “polyester/viscose” or “poly/viscose,” is a fabric or textile material that is made by blending polyester fibers with viscose (also known as rayon) fibers. It is a type of blended fabric that combines the properties of both polyester and viscose to create a fabric with desired characteristics.
Polyester is a synthetic fiber made from polymerized petrochemicals, while viscose is a semi-synthetic fiber made from regenerated cellulose, typically obtained from wood pulp. Polyester is known for its durability, wrinkle resistance, and moisture-wicking properties, while viscose is known for its softness, drapability, and breathability.
By blending polyester and viscose fibers together, a polyester viscose blend fabric can exhibit a combination of properties from both fibers. For example, the blend can have improved durability, wrinkle resistance, and moisture-wicking properties from polyester, as well as enhanced softness, drapability, and breathability from viscose.
Polyester viscose blend fabrics are commonly used in various types of clothing and textiles, such as apparel, suiting, uniforms, linings, and home textiles. They are often used in applications where a balance of comfort, durability, and performance is desired, and can offer a cost-effective alternative to fabrics made from 100% polyester or 100% viscose. The specific properties and characteristics of a polyester viscose blend fabric can vary depending on the ratio of polyester to viscose fibers, as well as the manufacturing process and any additional treatments applied to the fabric.
What is moisture content and its formula?
Moisture content, also known as moisture percentage or moisture level, refers to the amount of water or moisture present in a material, expressed as a percentage of the material’s total weight. It is an important parameter in many industries, such as agriculture, food processing, construction, and manufacturing, as it can affect the quality, stability, and performance of materials and products.
The formula for calculating moisture content is as follows:
Moisture Content (%) = (Wet Weight – Dry Weight) / Dry Weight × 100%
Where:
Wet Weight: The weight of the material sample after being exposed to the ambient environment and absorbing moisture, also known as the “wet” or “as-is” weight.
Dry Weight: The weight of the same material sample after all moisture has been removed, typically by drying in an oven or using a moisture analyzer, also known as the “dry” or “oven-dry” weight.
The difference between the wet weight and the dry weight represents the amount of moisture in the material. Dividing this difference by the dry weight and multiplying by 100% gives the moisture content as a percentage.
For example, if a material sample has a wet weight of 120 grams and a dry weight of 100 grams, the moisture content would be calculated as follows:
Moisture Content (%) = (120 g – 100 g) / 100 g × 100% = 20%
This indicates that the material has a moisture content of 20%, meaning that 20% of its total weight is attributed to water or moisture. The actual acceptable moisture content varies depending on the material and its intended use, and it is typically specified in industry standards or product specifications. Proper measurement and control of moisture content are important in many applications to ensure the quality, performance, and stability of materials and products.