Question

In long jets, the liquor to material ratio is

• A. 1:1.5
• B. 1:3
• C. 1:8
• D. 1:10

Hint:

• Liquor-to-Material Ratio (L:M Ratio) Ratio of weight of dye liquor to weight of textile material.
• Jet Dyeing Machines
  • Early/Conventional ("Long Liquor Ratio"): L:M ratios were high, e.g., 1:15 to 1:30.
  • Improved/Modern ("Short Liquor Ratio" - SLR): L:M ratios reduced, e.g., 1:8 to 1:12.
  • Advanced/ULR ("Ultra-Low Liquor Ratio"): L:M ratios very low, e.g., 1:4 to 1:6.
• "Long jets" is relative. If it means "not the most modern ULR types", then an L:M of around 1:8 to 1:10 is representative of many widely used "modern" (but not latest-gen ULR) jet dyeing machines.
• An L:M of 1:8 is a common figure for efficient jet dyeing.

Answer 1

The Correct Option is C

Liquor-to-Material Ratio (L:M ratio or L:R) in dyeing is the ratio of the weight (or volume) of the dye liquor to the weight of the textile material being dyed. L:M = Weight of Liquor : Weight of Material. Example: An L:M ratio of 10:1 means 10 kg of liquor is used for 1 kg of material. Jet dyeing machines circulate fabric in rope form through a stream (jet) of dye liquor. Different generations and designs of jet dyeing machines operate at different L:M ratios:

• Older / Conventional / "Long" Jet Dyeing Machines: These earlier designs typically operated with relatively high L:M ratios, often in the range of 1:15 to 1:30 or sometimes down to 1:10 to 1:12. The term "long jets" might refer to these, or to machines with long, large-capacity tubes requiring more liquor for fabric circulation.
• Modern / "Short Liquor Ratio" (SLR) / Low Liquor Ratio (LLR) Jet Dyeing Machines: Developments have focused on reducing water, energy, and chemical consumption. Modern machines operate at much lower L:M ratios, for example:
  • Medium L:M ratio: 1:8 to 1:10
  • Low L:M ratio: 1:5 to 1:7
  • Ultra-low L:M ratio (ULR): As low as 1:3.5 to 1:5 (sometimes even lower for specific technologies like air-jet or soft-flow dyeing with special designs).

The question specifies "In long jets". This likely refers to the older or more conventional type of jet dyeing machines that used longer liquor ratios compared to modern ultra-low liquor ratio machines. Let's look at the options: % Option (a) 1:1.5 - This is an extremely low L:M ratio, typical of padding or very specialized ULR machines, not "long jets". % Option (b) 1:3 - This is also a very low ULR, characteristic of advanced modern machines. % Option (c) 1:8 - This represents a medium to low L:M ratio. It could be considered "long" relative to ULR machines (like 1:4), but it's significantly lower than the very high ratios of the earliest jet dyers (e.g., 1:20). Many "modern" but not "ultra-low" jets operate around this range. % Option (d) 1:10 - Similar to 1:8, this is a medium L:M ratio. If "long jets" means "jets that are not ULR or very short liquor ratio", then a range like 1:8 to 1:15 might be considered. Option (c) 1:8 and (d) 1:10 both fall into a range that could be described as "longer" than the very modern ULR machines. The term "long jets" is somewhat relative. Historically, early jets had L:R of 1:15 to 1:20. Then improvements led to "short liquor ratio" jets around 1:8 to 1:12. Then "ultra-low liquor ratio" jets came in at 1:4 to 1:6. If "long jets" refers to the generation *before* the widespread adoption of ULR technology but an improvement over the very first generation, then 1:8 to 1:10 is plausible. The provided correct answer is (c) 1:8. This indicates that "long jets" in the context of this question refers to machines with moderately low liquor ratios, perhaps in contrast to even lower ratio machines. A ratio of 1:8 is significantly lower than the earliest jets but higher than cutting-edge ULR systems. It represents a common operational range for many existing production machines. \[ \boxed{1:8} \]