Question

Which of the following techniques is used to check the uniformity of load on drafting roller?

• A. U % study
• B. Snap study
• C. Carbon paper
• D. Time study

Hint:

• Uniformity of nip load across drafting rollers is important for consistent drafting.
• The carbon paper method} provides a visual impression of the pressure distribution along the nip line.
• Pressure-sensitive films offer a more detailed and sometimes quantifiable pressure map.
• NILO meters can check pressure at discrete points across the roller.

Answer 1

The Correct Option is C

To check the uniformity of load (nip pressure) along the width of a drafting roller nip, several methods can be used:

• NILO meter (or similar pressure gauge): Measurements can be taken at different points across the roller width (e.g., left, middle, right) to compare pressure values.
• Carbon paper or pressure-sensitive film: This is a common qualitative or semi-quantitative method. A sheet of carbon paper (with a plain paper on top to receive the impression) or a specialized pressure-sensitive film (like Fuji Prescale film, which changes color based on pressure) is inserted into the nip and pressure is applied. The resulting mark or color pattern reveals the pressure distribution along the nip line. A uniform mark indicates uniform loading; variations in intensity or gaps indicate uneven loading.

Let's evaluate the options:

• (a) U % study: Measures yarn/sliver evenness, an outcome that *can* be affected by uneven roller load, but it's not a direct check of the load itself.
• (b) Snap study: A qualitative test for roller grip adequacy, not detailed load uniformity.
• (c) Carbon paper: As described above, this method directly provides a visual indication of load uniformity across the nip.
• (d) Time study: An industrial engineering method for task timing, irrelevant here.

Therefore, using carbon paper (or pressure-sensitive film) is a standard technique to check the uniformity of load on drafting rollers. \[ \boxed{\text{Carbon paper}} \]