Subject : Production Process 2

Difficulty : Medium

The layout by which the blanks are produced from the sheet, such that percentage utilization of the sheet is maximum or percentage waste of the sheet is minimum.

Let s = feed of sheet

= x + a

L = Total length of sheet

N = no. of blanks produced from sheet

= $\frac{L - a}{s}$ = $\frac{L}{s}$

% utilization = $\frac {Area \ utilized}{Total \ area \ of \ sheet}$

= $\frac{n \ x \ x \ x \ y}{ Lx \ h}$

= $\frac{ n . (x.y)}{n.s.h}$

% utilization = $\frac{x.y}{s.h}$

Here, x.y = Area of blank and

s.h = Control area

In strap strip layout, margin must be provided to remove the edge damage present on sheet. This edge damage on sheet may because of rolling operation on sheet at the time of manufacturing.