STRIP LAYOUT

The strip layout module can be used for both progressive dies and transfer dies. It allows quickly modeling the true solid 3D strip in a very easy and logical way, resulting from our almost 20 years experience shared with passionate die designers.

In the design of blanking parts from strip material, the first step is to prepare blanking layout, that is, to layout the position of the workpieces in the strip and their orientation with respect to one another. While doing so, the major consideration is the economy
of material. Another important consideration in strip layout is the distance between the blanks and the strip edge and distance between blank to blank. To prevent the scrap from twisting and wedging between the punch and the die. The distance must increase with material thickness.

A general rule of thumb is to keep this distance equal to from 1 to 1.5times the material thickness. The following figure are example of strip layouts.

A – Front scrap
B – Bridge thickness
(space between parts and strip edge,and part to parts)
C – the distance from a point on one part to the
corresponding point on the next part.
H – Part width
l – Length of part
W – Width of strip
Y – Scrap recovery at end
N – Number of blanks
t– thickness of strip
L – Length of strip

B= 1.25t, when C is less than 2inch
= 1.5t, when C is more than 2inch
C = l + B
W = H + 2B
A = t + 0.015H
Y =L – Nc +B
N = L – B /C

PERCENTAGE OF UTILIZATION

Strip layout is important to have economy of press
tool operation. Scrap strip layout gives an idea on the
positioning of various punches, stops and pilots.
It ensures the ideal location of blanks in the stock strip.
Several trial layouts have to be made to confirm the
maximum percentage of utilization of stock strip. The
goal should be to have at least 75% utilization.

The percentage of stock used to calculated by the
formula:

% of utilization = Area of one blank X 100 /Lead X Width

Where, Lead = Length of component + Bridge thickness
Width= Breadth of component + 2 X Bridge thickness
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EXAMPLE 1: FOR STRIP LAYOUT CALCULATION

Length of part = 20mm : Breadth of part = 10mm
Thickness of part =1.5mm

Bridge thickness = one times of sheet thickness taken
= 1.0 X 1.5 = 1.50mm

Width of strip W = H + 2B
= 20 + 2 X 1.5 =23mm

Front scrap “a” = t + 0.015H
= 1.5 + 0.015 X 20
= 1.8mm

C =l + B = 10+1.5 =11.5mm