Mumbai University > Mechanical Engineering > Sem 5 > production process 3

Marks: 5M

Year: Dec 2015

In the blanking die-set design, the first step is to prepare blanking layout i.e. the position of the work pieces in the strip and their orientation with respect to each other. This is known as Scrap Strip Layout. Following are the factors which affects the strip or stock layout.

• Economy of Material:
  • As per arrangement in below fig. it can be worked at single row, single pass with a single punch.

• By feeding the material as per below fig. there is increase in material utilization upto some extent.

• Below figure shows a single row, double pass strip. Here, strip will have to be passed through the dies once turned over and passed through dies second time. Hence, there is a maximum utilization of the material and reduction in scrap.

• The front scrap may be determined by the equation,
  • a= t + 0.015h.
• The distance between successive blanks i.e. scrap bridge b is given in the below table:

• The feed or advance or the length of one piece of stock required to produce onblank is ,

  f= W + b

• The number of blanks which can be produced from one length of stock can be found as ,

• /////equation.

• Where , a = back scrap or front scrap

  b= scrap bridge

  h & w= Height and Width of the component.

  F=feed or advance.

  T=thickness of the material.

  L= length of the sheet.

  N= number of blanks to be produced.

  Y=scrap remaining at the end of the length.