TABLE OF CONTENTS Stripper plates remove the material strip from around blanking and piercing punches. Severe adhesion of strip to punches is characteristic of the die cutting process. Because of their low cost, solid strippers are the most frequently used type, particularly when running strip stock. Spring strippers, though more complex, should be used when the following conditions are present:
When perfectly flat, accurate blanks are required, spring strippers flatten the sheet before cutting begins.
When very thin material is to be blanked or pierced, to prevent uneven fracture and rounded blank edges.
When parts are to be pressed from waste strip left over from other operations, spring strippers provide good visibility to the operator for gaging purposes.
When stripping occurs immediately, small punches are not as subject to breakage.
When conducting secondary operations, such as in piercing dies, increased visibility provided by spring strippers allows faster loading of work and increased production.
Stripper plates may be made of cold-rolled steel if they are not to be machined except for holes. When machining must be applied to clear gages, the plates should be made of machine steel, which is not as subject to distortion. This chapter describes numerous methods of applying stripper plates and their components. These methods further explain Step 10 in Chapter 5 14 Steps to Design a Die.
Figure 15.1 shows the most common method of applying a solid stripper. Plate A, machined to receive blanking and piercing punches, is fastened in position on...
