Calculate the size of the press required to mold a part using a ...

[sammy]

Calculate the size of the press required to mold a part using a multicavity transfer mold in which the part size is 2.5 inches by 2 inches. The mold contains four cavities. There are four runners, each of which has a diameter of 0.375 inches and a length of 1.5 inches. The sprue has a projected area of 0.25 square inches. Assume that a transfer pressure 8,000 psi is needed.
 
  What will be an ideal response?

Question 2

Explain how foam-in-place and RIM differ.
 
  What will be an ideal response?

[stillxalice]

Answer to Question 1

2.5 X 2 X 4 = 20 in2 for the total projected surface area of the parts. 4 X .375 X
1.5 = 2.25 in2 for the projected surface area of the runners. 20 + 2.25 + .25 =
22.5 in2 for the total projected surface area. 8,000 psi X 22.5 in2 = 180,000 pounds of pressure. 180,000 pounds / 2000 pounds = 90 tons of pressure.

Answer to Question 2

In both foam-in-place and RIM the material is squirted into a closed mold until the mold is filled. The foaming usually occurs at the same time as the filling. The major difference is that in RIM the foamed part is removed after it has solidified and the mold is reused. In foam-in-place, the mold is the sides of the part that is to contain the foam and so the foam is not removed.

[sammy]

TY

[stillxalice]

You're welcome