H3sol - Massachusetts Institute of Technology 2.008: Design...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Massachusetts Institute of Technology 2.008: Design and Manufacturing II Problem Set 3 Solutions Problem 1-1. Thermoforming Consider the thermoformed part drawn in Figure 1 which was used to package last semester’s hamburger yoyo. This part was unapologetically difficult to manufacture, and this problem will investigate some of its pitfalls. Figure 1 : Thermoformed part (a) Compute the part’s draw ratio. Is it reasonable? The draw ratio is the depth over the width = 2 . 420 2 . 724 = . 888 which is perfectly reasonable. (b) The part was formed from a sheet of clear polystyrene with thickness . 030 inches and dimensions 4 inches by 4 inches square. The part was vacuum-drawn with a clamp that enclosed an area of approximately 3.5” by 3.5”. Assuming that the drawn part has uniform thickness, what is the wall thickness. First we need to approximate the surface area of the inside of the part. Kudos go to Brian Ruddy who generated a solidworks model that does all the hard work. His model reports an area of A = 27 . 57 inches 2 . The material that is drawn depends on the geometry of the mold. If you are optimistic and assume all of the material from the 3 . 5 inches 2 clamped area gets drawn, then the part thickness would be (0 . 030) 3 . 5 2 27 . 57 = . 013 in In reality, as soon as the lip of the warm plastic touches the sides of the mold no more of that external area gets drawn into the...
View Full Document

This note was uploaded on 02/24/2012 for the course MECHANICAL 2.008 taught by Professor Jung-hoonchun during the Spring '04 term at MIT.

Page1 / 3

H3sol - Massachusetts Institute of Technology 2.008: Design...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online