Materials Engineer

There are five grades of paper: Bond, offset or uncoated book, coated book, text, and cover.  Bond is used for letterheads, business forms, and fast printing jobs.  Offset or uncoated book is the most common grade of paper used for offset printing, and give a smooth uncoated look.  A coated book is a glossy paper that has bright colors and has excellent reproduction.  Text is high-quality and has a lot of texture.  It gives soft colors and a classy look.  The last grade of paper is cover and is used for book covers, postcards, and business cards.  You can get it coated or uncoated.

Weights of paper vary with the grade of paper.  Bond is usually 16# for forms, 20# for copying, and 24# for stationary.  Text ranges in weight anywhere from 60# to 100# but are usually 70# or 80#.  Offset is usually a 50# to 70# stock.  Coated book is usually between 30# to 70# for web, and 60# to 110# for sheetfield.  Cover comes in 60#, 65#, 80#, and 100# weights.

A manila folder’s grade is cover.

You can make paper stronger by corrugating it.  Corrugated paper has three layers

Adhesion is the ability to stick to the surfaces that it’s applied to.  Cohesion is the ability to stick to itself.

“For Van der Waals forces to work, there must be close contact between the two surfaces being joined--a separation of only a few angstroms. (An angstrom is one ten-billionth of a meter.) At that range the Van der Waals and other molecular forces interact strongly and the adhesive and the glued surfaces bond together.”

For my interview, I interviewed my uncle, Kent Riddle.  He is the Executive Vice President of Operation for Workstage.  He said for our structure to hold at least 45 pounds, we should either do it in the shape of a triangle, or in the shape of a cylinder.  He said to make a strong structure we should either make a tall cylinder, or build it up with triangles.  For our question should we layer the bottom of the structure, he said it wasn't really necessary. He said to make the top stronger you should make the bottom wider than the top.  My uncle took classes in engineering.  Some examples of those are ground surfaces, structure construction, and electrical wiring.  He also took classes in business management, and construction materials.  He said to make a 9 inch tall manila folder structure that will hold a lot of weight to make it either in the shape of a cylinder or triangle.  He said the structure should be the most reinforced in the top, bottom, and middle.

www.piag.org/buyers/tips/Paper_grades.htm

paper grades and weights

www.madehow.com/Volume-1/Corrugated-Cardboard.html

corrugated cardboard

www.straightdope.com/mailbag/mglue.html

glue, adhesion, cohesion

Kent Riddle: interview information

I think our design was suitable to meet the height and weight requirements, but I think if our structure was better designed and more balanced it could have held more weight.  Some benefits of our project were that we reinforced the middle and corners of our design and we corrugated our columns to make them stronger.  Some weaknesses of our structure were that it wasn't balanced very well and our columns on one side weren't as strong as those on the other to sides so the structure tipped to one side.  Some modifications I would have made on our structure are instead of having two layers of columns, I would have had only one layer that goes all the way up the structure, and I would have corrugated the columns more.  I would also use more glue because that made the structure hard and less likely to bend.  The last thing I would have done is I would have made the base wider than the tip of the structure so that the weight was more spread out.