STUDENTS-Check here First!

[Will Call]

Ok,
We seem to have had several posts in this and other forums pertaining to "How do I do This."

Let's see if we can get some interesting reading going by sharing some of the best design practices that you follow.

Knowing that most students achieve more satisfaction and knowledge retention by doing their own research, when they come in they'll have a place to readily find the information before they ask us to help with their homework.

Let's start by posting your favorite web site that you use for most of your design questions.

I'll post the first one (so nobody else can use it).

http://www.plastics.com/forums/

Who's next?

[Bryanthechewbacca]

Hello,

I am a student and I am not asking for anyone to do my hmwk. I would like to talk about current research in the polymer's area. I will be doing some research in January on nanofibers as sorbents. If anyone would like to talk about research just let me know.

Bryan

[DD]

Engineering Fundamentals ( - there is a fee to use the site, but you can browse about 4 or 5 free pages at a time for a quick overview):
http://www.efunda.com/home.cfm

Off-the-shelf Hardware and Materials for prototypes and experiments:
http://www.mcmaster.com

Macrogalleria - general plastics info and learning (got that one from someone else on this forum)
http://www.psrc.usm.edu/macrog/index.htm

Injection Molding Design Guidelines (IDSA)
http://www.idsa-mp.org/proc/plastic/inj ... sign_2.htm

Rotational Molding Illustration
http://www.goldshield.com/cap_pgs/overv ... tomold.htm

Sorry for any consequential advertising, but it kind of goes with the territory.

[Dr. Dick]

.
Good Idea Will Call. I am working on identifying good Plastics Glossary sites for the SPE Publications Committee.

Degradable Plastics(these sites in Australia have been moved, can one of our Australian members find where?) Thanks to Hav here are the sites
http://www.deh.gov.au/industry/waste/de ... index.html
http://www.science.org.au/nova/061/061key.htm

Composites ( Start your search here :!: )
http://composite.about.com/od/plasticsdefns/
This is the link to start with as it has 16 links to other information sources as well as a Composites Directory link.

Acronyms in addition to the home page Plastics.com
http://www.ets-corp.com/tools/acronyms.htm
http://members.aol.com/newimageplastics/types.html

Machinery
http://www.ctsmachinery.com/au/glossary.asp

General
http://www.ides.com/tools/glossary.asp

others to come as I check them out.

OK a couple more sites added 11/22.

For a list of links to the plastics industry go to
http://www.4spe.org and scroll down to the links item

For Grade and Highschool teaching help and plastic kits go to:

http://www.teachingplastics.org/

[Dr. Dick]

Here's another soure of information...NO LONGER ON LINE

Handy Plastics Reference

Here is your comprehensive—and free—guide to plastics design


Joseph Ogando
Design News
February 17, 2005



Want to know more about designing with plastics? Bayer
MaterialScience engineers can help. They recently distilled their
collective knowledge about plastic part and mold design into a free
guide available both on the web and on paper.

At 175-pages, the guide covers nearly everything you need to know about designing and manufacturing a plastic part. To make materials selection easier, it starts off with guidelines for determining a plastic part's performance requirements. Topics here include mechanical loading,
temperature effects, chemical exposure, electrical properties,
dimensional tolerances, agency ratings, and more.

goes on to cover part design fundamentals—topics such as wall thickness requirements, ribs, draft angles, corners, radii, undercuts, molded-in threads, and holes. Next come sections covering structural design, design for assembly, machining, finishing, painting, and plating. The guide continues with a chapter on mold design.

Two of these sections really stand out. “The sections on structural
design and mold design contain information that you rarely, if ever, run
across elsewhere,â€

[Dr. Dick]

Students and non-plastics professionals should find this of help.

Meaning and Relevance of Some Material Properties of Plastics

Property Meaning Relevance

Melt flow rate (MFR) Rate of flow of a polymer melt through a standard orifice of a capillary at a chosen temperature under a fixed load Single parameter useful to differentiate flow characteristics of different grades within the same polymer family; useful to verify lot-to-lot uniformity of a product

Tensile modulus Ratio of tensile stress to corresponding strain in the linear range Indicator of inherent rigidity of the plastic
Poisson’s ratio Relative deformations in lateral and corresponding longitudinal directions in response to applied axial stress Useful in estimation of bulk modulus from tensile modulus for isotropic material

Creep modulus Apparent modulus of the plastic under constant loads for a long duration of time Indicator of reduction in modulus of the material, useful in predicting dimensional changes as a result of long-term loads
Shear stress Ratio of shear stress to resulting angular strain in the range of small deformations Useful in buckling analysis

Notched impact strength Amount of energy absorbed in propagating a predefined notch under high rates of impact loading Indicator of the notch sensitivity and ductile-brittle transition temperature

Deflection temperature under load (DTUL) Temperature corresponding to a deflection of 0.25 mm (0.01 inch) under a prescribed load generating a fixed fiber stress Reference point for quality control
Continuous-use temperature Highest temperature at which a plastic can be expected to retain its performance under continuous exposure for extended periods of time Indicator of the maximum application temperature
Coefficient of linear thermal expansion (CLTE) Measure of change in linear dimensions with temperature Useful in determining dimensional stability of a molded part with changes in temperatures during use and estimation of thermally induced residual stresses in the part
Relative thermal index (RTI) The maximum temperature at which the plastic retains 50% of its mechanical or electrical properties when exposed for 10,000 hours Measure of thermal endurance, i.e., the ability of the plastic to retain 50% of its particular property when exposed to elevated temperature for extended periods of time
Dielectric strength Maximum voltage a plastic can withstand before electric breakdown Indicator of insulation characteristics of the plastic
Dielectric constant Ratio of the capacity of the condenser with the particular dielectric material to the capacity of the condenser with air as the dielectric material Insulating capacity of the plastic in terms of its ability to store electrical energy

Dissipation factor Amount of energy dissipated Measure of inefficiency of the plastic as an insulator

Adapted from SPE’s Plastics Technician’s Toolbox. 1. Fundamental Skills and Polymer Science.
*****
Every plastics processing company should own at least one copy of the Toolbox http://www.4spe.org

[Dr. Dick]

Plastics Technology has moved their web site to

http://www.ptonline.com

You may want to change your book mark.

[Will Call]

I copied this link from a post of dwightdixon's (hope you don't mind), in one of the other forums. It's has great information on identifying plastics.

http://www.consultekusa.com/links.htm

[Will Call]

[username]

I still believe there are a lot of sites that are available and will be posted.

Here's my challenge, Dr. Dick has posted a large number of shortcuts pertaining to material and process related articles. Anybody think they can find more than him? Once we have exhausted the internet, I will compile everything into 1 or 2 posts and give credit where credit is due.


~L

[PDF]

For quick access to material properties, its hard to beat Matweb.

http://www.matweb.com/search/SearchSubcat.asp

[PDF]

Recycling Symbols / Resin Identification Codes

http://en.wikipedia.org/wiki/Resin_identification_code

[Dr. Dick]

Another site for polymer information is at the ACS Polymer Division educational website. Working with Dick Jones and Prof. Richard Stein (UMASS Amherst) they have taken the contents of the educational CD and placed it on the web. Currently there is a link on the first page of the Polymer Division web site. You can access this website directly by visiting this address:

http://people.ccmr.cornell.edu/~cober/I ... index.html

Also for online courses see

http://www.nyproinstitute.com/


Will
You may want to put a sticky in the Education forum linking to this thread for Students

[Dr. Dick]

Info on obtaing a part illustrating various Injection Molding problems and solutions
is at this site in these forums

http://www.plastics.com/forums/viewtopic.php?p=35006

Also an additional web site for E-learning is at

http://www.plastics-elearning.com

[Len]

Late/Breaking news in Plastics.

http://www.plasticsnews.com

Len

[Dr. Dick]

Another materials site to help pick a resin(plastic, polymer) is at

http://www.protomold.com/designguidelines/resininfo

Also a free trial of IDES "Prospector Pro" courtsey of IDES and Protomold is available until July28, 2006

The shared account can be found at http://www.ides.com/login
Enter the username: protomold
and password: guest