Thursday, May 27, 2010

A Nice Teaching Resource

This press release led me to a very well executed teaching resource for anyone interested in plastics.

Connecticut Plastics, Inc. is a fabricator located in Wallingford, CT and specialized in the precision machining of parts from engineering thermoplastic materials. They've incorporated into their web site a Learning Center that's chock-full of excellent information. The original idea, apparently, was to provide a learning resource for their employees, but the site provides a wealth of knowledge for other interested folks.

The Learning Center offers five sections:

  • An Introduction to Plastics
  • The Ultimate Polymer Science Guide
  • The Ultimate Chemistry Homework Helper
  • Chemistry Resources on the Web
  • Engineering Information and Resources

Here's a suggestion. If there are young people in your life who will need to make career-path decisions, make sure their aware of the Ultimate Chemistry Homework Helper. And, ask them not to leave the Connecticut Plastics' Learning Center without taking the time to review the Engineering Information section. We really need to get more smart young people excited about science and engineering, and this resource can help.

Connecticut Plastics has done a Good Thing here.

Friday, May 21, 2010

Purging Tip of the Week: #13

When purging systems with vented barrels, vary the screw speed while loading purging compound into the system. This will create pressure variations in the flow that will cause purging material to surge into the vent openings, thus improving cleaning action.

For chemical purging compounds, it’s critical that the vents are capped during any soak period. Otherwise the gases that mediate the purging process will escape to the atmosphere prematurely. Use care in dealing with improvised vent caps, because pressure can build up beneath them.

Friday, May 7, 2010

Purging Tip of the Week: #12

Carbon Black presents a difficult purging challenge. To obtain reasonable purging results in these cases, pre-flush thoroughly using a clean, natural material that is stiffer (of greater viscosity) then the production material that contains the carbon black. A high-density polyethylene of appropriate Melt Index is a good choice for this use.

Flush until – in your judgment – the bulk of the black color has been removed from the system. Then finish up with a good purging compound, used in accordance with the manufacturer's recommended procedures.