Subject: Re: HELP, Please read this if you know about plastics drying
From: oligimer@aol.com
Date: 16 Jan 1997 13:56:28 GMT
In article <5bhjj8$cv9$2@news3.microserve.net>, cmos@me.com (cmos) writes:
>Subject: HELP, Please read this if you know about plastics drying
>From: cmos@me.com (cmos)
>Date:Wed, 15 Jan 1997 03:32:43 GMT
>
>
<< I was wondering about the placement of the dew point sensor.
I am thinking about putting it on the dry air input duct. Should
I place it before or after the heater? >>
The dew point sensor lead should be place at the inlet of the hopper dryer
itself, (placed at the bottom of the hopper)since that is the air quality
you
are concerned with. A return hose should come off the top of the hopper,
and
go back to the drying unit to achieve closed loop drying.
<< Also I would like to throw a duct open to dry the silica bed
when the dew point rises to -30 degrees, is this even posable?
I don't believe that the dessicant material will "dry" by opening a duct.
Typically it requires 500-700 deg F air movement to atmosphere to release
the moisture that has been adsorbed.( notice adsorbed, not absorbed) It
then
has to be cooled down to below 140deg F before it can be used again. Most
dryer systems have at least two dessicant beds for this reason. 1 in
process, one rgenerating. BTW, anything under 0 deg F, is fairly capable
of
drying most thermoplastic materials. -25 to -40 is great if you can hold
it
there, since the drying process is really just a vapor differential
equalization, and not a true "drying" mechanism.
>>I am unsure if it is best to controll the heater by turning it off
and on, or by controlling it analogly with an SCR or similar?
Place a good quality thermocouple at the inlet of the hopper as well, and
let
it dictate the on/off control of the process heaters. A small analog
thermometer for assurance can be placed here also. Make sure you have at
least 1 cfm air circulation/ per pound of material being processed/ per
hour
at all times. The dry heat itself will not do the job.
Additionally, the temperature, and airflow must be uniform throughout all
areas of the drying hopper. If the hopper is not insulated, there will be
a
drastic temperature difference from the center of the hopper to the side
walls. Thermoplastic drying is a time temperature relationship, and
uniformity is crucial.
For a somewhat detailed list of temperatures and time for various
materials,
visit the General Polymers / Ashland Chemical website at
http://www.ashchem.com/GP/trouble/index.html.
Choose the misc./technical page, for drying and more.
Hope this helps,
Alan Larsen
Subject: Re: INJECTION MOLD COSTS
From: Karl Donauer
Date: Thu, 16 Jan 1997 11:15:24 -0800
Samurai929 wrote:
>
> I was wondering if any toolmaker or a rep of a toolmaking cost could help
> me out with this:
>
> I have been wondering, out of curiousity, about the approx/ballpark costs
> of (single cavity) molds for the following products:
>
> 1) Dannon Yoghurt: any size
> BTW, how do you print on plastic moldings
>
> 2) tooth brush (ignoring issues relating to bristles; BTW, how are
> bristles incorporated into the tooth brush?)
>
> 3) 3.5inch plastic floppy diskette (one or both parts of the plastic
> enclosure)
>
> If you have any other examples that you may want to share, I would
> appreciate hearing from you. Thanks a bunch.
Printing on plastic mouldings
There is a process called "tampon printing". The tampon is pressed on a
collored metalplate which has the shape of the area to be coloured. Then
the tampon is pressed on the plasticpart. There can be as much collors
used as you want. But you have to use as much tampons as collors.
The tampon printing machines aren't very expensive. But you have costs
each working step you have to make. And the exact handling of the parts
isn't cheap.
The second process is called "In Mould Surfacing" (3M) or "in mould
decoration" (Kurz GmbH). A thin sheet of plastic is collored. This sheet
is fixed into the mould. During the injection the substratematerial
attaches to the plasticfilm, so that you can see the collor at the parts
surface.
The mould gets more expensive because you need very exact handling of the
plasticfilms.
Hope that helps
greatings
Karl Donauer
Subject: Re: Transparent polyurethane elastomer
From: rinkedinkus@earthlink.net (Rink E. Dinkus)
Date: Thu, 16 Jan 1997 00:06:26 -0600
In article <32D354CB.5FDE@netvalley.it>, Matteo wrote:
> I'm searching info about transparent polyurethane elastomers suitable for
> casting.
> Pot life, curing times, how to obtain high clarty and tranparency are
> main subjects for this request.
> Thanks for replying!
>
> Matteo Lagasi
matteo:
you dont' mention durometers in your request, so i'll assume it's not an
integral concern. contact smooth-on @ 800 7666841 and tell them what
you're looking for. i've seen a shore-80 sample that is crystal clear. pot
life would be around 15-20 minutes @ 70F. or so. cyre time would probably
be 6-hrs to overnight. i've never used this particular formulation, but
i'm TOTALLY familiar with their 744 compound.check them out! they're worth
the time (as opposed to some of the bigger companies, which aren't)
pcl
Subject: Re: Young's Modulus and Termperature
From: Peter Mott
Date: Tue, 14 Jan 1997 12:21:44 -0500
Barry O'Sullivan wrote:
>
> Hi all,
>
> I am attempting to develop an Artificial Intelligence based design tool to
> support designers at the conceptual phase of design. I have quite a strong
> engineering background. My question to the experts in this newsgroup is
> whether or not there exists an mathematical expression for determining the
> effect of temperature on the elastic modulus of a material (e.g. polymer).
> Up until now I have been using some graphical representation of these
> relationships. What I would like to do is to build this type of knowledge
> into the system that I am building. Any information relating to this topic
> would be a great help (references, formulae etc..)
Depends on the system and the temperature. For neat materials
near the glass transition temperature -- say, Tg +/- 50 C -- the
WLF (Williams-Landau-Ferry) eq works pretty good. Beyond this
range, above or below, I'd take the modulus to be a constant.
Unfortunately, many (if not most) engineering polymers are
complex, multi-phase systems that show much more complex
temperature dependence of the modulus than what can be described
by WLF.
For a discussion on the WLF eq, check out:
IM Ward & DW Hadley, "An Introduction to the Mechanical
Properties of Solid Polymers"
IM Ward, "Mechanical Properties of Solid Polymers" 2nd Ed.
NG McCrum, BE Read, & G Williams, "Anelastic and Dielectric
Effects in Polymer Solids"
WD Ferry, "Viscoelastic Properties of Polymers"
Peter Mott
Subject: Search for Technical Experts (5)
From: heerings@worldaccess.nl
Date: Thu, 16 Jan 97 18:47:10 GMT
SEARCH FOR TECHNICAL EXPERTS
Product and/or process development requires specific information, knowledge
and/or experience. Specific information/knowledge/experience is mostly not easy
to track down, even not in centres for technology. One reason is that specific
knowledge/experience is mostly linked to individuals, the experts on a
specific topic.
In order to further the search for specific knowledge I am setting up a
database that refers to experts on all kinds of technological topics.
Companies that look for specific knowledge/experience can use the database
to get in touch with the needed expert.
If you are an expert and you like to be included in the database, please
send me (by email) the following information:
KEYWORDS describing your expertise:
* Field of technology, e.g. chemistry: 1 keyword.
* Application in terms of product/process, e.g. thermocouples: 1 - 3 keyword(s).
* Application in terms of industry/activity, e.g. refinery: 1 - 3 keyword(s).
* Description of your specific expertise: preferably 3 keywords, e.g.
degradation, carbonmonoxide, misinterpretation; if not possible: a small text
is allowable.
Some Rules:
-For the selection of keywords you may use your own terminology.
-A keyword may consist of more than one word.
-Use the above description for each separate expertise you offer.
-If you feel the use of keywords is too restrictive for a good description,
your expertise is probably not specific but general.
PERSONAL details:
* Name.
* Name of company you represent (if applicable).
* Email address and/or facsimile number.
* Country/State.
Confidentiality: My name is J.H. Heerings (Dieren, The Netherlands). I am
writing from a personal interest and as an individual (no company is involved).
The above information will not be used for mailing lists or otherwise; only for
the abovementioned database. I will contact you at the moment the database will
start to run and is accessible to industry.
The information should be emailed to: heerings@worldaccess.nl
Subject: Polymer physicist looking for postdoc or R&D; position
From: Sergej Shilov
Date: Thu, 16 Jan 1997 19:34:03 +0000
Dear colleagues:
I am looking for postdoc or R&D; position in polymer science. Could
someone mail to me the relevant information? Please, find enclosed my
resume.
Sergej Shilov
RESUME
Sergej Shilov
Leipzig University, Linnestr 5, 04103 Leipzig, Germany
phone: +49 -341- 97 32 553
e-mail: shilov@august.exphysik.uni-leipzig.de
OBJECTIVE: Postdoc or research and development position (in academic
setting
or industry) that uses my knowledge of polymer physics and applied
spectroscopy.
PROFESSIONAL EXPERIENCE
1996-till March 1997. Research fellow of A. von Humboldt foundation at
Prof. F. Kremer's team, Leipzig University, Germany.
* Conducted own project on studies of segmental dynamics of
nonpolymeric,
polymeric and elastomeric liquid crystals (in book-shelf geometry and as
free-
standing films) in an external field (mechanical, electric and
electro-magnetic)
by time-resolved and phase-resolved step-scan FT-IR spectroscopy
* Further developed of 2D-IR method with application to liquid
crystals.
* Created the detailed model of segmental motion in course of
electroclinic
and ferroelectric switching
* Supervised of Ph. D. students
1995. Senior scientist, Inst. Macromolecular Compounds, Russian Academy
of
Science, St. Petersburg, Russia.
* Carried out basic research on orientational and conformational
ordering of
thermotropic main-chain polyesters
* As a member of analytical division analyzed the various samples by
vibrational spectroscopy using chemometrics software
* Participated in organization of the Center of Spectral
Research,St.Petersburg
1993-1994 Postdoc at Prof. H.-W. Siesler's team, Essen University,
Germany.
* Implemented the step-scan FT-IR technique on local spectrometer
* Set-up and conducted the experiments on segmental reorientation
dynamics of
nematics
* Created the near-infrared spectral library of industrial plastics and
find
the best conditions for fast and accurate identification of unknown
polymer
samples (part of the multi-million dollar EC project on polymer
recycling)
* Developed the research projects, including international cooperation
with the EC
* Advised graduate and Ph.D. students
1986-88 Researcher and
1988- 92 Research scientist. Inst. Macromolecular Compounds, St.
Petersburg,
Russia.
* Studied the orientation and conformation of main-chain polymers by
various
techniques
* Wrote and implemented the customized program on calculation of
possible
conformations of polymer chain in liquid crystalline melt
* Created the model of enhancing of polymer rigidity on isotropic -
liquid
crystal phase transition and proved this model experimentally
* Read courses on vibration spectroscopy
EDUCATION
April 1992, Ph.D. in Polymer physics, Inst. Macromolecular Compound,
Russia
Thesis: "Conformations and order parameters in a series of thermotropic
polyesters"
Thesis advisor: Dr. Boris Volchek
1980-1986 Physics Department of St. Petersburg University, Russia
February 1986, M.S. degree in Physics
SKILLS
Spectroscopy: professional knowledge of FT-IR and NIR spectroscopy
(including
microscopy, step-scan, time-resolved, 2D-IR, ATR, grazing angle,
imaging),
Raman and UV-VIS spectroscopy. Chemometrics data analysis.
Materials characterization: polarization microscopy, differential
scanning
calorimetry, viscometry.
Computing: data analysis and computer modeling, calculation of vibration
spectra
and molecular conformations; languages: FORTRAN, Matlab.
Teaching: read courses on vibration spectroscopy
Languages: Russian (native speaker), English (fluent), German (poor)
HONORS
1994 Grant of Procter & Gamble Company (USA) for research in the field
of
dynamical FT-IR spectroscopy.
1996 Research fellowships of Alexander von Humbolt foundation (Germany)
References and publication reprints available upon request.
Subject: Position Available: Elastomers Tech Support
From: Brad Kent
Date: Thu, 16 Jan 1997 11:13:08 +0000
In the spirit of announcing technical job opportunities to the largest
pertient audience, I hope no one in this newsgroup will object to the
following posting.
Ausimont USA, Inc., a world leader in the production of fluorochemicals
and fluoropolymers, has an immediate opening in the Corporate Technology
Center in Thorofare, NJ.
Position: Fluoroelastomer Technical Support/Application Development
Experience/Skills:
BA/BS in chemistry, chemical engineering, or related field
Hands-on elastomer molding experience in a technical support capacity
Knowledge of and ability to operate elastomer testing equipment
Excellent written and verbal communications abilities
Good analytical, interpersonal, and organizational abilities
Self-starter, able to work independently
Minimum 2 years elastomer compounding experience, preferably
with fluoroelastomers
Duties/Responsiblities:
Data analysis and report writing
Interface with customers
Some overnight travel
Telephone technical support
Technical support and troubleshooting at customer's site
Perform laboratory tasks as needed
Project management
Interface with and provide direction to laboratory technician(s)
Qualified candidates, please send resume for immediate consideration to:
Ausimont USA, Inc.
Attention: Dr. Brad Kent
10 Leonards Lane
Thorofare, NJ 08086
Subject: Re: Silicone Sealant Removal
From: b.ecurry@why.net
Date: Fri, 17 Jan 1997 12:32:13 GMT
On Mon, 13 Jan 1997 09:21:22 -0600, noel@qualcomm.com wrote:
>Hi,
>
>My next door neighbor just bought a model home where the builder sold her
>all the dishes and knicknacks glued together with silicone gel. This was
>done to prevent stealing from the model home. The builder, of course,
>tells here she bought the house as is. Now she has all these nice plates,
>glassware, artwork, and even books looking very pretty but all glued
>together.
>
>We went to a builder's supply and the best they could suggest was an
>Exacto knife. Does anyone know of a silicone remover that would loosen
>the silicone without etching glass and fired ceramics? It also needs to
>not kill my neighbor--she's about 80 years old!
>
>Thanks,
>Noel
>-------------------==== Posted via Deja News ====-----------------------
> http://www.dejanews.com/ Search, Read, Post to Usenet
According to GE, a manf. of silicone sealant, there is nothing that
dissolves the sealant. Their best advice was scraping and scrubbing.
My personal efforts confirm this so far and I haven't tried one
suggestion which is to use trichlorethane, a dry cleaning solvent
available at hardware stores. My guess is that you have to get most
of the residue off before using a solvent to "clean up" what's left.
bob curry
Subject: Re: Needless Loss of Eight Lives Working with High Pressure
From: *carrelda*@pore.dnet.dupont.com* (David Carrell)
Date: Fri, 17 Jan 97 02:59:46 GMT
In article ,
kcb@phoenix.net (K. C. Bennett) wrote:
>Status report:
>
>There are currently three separate investigations going on: OSHA, the
>Wyman-Gordon company, and an independent investigation by lawyers for the
>family of one of the men killed in the accident. According to the Houston
>Chronicle, they expect some results within a week or two.
>
>There was a joint memorial service here in northwest Houston this past
>Sunday, attended by over 2000 people.
>
>K. C. Bennett
Having been through a refining incident where a fatality occurred, I have to
say at this point: 1) The private investigation (by the lawyers) will not be
release at this point (parts yes, at trial maybe, if settled probably not),
2) OSHA may be leaving the site but you will not see their final report for
at least 3 months (probably longer, and maybe never), and 3) Any report by
the company will be considered (rightly or wrongly) suspect and biased.
It is a shame that these events occur. If the company was truly at fault,
the fines should be heavy. Personally (based on almost no knowlege of the
event) my _GUESS_ is human error or not following an established procedure
was the root cause.
My condolences to friends and families of the victims,
DAC
-------------------------------------------------------------------------
David Carrell All comments above are mine, and
Process Control Engineer do not necessarily reflect the
Conoco, Inc. opinions of Dupont and/or Conoco,
*carrelda*@pore.dnet.dupont.com* [and why should they]
(return address altered to reduce
adds, remove *'s for real address)
Subject: Re: Silicone Sealant Removal
From: bkeahey@uswest.com (Bruce Keahey)
Date: 17 Jan 1997 16:33:40 GMT
In <32df7098.55124397@news.why.net>, b.ecurry@why.net writes:
>On Mon, 13 Jan 1997 09:21:22 -0600, noel@qualcomm.com wrote:
>
>>Hi,
>>
>>My next door neighbor just bought a model home where the builder sold her
>>all the dishes and knicknacks glued together with silicone gel. This was
>>done to prevent stealing from the model home. The builder, of course,
>>tells here she bought the house as is. Now she has all these nice plates,
>>glassware, artwork, and even books looking very pretty but all glued
>>together.
>>
>>We went to a builder's supply and the best they could suggest was an
>>Exacto knife. Does anyone know of a silicone remover that would loosen
>>the silicone without etching glass and fired ceramics? It also needs to
>>not kill my neighbor--she's about 80 years old!
>>
>>Thanks,
>>Noel
>>-------------------==== Posted via Deja News ====-----------------------
>> http://www.dejanews.com/ Search, Read, Post to Usenet
>
>According to GE, a manf. of silicone sealant, there is nothing that
>dissolves the sealant. Their best advice was scraping and scrubbing.
>My personal efforts confirm this so far and I haven't tried one
>suggestion which is to use trichlorethane, a dry cleaning solvent
>available at hardware stores. My guess is that you have to get most
>of the residue off before using a solvent to "clean up" what's left.
>
>bob curry
I was able to remove silicone sealant from some old, weathered window frames
using a non-metalic paint removal wheel chucked in my electric drill. It's tough
dirty work, and since the wheel bites and grabs depending on thick the silicone is
and how much pressure you use, be careful and use eye protection. The process
did do some damage to the wooden window frames, but I expected that before I
started, and the level of damage was acceptable.
// Bruce Keahey, U S WEST Advanced Technologies, Boulder, CO
// "Never anger a dragon, for you are crunchy, and you go well with Brie."
Subject: Re: JOB
From: adler@pulsar.wku.edu (Allen Adler)
Date: 17 Jan 1997 11:12:58 -0600
As Grady Russell has ably explained, looking for a job is itself a
full time job. Accordingly, those who wish to learn a subject
deeply face a conflict of interests which tends to divide them
roughly into two groups:
(1) the body builders
(2) the estate builders
The former keep their minds on the subject they are learning.
The latter keep their minds on their personal advancement.
It would be nice if one could focus on perfecting oneself in
the subject one is learning and be rewarded for it. Instead,
one is rewarded for neglecting the subject one is learning
and concentrating on administrative work; in the present
instance, the adminstration of one's job hunting and career
development.
There needs to be a place, and not a dismal one, for the idea
that it is worthwhile to develop oneself in ways that are not
specifically related to one's marketability.
Allan Adler
adler@pulsar.cs.wku.edu
Subject: Re: Needless Loss of Eight Lives Working with High Pressure
From: Rodney Taylor
Date: 17 Jan 1997 19:03:39 GMT
*carrelda*@pore.dnet.dupont.com* (David Carrell) wrote:
>Having been through a refining incident where a fatality occurred, I have to
>say at this point: 1) The private investigation (by the lawyers) will not be
>release at this point (parts yes, at trial maybe, if settled probably not),
>2) OSHA may be leaving the site but you will not see their final report for
>at least 3 months (probably longer, and maybe never), and 3) Any report by
>the company will be considered (rightly or wrongly) suspect and biased.
>
>It is a shame that these events occur. If the company was truly at fault,
>the fines should be heavy. Personally (based on almost no knowlege of the
>event) my _GUESS_ is human error or not following an established procedure
>was the root cause.
I have to comment that this is where I see a societal evil of lawyers - data
suppression. True facts revealed would save lives elsewhere, in other industries.
That they are not revealed (expected) means some one else gets to learn the hard
way. The company _might_ privately share this with local competitors, but the
learning then does not extend to other countries or industries with similar
pressurized systems for whatever purpose. This is not socially responsible use of
information obtained via loss of life.
Diligence by workers and supervisors is a required component of safety programs.
- - - Unsolicited ad response starts with complaint to your sysop! - - -
Rodney Taylor Competitive Assistance for Business
rodney@onramp.net Analysis, Planning, and Reporting - made easier
background overkill - http://rampages.onramp.net/~rodney (in Houston)
Subject: SBR and Acrylic Textile Laxtex(Rubber) Backings
From: "Frank C. Grace"
Date: Fri, 17 Jan 1997 11:34:03 -0800
Hello,
I work in a mill that makes upholestry fabric. We put a backing on the
back of the fabric when the fabric is weak. Two different types of
latex are used. The first type is Styrene Butadiene Rubber(SBR) and
Arylic latex. These two backing are not used together. Sometimes the
two get confused after they are applied and dried on the fabric. I was
wondering if there is a 'quick' test that could be used to distinguish
between the two. For example dropping a reagent on the backing to see a
color change or something to that effect. I am a student of textile
chemistry and I haven't taken polymer chemistry as of yet. I noticed
that the R groups on the polymer chain contain Ethyl Acrylate, Butyl
Acrylate, Acrylonitrile, N-Methylol Acrylomide, and Acrylic Acid.
Whereas the SBR of course in just C and H with unsaturation. Maybe if I
could identify the N or C=O in the acrylic???? Please I need some help.
Please E-Mail me if you have could be of any help, Thanks
Frank C. Grace
frankie1@ici.net
