Acronyms: HGM or HGMS hollow glass microspheres, also called microballoons
Here is a short overview:
The production of HGM is a well-established technology. There are
several methods available to produce HGM, but every approach depends
on the decomposition of a substance known as a ?blowing agent? to form
a gas within in a liquid. The rapid expansion of this gaseous product
causes the formation of a bubble. One of the most common methods for
producing HGM is to intentionally mix a trace amounts of a
sulfur-containing compound such as sodium sulfate with a sodium
borosilicate glass that is similar in composition to traditional
Pyrex® glassware.1-2 This mixture is then dropped into a hot flame
that melts the powdered glass and sodium sulfate. The melting of
sodium sulfate results in a decomposition reaction that releases
minute amounts of sulfur gas that form bubbles within the molten glass
Here is a more detailed report
producing hollow microspheres Journal of Glass and Ceramics
Publisher Springer New York
ISSN 0361-7610 (Print) 1573-8515 (Online)
Subject Chemistry and Materials Science and Russian Library of Science
Issue Volume 45, Number 8 / August, 1988
Online Date Tuesday, December 07, 2004
Here is scholarly Review -- Hollow Microsperes
J. Bertling *, J. Blömer, R. Kümmel
Hollow microspheres are spherically symmetrical particles consisting
of at least two phases. Their sales are continuously increasing
because of a large number of well-known and new applications. While
most of the current needs for hollow microspheres are met by inorganic
byproducts of combustion processes (cenospheres), the fabrication of
tailor-made hollow sphere structures by processes like spray-drying as
well as dripping, emulsion and suspension techniques is gaining more
and more interest. Surface phenomena play an important role as far as
formation, properties and stability of hollow microspheres are
concerned. Template techniques can be used to yield structures that
have not been available so far. Modeling and simulation of the
formation processes are useful tools to understand the formation
mechanisms and to simplify the scaleup.
Fabrications methods for specialised applications
Manufacture of DT-filled, hollow glass microsphere, laser targets
P. C. Souers, R. T. Tsugawa, and R. R. Stone
Lawrence Livermore Laboratory, University of California, Livermore,
The fabrication of highly characterized DT-filled, hollow glass
microsphere targets is described.
Review of Scientific Instruments -- June 1975 -- Volume 46, Issue 6, pp. 682-685
Full Text: [ PDF (766 kB) ] Order
Commercially availbale HGMs
3M? Glass Bubbles
Hollow glass microspheres with a high strength to density ratio.
Lightweight but with a strength for processing survival.
This technology enables the efficient conversion of perlite
(obsidian), a common volcanic glass, to high-quality, glass
The process involves an acid-leaching treatment with hydrochloric or
sulfuric acid at 150 to 200 degrees C, followed by a heat treatment
process for finishing.
Current U.S. patents granted that protect the technology include:
Patent Key Features
6,110,528 Efficient preparation of TiO2-coated hollow glass spheres.
5,833,728 Hollow glass spheres with high strength and excellent whiteness.
Similar claims to ?255 with terminal disclaimer.
5,614,255 Uses aluminum sulfate and urea foaming solution.
Excellent whiteness and mechanical strength.
5,017,523 Enables production of hollow glass spheres from starting
material of 20µm or less.
AIST is seeking to license these technologies and assist with their
production of hollow microspheres by thermal expansion of glass
Patents by Date - PatentStorm - Oct. 26, 1993Processes and apparatus
for the production of hollow microspheres by thermal expansion of
glass particles including the thermal treatment of extremely small ...
There is a active US gov funded research program
of manufacturing HGMs for Hydrogen Storage (to be used as fuel carrier) at the
Alfred, NY 14802
Hollow-glass microspheres.(MATERIAL PRODUCTS)
Hollow Sphericel 34P30 glass microspheres boost buoyancy and thermal
insulation of syntactic foams. The microspheres' high
strength-to-weight ratio, ...
Machine Design, 7/7/05
Topic is too wide to allow manufacturing cost estimates.
Product can be material consisting of mix of different sizes or microspheres
or " substantially uniform diameter and of substantially uniform wall thicknes"
Neverthless here is a prognosis of costs HGM materials:
Overall the eleven markets investigated are expected to grow in volume
at over 10% per year through 2009 and have an average selling price of
over $2 a pound. Depending on the application, type of material, and
whether they are solid or hollow, microspheres provide a variety of
functional benefits in these applications ..
Clarification of Answer by
23 Aug 2006 06:13 PDT
I understand that you are dissapointed. Some of that be remedied if
you are willing to learn to formulate your questions better. Part may
be due to
true limitation of what this service can provide fro $100 -- $200.
" I have already found a lot of this information and these links..."
Well posed question is half of the answer and requirement
#1 is to say what you already know and
#2 is to narrow and focus the search.
Examples (of importance of the formulation):
(This BTW applies to your other question (modified gelatine) as well:
What the 'modified' means: Change primary structure of the polymer?
"Not flocculate in cold water so that it remains dispersible..."
mean? If it is not soluble, it will precipitate and form a dispersion. Are
you asking how to make the disperesed particles small? What concentration range?
Why aren't the pateneted processes suitable? )
For the given price you are buying certain amount of researchers time
You do not expect that someone will invent a new process (which will be
'suitable') and post on the internet, do you?
Any time spent on duplication of what you know, or what is outside your
application is wasted. As I said in the answer:
"Topic is too wide to allow manufacturing cost estimates.
Product can be material consisting of mix of different sizes or microspheres .."
If you cannot describe what your purpose is, it may be necessary to at least TO
provide some parameters: What volume of production, what uniformity of spheres,
filled with what gas ...
If the parameters and goals are confidential, it may be better for you to find
a consultant with whom you will have Nondisclosure agreement and then
It also is true that only a small fraction of technical knowledge is available
on the internet for free. We can't post here copyrighted information. To get
"full detailed explanation of the
process all fully documented. This would include photographs or
drawings of the process and arrangement .."
You certainly would have to spend some money on books, technical
journals and/or consultants.
So, you have three choices:
1) You can ask me to withdraw the answer (you will be charged only a
small listing fee) you can then look for an on-line consultant etc
2) you may have this question reposted here and see if some other GAR
will pick it up and perhaps do a better job [possible but unlikely].
3) you may focus your question, Tell us more about what you know, have and want
to do. I would give it another try - but likely result will me more books and
technical reports. Technical experts rarely post their knowledge on the
Internet for free. If you choose this option, it will be on the 'best
effort' basis. I doubt that I will find free on line description of
the process (or all the processes, of which one may fit your
unspecified goal). I can probably find
more literature related to a particular requirements.
How do you plead?
PS: You do not need any registration or pay a fee to get the first link.
It is .doc format and all you need to set up your browser to
call appropriate helper application (MS word, or OpenOffice ..) to read it.
Second link leads to a subscription journal. Publisher Springer charges for
access, but allows some guest access:
" Access to Springer Online Archives Collection
All institutions currently holding SpringerLink subscriptions and
guest users with valid passwords will have free access to the more
than 1.8 million archive records in the abstract database as they
become available. Consortia pricing and flexible terms are available.
For more specific pricing and title information, contact your local
Springer representative or visit springeronline.com/librarians..."
Link will however you the full reference,
which you can take to the nearest college library. If they do not
subscribe to the journal, the may get it for you via inter-libary loan.
Most libraries will charge for that, but they may tell you for free which
neares library has it.
Request for Answer Clarification by
23 Aug 2006 09:28 PDT
I apologise for the lack of background and specifics. I had hoped that
there would have been a quick and easy answer to this question. As I
have absolutley no background about this process, I didn't realise how
many factors would have to be taken into consideration. So, again, I
apologise for not being more specific. However, the link you kindly
added in your comments for me said 'Please be sure to check questions
priced at this level frequently as researchers are likely to have
questions for you about the answer you want'. Based on this, you could
have simply asked me for clarification or specifics before you went
and answered the question.(http://answers.google.com/answers/pricing.html)
Anyway, your time and effort is appreciated and your content has given
some good insights. I will therefore rate your question as very
May I just add, that it wasn't my intention to upset you (although its
pretty evident that I have). I would have appreciated it if we could
have resolved this without the need for name calling. Were not in the
school yard now and there are better and more effective ways of giving
feedback. Please remember that not everyone is as well versed on this
facility as you are.
You will be pleased to know that I have taken your comments on board
and next time I will formulate my questions so it makes your job a lot
Clarification of Answer by
23 Aug 2006 10:55 PDT
I have gave you those two example links so that you see how
clarification process, sometimes before, sometimes after I answer a
question works. I wonder if you read them (?)
In link 1. I said
" We do make special allowances for new customers, and so please take this
as a polite request, not as a criticism.
If you are looking specifically for 'something like Biarc algorithm', perhaps
a program, perhaps theory, you have to say that. Literature on
'fitting circles' is enormous, and chances that we find a fit [ :-) ]
by shooting at random are slim. Also, I wonder if you looked at all
the references I gave you. .."
It worked in that case, and believe me, the same applies to our case here:
" Please take this and the previous Clarification
as polite requests, perhaps advice, not as a criticism".
There may be some cultural differences here: I spent only one year in UK.
I do try, but I know I did not mastered the art of a polite dialog. Actually
until your RFC, I did not even know you are in UK. Often customers do forget
that this is a global enterprise and assume we know more than we can.
I do use the my best judgment and experience, both as GA researcher (GAR)
and in technical subjects to be helpful and to get 5 stars.
I do not always succeed, but I always appreciate the rating - it
helps me to improve.
I was not and am not upset, and (to continue being frank) I am not
aware if any name-calling (except mightymac, which I hope is not
"You will be pleased to know that I have taken your comments on board
and next time I will formulate my questions so it makes your job a lot
I am pleased. That was the goal of my remarks. I do believe that to
'ask the question' is a greater art, then to answer it.
Both can be improved by experience.
So, please, do not let this experience turn your off and give us another chance.