At Midwest Freeze Dry no ozone bleaching or environmentally dangerous
chemicals are used in the vacuum freeze dry process to treat mold on leather books, vellum books, paper books,
documents, artworks and textiles after water damage and there are no harmful
gasses or waste to dispose. We have adapted a cost-effective,
scientific, vacuum freeze drying method which is normally used in decaffeinating coffee
to kill molds. Independent clinical tests prove that our vacuum freeze drying
is capable of reducing
molds by 95%. Our vacuum chamber is a cost-effective treatment that uses near and supercritical carbon
dioxide which effectively destroys molds and bacteria after water damage. The
vacuum freeze drying process is
suitable for books, documents, archival records, art works and textiles. Our
vacuum freeze drying method has taken us several years to develop. The vacuum
freeze drying process is non-destructive
and environmentally safe unlike other methods.
Freeze-drying is a technique by which material is frozen, then dehydrated
by sublimation, with complete retention of form. In the first step
before vacuum freeze drying, the water damaged documents and water damaged books
are quickly frozen. This minimizes large ice blocks which can damage the paper in water damaged leather
or vellum books, paper books, or documents.
Sublimation is the process by which the contained water passes from a
frozen to a gaseous state.
Frozen material is placed into a vacuum chamber where the freeze-drying
process takes place. The time needed to completely dry materials varies
according to the thickness of a volume, type of paper and the degree of
saturation. Vacuum freeze drying is noninvasive and produces no chemical
Normal freeze drying is a good second step if the water damaged textiles,
water damaged books or water damaged documents being treated contain water but
is not without its drawbacks. Freeze drying removes the water, but on its own,
freeze drying is an unacceptable form of treatment for mold on books, papers,
and documents after water damage. This is because mold has a protective
mechanism within its life cycle which can help it to survive against such
extremes as freezing and desiccation. When this occurs mold forms rough, thick
walled protective coatings called zygosporangia which allow it to
become metabolically inactive until such time that conditions improve
(conditions where the temperature is warmer and there is more water). Many
laboratory suppliers make use of this mechanism and commercially freeze dry mold
samples to sell to researchers. So, normal freeze drying is not enough, further
treatment is required.
Midwest Freeze Dry, Ltd.'s innovation involves the
process of decontamination which is continued using a series of other
techniques. After vacuum freeze drying the material is treated with plasma. The plasma is generated using a
dielectric field and a special mix of gases which are all contained in a
customized vacuum chamber.
Plasma is considered by physicists to be a fourth state of matter. It is a
highly ionized neutral gas in which the number of free electrons is
approximately equal to the number of positive ions. Particles present in the
plasma such as ions and free radicals have a high activity and do the work on
the moldy books, documents, papers, photographs, manuscripts, maps, slides, microfilm,
microfiche, x-rays and books. Their high activity is related to the process
After plasma treatment the leather books, vellum books, paper books or
documents are treated with carbonic acid. Carbonic acid (H2CO3) is a dibasic
acid which is formed when carbon dioxide is dissolved in water. It is a chemical
reaction which occurs in nature when rain water is formed.
Midwest Freeze Dry acknowledges that freeze drying alone does not kill mold.
We believe that further treatment with supercritical and near supercritical CO2
is a satisfactory and environmentally safe mold treatment for materials such as water damaged documents and water damaged books. No ozone is used in any of our
processes because our research has shown that paper is degraded by bleaching causing
accelerated aging and subsequent fading and loss of tensile strength. It also
reduces the life expectancy of vellum books, paper books, documents, paper,
archival records, flight logbooks, art works and textiles.
Our new non-ozone process has been used to treat numerous libraries,
collections, legal documents and as an alternative to replacement in insurance
In addition to our unique non-ozone mold treatment, we provide a number of
supporting restoration services.
Our team can ascertain the level of damage caused by fire, soot, smoke,
water and mold to water damaged leather books, water damaged vellum books,
water damaged paper books and water damaged documents, including on site
assessment and can co-ordinate with your staff to ensure that your disaster
response is timely, efficient and does not cause the situation to worsen, saving
you time and money.
We can co-ordinate with your staff to catalogue and to pack and safely ship
all your books and documents.
At your request your books and documents can be clipped,
cleaned and re-filed.
Take some time to explore our site and learn about the benefits of vacuum
freeze drying as well as freeze drying, plasma fumigation and our other
conservation/restoration methods. These useful and cost-effective
tips will help you develop a disaster plan, as well as mitigate and
manage your plan should an event occur. You will also gain valuable insight into how
our vacuum chamber is used to restore and/or conserve your valued items.