Drying
Pulp
and cellulose fibre
Today
there is a rising demand for cellulose fibre packages adapted for recycling.
Local as well as international companies have become environmentally aware,
which make them favour packages made from cellulose fibre in place of plastics.
At Celtec Developments'
new plant in Vaggeryd, Sweden, troughs for foodstuff are made from cellulose
fibre. After the troughs have been vacuum formed, they pass through a continuous
microwave drier where they are dried.
http://www.celtec-packaging.com/
Paint
For painting of wood water
soluble types of paint are often used. By using microwave energy technology
(continuous drier) a faster drying process and a better quality can
be achieved.
Gisip has supplied a continuous
drier to Eurocoustic in France. This drier is used for drying painted
sound insulating boards. Drying by means of microwaves is fast and the
paintwork acquires a smooth and good looking finish.
Assembled and bulky painted
products are more readily dried in a batch drier. In this type of drier,
one or a number of products are placed to be dried. Fonus, which is Sweden's
largest producer of coffins uses this technology from Gisip.
Wood
In many countries with
important forest industry, among them Sweden, an intense development work
is going on with the aim to increase the level of processing of timber
in such a way that it is given new qualities before it is sold. Today,
almost all sawn wood is dried by hot air drying in chamber or travelling
driers, a method which takes a long time, usually several weeks. In addition,
the level of rejection is rather high.
Extensive tests of the use
of microwaves have shown very good results concerning drying time in the
same time as the amount of damage caused by the drying process has been
reduced. In addition, the timber acquires new qualities in the drying process
which give it a better value on the market.
Gisip has designed a microwave
oven for laboratory work at the Luleå Institute of Technology (Luleå
Tekniska Högskola) and has a close cooperation with their department
for research in the field of wood drying technology.
Biological
Material
The view of what was
formerly seen as troublesome, messy and smelly waste from restaurants,
catering services, private homes and grocery stores is now dramatically
changing. Fruit, vegetables, meat and fish which are no longer useful for
food nevertheless contains valuable nutritive substances which are of valuable
when recycling.
When drying the biological
material with microwaves, the weight is reduced by 70-80 percent
and the volume is dramatically reduced, which leads to lower costs of transportation.
The dried remnants are free from smell and easy to handle.
http://www.sik.se/
Other
Drying Processes
Microwave energy technology
combined with air treatment is used in many other drying processes. A few
examples:
Drying
of blacked moulds of sand for casting shops
Drying
of cheramical materials, e.g. in basins and water closets
Drying
of various fruits and vegetables
Drying
of solvent solvable paints with recirculation of the solvent in a combined
microwave and vacuum oven
Drying
of plastic granulate before moulding.
Foodstuff
When heating foodstuff
pasteurization is achieved which leads to better keeping qualities reduces
the need of preservatives. When producing bread the rising process can
be shortened by means of microwaves.
Glue
By using microwave energy
technology glue sets in faster and makes a more efficient production possible,
e.g. when producing cardboard packing which is to be made without interruption.
http://www.ergodesign.se/
Paint Removal
Microwave energy technology
is well suited for paint removal at careful renovation, e.g. of windows
and doors in old buildings of historical value. By means of microwaves
the paint can be dissolved without damaging neither wood nor irreplaceable
hand made window panes.
Other Heating Processes
Microwave energy technology
is also suitable for heating in many other processes:
Heating
and sterilization of liquids
Preparing
of furniture timber for steaming
Heating
of solid organic material
Vulcanisation
of rubber
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