Civil Engineering Reference
In-Depth Information
In the production process workers can be exposed to dust made up of
paper and fine particles of boric salts. There are no records of serious dangers
from breathing in dust from paper, but it is generally advisable to be careful
with very fine-particled dust because of its potential to irritate the lungs.
Exposure to dust can occur at all stages from production to installation on
site, but once installed correctly the fibre should cause no problems for those
using the building. Cellulose fibre products have good moisture-regulating
properties and are much less susceptible to mould than the mineral wool
alternatives.
The products can be re-used and recycled, but cannot be burnt for energy recy-
cling because of their fire-retardant nature. As waste boric salts and printing ink
can seep into the earth or ground water. The effluent also contains eutrophicat-
ing substances which require special waste disposal.
Cellulose paper and boards
Cellulose building paper is usually manufactured from recycled paper and
unbleached sulphite cellulose. It can also contain up to 20 per cent pulp. Boards
are manufactured by laminating the sheets of paper together to 2-3 mm thick-
ness, with PVAC glue (about 3 per cent by weight).
Cellulose building paper is used for covering joints, sound insulation in inter-
nal walls and for surrounding loose fill insulation. The boards are used for
weather-proofing and are usually covered with black polyethylene on a mois-
ture-resistant coating of natural latex. Thermal insulation panels are also made
using sheets of corrugated cardboard which are laminated to different thickness-
es. These were very popular between 1945 and 1950, and were often impregnat-
ed with bitumen to prevent damp.
The basic raw material of these products is environmentally positive, ignoring
the consequences of the relatively small amounts of polyethylene, PVAC glue
and bitumen. The same can be said of the manufacturing process except for the
production of sulphite cellulose; depending upon the factory's cleaning technol-
ogy, this can release huge amounts of eutrophicating substances. With the excep-
tion of bituminous products, they are relatively free of problems once in the
building.
Durability is relatively good. Pure cellulose paper and laminated weather-proof-
ing boards (with natural latex) can most probably be recycled into new cellulose
products. The other products are best suited as a low quality cellulose fill in
asphalt, etc. The materials can be burned for energy recycling, provided that the
effluent gases are filtered from products containing plastic. Bituminous products
that are not burned have to be safely disposed of, as do those containing small
amounts of plastic. Dumping cellulose products will lead to an increased level of
