Note: Descriptions are shown in the official language in which they were submitted.
.
The present invention relates to new products with multiple appli-
cations e.g., construction and coating (of floors, walls, etc...), insula-
tion (heat~proofing and sound-proofing) and packing in all its forms. It
also relates to a prodess for obtaining such products.
The pressing economic need of up-grading, as much as possible, all
wastes (both industrial and agricultural) on the one hand, and the fight
against pollution and degradation of the natural environment on the other
hand have led the applicant, specialized in the paper-making field, to
strive for means for recovering and reusing paper-making sludges.
The present invention has for its main object the provision of
~lexible products for construction, coating, insulating or packing, formed
~rom paper-making sludges from decantation basins.
The present inven-tion aims more particularly at providing novel
products for coating, insulating, and packing obtained from industrial
wastes, the process for preparing same, the means suitable for implementing
this process, as well as the general processes and the production lines in
which the process and the products in accoxdance with the present invention
are included.
By one broad;aspect of this invention, a process is provided for
preparing a natural color or dyed flexible product for construct:ion, coat-
ing, insulating or packing, comprising the following steps in sequence:
(a) suspending paper-making sludges in water at a p~ close to neutrality
and at a concentration between lS and 50 g/liter; (b) adding a firs-t
addition of a cross-linking agent formedlby a low molecular weight diamide
and ~ormaldehyde condensate; (c~ adding an acrylic latex in an amount of
3-75~ by weight weigh respect to the dry weight of the sludges usedi ~d)
adding a second addition of said cross-linking agent to cross-link said
acrylic latex; and (e) adding at least one of a mineral or vrganic filler.
By one variant thereof, the acrylic latex is added in an amount
of 30-403 by weight.
By another variant thereof, the process includes adding 0.1-2~
by weight of a phenolic resin, especiall~- where the phenolic resin i5 a urea-
formaldehyde resin~
By yet another variant thereof, the pasty mixture is fed into the
manufacturing circuit of a paper-making machine.
By another variant thereof, the initial product comprises a pasty
mixture, and wherein said pasty mixture is fed to molds for pressure forming
different panels in any desired shape.
~ y a still another variant thereof, the initial product comprises
a pasty mixture, and wherein said pasty mixture is fed to molds for pressure
forming different panels in any desired shape, and wherein said panels formed
in said molds are formed under pressure between 30 and 150 kg/cm .
By a still further variant thereof, the polarity of the cross-
linking agent used is of a sign opposite that of the latex, which sign is
identical to that of the sludges.
By yet another variant thereof, the weight of -the cross-linking
agent added is from 0.01 to 10~, with respect to the dry weight of the latex
used for the first addition, and from 0.01 to 5%, with respect to the weight
of the latex for the second addition.
By still another variant thereof, the weight of the cross-linking
agent added is from 2 to 6%, with respec-t to the dry weight of the latex used
for the first addition, and from 1.5 to 3.5%, with respect to the weight of
the latex for the second addition.
By a still further variant thereof, the paper making sludges com-
prise a major amount of mineral fillers and a minor amount of cellulose fibers.
;3
By a variation thereof, the process includes the suspension of
bleached resinous pulp and fine sawdust in step ~a).
By another variation thereof, the prscess includes the suspension
of bleached resinous pulp and finely ground leather wastes in step (a).
By yet another variation thereof, the process includes the sus-
pension of unbleached resinous pulp, ground leather waste and nylon fibers
in step (a).
By still another variation thereof, the process includes the
final step of adding synthetic bonding agent and a cationic s-tarch cross~
link~ng agent for the synthetic bonding agent.
By another aspect of this invention, a composition is provided
comprising: 10-92% by weight of paper-making sludge; 3-75% by weight of an
acrylic latex; 2-6% of a cross-linking agent for the acrylic latex, the
cross-linkiny agent comprising a low molecular weight diamide and formalde-
hyde concentrate; and 5-70% of at least one of mineral or organic filler.
By one variant thereof, the mineral or organic fillers are one or
more of calcium carbonate, magnesium carbonate, kaolin, talc, titanium oxide,
gypsum, natural ochres, silico-aluminates, asbestos, aminoplasts, pheno-
plasts, leather wastes, sawdust, bonding agents, starches and bleached or
unbleac]led, paper-making pulps of vegetable origin.
By another variant thereof, the composition includes 0.1 to 6%
of a phenolic resin, e.g. a urea-formaldehyde resin.
Typical e~amples of such compositions include the following:
paper-making sludge, comprising a major amount of a mineral filler and a
minor amount of cellulose fibers 12%, bleached resinous pulp 1~3%, fine saw-
dust 30%, acrylic resin 30%, phenolic resin 6%, and cross-linking agent 4%;
paper-making sludge, comprising a major amount of a mineral filler and a
minor amount of cellulose fibers 10%, bleached resinous pulp 40%, finely
ground leather wastes 19%, acryllc latex 23%, and cross-linking agent 2%î
paper-making sludge, comprising a major amount of a mineral filler and a
minor amount of cellulose fibers 12%, unbleached resinous pulp 20%, ground
leather wastes 16%, nylon ~ibers 16%, acrylic latex 32%, and cross-linking
agent 4%; and paper-making sludge comprising 70% mineral fillers and 30%
cellulose fibers 68.9~, urea-formaldehyde resin 0.1%, acrylic latex 20.7%,
cross-linking agent 6.6~ synthetic bonding agen-t 3.4%, and cationic starch
cross-linking agent 0.3%.
These compositions may be in the form of continuous sheets or
molded panels, either of which may be dyed in situ.
The following e~amples relate to compositions and preparation of
the products in accordance with aspects of the invention. It should however
be understood that the examples described hereafter are given solely by way
of illustration of the subject of the invention.
- 3a -
I Examples of compositions of the startin~ _aw material
(Percentages are expressed as dry products)
Example 1
Paper-making slu~ges 12%
Bleached resinous pulp 18%
Fine sawdust 30%
Acrylic latex 30%
Phenolic resin 6%
Cross~linking agent 4%
Example 2
Paper-making sludges 10%
Bleached resinous pulp 45%
Finely ground leather wastes 19%
Acrylic latex 23%
Cross-linking agent 2%
Example 3
Paper-making sludges 12%
Ur,bleached resinous pulp20%
~ Gro~1nd leather wastes 16%
Nylon cable, length 13mm16%
Acrylic latex 32%
Cross-linking agent 4%
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II Examples of preparation
1. Preparation of continuous sheets
100 kg of dry paper-making sludges are taken. The contain 70 kg
of mineral fillers (principally calcium carbonate) and 30 kg o cellulose
fibers. The sludges are suspended in 5000 liters of water to have a con-
centration of 20 g/liter. The pH is adjusted, if need be, to 7-7.2 0.02%
of a urea-formaldehyde resin with respect to the dry weight of the mixture
is added. At this stage, it is possible to use synthetic or natural dyes,
then 6% of a low molecular weight diamide and formaldehyde condensate with
respect to the weight of the latex and serving for cross-linking this latter,
is added.
Then 30% of latex is added (with respect to the weight of the dry
sludges) after which a new amount of the cross linking agent (3.5% with
respect to the weight of the dry latex) is added. After homogeniza-tion, 5%
(with respect to the total weight of sludges + latex) of a synthetic bonding
agent (for example that known by the Trade Mark "AQUAPEL" from HERCULES) is
added, then 0.5% (still with respec-t to the total weight of sludges + latex)
of cationic starch serving as cross-linking agent for the synthetic bonding
product.
The homogenized mixture is then fed to the conventional manuEac-
turing circuit o a paper-making machine.
The sheet obtained has the fo]lowing characteristics:
Weight per unit area 405 g/m
M~llen index 8.~
Ash percentage 70.2%
AFNOR ink adhesion 5/5
Breaking length 987 m
Latex 23%
2. Preparation of panels
The final composition of the mixture was the
following :
Paper-making sludges 20 parts
Cellulose 30 parts
Fine sawdust 50 parts
Latex 50 parts
Phenolic resin 10 parts
This mixture was then pressed ~etween two steel
disks (30 to 40 kg~cm2).
The final drying was also carried out under pressure.
I`he panel thus obtained was coated, before use, on
both faces with a plastic resin (e.~, that krlown by the Trade Mark
"AQIIAPLAST") and clried.
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