204° F., with 50 parts, by weight, of caustic potash, of 50° Bé., to
which 50 parts, by weight, of water have previously been added. Forty
parts, by weight, of cooler water are then added slowly, care being
taken to keep the temperature of the mixture constant. As soon as
the liquor begins to rise, 40 parts, by weight, of cooler water are
again added, with the same precaution to keep the temperature from
falling below 204° F. At the same time care must be taken to prevent
the liquor boiling, as this would produce too great saponification. By
the prolonged action of heat below the boiling point, the oil absorbs
water and caustic potash without being changed, and the whole finally
forms a perfectly limpid, nearly black liquid. This is diluted with
5 times its weight of hot or cold water, and is then ready for use
without any further preparation. Other vegetable oils may be employed
besides castor oil, and the quantity of unsaponified oil present may
be increased by stirring the prepared liquid with a fresh quantity of
castor or other vegetable oil. The product is slightly alkaline, but
wool fiber is not injured, as the oiling may be done in the cold. The
solution is clear and limpid, and will not separate out on standing
like an emulsion. This product in spinning gives a 10 per cent better
utilization of the raw material owing to the greater evenness and
regularity with which the fibers are oiled; in weaving less oiling is
required.
The product can be completely removed by water, preferably by cold
water, and scouring of the goods subsequently with soap, soda, or
fuller’s earth can thus be dispensed with.
XVIII.—Cloth may be rendered waterproof by rubbing the under side with
a lump of beeswax until the surface presents a uniform white or grayish
appearance. This method it is said renders the cloth {750} practically
waterproof, although still leaving it porous to air.
XIX.—Coating the under side of the cloth with a solution of isinglass
and then applying an infusion of galls is another method, a compound
being thus formed which is a variety of leather.
XX.—An easy method is the formation of aluminum stearate in the fiber
of the cloth, which may readily be done by immersing it in a solution
of aluminum sulphate in water (1 in 10) and without allowing it to dry
passing through a solution of soap made from soda and tallow or similar
fat, in hot water. Reaction between the aluminum sulphate and the soap
produces aluminum stearate and sodium sulphate. The former is insoluble
and remains in the fiber; the latter is removed by subsequently rinsing
the fabric in water.
XXI.—A favorite method for cloth is as follows: Dissolve in a
receptacle, preferably of copper, over a bright coal fire, 1 liter
(1.76 pints) of pure linseed oil, 1 liter (1.76 pints) of petroleum,
1/2 liter (0.88 pints) of oil turpentine, and 125 grams (4.37 ounces)
of yellow wax, the last named in small bits. As there is danger of
fire, boiling of this mass should be avoided. With this hot solution
removed from the fire, of course the felt material is impregnated; next
it is hung up in a warm, dry room or spread out, but in such a manner
that the uniform temperature can act upon all parts.
«Waterproofing Leather.»—I.—Tenning’s process is as follows: Melt
together equal parts of zinc and linseed oil, at a temperature not
above 225° F. Put the leather in the molten mixture and let it remain
until saturated. The “zinc soap” is made by dissolving 6 parts of white
soap in 16 parts of water, and stirring into the solution 6 parts of
zinc sulphate. To make sure of a homogeneous mixture remelt the whole
and stir until it begins to cool. The process, including the saturation
of the leather, requires about 48 hours. Instead of zinc sulphate,
copper or iron sulphate may be used. The philosophy of the process is
that the moisture and air contained in the pores of the leather are
driven out by the heat of the soap mixture, and their place is taken,
on cooling, by the mixture. The surface of the leather is scraped after
cooling, and the article is dried, either by heating over an open fire
or by hanging in a drying room, strongly heated.
II.—Prideaux’ process consists in submitting the leather to treatment
with a solution of caoutchouc until it is thoroughly saturated with
the liquid. The latter consists of 30 parts of caoutchouc in 500 parts
of oil of turpentine. Complete impregnation of the leather requires
several days, during which the solution must be frequently applied to
the surface of the leather and rubbed in.
III.—Villon’s process consists in applying a soap solution to the
leather, about as follows: The leather is first treated to a solution
of 62 parts of soap, 124 parts of glue, and 2,000 parts of water. When
it has become saturated with the solution, it is treated to rubbing
with a mixture of 460 parts of common salt and 400 parts of alum,
in sufficient water to dissolve the same. After this it is washed
with tepid water and dried. This process is much the quickest. The
application of the soap requires about 2 hours, and the subsequent
treatment about as much more, or 4 or 5 hours in all.
«Oilskins.»—The art of painting over textile fabrics with oily
preparations to make them waterproof is probably nearly as old as
textile manufacture itself, an industry of prehistoric, nay, geologic,
origin. It is certainly more ancient than the craft of the artistic
painter in oils, whose canvases are nothing more nor less than art
oilskins, and when out of their frames, have served the usual purpose
of those things in protecting goods or the human body before now. The
art of waterproofing has been extended beyond the domain of the oilskin
by chemical processes, especially those in which alum or lead salts,
or tannin, are used, as well as by the discovery of India rubber and
gutta percha. These two have revolutionized the waterproofing industry
in quite a special manner, and the oilskin manufacture, although it
still exists and is in a fairly flourishing condition, has found its
products to a very large extent replaced by rubber goods. The natural
result has been that the processes used in the former industry have
remained now unchanged for a good many years. They had already been
brought to a very perfect state when the rubber-waterproofing business
sprang up, so that improvements were even then difficult to hit upon
in oilskin making, and the check put upon the trade by India rubber
made people less willing to spend time and money in experimenting with
a view to improving what many years had already made it difficult to
better. Hence the three cardinal defects of the oilskin: its weight,
its stiffness, and the liability of {751} its folds to stick together
when it is wrapped up, or in the other extreme to crack, still remains.
The weight, of course, is inevitable. An oilskin must be heavy,
comparatively, from the very essence of the process by which it is
made, but there seems no reason why it should not in time be made much
more pliable (an old-time oilskin coat could often stand up on end when
empty) and free from the danger of cracking or being compacted into a
solid block when it has been stored folded on a shelf.
Probably the best oilskins ever made are those prepared by combining
Dr. Stenhouse’s process (patented in 1864) with the ordinary method,
which consists in the main of painting over the fabric with two or
more coats of boiled linseed oil, allowing each coat to dry before the
next is applied. This, with a few variations in detail, is the whole
method of making oilskins. Dr. Stenhouse’s waterproofing method is to
impregnate the fabric with a mixture of hard paraffine and boiled oil
in proportions varying according to circumstances from 95 per cent
of paraffine and 5 of oil to 70 per cent of the former and 30 of the
latter. The most usual percentages are 80 and 20. The mixture is made
with the aid of heat, and is then cast into blocks for storage. It is
applied to the cloth stretched on a hot plate by rubbing the fabric
thoroughly all over with a block of the composition, which may be
applied on one or both sides as may be wished. The saturation is then
made complete, and excess of composition is removed by passing the
cloth between hot rollers. When the cloth is quite cold the process is
complete. The paraffine and the drying oil combine their waterproofing
powers, and the paraffine prevents the oil from exerting any injurious
action upon the material. Drying oil, partly on account of the metallic
compounds in it, and partly on account of its absorbing oxygen from the
atmosphere, has a decided slow weakening effect upon textile fibers.
Dr. Stenhouse points out that the inflammability of oilskins may be
much lessened by the use of the ordinary fireproofing salts, such as
tungstate of soda, or alum, either before or after the waterproofing
process is carried out.
The following are some of the best recommended recipes for making
oilskins:
I.—Dissolve 1 ounce of yellow soap in 1 1/2 pints of boiling water.
Then stir in 1 quart of boiled oil. When cold, add 1/4 pint of gold
size.
II.—Take fine twilled calico. Soak it in bullock’s blood and dry it.
Then give it 2 or 3 coats of boiled oil, mixed with a little litharge,
or with an ounce of gold size to every pint of the oil.
III.—Make ordinary paint ready to be applied thin with a strong
solution of soap.
IV.—Make 96 pounds of ocher to a thin paste with boiled oil, and then
add 16 pounds of ordinary black paint mixed ready for use. Apply the
first coat of this with soap, the subsequent coats without soap.
V.—Dissolve rosin in hot boiled oil till it begins to thicken.
VI.—Mix chalk or pipe clay in the finest powder, and in the purest
state obtainable to a thin paste with boiled oil.
VII.—Melt together boiled oil, 1 pint; beeswax and rosin, each, 2
ounces.
VIII.—Dissolve soft soap in hot water and add solution of protosulphate
of iron till no further precipitate is produced. Filter off, wash, and
dry, and form the mass into a thin paste with boiled oil.
All these compositions are painted on with an ordinary painter’s brush.
The fabric should be slightly stretched, both to avoid folds and to
facilitate the penetration of the waterproofing mixture. To aid the
penetration still further, the mixture should be applied hot. It is of
the greatest importance that the fabric should not be damp when the
composition is applied to it. It is best to have it warm as well as the
composition. If more than one coat is applied, which is practically
always the case, three being the usual number, it is essential that
the last coat should be perfectly dry before the next is applied.
Neglect of this precaution is the chief cause of stickiness, which
frequently results in serious damage to the oilskins when they have to
be unfolded. In fact, it is advisable to avoid folding an oilskin when
it can be avoided. They should be hung up when not in use, whenever
practicable, and be allowed plenty of room. It goes without saying that
no attempt should be made to sell or use the oilskin, whether garment
or tarpaulin, until the final coat of composition is perfectly dry and
set. It is unadvisable to use artificial heat in the drying at any
stage in the manufacture.
«Waterproofing Paper.»—Any convenient and appropriate machinery or
apparatus may be employed; but the best method for waterproofing paper
is as follows: The treatment may be applied {752} while the pulp is
being formed into paper, or the finished paper may be treated. If the
material is to be treated while being formed into paper, then the
better method is to begin the treatment when the web of pulpy material
leaves the Foudrinier wire or the cylinders, it then being in a damp
condition, but with the larger percentage of moisture removed. From
this point the treatment of the paper is the same whether it be pulp in
a sheet, as above stated, or finished paper.
The treatment consists, first, in saturating the paper with glutinous
material, preferably animal glue, and by preference the bath of
glutinous material should be hot, to effect the more rapid absorption
and more perfect permeation, impregnation, and deposit of the glutinous
material within all the microscopic interstices throughout the body
of the paper being treated. By preference a suitable tank is provided
in which the glutinous material is deposited, and in which it may
be kept heated to a constant temperature, the paper being passed
through the tank and saturated during its passage. The material being
treated should pass in a continuous sheet—that is, be fed from a roll
and the finished product be wound in a roll after final treatment.
This saves time and the patentee finds that the requisite permeation
or incorporation of glutinous matter in the fiber will with some
papers—for instance, lightly sized manila hemp—require but a few
seconds. As the paper passes from the glutin tank the surplus of the
glutinous matter is removed from the surface by mechanical means, as
contradistinguished from simply allowing it to pass off by gravity, and
in most instances it is preferred to pass the paper between suitable
pressure rolls to remove such surplus. The strength and consistency of
the glutinous bath may be varied, depending upon the material being
treated and the uses for which such material is designed. It may,
however, be stated that, in a majority of cases, a hot solution of
about 1 part of animal glue to about 10 parts of water, by weight,
gives the best results. After leaving the bath of glutinous material
and having the surplus adhering to the surfaces removed, the paper
before drying is passed into or through a solution of formaldehyde and
water to “set” the glutinous material. The strength of this solution
may also be variable, depending, as heretofore stated, upon the paper
and uses for which it is designed. In the majority of cases, however, a
solution of 1 part of formaldehyde (35 per cent solution) to 5 parts of
water, by weight, gives good results, and the best result is attained
if this bath is cold instead of hot, though any particular temperature
is not essentially necessary. The effect of the formaldehyde solution
upon the glutin-saturated paper is to precipitate the glutinous matter
and render it insoluble.
As the material comes from the formaldehyde bath, the surplus adhering
to the surfaces is removed by mechanical means, pressure rolls being
probably most convenient. The paper is then dried in any convenient
manner. The best result in drying is attained by the air-blast, i.
e., projecting blasts of air against both surfaces of the paper. This
drying removes all the watery constituents and leaves the paper in
a toughened or greatly strengthened condition, but not in practical
condition for commercial uses, as it is brittle, horny, and stiff,
and has an objectionable odor and taste on account of the presence
of the aldehydes, paraldehydes, formic acid, and other products, the
result of oxidation. Hence it needs to be “tempered.” Now while the
glutinous material is rendered insoluble—that is, it is so acted upon
by formaldehyde and the chemical action which takes place while the
united solutions are giving off their watery constituents that it
will not fully dissolve—it is, however, in a condition to be acted on
by moisture, as it will swell and absorb, or take up permanently by
either chemical or mechanical action a percentage of water, and will
also become improved in many respects, so that to temper and render
the paper soft and pliable and adapt it for most commercial uses it is
subjected to moisture, which penetrates the paper, causing a welling
in all directions, filling the interstices perfectly and resulting in
“hydration” throughout the entire cellular structure. Two actions,
mechanical and chemical, appear to take place, the mechanical action
being the temporary absorption of water analogous to the absorption
of water by a dry sponge, the chemical action being the permanent
union of water with the treated paper, analogous to the union of water
and tapioca, causing swelling, or like the chemical combination of
water with lime or cement. For this purpose it is preferred to pass
the paper into a bath of hot water, saturated steam or equivalent
heat-and-moisture medium, thus causing the fibers and the non-soluble
glutinous material filling the interstices to expand in all directions
and forcing {753} the glutinous material into all the microscopic
pores or openings and into the masses of fiber, causing a commingling
or thorough incorporation of the fibers and the glutinous compound.
At the same time, as heretofore indicated, a change (hydration) takes
place, whereby the hardened mass of fiber, glutinous material, and
formaldehyde become tempered and softened and the strength imparted
by the previous treatment increased. To heighten the tempering and
softening effect, glycerine may, in some instances, be introduced in
the tempering bath, and in most cases one two-hundredths in volume of
glycerine gives the best results.
The paper may be dried in any convenient manner and is in condition for
most commercial uses, it being greatly strengthened, more flexible,
more impervious to moisture, acids, grease, or alkalies, and is
suitable for the manufacture of binding-twine, carpets, and many
novelties, for dry wrappings and lining packing cases, etc., but is
liable to have a disagreeable taste and may carry traces of acids,
rendering it impracticable for some uses—for instance, wrapping butter,
meats, cheese, etc., after receiving the alkali treatment. The paper is
also valuable as a packing for joints in steam, water, and other pipes
or connections. For the purpose, therefore, of rendering the material
absolutely free from all traces of acidity and all taste and odors
and, in fact, to render it absolutely hygienic, it is passed through a
bath of water and a volatile alkali (ammonium hydrate), the proportion
by preference in a majority of cases being one-hundredth of ammonium
hydrate to ninety-nine one-hundredths of water by volume. A small
percentage of wood alcohol may be added. This bath is preferably cool,
but a variation in its temperature will not interfere to a serious
extent with the results. The effect of this bath followed by drying
is to complete the chemical reaction and destroy all taste or odor,
removing all traces of acids and rendering the paper hygienic in all
respects. The material may be calendered or cut and used for any of the
purposes desired. If the material is to be subjected to the volatile
alkali bath, it is not necessary to dry it between the tempering and
volatile alkali baths.
The paper made in accordance with the foregoing will, it is claimed,
be found to be greatly strengthened, some materials being increased in
strength from 100 to 700 per cent. It will be nonabsorbent to acids,
greases, and alkalies, and substantially waterproof, and owing to its
component integrate structure will be practically non-conductive to
electricity, adapting it as a superior insulating material. It may
with perfect safety be employed for wrapping butter, meats, spices,
groceries, and all materials, whether unctuous or otherwise.
The term “hydration” means the subjecting of the material (after
treatment with glutinous material and formaldehyde and drying) to
moisture, whereby the action described takes place.
A sheet or web of paper can be treated by the process as rapidly as
it is manufactured, as the time for exposure to the action of the
glutinous material need not be longer than the time required for it to
become saturated, this, of course, varying with different thicknesses
and densities, and the length of time of exposure may be fixed without
checking the speed by making the tank of such length that the requisite
time will elapse while the sheet is passing through it and the guides
so arranged as to maintain the sheet in position to be acted on by such
solution the requisite length of time. Four seconds’ exposure to the
action of formaldehyde is found sufficient in most cases.
«Waterproof Ropes.»—For making ropes and lines impervious to weather,
the process of tarring is recommended, which can be done either in the
separate strands or after the rope is twisted. An addition of tallow
gives greater pliability.
«Waterproof Wood.»—I.—Soak in a mixture of boracic acid, 6 parts;
ammonium chloride, 5 parts; sodium borate, 3 parts, and water, 100
parts.
II.—Saturate in a solution of zinc chloride.
«Wax»
«Adulteration of Wax.»—Wax is adulterated with the following among
other substances: Rosins, pitch, flowers of sulphur, starch, fecula,
stearine, paraffine, tallow, palm oil, calcined bones, yellow ocher,
water, and wood sawdust.
Rosins are detected by cold alcohol, which dissolves all rosinous
substances and exercises no action on the wax. The rosins having
been extracted from the alcoholic solution by the evaporation of the
alcohol, the various kinds may be distinguished by the odors disengaged
by burning the mass several times on a plate of heated iron.
All earthy substances may be readily {754} separated from wax by means
of oil of turpentine, which dissolves the wax, while the earthy matters
form a residue.
Oil of turpentine also completely separates wax from starchy
substances, which, like earthy matters, do not dissolve, but form a
residue. A simpler method consists in heating the wax with boiling
water; the gelatinous consistency assumed by the water, and the blue
coloration in presence of iodine, indicate that the wax contains
starchy substances. Adulteration by means of starch and fecula is
quite frequent. These substances are sometimes added to the wax in a
proportion of nearly 60 per cent. To separate either, the suspected
product is treated hot with very dilute sulphuric acid (2 parts of
acid per 100 parts of water). All amylaceous substances, converted
into dextrin, remain dissolved in the liquid, while the wax, in
cooling, forms a crust on the surface. It is taken off and weighed; the
difference between its weight and that of the product analyzed will
give the quantity of the amylaceous substances.
Flowers of sulphur are recognized readily from the odor of sulphurous
acid during combustion on red-hot iron.
Tallow may be detected by the taste and odor. Pure wax has an
aromatic, agreeable taste, while that mixed with tallow is repulsive
both in taste and smell. Pure wax, worked between the fingers, grows
soft, preserving a certain cohesion in all parts. It divides into
lumps, which adhere to the fingers, if it is mixed with tallow. The
adulteration may also be detected by the thick and nauseating fumes
produced when it is burned on heated iron.
Stearic acid may be recognized by means of boiling alcohol, which
dissolves it in nearly all proportions and causes it to deposit
crystals on cooling, while it is without action on the wax. Blue litmus
paper, immersed in alcohol solution, reddens on drying in air, and thus
serves for detecting the presence of stearic acid.
Ocher is found by treating the wax with boiling water. A lemon-yellow
deposit results, which, taken up with chlorhydric acid, yields with
ammonia a lemon-yellow precipitate of ferric oxide.
The powder of burnt bones separates and forms a residue, when the wax
is heated with oil of turpentine.
«Artificial Beeswax.»—This is obtained by mixing the following
substances, in approximately the proportions stated: Paraffine, 45
parts, by weight; white Japan vegetable wax, 30 parts, by weight;
rosins, or colophonies, 10 parts, by weight; white pitch, 10 parts,
by weight; tallow, 5 parts, by weight; ceresine, colorant, 0.030
parts, by weight; wax perfume, 0.100 parts, by weight. If desired, the
paraffine may be replaced with ozokerite, or by a mixture of vaseline
and ozokerite, for the purpose of varying the fusing temperature, or
rendering it more advantageous for the various applications designed.
The following is the method of preparation: Melt on the boiling water
bath, shaking constantly, the paraffine, the Japan wax, the rosins, the
pitch, and the tallow. When the fusion is complete, add the colorant
and the perfume. When these products are perfectly mingled, remove from
the fire, allow the mixture to cool, and run it into suitable molds.
The wax thus obtained may be employed specially for encaustics for
furniture and floors, or for purposes where varnish is employed.
«Waxes for Floors, Furniture, etc.»—
I.—White beeswax 16 parts
Colophony 4 parts
Venice turpentine 1 part
Melt the articles together over a gentle fire, and when completely
melted and homogeneous, pour into a sizable earthenware vessel, and
stir in, while still warm, 6 parts of the best French turpentine. Cool
for 24 hours, by which time the mass has acquired the consistence of
soft butter, and is ready for use. Its method of use is very simple. It
is smeared, in small quantities, on woolen cloths, and with these is
rubbed into the wood.