TECHNICAL PAPER # 54
 
                     UNDERSTANDING SMALL-SCALE
                            PAPERMAKING
 
 
                                By
                    John Vogler & Peter Sarjeant
 
                        Technical Reviewers
                            Philip Barr
                         Dr. I. B. Sanborn
                         Dr. Robert Brooks
                           William Burger
 
 
 
                                VITA
                  1600 Wilson Boulevard, Suite 500
                    Arlington, Virginia 22209 USA
               Tel:  703/276-1800 * Fax:   703/243-1865
                    Internet:  pro-info@vita.org
 
 
 
                Understanding Small-Scale Paper Making
                          ISBN:   0-86619-271-9
             [C] 1986, Volunteers in Technical Assistance
 
 
 
                             PREFACE
 
This paper is one of a series published by Volunteers in Technical
Assistance to provide an introduction to specific state-of-the-art
technologies of interest to people in developing countries.
The papers are intended to be used as guidelines to help
People choose technologies that are suitable to their situations.
They are not intended to provide construction or implementation
details.  People are urged to contact VITA or a similar organization
for further information and technical assistance if they
find that a particular technology seems to meet their needs.
 
The papers in the series were written, reviewed, and illustrated
almost entirely by VITA Volunteer technical experts on a purely
voluntary basis.  Some 500 volunteers were involved in the production
of the first 100 titles issued, contributing approximately
5,000 hours of their time.  VITA senior editor Margaret Crouch
edited this paper, and served as overall project manager, with
Suzanne Brooks handling typesetting and layout.
 
The VITA Volunteers who wrote and reviewed this paper have many
years of experience in the paper industry.   Jon Vogler, author of
Work from Waste, specializes in small-scale industries, particularly
those based on recycled materials.   Peter Sarjeant, dedicated
to keeping alive the processes of the old master papermaker's
craft, is the author of Hand Papermaking Manual.   I. B.
"Bruce" Sanborn is associate director of research and development
at Consolidated Papers, Inc.; Phil Barr is fiber logistics manager
for the Weyerhaeuser Company; and Dr. Bob Brooks, also of
Weyerhaeuser, is the manager of pulp and paper educational activities.
William Burger, retired mechanical engineer from Kimberly-Clark
Corporation, assisted in the design of equipment for a
micro paper factory in Tanzania.
 
VITA is a privates, nonprofit organization that supports people
working on technical problems in developing countries.   VITA offers
information and assistance aimed at helping individuals and
groups to select and implement technologies appropriate to their
situations.  VITA maintains an international Inquiry Service, a
specialized documentation center, and a computerized roster of
volunteer technical consultants; manages long-term field projects;
and publishes a variety of technical manuals and papers.
 
          UNDERSTANDING SMALL-SCALE PAPER MAKING
 
              by Jon Vogler & Peter Sarjeant
 
I.  INTRODUCTION
 
Papyrus, from which the word paper is derived, is known to have
been in use as early as 3000 B.C.   Developed in the Nile Valley,
it was made of strips cut from the papyrus plant stem, soaked,
and laid, first lengthwise, then crosswise, to form a mat.  The
mat was then pounded and pressed into a thin sheet.   Later,
similar processes elsewhere used other fibers such as silk.
 
True papermaking, which began in China about A.D. 105, uses an
entirely different process than the preparation of papyrus.  It
begins with rags, straw, bark, wood, or other fibrous materials
that are chopped or cut fine.   The fibers are pounded or pulped
until they are separated from each other and mixed with water.
Then the fibers are lifted from the water in a sieve-like screen
that allows the water to drain away, leaving a thin mat of fibers.
The fiber mat, which can be dried in place or removed and
dried separately, becomes a sheet of paper.
 
The earliest recorded manufacture of paper is credited to one of
the first "purchasing officers," Ts'ai Lun, head of the Imperial
Supply Department of Emperor Ho of China.   Ts'ai Lun experimented
with a variety of materials:   vegetable fibers, old hemp, cotton
rags, old fishnets, and mulberry bark.   The paper produced was
cheap and durable and the surface was good.
 
The technology spread to Japan by the third century A.D. and
reached India in the seventh.   Papermaking spread westward to
North Africa and finally reached Europe in the twelfth century
A.D.
 
Early European papers were made from linen or cotton rag.  It was
thick and rough, and the surface needed to be   sized" with gelatin
or the ink soaked in.  Ulman Stromer set up a mechanized
papermill in Nuremberg, Germany, in 1390, using water-powered
hammers for beating the material, a method already used by the
Chinese.  The craft accompanied the early settlers to America.
 
True mechanization was not achieved until 1799, when the Frenchman
Nicholas Robert built a machine with an endless wire mesh and
a pair of squeeze rolls.  The device was taken to England and marketed
by two stationers, the Fourdrinier brothers.   In 1804, Brian
Donkin, a millwriqht-engineer, built the first successful papermaking
machine, in Two Waters Mill, Hertfordshire, England, and
another in America in 1827.  Crude early designs improved steadily.
By the end of the nineteenth century, Fourdrinier technology
was widespread; machines just over 2 meters wide supplied 25
metric tons per day to the growing market for newsprint.
 
Modern machines form paper in a continuous ribbon or web, not a
single sheet at a time as did the ancients.   A good papermaker in
the olden days could make enough sheets in a day to weigh about
90kg.  Today, an average machine makes 90,000kg per day! Yet the
process of making paper--separating fibers in water and draining
them through a fine screen to form an interwoven mat that is then
dried--is identical in principle.   The actual formation of paper
has been the same for almost 2,000 years.
 
II.  MODERN PAPERMAKING
 
FIBERS AND PULPS
 
Fibers are the finer thread-like wisps from which paper, textiles,
and many other materials are made.   Tear a piece of paper
and the fibers can be seen at the torn edge (more clearly with a
magnifying glass).  Paper fibers are made of cellulose, the basic
building material of plants and trees.   These materials can be
made into paper by pulping (breaking them down until the fibers
are loose and free of the substances that bind them), then reforming
them while wet and finally drying.
 
Softwood (or coniferous) pulps are used for tough wrapping and
packaging papers because of their long fibers; decidous or hardwood
pulps provide fine fibers for printing and writing papers.
 
To understand the paper industry it is important to know about
the major types of primary wood pulp used in papermaking:   mechanical
pulp and chemical pulps, which include kraft pulp and
sulphite pulp.  Pulp made of recycled paper is known as secondary
pulp.  Most small-scale paper producers rely primarily on
secondary pulp.  See also VITA's technical paper "Understanding
Paper Recycling" for information on collection and use of
waste paper.
 
Mechanical Pulp
 
Mechanical pulps yield the most paper per ton of wood, but are
the weakest.  They are made by pounding or grinding cellulose
fiber, such as wood or sugar cane bagasse.   One of the commonest
uses of mechanical pulps is in the manufacture of newsprint.
Newsprint is relatively weak and loses its strength altogether if
wetted--a characteristic of mechanical pulp.   It is used for rapid
newspaper printing because printing ink is soaked up and dries
very quickly, but it lacks the permanence of paper made from
kraft or sulphite pulp.  Strong chemical pulp is often added to
mechanical pulp to give newsprint better strength.   Mechanical
pulp often contains tiny particles of wood that have not been
reduced to fiber and are visible to the naked eye, so paper made
from it is described as "woody."
 
Chemical Pulps
 
A stronger paper product is most cheaply made by pulping cellulose
fibers in such a way that they are not weakened by mechanical
damage.  The wood or stalks are first reduced mechanically to
small chips, then cooked at high pressure with chemicals that
attack the bonds between the fibers.   The chemicals most commonly
used are:
 
     1.   Caustic soda and sodium sulfate, which produce coarse,
         very strong papers known as kraft, suitable for paper
         sacks and boxes that hold heavy weights.
 
     2.   Various sulfites (such as ammonium and calcium), which
         produce finer fibers, suitable for making high quality,
         strong (but expensive) printing and writing papers
         (usually bleached white).
 
Secondary Pulp
 
Secondary  or recycled pulp is made by vigorously agitating wastepaper
in water (usually in a hydro-pulper, a tank containing
rotating blades) to separate the fibers bonded during the original
papermaking process.  As these bonds are weaker than those of
the original cellulose plant, hydro-pulping is a more gentle
process than primary wood pulping and consumes less energy.  Even
so, each time paper is recycled, it becomes weaker.   Secondary
pulp is, therefore, never as strong as the primary fiber from
which it was made.  It can be almost as good, provided pure waste
paper of the same type is used.   For example, pulp made by hydro-pulping
clean kraft sacks will make new sacks of only slightly
lower quality, particularly if mixed with a proportion of primary
kraft pulp.  If, however, the secondary pulp is made from material
that contains newspapers, or dirt, dust, or clay or some
other weaker mechanical pulp product, it will not be strong
enough to make sack paper.
 
Coated Papers.  In some cases the matted, absorbent surface of a
paper is coated with a material that makes it glossy and smooth.
This coated paper is better for printing.   Coated papers are
frequently used in magazines that are financed by the advertisements
printed.  In the process of hydro-pulping coated waste
paper, the coating is washed out; thus, the weight of fiber
obtained from a ton of coated paper is less, often by 20 percent,
than that obtained from a ton of uncoated paper.   As a result,
the value of scrap coated paper to the paper mill, and its selling
price, will be lower.
 
If the coating is plastic or other material that will not dissolve
in water, the waste paper will require specialized machinery
to recycle it and may reduce the value of more pure paper
with which it is mixed.  The same is true of polyethylene film,
cellophane, glued paper, string, and any material that will not
break down in water.  Some of the various coated papers can be
kept warm and wet in storage, then cooked in a hot caustic solution
in order to biodegrade and break down the coating to release
the fibers.  Again, these papers require special machinery and
handling to recycle and they may not be as valuable as simpler,
plain paper.
 
Printed and Colored Papers.  Both printing and tinting reduce the
value of paper to be recycled.   They make the pulp, and the paper
made from it, dull gray in color unless bleached (which is expensive),
or de-inked (which is also expensive).   Tinting colors the
Pulp, which must then either be used for a limited range of
similarly colored products (or cheap grey products), or must be
bleached.  Therefore, white waste paper is more valuable than
similar material that is colored.   Unprinted waste paper is of a
greater value than the same material printed.
 
STRUCTURE OF THE PAPERMAKING INDUSTRY
 
The manufacture and use of paper is one of the world's biggest
industries; it takes place in:
 
     1.   pulp mills, which process wood chips or other materials
         to make pulp;
 
     2.   paper mills and board mills, which use pulp or
         waste paper to produce finished paper and board;
 
     3.   Paper converters, which use paper or board to produce
         boxes, tubes, rolls of tissue, boxes of blank office
         paper, stacks of printing paper cut to standard sizes,
         etc.;
 
     4.   printers, who usually buy from converters, although
         larger firms such as newspaper presses may buy directly
         from the paper mills; and
 
     5.   "integrated" mills, which make pulp and then use it
         themselves to make paper.
 
These industries are huge, highly mechanized, and efficient.
There are many of them, so they compete fiercely for the available
markets.  In countries where huge markets, skilled managers
and technicians, and the massive capital needed for investment
are available, handmade and small-scale paper manufacturers find
it very hard to compete.  In the developing world, opportunities
may be better, but are rarely undertaken largely due to insufficient
technology, skill, capital, and other inputs.
 
To put small-scale or handmade paper production in perspective,
it is important to realize the vast range of production capabilities
within the industry.  For example, one person working out of
a home workshop with minimal equipment can possibly produce as
much as 45kg of paper per day, while a partially mechanized micro
factory can turn out about 225kg daily.   By contrast, the International
Labor Office defines small scale to include production
capacity of up to 27 metric tons per day.   And a single machine
in a large modern operation can produce 270 metric tons of paper
per day.  It should be obvious that only in very special circumstances
and for very special markets can small-scale operations
compete effectively in today's paper industry.
 
One field in which hand and small-scale papermakers do find a
niche is the production of the very highest quality "art" papers,
or the manufacture of a variety, of paper products or small local
markets that are not served by large producers.   Another area in
which papermaking processes can be applied on a small scale is
the manufacture for local markets of a variety of products such
as egg cartons, flower or plant pots, rough boxes, or roofing
materials.  These are considered in detail in later sections of
this paper.
 
III.  HAND PAPERMAKING
 
Whether paper is made in the home workshop or the micro factory,
the production processes for hand papermaking are quite similar.
The scale of the equipment changes with the volume of production
and the raw materials vary with what is available and the quality
of paper to be produced.
 
PAPERMAKING PROCESSES
 
Pre-processing
 
Cotton or other rags and waste paper to be recycled are sorted
thoroughly to remove all non-fibrous materials such as staples,
paper clips, cellophane, nails, buttons, zippers, etc.   Both rags
and paper are cut or shredded into small pieces.
 
Pulping
 
The cleaned and shredded raw materials are brought to the boiling
point and cooked for two to six hours.   They are rinsed thoroughly
to remove impurities that might have separated out during
the cooking process.
 
The beater--this can range from a kitchen blender to a specially
made tank--is filled with the required quantity of water, and the
cooked, chopped rags or paper are added gradually with high speed
agitation.  Bleaching powder or liquid bleach (1 percent) is then
added.  The pulp is washed thoroughly, a process that may take
another six to eight hours.  Additives that may be used include
titanium dioxide or other fillers, dyes (for colored paper), or
optical bleaching agents (for white paper).   Rosin soap and alum
are added later.
 
Lifting, Couching, and Stacking
 
When the pulping process is complete, the pulp is transferred to
storage containers or vats.  Depending on the scale of the operation,
the pulp is then mixed with a sufficient quantity of water
to dilute it to form a uniform suspension, free of lumps.  In the
home workshop, the pulp is mixed in quantities to make one sheet
at a time.  In the small factory, a larger quantity may be mixed
at one time.  The diluted pulp is then lifted from the water on
wire screens, and the resulting sheets are covered by felt or
other absorbent cloth.  With the cloth in place, the still wet
pulp layer is carefully lifted from the screen.   This process is
called couching (pronounced cooching).   The couching cloth, paper
side down, is placed on a felt covered board and smoothed to
remove wrinkles or air bubbles.   Each succeeding sheet is placed
in a stack over the first.
 
 
Pressing and Drying
 
When a sufficient number of sheets have been formed, they are put
under a press to remove the water.   The sheets are then separated
and, to avoid shrinkage, placed under absorbent boards and
pressed again.  The sheets are hung to dry in bunches of three to
six, according to thickness, or dried in a warm oven.
 
Sizing
 
Sizing gives paper a harder finish so that water based paints and
inks will not bleed or run.  Paper may be sized internally, by
adding the sizing agents to the pulp, or externally, by painting
or dipping the dried sheets.   For internal sizing, alum, rosin,
gelatin, cornstarch, or linseed oil may be added in very small
quantities at the end of the pulping stage.   For external sizing,
the dried sheets are dipped in a dilute glue or starch solution,
Pressed to remove the excess, and hung up to dry again.   In the
home workshop, the individual sheets may be painted with the
dilute solution.
 
Blotting paper, filter paper, toilet tissue, grey board, and some
art papers may require very little, if any, sizing.
 
Calendering
 
The dried sheets are placed alternately between metal plates into
a stack or "post."   The stack is passed between calender rollers
to obtain the desired smoothness.   This can be done in the home
workshop by pressing the paper sheet between sheets of aluminum
foil with a hot iron.
 
Sorting and Cutting
 
After calendering, the sheets are carefully sorted and cut to
size for packing and shipment.
MAKING PAPER IN THE HOME WORKSHOP
 
Papermaking at this scale can be done as a hobby, for gifts, or
as demonstrations in schools.   Or, if the market exists for top
quality handmade sheets, it can form the basis for a small business.
Artists, bookbinders, and museums--or individuals seeking
fine writing paper--are potential customers.   The necessary equipment
may already be available in some kitchens, but the markets
should be considered carefully before any investment is made.
 
This process assumes that waste paper or cotton cloth will be
used to make the paper.  Approximately 50 sheets (21.5cm x 28cm)
can be made from a pound of waste paper.   Household bleach, alum,
gelatin, cornstarch, and animal glue may also be needed.  And
ordinary fabric dyes can be used to produce tinted or colored
papers.  The process also assumes the availability of adequate
water and electrical or other power supplies.
 
Equipment and Materials
 
The following equipment is needed:
 
     Deckle box and mold, made of oiled wood (Figure 1)

21p08.gif (600x600)


     Power food mixer or blender
     Stainless steel or enamel pot (not aluminum)
     Steam iron
     Stove with oven
     Sink, tub, or wash basin
     Couching cloth (i.e., cotton sheeting), cut to size
     Felt or absorbent terry cloth, cut to size
     Thin metal sheet
     Flat "receiving" board, lcm plywood or other board
 
Pulping
 
Choose paper with minimal printing.   Old envelopes are good for
this reason:  the glue on the flap won't matter.  Colored paper
is acceptable; the dye usually comes out when it is boiled.
Avoid paper that has wet "strength" such as paper towels.  Be
careful how many brown paper bags you use.   Unbleached kraft
paper lowers the brightness or whiteness of the pulp, but it is
Strong and will give your paper toughness.   Newsprint alone makes
a weak pulp, grey in color.  It adds little but bulk.  Cotton or
other cloth or yarns may also be used.   They must be cut or
shredded into very small pieces to avoid jamming the mixer.
 
Cut or tear the paper into small pieces, about 5cm x 5cm.  Shred
any cloth that may be used.  Put the pieces in the pot, cover
with water, and add a few tablespoonfuls of household bleach.
Turn on the heat, cover the pot, and bring to a gentle boil.
Stir occasionally for a couple of hours to ensure that the bleach
is mixed and all the paper is wetted down well, then cool.
 
After the batch has cooled, try to break up the lumps and any
remaining pieces of paper still holding together.   The smaller
the pieces in the beginning, the easier this step is now.  The
pulp can then be drained and stored in plastic bags in a
refrigerator until you are ready to make the sheets.   It will
keep for weeks without any change.
 
Making the Sheets
 
Take a lump of the semi-moist pulp you have prepared.   Press as
much moisture out of it as possible to leave-a ball about the
size of a pigeon egg (7g dry weight).   This is enough pulp to
make one 21.5cm x 28cm sheet.   Make the sheets, one at a time, as
follows:
 
     1.    Blend and mix pulp in blender 3/4 full of water.  Add
          additives.
 
     2.    Put mold in box, screen side up and immerse in sink.
          Rap box to get rid of air bubbles.
 
     3.    Pour pulp into box.
 
     4.    Holding box down, agitate the water in the box with
          fingers so that the pulp spreads evenly over the mesh.
 
     5.    Grasp box and mold firmly and lift quickly and evenly
          to surface (feel suction).
 
     6.    Hold for 10 seconds or so to drain.
 
     7.    Lift up out of water and hold vertically to drain.  If
          sheet looks okay, proceed; if flawed, put box and mold
          back into sink and repeat steps 4 to 7.
 
     8.    Set box on flat surface and carefully remove box.
          Note:   Water drops on wet web will make marks!
 
     9.    Carefully lay cotton couching cloth over web and smooth
          gently.
 
     10.   Place absorbent felt over couching cloth.  Smooth and
          press down from center out.
 
     11.   Remove felt and wring out water.
 
     12.   Repeat 10 and 11 until no more water comes out.
 
     13.   Couch off sheet, starting at corner and peeling back
          quickly.
 
     14.   Place couched sheet, paper side up or down on flat
          absorbent surface.  Smooth and press down to remove
          trapped air.
 
     15.   Repeat for each sheet until a neat stack is built up.
 
Pressing and Drying
 
The sheets can be dried quickly by pressing them with a hot iron
and an aluminum sheet or slowly (2-3 hours) by placing them in a
120 [degrees] C oven, with the couching sheets tacked down to the receiving
board all along the edges of the paper sheets.   The first method
gives a smooth surface on one side, embossing with cloth marks on
the other; the second gives embossing on both sides.
 
A very slick surface can be obtained by smoothing the couching
cloth, paper side down, against an aluminum or oiled galvanized
sheet.  A squeegee can be used to get rid of all the air.  Dry in
air or in a 120 [degrees] C oven.
 
Sizing and Coating
 
A simple method of internal sizing uses a combination of pure
gelatin and cornstarch (either laundry or cooking type).  The
gelatin is dissolved in boiling water and cornstarch is added to
make a clear, thick mixture to add to the pulp.   Use about one
teaspoon of this per 21.5cm x 28cm sheet.
 
Another simple internal sizing procedure is to add about 1/4
teaspoon of linseed and/or a teaspoon of cornstarch solution
while the pulp is being mixed at Step 1.   The oil is dispersed in
the water and precipitates on the fiber.   The starch will be
caught on the fibers and during the drying stage will set to give
a stiffer sheet.
 
External sizing is done when the sheet is coated with a water
based solution after the paper has been dried.   With an ordinary
4cm paint brush, coat each sheet with a 7 percent straight corn
starch solution.  One tablespoonful of cornstarch added to a cup
of water will be enough for 20 to 25 sheets (both sides).  Animal
glue can be added to the starch to improve the water resistance.
Modern glues can be added also.
 
When the coated sheets are nearly dry to the touch, place them in
a neat stack.  They should be somewhat limp but not wet.  Put a
metal sheet or smooth board on top.   Allow the stack to dry overnight.
The sheets can then be trimmed if necessary and packaged
for sale.
 
MAKING PAPER IN THE MICRO FACTORY
 
On a somewhat larger scale, but still in an essentially hand
process, paper can be made in a micro factory capable of producing
about 240kg (1/4 ton) of paper per day.   Such small factories
are fairly common in India, and VITA has assisted at least one
such operation in Tanzania.  This process uses wastepaper or rags
to make pulp, or pulp purchased from a pulp mill.   It can produce
good quality bond or drawing paper, card stock, school tablets,
filter paper, toilet tissue, grey board, and album or blotting
paper.  It can also turn out such articles as egg cartons, flower
pots, seed flats, hospital trays, etc.
 
In addition to an identified, reliable market, the small factory
requires a steady, reliable supply of raw materials, water, and
power.  Suggested facilities include a building of about 300
square meters for operations and a shed of about 185 square
meters for collecting and sorting the materials.   Six administrative
staff and as many as 100 laborers working in two or three
shifts are needed.  The U.N. Industrial Development Organiztaion
(UNIDO) estimates an investment of approximately US$26,000 for
the total cost of installation.   Production may be increased by
installing one or two more beaters and operating the vats in
three shifts.  Beyond that capacity, however, economies of scale
decline.  For larger production, a mechanized small-scale plant
should be considered (See Section IV).
 
The following lists of equipment, supplies, and staffing are
drawn largely from UNIDO's monograph on small-scale paper production.
Molds and presses for specialty items are not included.
Production processes follow the steps given at the beginning of
this section.
 
Machinery and Equipment
 
     Vomiting type digester, 1.5m x 1.2m
     Rag chopper, 25.5cm blade with 3-hp motor
     Beater, 61cm x 76cm roll size (x2)
     Electric motor for beaters of 20 hp, 960 rpm, slip-ring with
          oil-immersed starter (x2)
     Lifting semi-automatic vats (x6)
     Hydraulic press, 102cm x 127cm plate size, double ram with
          5 hp motor
     Screw press (91.5cm x 107cm or 89cm x 114cm plate size
          for processing of sized paper, etc.)
     Calender machine for paper glazing (30.5cm x 91.5cm roll
          size, complete with accessories)
     Electric motor for calender machine (10 hp, 960 rpm, with
          starter)
     Paper-cutting machine (107cm x 122cm blade size)
     Small beater of 2 kg capacity with 1/2 hp motor for
          experiments
     Washing machine
     Chain pulley block with tripod, 2-t capacity
     Platform weighing balance, 500 kg capacity
     Pulp storage tanks for lifting vats (x6)
     Washing cradles for pulp washing
     Press boards for calender machine, 1.2m x lm(x40)
     Woollen felts x(400)
     Complete sets of carpentry tools, pipe-fitting tools, etc.
     Small (2 kg) pan balance
     Towel horses for keeping felts (x6)
     Sizing trays
     Grinder
     Dusting frame
     Spare parts for molds, etc.
     Couching tables (x6)
     Stools for vats, paper separation
     Drying arrangement
     Other miscellaneous articles:  buckets, brushes, hardware
          stores, etc.
     Miscellaneous office equipment:  typewriter, cupboards,
          tables, chairs, racks, clocks, etc.  Storing arrangements
          for finished paper, chemicals, etc.
 
Raw Materials and Chemicals
 
     New rags and clean waste paper, 90 tons
     Caustic soda flakes, 1 percent:  900 kg
     Bleaching powder, 1 percent:  900 kg
     Titanium dioxide, 1 percent:  900 kg
     Rosin, 1.5 percent:  1,350 kg
     Soda ash, 400 kg
     Alum (non-ferric), 3 percent 2,700 kg
     Glue flakes, 3 percent:  2,700 kg
     optical bleaching agent:  50 kg
     Formalin, 720 1:  approximately 700 kg
     Diacol M, 15.5 percent:  450 kg
     Miscellaneous:  dyes, soap kerosene, ultramarine blue, etc.
 
Labor
                                          No. of
                                          persons     Remarks
 
     Rag sorters                               6         General shift
     Rag dusters                               4         General shift
     Rag cutters                              22         In shifts
     Digester operators                       2         In shifts
     Beater operators                         4         In shifts
     Beater assistants                        4         In shifts
     Vat operators                           12        In shifts
     Couchers                                 12         In shifts
     Press and wet paper separating           8         In shifts
     Paper drying                             4        General shift
     Paper sorting                            6        General shift
     Glue sizing                               4         General shift
     Calendering                               2         General shift
     Paper cutting and packing                1         General shift
     Miscellaneous work                       5         In shifts
     Night watchmen                           4        In shifts
     Carpenter/mechanic                        1         In shifts
     Helper                                    1         In shifts
 
IV.  SMALL-SCALE MECHANICAL PAPERMAKING
 
Mechanical papermaking--even on a small scale--is highly
technical and complex.  More detailed descriptions may be found
in the publications listed in the Bibliography.   The following
sections give an overview of the basic processes for producing
paper from waste paper for two different scales of operation.
ONE-TON-PER-DAY PAPERMAKING PLANT
 
In India, very small (one-ton per day) "cylinder mold" machines
are used to produce paper.  These machines are simple to operate
and can use either waste paper or agricultural wastes such as
sugar cane, sisal, banana, or bamboo.   Cotton rag, widely available
in India, is also used.
 
The raw material is first passed through a chopper, then broken
down to basic fibers in a "Hollander Beater."   This takes between
one and a half and three hours.   The pulp is washed and bleached
if required, then diluted with plenty of water and fed into the
"cylinder mold" machine, which forms the paper.
 
A wire mesh covered cylinder revolves in a vat full of pulp.
Water is sucked out through a drain in the cylinder, leaving a
layer of pulp on the wire mesh surface.   At the top of the
cylinder an endless band of wool felt picks up the layer of wet
pulp and conveys it to the cutting roll where an operator makes a
cut parallel to the roll axis and peels off the pulp in sheets
that are stacked for squeezing in a hydraulic press.  Finally,
the sheets are dried and calendered (squeezed between smooth
rollers).
 
Each sheet is 86 x 56cm.  The weight of the paper ranges from 65
grams per square meter (gsm) for writing and printing papers to
over 300gsm for packaging.  Among the many applications are
envelopes, file covers, file cards, insulation, and filter paper.
 
Most of the water used in the process is recovered but there is a
net consumption of about 46,000 liters in 24 hours.   The plant
includes a number of three-phase electric motors.   It employs 12-16
workers per shift, plus management.   According to UNIDO estimates,
capital investment in a mill in this size range would be
about US$100,000.
 
FIVE- TO THIRTY-TON-PER-DAY PAPER PLANTS
 
 
A typical machine in this range is illustrated in Figure 2.  A 30-ton-per-day

21p14.gif (600x600)


machine would not be greatly different:   it would
have more dryers, probably a third press, and would run faster,
fed with suitable stock.  Capital investment for a 10- to 25-TPD
machine is estimated by UNIDO to be approximately US$4 million.
 
A simple hydropulper is used for making pulp.   It has a cylindrical
steel tank with a rotary "impeller" (like a strongly constructed
fan) in the base.  The impeller swirls the water, chops
the paper, then mixes the pulp.   The process is performed in
batches and some contraries are physically removed at intervals.
Other contraries, such as string, wires, wet-strength papers, or
plastic, are continuously removed by a "ragger rope" or, occasionally,
a "junk trap."  High-density centrifugal cleaners and
pressurized or vibrating screens are also used.   This is followed
in some instances by low-density cleaners with up to three
stages, for removing plastics and adhesives.
 
The output of the pulp mill requires beating or refining before
it can be made into paper.  This is done with a "Hollander," a
roll carrying heavy bars that rotates in a strong trough, at the
bottom of which are more bars.   The roll batters the fibers
against the trough bars and also pumps the pulp around the
trough.  Refining strengthens the paper product, and produces a
more consistent pulp.
 
Consistency is the percent by weight of the weight of dry pulp to
the weight of the wet slurry (or semi-dried mixture of pulp and
pulp plus water).  For example, 6 percent consistency is about
6kg of dry pulp plus 100kg of water, and this is like a thick
soup; 30 percent consistency is like a wet but not dripping newspaper.
 
Papermaking involves the handling and processing of very thin
layers of pulp, which is weak in its wet state.   Maintaining the
proper consistency is therefore vital.   But one of the problems
of small-scale papermaking is that the necessary controls for
maintaining the right consistency may be omitted to reduce costs.
Stock preparation also includes cleaning, screening (to remove
lumps of pulp or foreign matter), and the addition of chemicals
or dyes.
 
In more modern mills, refiners are used.   In a refiner, pulp
stock is fed into the center of two flat plates with bars for
brushing the fiber.  One plate is fixed, the other rotating.  As
the fiber, at 3-4 percent consistency, moves from the center to
the edge, it is brushed by the bars.
 
In India (but almost nowhere else), small Fourdrinier machines
are cheap and readily available.   The pulp is dispensed from the
"head box" onto a continuous loop of fine wire mesh supported by
rapidly rotating rollers that suck the water from the pulp.  The
roller sucks out sufficient water for the sheet, now semi-solid,
to leave the mesh wire and, supported on porous felt belts, to
pass through two or three sets of press-rolls.   It leaves these
with about 60 percent water.   The excess water is removed by the
dryer, an array of 16 steam-heated drying cylinders, each about
1.5m in diameter, against which the paper is firmly held by felts
and smaller rollers.  A set of shiny-smooth calender rolls gives
a hard, smooth surface finish to the paper, which is then wound
in a continuous length onto strong cardboard cylinders, to form a
reel of over a meter in diameter, containing hundreds of meters
of continuous paper.
 
The width of the small Fourdrinier machines is rarely more than
1.75 to 2.5 meters.  Plants of this kind can produce papers from
50gsm to 150gsm in most grades, and run at over 100 meters per
minute.  The tonnage of paper finally produced will be around 85
percent of the weight of waste paper input, and this can be improved
if the water is cleaned and recirculated, so that no fiber
is lost.
 
V.  ALTERNATIVE PRODUCTS FROM WASTE PAPER
 
FRUIT AND EGG CARTONS PROM WASTE PAPER PULP
 
Another process makes egg cartons from paper pulp using a small-scale
paper plant called the Super Melbourne.   Waste paper is
first soaked, then pulped and refined.   Pulping can be done in a
domestic washing machine.
 
The equipment includes a refiner that reduces the pulp to basic
fibers.  The slurry that results is poured onto a sheet of mesh
stretched over the forming tank of the Super Melbourne and a
valve in the tank is opened.   The water draining from the tank
sucks moisture from the layer of pulp, which is then pulled from
the tank on its sheet of mesh.   The layer of pulp is folded over
once and pressed between specially shaped dies, then it is laid
to dry.
 
The process employs four people, but labor costs are reduced when
Super Melbourne machines are batched together for greater output.
Output is 60 egg trays per hour, or 60 sheets of paper 84 x 66cm.
The machine requires only 300 watts of electrical power.  Most of
the water used is recycled.  Floor space required is 2 square
meters for the machinery and 5 square meters for drying.
 
More sophisticated machinery is available for producing from 200
to 4,000 30-egg trays or equivalent products per hour.   Such a
machine is made by Tomlinsons, but careful market research is
essential before contemplating the heavy cost of a machine that
tends to saturate any but the largest market.
 
Similar machinery is available or can be specially designed to
produce flower pots, seed flats, hospital trays, etc. (Figure 3).

21p17.gif (600x600)


A careful market study should be made before investing in such
equipment.
 
ASPHALTED ROOFING SHEETS
 
Low-quality, low-cost roofing sheets with a life of about five
years can be made from the very lowest grades of mixed waste
paper grades that would not be acceptable for papermaking due to
the amount of dirt and contraries present.   A factory with three
molding machines costs about $200,000 for plant and machinery and
can produce about 8,000 sheets daily, each about 1 square meter
in area (over two million square meters annually).   About 35
people are employed and 50 metric tons of paper per week are
used.  In India, the roofing material retails at around $0.25 per
sheet; in South America, at about $0.60 per sheet.   The manufacturing
process consists of the following steps:
 
     1.   The waste paper is washed and pulped in a hydropulper.
         A mechanical hammer mill or a Hollander beater may be
         used instead.
 
     2.   The pulp is passed through a screen, to remove dirt,
         grit, or other impuities, and a board-forming machine
         (similar to that already described for a one-ton-per-day
         paper machine), to produce a continuous length of
         board that is cut to length as it comes off the machine.
 
     3.   The board is spread on the ground and dried in the open
         air.   The edges are trimmed on a rotating slitter.
 
     4.   The board passes through an oven at the end of which
         are corrugating rollers.  The corrugated sheets are
         then trimmed again and stacked in cradles.
 
     5.   Next, they are dipped in a bath of hot asphalt.
         (Asphalt is flammable so the means of heating must be
         carefully chosen.)  The asphalt hardens rapidly at air
         temperature and the sheets are unloaded and stacked.
 
     6.   When quite hard the sheets are either:
 
         o     taped in bundles for sale as third quality;
 
         o     sprinkled with mineral chips (while asphalt is
              soft) prior to packing as second quality; or
 
         o     hand painted and packed as first quality.
 
              BIBLIOGRAPHY/SUGGESTED READING LIST
 
Ainsworth, J.H.  "Paper the 5th Wonder," Thomas Printing and Publishing
     Company, 1959.
 
Appropriate Industrial Technology for Paper Products and Small
     Pulp Mills.   Vienna, Austria:   United Nations Industrial
     Development Organization (UNIDO), 1979.
 
Brook, S.  "The Fine Art of Printing," Atlantic Monthly, April,
     1974 (112-115) .
 
Becker, W.J.  "The First Ten Years of the Fourdrinier," Paper
     Trade Journal, April 17, 1972 (34-41).
 
Becker, W.J.  "The First 145 Years of the Paper Machine in the
     U.S.," Paper Trade Journal, May 27, 1972 (140-150).
 
Casey, James P.  "Papermaking," Pulp and Paper, Vol. II, New York, New
     York:   Interscience Publishers, Inc., 1960.
 
Goodwin, Rutherford "The William Parks Paper Mill at Williamsburg,
     Virginia", Lexington, Virqinia:  Bibliographical Society
     of America, 1939.
 
Hunter, Dard Papermaking Pilgrimage to Japan, Korea, and China,
     New York, 1936.
 
Hunter, Dard Papermaking, New York, New York:   Alfred A. Knopf,
     1967.
 
Hunter, Dard Papermaking in the Classroom, the Manual Arts Press
     Peoria, Illinois.
 
Hunter, Dard "Watermarking Handmade Papers," Scientific American,
     March 26, 1921.
 
Norris, F.H.  Paper and Paper Making, New York, New York:  Oxford
     University Press, 1951.
 
Sarjeant, Peter T.  Hand Papermaking Manual.  Covington,Virginia:
     Paper Make, 1976.
 
Small-scale Paper-making, ILO Technical Memorandum No. 8.
     Geneva, Switzerland:   International Labour Office, 1985.
 
Sweetman, J.  "Making Paper by Hand," Appropriate Technology,
     Vol. 3, No. 4.  London:   Intermediate Technology Publications
     Ltd.
 
Thomas, C.  The Paper Chain.  London:   Earth Resources Research
     Ltd., 1977.
 
Tsein, Tsuen-Hsuin "China, the Birthplace of Paper, Printing an
     Moveable Type," Pulp and Paper International Journal, February,
     1974.
 
von Hagen, V.W.  The Aztec and Maya Papermakers, New York, New
     York:   Hacker Art Books, 1944.
 
Western, A.W.  Small Scale Pulp and Paper Manufacture, London
     Intermediate Technology Publications Ltd., 1979.
 
                       EQUIPMENT SUPPLIERS
 
          Paper Mill Plant and
          Machinery Manufacturers Ltd.
          181 S V Road
          Jogeshwari, Bombay
          400060 India
 
          Hindon Engineering Works
          Clubley, Bajoria Marg,
          Saharanpur 247001
          UP India
 
          Indo Berolina Industriea, Pvt. Ltd.
          I.B.I. House
          5-86 Andheri Kurla Road
          Bombay
          400059 India
 
          Jessop and Co Ltd.
          63 Netaji Subhas Road
          P.O. Box 108
          Calcutta, India
 
                       SOURCES OF INFORMATION
 
Association of the Pulp and Paper Industry
One Dunwoody Park
Atlanta, Georgia 30341
 
Write for free four-page booklet, "How You Can Make Paper":
     American Paper Institute
     260 Madison Avenue
     New York, NY
 
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