Paper is one of the highest consumed natural materials for commercial
as well as domestic use, for a large spectrum of applications. This
means that paper is the greatest culprit for problems of ecology
and enviornment, because most of the paper produced results in the
cutting down of forests.
With a view to preserve the forests, development of synthetic paper
has been on for almost four decades. A first major break-through
was production of thin gauge partially oriented HM-HDPE film, around
1966 in India. But it was not very close to natural paper in many
important properties.
The synthetic paper that is now developed and commerically gaining
a substantial penetration in the paper domain is based on HDPE and
PP by blown and cast processes, using a specially developed paper
masterbatch.
The paper master-batch for HDPE / PP is offered by Schulman and
represented by Reifenhauser Marketing in India.
The trials were taken on Kolsite 3-Layer blown film line and Colines
CPP Film line using HDPE and PP with the Masterbatch and the results
were encouraging. The results with HDPE on a Blown Film Line with
a little orientation were excellent.
Salient properties
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Synthetic paper contains no fibres and is not coated. Therefore
it is ideal for those applications where contact with water and
moisture is likely. |
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The paper is tough, with outstanding tear resistance, folding strength,
tensile strength and shock resistance. |
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This paper has excellent resistance to chemicals. |
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It has outstanding smoothness, which ensures high print quality
and the finest finish by coating and lamination. |
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It is absolutely safe for the environment and is fully recycleable. |
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The paper thus produced has all the properties very close to that
of natural paper - it can be printed by all the known methods,
can be written on by ball pen, computer printouts with dotmatrix as
well as laser printers are possible. It can be folded,
creased, and also stuck with an adhesive. |
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It is very ideally suited as a packing paper for applications such
as laminated soap wrappers, twist-wrap as well with great
advantage for advertisement billboards, machine catalogues, annual
reports, documents required to be preserved, calendars,
tourist maps, cards for educational equipments, book covers, book
pages, etc. |
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One great advantage is that it can be recycled like any plastics
film. |
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The synthetic paper has dimensional stability, waterproofness, resistance
to chemicals, smoothness, whiteness and can be washed
clean. These properties have replaced the synthetic paper instead
of paper in applications such as copy papers, second
originals, thermal papers for clean room, bar code labels and video
printer, computer forms, drawing papers,plotter
papers, etc. |
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The market is importing its requirements mainly from Japan, but
no special efforts have been made to develop themarket. |
Printing
The paper can be printed on a regular offset printing machine commonly
used for printing paper. For best results, the top and bottom sheet
that have been kept in contact with the cardboard packing sheet of
each pack, should be discarded. The paper should be brought into the
printing room at least a day before printing, in order to condition
it to the room temperature and prevent moisture condensation. The
relative humidity at the machine should be maintained at not less
than 50% to minimize electrostatic problem.
Printing conditions
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Feeder
Unwrapped sheets should be fanned before stacking to ensure smooth
feeding. Folding is prohibited. The stacking should not be loaded
with more than 5,000 sheets at a time. |
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Abrasions and Marks
To avoid sucker marks, minimize the suction pressure and/or
cover the rubber part of the sucker with cloth tape to avoid wheels
and brushes marks, move them away from the image area or cover them
with either PP tape or cloth tape. |
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Plates
Pre-sensitized (PS) Plates are the most recommended. |
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Press setting
Printing pressure should be maintained as high as possible.
The blanket will sometimes show whitening which comes from the inorganic
fillers and normally has no effect on print quality. |
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Dampening water
As the paper is not absorbent, it is important to keep the amount
of the dampening water to a minimum, so as to avoid poor ink adhesion,
longer drying times, set-off and washed out printed images. |
Packing
Spray powder should be used and it should be of the hydrophilic
type (i.e. having an affinity for water, but not soluble). Soluble
or water-repellent powders are not suitable.
It is suggested that:
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sheets should be stacked in piles of 500-1000. |
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air-pressure and jogging should be reduced to a minimum. |
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sheets should not be subjected to impacts or shocks. |
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humidity at delivery should be kept over 50% at least to avoid
static problem. |
Drying
This paper is not absorbent, and therefore, drying will take longer
than with paper. Typical drying time :
1 colour 4-6 hours, 2 colour 5-8 hours, 4 colour 6-10 hours.
Inks
Inks must be specially formulated for synthetic papers and consist
of 100% solids, contain less than 3% mineral oil and dry by oxidation.
Applications
Some of the very common applications in Japan as per one of the
very large manufacturers like YUPO (Japan) include the following:-
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General graphics: Outdoor posters, sign boards, catalogues,
pamphlets, calendars and menus. |
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Publication: Book pages, children books and maps. |
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Packaging: Mould-in labels, overwraps, blister packs,
labels of all kinds including self-adhesive labels. |
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Bags: Shopping bags, envelopes, courier bags, x-ray envelopes
and preservation bags. |
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Special applications: Ballot papers, golf score cards,
ski tickets, various manuals, business cards and battery insulation
paper. |
The market potential appears extremely good, particularly because
it can be produced on Indian equipments, with Indian Polymers and
with comparatively small investments.
For more details, contact plastemart.com
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