Du Pont's web page TyvekŪ for Graphics features a description of TyvekŪ's properties and possible uses for that material. There is no suggestion for the use of TyvekŪ in the production of bank notes. Nevertheless, the web page gives a general idea about TyvekŪ that had been used for printing banknotes in 1980s. Below are some excerpts from that web page.
TyvekŪcreating new dimensions in graphics
brand protective material is a miracle of science from DuPont. It is a family of
tough durable sheet products of high-density polyethylene fibers. The sheet is
formed first by spinning continuous strands of very fine interconnected fibers,
and then bonding them together with heat and pressure.
TyvekŪ is white, non-toxic, chemically inert and contains no binders. The non-woven sheet, after bonding, combines a good printing or coating surface, high opacity and toughness to a degree unique among sheet products of similar weight and price.
TyvekŪ is produced in three different types, namely 10, 14 and 16. The fibers in Type 10 Style are bonded to form a tough, dense, opaque sheet. The dense packing of the fine, interconnected fibers produces a smooth surface, high opacity and whiteness. The large number of bonds per unit area results in a stable and abrasion resistant surface with a stiffness similar to paper. Fiber bonding of Types 14 and 16 is restricted to discrete points in the non-woven sheet, producing a high degree of fiber mobility, and giving the non-woven a fabric-like drape.
Made by bonding webs of fine fibers with heat & pressure, nonwovens are an incredibly durable printing surface.
A unique, proprietary manufacturing process perfected by DuPont over 24 years ago makes TyvekŪ ideal for a variety of applications.
TyvekŪ is a
unique nonwoven printing medium. It's not paper. It looks different from paper.
Its not like synthetic films. It feels more natural, with flat, precision
folding qualities. Its not a fabric, although it can be used like fabric.
bonding webs of fine fibers with heat and pressure, nonwovens are an incredibly
durable substrate. TyvekŪ blends the best traits of fabric, film and paper.
Account for the differences TyvekŪ brings and get reliable printing results
can be printed by all conventional printing processesletterpress, offset
lithography, heat-set web offset, flexography, gravure, and screenprinting.
is also thermal transfer printable. For best thermal transfer results, printing
on the smooth side of TyvekŪ Brillion styles is recommended.
wide format ink jet printing, a TyvekŪ with an ink jet receptive coating is
required in order to achieve acceptable results. Numerous companies offer ink
jet compatible TyvekŪ based products.
process laser printing and photocopying are not suitable with TyvekŪ.
DuPont TyvekŪ is composed of 100% high density polyethylene fibre. It is a
tough, durable, tear-resistant material that is unaffected by water. TyvekŪ
retains its flexibility to -73°C (-100°F) but being a thermoplastic material
it melts at 135°C (275°F). TyvekŪ can be converted in much the same way as
paper or plastic films and on the same equipment. If you understand the
properties of TyvekŪ , you will find converting to be much easier.
All styles of TyvekŪ with a "D" or a "R" suffix are
antistated and permanently corona treated.
TyvekŪ will stretch up to 30% before breaking. To minimize distortion or
neck down during roll fed converting, keep tension less than 1.4 N/cm (0.75
pounds/inch.) A floppy web is recommended. This is particularly true when die
cutting TyvekŪ business forms with rotary punched sprocket holes.
Slitting, Sheeting, Cutting
Because TyvekŪ fibres are very strong, each must be completely severed;
hangers will not break off. Knives, dies and punches must be set to close
tolerances. A sharp, slightly rounded edge gives longer service than a pointed
edge for crush cutting, but a sharp edge is preferred for other slitting
Rotary Die Punching
Because soft steel male/female rotary dies dull quickly when Set to the
close tolerances required to punch TyvekŪ cleanly, the use of rotary dies made
of hardened tool steel or tungsten carbide is recommended. A list of
manufacturers of these dies for TyvekŪ is available from your TyvekŪ Technical
TyvekŪ can be die-cut using either steel rule, male/female or closed dies.
TyvekŪ fibres must be completely cut and dies must be in good condition with
sharp, nick-free edges. Dull dies cause edges to curl. When using closed dies,
the use of a side cutter with internal relief is recommended. Deaerate and keep
lift height below 7.6 cm (3 inches) when die cutting to avoid oversizing to
TyvekŪ can be punched on tag, letterpress and rotary line-hole equipment.
Best results are obtained for sharp, well registered and closely fit punches.
Punches may be either smooth or serrated and cut best if ground concave on the
ends. A soft self-honing male punch in a hardened female die is recommended.
TyvekŪ will take a dead fold and can be folded on conventional bindery
folders. An increase in roller and spring tension will produce sharper creases.
Due to the inherent slippery surface of TyvekŪ, soft, rubber-covered rollers
will aid feeding.
For clean-tearing perforations, use the maximum practical number of cuts
with the smallest land (reserve) between them. An 8:1 ratio (1/4 [6.4mm] cut
with 1/32 [0.8mm] reserve) is recommended.
TyvekŪ can be embossed with either high or low pressure equipment. Cold
embossing does not significantly reduce the strength of TyvekŪ. It does,
however, reduce opacity. Embossing cylinders used for TyvekŪ usually are very
shallow, having a depth of only 0.13-0.65 mm (5-25 mils.). A Shore "D"
hardness of 70-80 for the rubber back-up cylinder is preferred.
This is readily accomplished on TyvekŪ due to its thermoplastic nature. A
variety of foils is available from suppliers for label and book cover
applications. A foil that will transfer cleanly to TyvekŪ between 135-160°C
(275-325°F) should be chosen. Large, solid foil-stamped areas tend to pucker
and distort TyvekŪ and should be avoided.
When coating or laminating TyvekŪ, the web temperature should not exceed 79°C
(175°F). Coatings are used to color, improve print fidelity, add gloss or mask
the fibre pattern of TyvekŪ. Air-knife coating is preferred for aqueous coating
because it applies a uniform thickness of coating on TyvekŪ. Usually an
increase in binder content is needed to achieve acceptable coating adhesion to
TyvekŪ. The air knife also produces a very smooth surface which is ideal for
printing. Gravure coating is preferred for solvent-based systems, particularly
where deep coloration is required.
Conventional textile dyeing processes do not impart permanent color to TyvekŪ.
For this reason, Type 14/16 TyvekŪ is usually printed by the flexographic or
gravure process using either solvent or water base inks. Sublistatic printing of
TyvekŪ is not recommended because of the high temperatures used.
TyvekŪ can be extrusion, adhesive and calender laminated. Extruded,
branched polyethylene is an excellent adhesive for laminating foil and film to
TyvekŪ. Polyurethane adhesives can be used to adhere a variety of films and
fabrics to TyvekŪ. When laminating TyvekŪ to paper or board, it is important
to completely cover TyvekŪ with adhesive to prevent bubble formation.
Heat Sealing/Dielectric Sealing/Ultrasonic Sealing
Heat sealing TyvekŪ to itself or other films is usually accomplished by
applying a heat seal coating such a branched polyethylene to one of the
materials. High seal strength can be achieved using hot-bar or impulse
techniques. TyvekŪ cannot be dielectrically sealed under ordinary conditions
because it is non-polar. Recent developments in ultrasonic sealing have
demonstrated seals almost equivalent to heat seals.
Natural product adhesives based on dextrin, casein or animal byproducts can
be used to adhere TyvekŪ to itself and a variety of paper materials. Water
based synthetic lattices such as the ethylene/vinyl acetate adhesives form fibre
tearing bonds with TyvekŪ. Hot melt polyamide adhesives are available which
form good bonds to TyvekŪ with a variety of materials. Acrylic pressure
sensitive adhesives are commonly used with a release liner.
TyvekŪ can be sewn on conventional sewing machines. Best results are
obtained with machines equipped with puller or drop-feed. Smooth, rubber covered
rolls should be used rather than knurled metal rolls which tend to leave
impressions on TyvekŪ.
When stitching the Type 10 styles of TyvekŪ, 2-3 stitches/cm (4-5/in.) and
the smallest needle practical should be used to avoid postage stamp tears. On
soft type 14/16 TyvekŪ, it is recommended to sew rough side to rough side.
TyvekŪ offers superior strength and durability relative to its light
weight. TyvekŪ typically weighs half as much as other printing substrates. TyvekŪ provides significant source reduction opportunities, helping to meet
resource conservation goals. It simply takes less material to make TyvekŪ when
compared to other film and paper substrates.
If reuse or recycling is not an option, TyvekŪ can be cleanly incinerated,
and the high energy value can be utilized. Also, because TyvekŪ is chemically
inert without binders, it can be safely disposed of in landfills.
TyvekŪ is made entirely of high-density polyethylene (HDPE), one of today's
most commonly recycled plastics. More than 70 facilities in North America are
available to recycle TyvekŪ.
Q: Does TyvekŪ require special printing inks?
A: Yes. TyvekŪ normally requires inks that are of a different
formulation. This is not necessarily a problem since the majority of ink
manufacturers can supply this ink. This ink sensitivity is also true of other
Q: Does TyvekŪ come in pressure sensitive grades?
A: DuPont relies on pressure sensitive coating companies to coat TyvekŪ
for pressure sensitive label applications. TyvekŪ is compatible with a wide
variety of pressure sensitive adhesives.
Q: Which printing processes are compatible with TyvekŪ?
A: TyvekŪ can be printed using the following methods: offset (sheetfed
& web), flexography, letterpress, gravure, thermal transfer, and dot matrix.
In general, if the temperatures of the process stay below 175 degrees F,
then TyvekŪ can be imaged. Keep in mind that part of the process is drying and
the dryer temperatures must adhere to the 175 degree rule. TyvekŪ does not produce acceptable results when imaged with a wide format
inkjet printer. For wide format inkjet printing, a TyvekŪ with an inkjet
coating is required. Numerous companies offer inkjet compatible TyvekŪ.
Q: Will a die last as long on TyvekŪ as on paper?
A: Because of the superior strength and durability of TyvekŪ over paper,
certain considerations should be made when cutting TyvekŪ. Hardened dies in
good, sharp condition provide the best optimum performance for cutting TyvekŪ.
Copyright Đ 1995,
1996, 1997, 1998, 1999, 2000 E. I. du Pont de Nemours and Company