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C241
- Display Promotions Ultrascreen Ltd - Printing - Wellington
Region
Summary
The company prefers to use water-based inks and coatings, which are easier
and healthier to work with than traditional inks and coatings. At present,
20% of all coatings are water-based, but the proportion will increase as
their range and properties are developed to make their use as reliable as
solvent-based and UV inks. The company has moved from cleaning screens with
aggressive solvent-based products, to a new system as friendly to the environment
and the user as current technology permits. An off-site recycling service
for used cleansing solvents has saved the company $2000 annually. Plastic
pails used for UV coatings are reused for plant pots. The company has an
in-house policy of reusing and recycling materials itself and passing them
on to schools for use as art materials.
Business Profile
Display Promotions Ultrascreen Ltd produces display and advertising material,
usually on a substrate of plastic, card or paper, through mechanised screen
printing and signwriting. The company employs approximately 27 people.
Type of Project(s)
Energy conservation, material substitution, material reuse, material recycling,
reduction in use of hazardous substances.
Reasons for Project
To reduce resource use; improve the working environment; reduce costs; and
protect the natural environment.
The Projects
Water-Based Inks
Displays, by their very nature, are much larger than most other printed material.
Consequently, the company uses large quantities of coatings comprising inks and
finishes. Inks, conventionally, have been solvent-based and dried in an infra
red (IR) dryer. Finishes are usually clear, high gloss coatings cured with ultra
violet (UV) light, although some are pigmented. They are not water soluble. Water-based
inks are preferred for convenience. Their technology is improving to the extent
that they now account for 20% of the total coating usage (50% are solvent-based
and 30% are UV coatings).
The introduction of water-based inks has been an on-going ad hoc process governed
by what is available. The economy of usage (eg. Kg/tonne) is a difficult parameter
to derive for a jobbing screen printer. The benefits are primarily convenience
(clean up, wash down, etc) but the working environment and health aspects have
improved too. One problem anticipated is that the use of water-based inks may
lead to greater losses to sewer as a resource trade-off for improved conditions.
Cleansing Solvent
The final cleaning of screens impregnated with solvent-based inks and coatings
requires a cleansing solvent. Former practice was to use expensive virgin
solvent. The washings were recycled on-site until unusable, when they and
the sludges were landfilled. Now, a local off-site re-processing distillation
service supplies a lesser but adequate grade solvent and takes back spent
solvents and sludges. Up to early 1997, 2700 litres of cleansing solvent
were used annually. Only 50 litres of this, other than in sludges, were returned
for re-processing. Most cleansing solvent therefore ended up in rags which
were landfilled, or in the drainage system. The company has since changed
to a system of environmentally responsible screen printing.
The saving in using a lower grade solvent is $2000 annually. Now that the
company has changed to a new cleaning system, the use of recycled thinners
will drop by about 50%, or $1000, annually. The use of an environmentally responsible
cleaning system will cost about $2000 to set up and a further $4000 per year
in product. Resource use has been reduced and reuse also occurs. The working
environment has improved. There is a 50% reduction in solvent laden rags sent
to landfill. Thinners no longer go down the drain to the sea.
Plastic Pails
The clear, high gloss UV coating is supplied in 20 litre black plastic pails,
one of which is used each week. The coating drains well, leaving only a thin
film on the pail, but retains a tacky touch as it does not cure without UV
assistance. The pails are difficult to clean (even with solvent) and therefore
to recycle. At present they are reused as plant pots. Delivery of the coating
in bulk or in larger containers is neither practical nor economically viable.
Energy
The dryers and curers account for about 20% of the annual energy bill of $26,000.
A 20 second exposure in the IR dryer is required for drying. Water-based
inks take longer. Some energy is used for subsequent rapid cooling with copious
quantities of ambient air. IR dryers are turned off between colours or runs
as they need only 5 minutes to stabilise. UV curers, on the other hand, need
to be left on to reduce lamp shock and because they take 20 minutes to stabilise.
The potential for energy savings will be examined.
For additional information contact:
Director (Neil Hickman)
Display Promotions Ultrascreen Ltd
P O Box 30 655
Lower Hutt
Phone: (04) 568 2865
Fax: (04) 568 9642
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