The document discusses a new approach to disposing of medical plastic waste called Sterimelt. It works by applying controlled heat to re-melt plastic waste like medical "Blue Wrap" into dense briquettes that reduce its volume by 85%. This allows the waste to be categorized as non-hazardous instead of hazardous, saving hospitals substantial disposal costs. Over a 5-year period, each Sterimelt machine could divert over 182 tons of plastic waste from landfills or incineration by recycling it into new products. Full-scale trials of the Sterimelt process are beginning this month.

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Also in this issue:
What Progress
on WEEE?
How Best To Invest
In Waste Equipment
www.ciwm-journal.co.uk September 2015
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The Dukes
Of HazardRead how the industry manages
and categorises its radioactive
waste in our healthcare &
hazardous waste focus

2. CIWM | Journal September 2015
T
ypically, in the UK and USA, it is estimated that each
hospital bed generates at least 5.5kg of waste a
day of which, on average, 20 percent or 1.1kg will
be plastic waste. Plastic waste generally has a low
volume to weight ratio and, as a consequence, the 20 percent
plastic content of the hospital waste stream in respect to
disposal will be in excess of 40 percent by volume.
The cost of waste handling is based on both weight
and volume, with the waste contractors focussing on the
dimension that produces the most revenue for their service;
so clearly plastic, representing 40 percent by volume of
a typical waste stream, should be targeted for volumetric
reduction to reduce cost. Of this waste, 15 percent will be
considered infectious and require special handling, and the
cost of this can be 10 times greater than handling non-
infectious waste. As a consequence of cross-contamination,
it would seem financially logical to segregate infectious
waste from non-infectious waste whenever possible, to
reduce costs.
A primary source of waste plastic material generated
in hospitals are the used sterile sheets generically known
as "Blue Wrap". This material is used globally and has
the distinction that it can be very easily recognised and
segregated because of its colour.
Medical Blue Wrap is a non-woven polypropylene sterile
wrap that is used to maintain the sterility of instruments
and equipment, and is also used as bed sheets and covers
in the operating theatre. In US hospitals 2.2bn kg of medical
waste is generated each year, and 20 percent of all operating
theatre waste is Blue Wrap. An average sized hospital will
generate approximately 100kg of Blue Wrap material a day,
which is currently being disposed of by autoclaving, prior to
incineration or landfill. The use of Blue Wrap saves hospitals
huge amounts of money in respect of laundry bills, and
is clinically proven to be more hygienic that conventional
textiles. But, as a disposable product, there are challenges in
respect of its end of life disposal.
In 2013 Kimberly Clark (now Halyard Health) determined
that many of its customers demanded a environmental
solution to the end of life of this material and discussions
were held with Styromelt. Our company manufacture
Styrofoam densifiers and the patented technology is referred
to as "thermal compaction", which utilises controlled heat
to volumetrically reduce polymer materials into dense
briquettes that are easily transported for recycling.
A machine called "Sterimelt" was developed for trials
– it can be compared to a large oven, and the principle of
operation is also very simple. All plastic material is moulded,
extruded or woven using heat to create the plasticity of the
material to allow it to be formed. The original raw material
That's A WrapOne company believes it has developed a new, and novel, approach to the disposal
of waste medical disposable plastics. Styromelt's David Scheeres explains
how tonnes of medical Blue Wrap could be turned into valuable recyclate
HEALTHCARE & HAZARDOUS WASTE
Healthcare & Hazardous Waste – CIWM September 201540

3. September 2015 CIWM | Journal
that is used to make Blue Wrap consists of dense
beads, or pellets of polypropylene, which are
melted to produce the finished product.
The Sterimelt machine simply reverses the
manufacturing process by applying carefully
controlled heat to re-melt the Blue Wrap
material, converting it into a liquid that will
flow into a mould cavity to cool and create a
block of material that is dense and sterile. The
operating temperature needed to melt the
material to a liquid is significantly higher than
normal sterilisation thresholds, but lower than
the carbonisation or deterioration level of the
material. The end block of solidified material has a
proven recyclate value and the machine produces
one 20kg block of sanitised polypropylene during
each cycle, with a volumetric reduction of at least
85 percent.
It is very simple to operate; the door of the
machine is opened, the Blue Wrap material is
placed inside and the door is closed. It is started
with the press of a button and the machine then
processes the material automatically with no
further operator input. At the end of the machine
cycle the solidified material is removed, the
machine refilled and the process started again.
During the process the machine is kept under
partial pressure by a fan and the machine exhaust
is filtered through a bag filter and activated carbon
filter. The machine does not liberate any harmful
gasses or VOCs during operation, but plastic is
an aromatic and the filter is necessary to reduce
unfamiliar odours in the workplace. There is
no significant additional labour cost to run the
machine as the operator is simply substituting the
machine for the conventional waste skip or bin –
in effect the machine is an electric skip!
There are several logistical and cost advantages
to using this technology, we believe, in respect
of the hospitals' waste management protocols.
Normally medical waste is segregated into
hazardous and non-hazardous waste streams.
Hazardous waste streams require specialist
handling and cost substantially more than non-
hazardous waste streams to remove. By sanitising
the Blue Wrap material in-situ, the material can
be decategorised to allow its removal as standard
waste, which is substantially less (by a factor of up
to 10) than removing contaminated waste.
As the blocks are inert, there is no imperative
to remove them and, as the volumetric reduction
is at least 85 percent, they do not occupy very
much space. In actual fact, as the material is
solidified polypropylene, it has a recyclate value so
the removal will be actioned with no charge and
it is feasible that a rebate could be offered to the
hospital for the material – the removal becomes a
revenue stream instead of a cost.
Although simple to operate, the internal control
of the Sterimelt machine is sophisticated and allows
the site operator to data log the process for historical
audit purposes to ensure each batch of material
achieves the correct temperature, similar to the
management of industrial sterilisation autoclaves.
Manufactured from stainless steel and with
few moving parts, the machine also has a small
footprint – significantly less than a 9yd skip – and
is designed to be operated out of doors, so the
restrictions on location are minimal.
Other significant benefits achieved in the
volumetric reduction of any waste stream
is reduced traffic to the site generating the
waste along with pro-rata cost reductions and
environmental improvements, effected by reduced
traffic movements.
On the basis of a machine processing 100kg of
material a day, during the a typical five-year lease
life of a machine, we calculate that it could divert
a staggering 182.5 tonnes of plastic material away
from landfill or incineration, providing a valuable
material to be manufactured into new products.
Each time a polymer is melted, the melt index,
which dictates its recyclate use, changes slightly
so regulatory bodies – such as the FDA in the
USA, and machine users – can be assured that
the material will not re-enter the healthcare
environment as an inferior product, but will be
processed into structural mouldings with no
similarity to the original form.
We believe that a potential future development
of the machine could be to volumetrically reduce
and sterilise plastic irrigation bottles, which are
used to dispense fluids and drugs to patients.
These containers form a much larger waste
stream than Blue Wrap material, but have the
same adverse high volume to low weight ratio
characteristics as Blue Wrap.
This would be a logical progression for the
use of thermal compaction and trials have
already been conducted with different medical
disposables. In the event of sharps, such as
syringes and scalpels entering the machine, they
are encapsulated into the block, reducing the
potential for injury.
Full scale trials commence this month in a
teaching hospital and it is anticipated that the
equipment will be available for commercial sale
during 2016. <
The Author
David is the
managing director
of Styromelt
Ltd and a serial
inventor with
several patents
including the
Insulwatt energy
efficient electrical
heater. He has
a successful
Queens Award
nomination for
environmental
achievement,
with patents
also granted on
Massmelt and
Styromelt waste
densifiers.
The Blue Wrap, after the Sterimelt treatment
HEALTHCARE & HAZARDOUS WASTE
Healthcare & Hazardous Waste – CIWM September 2015 41