The possibility of using only Cork Material for the Cups was explored. having a Mono-material product is beneficial as it does away with the need for material separation during recycling as well reduce the amount of raw materials extracted and manufactured.
Top left shows Portuguese Design Company Simple Forms using both Natural Agglomerated Cork and a Cork-Rubber Composite for wash basins.
The idea of using just agglomerated cork for a product that's constantly in contact with moisture as well as the properties it must have to ensure hygiene standards was intriguing
Below are images of various cork bowls; it was found that these bowls are not dishwasher safe, and most of the time are for display use only e.g. fruit bowl.
The collection of cork vessels from Detroit designer Nicholas Stawinsky seem to be functional cups and bowls for use in a dining context, however, after email Nicholas without reply, this assumption can not be confirmed.
Without confirming any cases where cork is the sole material used as a drinking vessel, it was determined that the design of cork tea cups had to be a multi-material product.
To abolish the need for separation in the recycling process, it was decided to design the tea cup as two separate components: the cork exterior providing aesthetics, insulation and grip, and a porcelain insert that can be removed for washing.
This design concept links back to the initial inspiration Brr Mugs by Delta Faron (see bottom left in the above image).
Materials Research
Cork
- ^expansionà^insulation
- Sustainable (regenerates every 9 years for
harvest
- Sophisticated, natural touch, unique sensory
experience
- Recycled cork
- Natural agglomerate cork
- 100% recycled cork, biodegradable, heat
resistant, local
- Plastic Inner casing
Source: Sustainable Vision 2-Cork Design, Matrec, 2012
- Cork
is composed of dead cells that accumulate on the outer surface of the cork oak
tree.
- An incredibly versatile natural material, cork is
harvested from living cork oak trees somewhat like wool is gathered from sheep.
The trees are unharmed by the process, and they continue producing cork for an
average of 150 years.
- honeycomb-like
structure, cork consists largely of empty space
- cork
consists of irregularly shaped and spaced cells
- empty
cells =(40 million per cubic centimeter),
- large
amount of dead-air space makes cork an effective insulation material for both
temperature and noise.
- Fire
retardant; no toxic fumes are generated
- Cork
absorbs neither dust nor moisture, and it resists both rot and insects
- American
named John Smith developed a technique for producing pure-cork agglomeration
out of waste material by subjecting cork particles to heat and pressure without
adding any binder.
- evergreen Quercus
suber or the deciduous- Quercus occidentaliscork oak trees
- Portugal's cork forests are the most productive.
Accounting for 30% of the existing trees, they produce half of the world's
harvested cork.
- first
harvest is of poor quality, and can only be used to make agglomerated cork
products.
- Production
of compound agglomerated cork involves adding a binder or adhesive agent to
cork granules
- Different
binders are chosen, depending on the qualities desired in the ultimate product
(e.g., flexibility, softness, resistance to wear). Among those frequently used
are asphalt, rubber, gypsum, glue, and plastic.
Source: Made How 2013, Advameg Inc, Accessed on 29 April 2013,
- cork life cycle, from
production to recycling, is a clean one, without any by-products
- all waste from production;
lower quality material or obsolete product is grind to obtain the granules from
which are made recycled cork blocks
- water
in which the material has to be boiled after collected is not polluted by the
process; all means to work and prepare cork are mechanical based and even the
dust resulting from this is used to generate electric energy.
- present
in everyday rituals and objects – from drinking vessels (which shape is
directly cut off the tree) to seating benches.
- structure and chemical
composition of cork give it remarkable properties: its tissue is 89,7%
comprised of an air-like gas that makes the material very lightweight (0,16g
per cubic centimeter) and low density; impervious to liquids, a very good
thermal insulator; chemically stable and mostly unaffected by microbial
activity – highly resistant to humidity and oxidation.
- honeycomb cellular
structure
45% suberin (responsible for corks resilience), 27% lignin (the binding
compound), 12% cellulose and polysaccharides (cell wall compounds that help
define cork texture), 6% tannis (compounds responsible for colouring), 5% wax
(hydrophobical compounds that assure the corks impermeability), 5% ashes, among
other elements like mineral water, glycerine, etc).
- Suberin
is the natural waxy substance responsible for making cork anti-allergenic
(mold, mites and even termites are repelled by cork) and fire (it is a natural
fire inhibitor and also does not release any toxic gases during combustion).
Suberin also prevents cork from rotting even when completely submerged under
water for long periods of time.
- The
montado ensures the life of its population in areas of hostile climate and poor
grounds, as well as it sustains a biodiversity greater than any other
agricultural system. Therefore it has a large ecological, economical and social
importance.
- Portugal has the largest
cork production (21% of national forest area) and transformation industry of
today.
Source: The Home Project Design Studio 2013, Accessed on 29 April 2013,
The
Manufacturing
Process
- 1 Using a specially designed hatchet, the harvester slices through
the cork layer on the trunk of the tree, taking care not to cut deep
enough to damage the living portion of the trunk. Horizontal cuts are made
at the base of the trunk and just below the lowest branches. A few
vertical cuts separate the circumferential cork ring into sections of an
appropriate size. Using the wedge-shaped handle of the hatchet, the
harvester strips each panel of cork from the tree. On some large trees,
cork is also stripped from the lower branches.
- 2 The cork planks are stacked outdoors and left to cure for a time
ranging from a few weeks to six months. The fresh air, sun, and rain
encourage chemical changes that improve the quality of the cork. By the
end of the curing process, the planks have flattened out and lost about
20% of their original moisture content.
- 3 The planks are then treated with heat and water to remove dirt
and water-soluble components like tannin, and to make the cork softer and
more flexible. This process typically involves lowering stacks of cork
planks into large copper vats filled with boiling water containing a
fungicide. Heavy weights are placed on top of the cork to keep it
submerged for 30-75 minutes.
- 4 When the planks are removed from the vat, a hoe-shaped knife is
used to scrape off the poor-quality outer layer of cork, which amounts to
about 2% of the volume of the plank but 20% of its weight. The planks are
stacked in a dark cellar and allowed to dry and cure under controlled
humidity for a few more weeks.
- 5 The cork planks are trimmed to a uniform, rectangular shape and
are sorted by quality. The finest quality material will be used to make
natural cork products like wine bottle stoppers. Poorer quality material
will be ground and used to make composition or agglomerated cork.
Boffle
corks
- 6 Cork slabs of the desired thickness are placed in a steam chamber
for 20 minutes to soften them. The slabs are then cut into strips whose
width corresponds to the intended length of the bottle stoppers. The
strips are fed through a machine that punches hollow metal tubes through
them, removing cylinders of cork.
- 7 Although some beverage bottlers want cylindrical corks, others
want tapered ones. To achieve this shape, the cylinders are arranged on a
slanted conveyor that carries
- 8 Both cylindrical and tapered corks are washed, bleached, and
sterilized in large vats. Rotating wooden paddles continually push the
corks down into first a washing solution and then a neutralizing solution.
- 9 After being dried in a large centrifugal dryer, the corks may be
marked with an identifying label (with ink or a hot-metal stamp). Some are
also coated with a sealant such as paraffin or silicone. Then, they are
packed in airtight bags in quantities of 1,000 or 1,500; the air is
removed from the bags and replaced with sulfur dioxide (SO 2 )
to keep the corks sterile.
Agglomerated
cork
- 10 Waste cork is passed through a machine that breaks it into small
pieces. The pieces are washed and dried, and then sent through two
successive grinders to further reduce the particle size. After another
washing and drying process, the particles are screened for uniform size.
- 11 Pure agglomerated cork is formed by packing cork particles into
a mold and covering it securely. Superheated steam (600° F or 315° C) is
passed through the
12 Compound agglomerated, or composition, cork is made by uniformly
coating the cork granules with a thin layer of an additional adhesive
agent. The coated granules are pressed into a mold and slowly heated (the
temperature varies, depending on the adhesive used). When removed from the
mold and cooled, the blocks are stacked to allow air circulation and are
allowed to season.
- 13 The agglomerated cork is cut for its intended use. For example,
sheets may be cut from rectangular blocks. Or if a tubular mold was used,
the resulting cork rod may be sliced into discs. A large, cylindrical
block might by revolved against a knife blade to shave it into a long,
continuous sheet that is rewound into a roll.
Cork waste generated during the
manufacturing process is ground and used to make agglomerated cork products.
Cork powder that is generated by the grinding process is collected and burned
to help fuel the factory.
Source: Made How 2013, Advameg Inc, Accessed on 29 April 2013,
Recycling
- Off cuts from cork production can me combined
with granules to make lower quality cork products
- Dust can be used as fuel to power factory
- Water not polluted, used over and over
- water in which the material
has to be boiled after collected is not polluted by the process; all means to
work and prepare cork are mechanical based and even the dust resulting from
this is used to generate electric energy
- Chemical
components removed from cork during its processing can be recovered as useful
byproducts and include tannin (used for curing leather), hard wax (used in
products like paraffin, paint, and soap), resinous gum (helps vanish adhere to
copper and aluminum), and phonic acid (used to make plastics and musk-scented
toiletries).
- Cleaned, shredded, combined with adhesive, used
to make other products
Source: Cork Recycling Program 2007, Web Video of Money Wise (TV Program) News Report, Accessed on 29 April 2013,
