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HOW CORK IS MADE

By Ray Hu - September 11, 2011

Cork Farms Cork farms as seen from a balloon over the Alentejo region of Portugal, near the town of Beja, 2 hours SE of Lisbon. Daniel Michalik 1 of 70

Cork Farms Cork trees as seen from a balloon over the Alentejo region of Portugal, near the town of Beja, 2 hours SE of Lisbon. Daniel Michalik 2 of 70

Harvesting Two men work on one tree simultaneously, and are able to strip the bark in as little as 10 minutes. Stripping a tree with an axe is highly technical- one must work quickly and accurately without causing any damage to the tree. Daniel Michalik 3 of 70

Cork Farms Cork farms as seen from a balloon over the Alentejo region of Portugal, near the town of Beja, 2 hours SE of Lisbon. Daniel Michalik 4 of 70

Harvesting Tools of the trade: Left: The Machada is the traditional multi-function ax used to strip bark from a tree. Right: a knife used to cut slabs of cork bark into small pieces for punching out wine stoppers. Daniel Michalik 5 of 70

Harvesting Left: Cork bark freshly stripped, remote forest in Alentejo. Right: Freshly harvested tree. Daniel Michalik 6 of 70

Harvesting Trunk showing inner bark that carried nutrients, with two consecutive harvest cycles, spanning 18 years. The inner bark is kept from damage during harvest, as healthier trees make for more profitable forests (and better environemtal conditions overall). Daniel Michalik 7 of 70

Harvesting Left: Corticadores removing a 5-meter, 1/2 round length of cork. Right: Antonio with a 2.5 meter length Daniel Michalik 8 of 70

Harvesting Corticadores and their work. The harvesters are highly skilled (and compensated accordingly), using hand skills passed down through generations to stip massive lengths of cork bark without doing any damage to the tree. Daniel Michalik 9 of 70

Harvesting Tractor hauling away an hour's worth of work from the forest to a local road, where it will be picked up for processing. Daniel Michalik 10 of 70

Harvesting Hermaino, Antonio, Miguel. Daniel Michalik 11 of 70

Harvesting Left: The end of the Machada handle, which is wedged between the outer and inner layers of bark to peel the cork bark from the tree. Right: A modified glove to help the same process Daniel Michalik 12 of 70

Harvesting Corticadores at work. Daniel Michalik 13 of 70

Harvesting Black pigs on a nearby farm. These animals are a staple of the Southern Portuguese diet, the smoked meat showing up on many tables. Daniel Michalik 14 of 70

Harvesting After harvest, all trees are painted with a number corresponding to the year of harvest. This is normally done by women during the harvest, who also hand-carry loads of bark lengths from the trees to the tractor. A tree is harvested every 9 years. Daniel Michalik 15 of 70

Harvesting A means to get up the tree. Daniel Michalik 16 of 70

Harvesting At work in the forest. Daniel Michalik 17 of 70

Harvesting It is common for those that carry a sharp machada to fashion a cover for the blade out of cork bark. Daniel Michalik 18 of 70

Harvesting The blade of the machada. Hand-forged and razor sharp, each corticador carries and keep sharp his own. Daniel Michalik 19 of 70

Harvesting Traditional craft: The cork oak growns many burls, and the bark from these areas is removed in a single piece and repurposed as vessel forms. Daniel Michalik 20 of 70

Harvesting A traditional vessel for drinking water, carved from bark. Daniel Michalik 21 of 70

Harvesting Left: A traditional lunch pail carved from cork bark. Right: lengths of bark wrapped into a stool. Daniel Michalik 22 of 70

Harvesting Freshly harvested bark, removed via tractor from the remote forests, stacked and awaiting transport to processing facilities nearby and in the north. Daniel Michalik 23 of 70

Harvesting Stacking lengths of bark. Daniel Michalik 24 of 70

Harvesting Branch bark removed in a single, tubular shape. Daniel Michalik 25 of 70

Harvesting A remote area of wild cork forest, 50 km east of Coruche. Daniel Michalik 26 of 70

1st Stage Processing - Amorim The images that follow are from the industrial facilities of Amorim, Portugal's leading producer of cork and cork products. A stack of FSC-certified cork awaits the first processing stages. Daniel Michalik 27 of 70

1st Stage Processing FSC-certified cork awaits the first processing stages. Daniel Michalik 28 of 70

1st Stage Processing FSC-certified cork awaits the first processing stages. Daniel Michalik 29 of 70

1st Stage Processing "Virgin" cork, or cork from the first 2 growth cycles of the cork oak. Uniform density and form has not yet formed and this material is unsuitable for stopper production. It is ground for use in agglomerated material. Daniel Michalik 30 of 70

1st Stage Processing Bark that has been boiled in water to soften and flatten into usable sheets. Daniel Michalik 31 of 70

1st Stage Processing The pressurized boilers. Each chamber holds two pallets of bark, which are boiled in pure water for 20-30 minutes. The water is recycled throughout the system. Daniel Michalik 32 of 70

1st Stage Processing 1st quality cork, sized and ready for punchinginto wine stoppers. Daniel Michalik 33 of 70

1st Stage Processing A bundle awating the sorting and sizing process. Daniel Michalik 34 of 70

1st Stage Processing Quality control classifications. The left column indicates thickness, the right indicates quality. Daniel Michalik 35 of 70

1st Stage Processing Raw bark in a sorting bin. Daniel Michalik 36 of 70

1st Stage Processing Left: a stack of cork awaiting sorting. Right: hand-cutting to size. Daniel Michalik 37 of 70

Wine stopper production - Amorim & Irmaos, S. Paio de Oleiros Cutting bark lengths to size equaling the length of a stopper. Daniel Michalik 38 of 70

Wine stopper production Left: Cork trim saw. Right: a pallet ready for trimming and punching. Daniel Michalik 39 of 70

Wine stopper production Hand-punching wine stoppers. 100 percent of the leftover material is reused, made into agglomerated sheets, blocks and other items. Daniel Michalik 40 of 70

Wine stopper production Machine sorting for quality control. Daniel Michalik 41 of 70

Wine stopper production 3mm cork veneer, used for punching out discs. Daniel Michalik 42 of 70

Wine stopper production 3mm discs. Lefotver material is recycled into other products. Daniel Michalik 43 of 70

Wine stopper production Hand-sorting various stopper grades. Daniel Michalik 44 of 70

Wine stopper production Top-quality stoppers. Daniel Michalik 45 of 70

Wine stopper production At the stopper factory. Daniel Michalik 46 of 70

Cork flooring factory - Amorim Rivestimentos, S. Paio de Oleiros Underlayment sheets made from recycled cork. Humidifiers keep both material and employees happy. Daniel Michalik 47 of 70

Cork flooring factory Robots load underlayment onto belts for flooring production. Daniel Michalik 48 of 70

Cork flooring factory Samples of new finishes. Wood veneer is laid up on cork underlayment. Daniel Michalik 49 of 70

Cork flooring factory Cork/formaldehyde-free MDF underlayment for veneered flooring tiles. Daniel Michalik 50 of 70

Cork flooring factory Factory floor. Daniel Michalik 51 of 70

Cork flooring factory Factory exterior. Daniel Michalik 52 of 70

Dark cork insulation factory - Amorim Isolamentos, Vendas Novas. In contrast to the automation of the flooring factory, the dark cork factory employs crude tooling for a robust process. Granulated cork "waste" is heated in autoclaves until the grains expand like popcorn in a sealed pot. Pressurized and heated, the material's natural resins bonds it into a block. The extreme heat darkens but doen not ignite the cork. Steam from the molding prcess rises from the stack. Daniel Michalik 53 of 70

Dark cork insulation factory Molded blocks. Daniel Michalik 54 of 70

Dark cork insulation factory An autoclave at work, with a still-smoldering block in the background. Daniel Michalik 55 of 70

Dark cork insulation factory Autoclave and hopper. Daniel Michalik 56 of 70

Dark cork insulation factory Racks. Daniel Michalik 57 of 70

Dark cork insulation factory After molding, the blocks are cooled and expansion is stabilized. Daniel Michalik 58 of 70

Dark cork insulation factory Left: Blocks rising out of the autoclave. Right: steam injectors. Daniel Michalik 59 of 70

Dark cork insulation factory Dark blocks. Daniel Michalik 60 of 70

Dark cork insulation factory Autoclaves at work. Daniel Michalik 61 of 70

Dark cork insulation factory Factory exterior. Daniel Michalik 62 of 70

Dark cork insulation factory Cork "waste" awaiting grinding. Daniel Michalik 63 of 70

Dark cork insulation factory Blocks. Daniel Michalik 64 of 70

Amorim factories are powered by cork biomass. The beginning and the end of the cork process. Left: raw bark from the forest, awaiting the first processing stages. Right: A bag of cork dust and particles. This material is used as fuel to power the machines in the factories making products from cork, post stopper production. As opposed to the burnign of coal and petroleum, biomass fuel has a net zero carbon release (since the trees absorb carbon). Between these two photos, countless cycles of material release occur, creating a closed-loop, vi Daniel Michalik 65 of 70

Biomass power supply Dark cork dust bound for the furnace. The dark cork factory in Vendas Novas is 90% powered by biomass. Daniel Michalik 66 of 70

Biomass power supply The furnace, burning cork dust at 900 degrees centigrade. Daniel Michalik 67 of 70

Biomass power supply Left: furnace gate and primary chamber. Right: interior view of the incinerator with cork dust being injected. Daniel Michalik 68 of 70

Biomass power supply Left: Hand truck, Vendas Novas. Right: Blast furnace. Daniel Michalik 69 of 70

Biomass power supply Biomass furnace smokestack, Amorim Isolamentos. Daniel Michalik 70 of 70

Brooklyn-based furniture designer and educator Daniel Michalik's work explores the rich potential of cork. To learn more he visited Portugal documenting it's harvesting, multiple manufacturing cycles, and end-use as biofuel creating a closed-loop, virtually waste-free industry.