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Kochi Sekkai Limited

Into modern forms with traditional materials

3143-1 Inabu, Nankoku-shi, Kochi JAPAN

[Manufacturing products]
plaster for interior/exterior walls and roof
slaked lime, slaked lime for fertilizer
[Merchandise products]
lime for line
cobblestone, gravel
mortar, silica sand and various plastering materials

Traditional materials are recognized once again

We deal with various plasters and slaked lime for industrial use, and from these, plaster is our main product.
Plaster is a safe and popular wall-finishing material which is excellent for humidity control and antibacterial, but because the number of traditional Japanese constructions are reduced, the demand for plaster was also keep decreasing for long period.
But in this 10 years, the health impairment called "sick-house syndrome" which is the result of adhesive agent used in new building materials has been focused, and according to this incident, the buildings constructed which avoided to use new materials and instead applying the natural materials or traditional construction itself have been reassessed.
This trend leads to the reassessment of wood, soil and paper, they are all traditional building materials and plaster is focused as one of them.
It is too soon to say as rapid recovery, but the past few years the decreasing of demand is gradually slow and there are new needs are increasing.
Today this new way of life of natural-oriented and less burden to natural environment are beginning to be fixed, We think that the future of plaster which is on one of typical wall-finishing natural material, is very bright.

Self-plastering by new users

As a manufacturer, we especially feel happy that young people are "rediscovering" the plaster.
Plasters are used in all over the world, and by finding the walls which are finished as rough surface in the areas of Southern Europe, the number of people is increasing that they want to plaster by themselves.
The biggest weakness point of plaster is used to be very expensive as a result of time-consuming work to finish up.
The cost of plaster itself is usually abuot 300 Yen/mm2, but to finishing up walls and fences beautifully by traditional way in Japanese-style architecture, it takes time and needs the craftsmanship including undercoating. and if you order these works to plasterer, it will cost about 5000 Yen/m2, and can be 10,000 Yen/m2 for high-class finishing.
However, if you choose "Southern European-style" and carefully take the basic process such as undercoating, even amateurs are able to finishi up in their own way.
The rest is denpends on their determination.
However this really is a difficult work, but with the help from their families and friends, number of people are increasing, determined to accomplish their purpose little by little.
Quite recently we gave advice to the people who want to try to plaster the interior decorations of new opening cafe. They finished up the area of about 10 bags of 20kg of plaster.

What is a plaster?

As you may know, raw material of plaster is limestone.
There are plenty of limestone in Kochi, and even better, stones mined in this area are said to be high in brightness and excellent quality.
When you heat the limestone at about 1000c, it will be turn into quicklime (calcium oxide). Next, you add water to make slaked lime(calcium hydroxide), to mix with plant fibers (mostly hemp) and seaweed, then kneading well with more water would finally become a plaster.
Normally plaster will be sold in powdery form, but products which can be used easily by adding water and mix roughly are also available.

In Kochi, there is a original plaster called Tosashikkui which is different from normal plasters.
Instead of hemp fibers and seaweed, mixed with fermented straw. The fibers of straw replace the hemp and stickiness as result of fermentation works instead of seaweed.
It is fairly cream colour right after plastered, but later becomes white which is used even at Kochi Castle.
Some may remember that even from far, part of the castle seem to be in cream colour for about half a year when the re-plaster is done during the restoration of castle.
We include the word "Tosa" in the name of our products to show the quality of lime of Kochi.

Professionals are welcome

The plasterers in old time were usually making their own original recipe of plaster, but nowadays this case is less and most of the time, the simple plasters are required even for the professionals.
Therefore, we are also selling the plaster for exterior walls which is mixed to improve the durability and reduces the chance of cracks by adding more aggregate such as granular marble, etc. and plaster for roof which is strong against the rain with advanced arrangement.
Also, in order to meet the requirement from design side, 10 different colours are available to feel more familiar for the clients.

However, we do not try to create the products to emphasise the functionality such as extremely improve the function of humidity control by mixing special materials.
To be honest, the plaster is difficult for differentiation and it is true that there is a temptation to make the products with special function to differentiate from other companies' products.
But we think mixing the artificial materials will result the contrary aim which our consumers are truely looking for.
Therefore we stubbornly set our basic policy to make plasters by using the natural materials in traditional way.

Devoted for lime and plaster -history of 100 years

We have established at present place in 1918 and we will soon cerebrate the centennial anniversary.
Because this Inabu area used to be well known for excellent quality of limestone, there were many lime-ralated plants centralized, even though limestone is now depleted there are still 7 companies in operation.
We form the Tosa Lime Chemical Cooperative Union with 4 companies from above to do the pretreatment of limestones at Inabu, which are mined and transported at Tosayama and Shirakidani area in Kochi City.

We have said that our main products are various plasters, but slaked lime is an also important product which is a raw material of plaster makes up of 30% of total sales.
As for the industrial use, as well as for tennage and wire drawing of thin lines from iron meterial, they are shipped as fertilizer for soil amendments.
A powdery form of limestone is also shipped as line powder for white lines which you may feel more familiar.
As an addition, apart from lime we deal with various mortars, cobblestones and gravels.

For the future

The plasters would become a material which will be reconsidered.
In summer 2011, research result was introduced in national newspaper that plaster is effective to kill the virus of avian influenza.
Originally, slaked lime as is a raw material, is strong alkaline and disinfection effect which sprinkled together with disposed domestic animals whose infected by avian influenza, therefore, there is no wonder it enables to kill the virus, it may has more possibilities which we still yet to know.
it has a wide range of usage, applied to many architectures from home to museums and hotels.
We will continue to provide high quality and authentic plaster which are natural and simple as truly required by the consumers in addition to make the products which are easy to use by keeping the traditional method and at the same time applying the research result and new requirement.

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