How to make spun bamboo products- Indochina.,JSC

PRODUCTION PROCESS

1, Material

Bamboo is the fastest growing plant and now one of the most eco-friendly materials. In Vietnam, bamboo both grows naturally and is cultivated in highlands and delta areas which is harvested every 3-5 years.

Spun bamboo is made exclusively from the Nua- Neuhouzeaua Dullooa variety which often grows in the Northern provinces of Vietnam such as Thanh Hoa, Ninh Binh, Son La, Yen Bai, Tuyen Quang provinces. This kind of material is soft and easy to bend thus suitable for making the products in round shapes

Bamboo trees are cut at knots and chopped into smaller pieces/bars of 70-80 cm length for easier transportation by qualified suppliers then delivered to us in trucks.

Bamboo then goes into soaking process in water (mud) for at least 90 days to remove the sugar inside bamboo in order to prevent mold and insects and make it softer as well. After that, bamboo is removed from water, and left dry in the sunlight. The treated bamboo will be kept and used all the year round. This is to ensures that all buyers are provided the most professional and quality products in South East Asia.

2) Bamboo processing

At families, soaked bamboo pieces/bars are chopped again by hand into smaller slats with width of 1-2 cm for different products. They are then skinned and bent into curved rings by simple machines which carve deep lines in them, allowing for glue to fit in better and make stronger bond.

3) Molding/ Shape making

Different bamboo slats are dipped into PVA glue, spun/coiled by hand into a kind of flat form like mats and fixed by steel outer rings. When these mats are half dried, they are bent with wooden or cement molds to make bowl shapes. These primary molds are then dried in the sunlight.

4) Planning

The surface of dried molds is very rough so these molds go through planning process to make it smoother. Skillful workers are used to deliver the smooth surface of all molds. After that these molds are kept at family stock, ready for delivery.

6) Mold gluing and drying

The first step of finishing molds is gluing. Molds are dipped into water-resistant glue which makes them sturdy and durable. They are then dried in drying chambers for around 4-6 hours at the outcome moisture level of 6-8%. At this moisture level, molds dry well and will crack if the structure is not good or material is too wet. Cracked molds will be sorted out for filling and fixing with a mixture of strong PVA glue and stone powder. This is an important process to make sure that products will not emit humidity and crack again when they come to difficult markets with cold and dry climate.

7) Filling

At this stage, the surface of molds is still rough and there are many small gaps or holes because bamboo slats dry and condense. We will use filler, a mixture of stone powder and water-resistant glue, to cover the surface of molds and let molds dry again.

8) Sanding

After the products are filled, they will be sanded by simple machines to make smooth surface and ready for paint application.

9) Painting

Painting is the most important process for making spun bamboo products. Defects are often found at this stage.

Only skillful and trained workers, who have studied and practiced for 2-3 years, are selected to paint products.. We are using painting rooms with running water to extract and absorb the smell of paint and thus protect workers’ health.

Bamboo bowls are painted both sides. The outside part of bowls is covered with special PU paints and pigments for protecting bowls from scratches and achieve colors requested by buyers. The inside part, which is normally in natural, is painted with water-based paint for food-contact purpose.

There are 3 common kinds of finishing: Transparent or grainy color where bamboo grain exposes and you can see; Solid matte is the color which covers or hides bamboo grain. Solid glossy is like lacquer, delivering a shiny surface while covering bamboo grain.