COCONUT WOOD METHODS OF TREATMENT AND PRESERVATION

I. Introduction

The coconut palm (Cocos nucifera, L.) has multifarious uses. It is often described as a tree of life and is one of the most important crops in the tropics. It is also considered as one of the world's most beautiful trees. Practically all parts of the coconut can be manufactured into commercial products. The coconut provides food, shelter and fuel especially in countries in Asia and the Pacific where it is abundantly grown. Coconut wood is one of about 75%-80% wood in the world that has low natural resistance against insects and fungi. Its durability depends mainly on climatic condition and the environment. Because of its low natural durability a preservative treatment is generally regarded necessary.

One of primary uses of coconut timber is for building construction. Coconut timber is suitable for housing components like trusses, purlins, walls, joists, doors, window frames and jalousies. Its beautiful grain and attractive natural appearance also can be promising material for furniture, handicrafts, etc. Table 6 could serve as a guide for prospective users of coconut timber for building construction. Table 7 lists the different coconut timber derived products and the recommended characteristics of raw materials to use.

Low density coconut wood materials (from the centre of the stem) should be used only in non-load structures like walls and panels. Medium density boards can be effectively used for walling, horizontal studs, ceiling joists and door/window frames. As a rule, coconut wood with density below 400 kg/m 3 should not be used as structural framing materials . However, they can be used in the internal parts of a building as ceiling and wall lining in the form of boards and shingles. While high density coconut wood (from the perimeter of the stem/sapwood) can be used for load-bearing structures like trusses and joints.

From the economic and environmental point of view, it is practical to process and add value to a potentially useful resource rather than see it go to waste and pose a hazard to the environment. From the forest conservation perspective, increased used of coconut wood could potentially reduce the pressure exerted on natural forests by providing alternative or complementary raw material for housing, building construction and other uses. In many forests around the world, logging still contributes to habitat destruction, water pollution, and earth climates changing. The conservation of natural forest is very important for the future to provide fresh air and reduce the glass house pollution effects.

II. Wood Treatment Methods

There are two kinds of methods which may be used to increase the durability of coconut wood: non-chemical methods, in which preservatives are not involved and chemical methods. Dry kiln is the simplest way of non chemical method very important to reduce shrinkage risk for a long time purpose.

An extensive application of the cocowood preservation is, however, rare. This is mainly due to the fact that cocowood is a low-cost material, which would become more expensive and less accessible to the local market after proper preservation. Although, it certainly more economical at the end. Today it is possible to treat wood in effective preservatives and to develop simple efficacious systems for its treatment. Despite the fact that fungal decay can be prevented by architectonic and constructive details that keep Coco wood dry, insect attack can be avoided efficiently only by a suitable chemical preservation.

We use chemical methods in pressure treatment; our technique is by using Borax and Boric acid (Timbor) through the wood in pressure tank and water as conversion aspect. Borate will penetrate to the whole inside area of coconut woods. Whether is a beam or pole, “Why Borax and Boric?”…. We use timbor instead of CCA (copper- chromium- arsenic) is because it is friendly to environment. Chemicals are practically nontoxic to birds, mammals, and friendly to environment in accurate constituent. It is also relatively nontoxic to bees and plants. Timbor prevent the growth of fungi (preventative fungicide). Relatively high concentrations of Borax compounds are toxic to insects, and borax is used for insect control in some cases.

Coco wood has proven to be comparable to conventional wood in terms of durability, sturdiness, and versatility at considerable lower cost. The use of coconut wood as a substitute material for building construction could reduce cost of housing unit. This is because its cost is half or a little more than half the price of conventional wood. “Those technique may use to another softwood, rubber wood for an example”.

Drykiln

Coconut wood must also undergo seasoning process to minimize if not completely avoid problems in its utilization: the appropriate moisture content levels of coconut wood for various uses are as follows: furniture - 10 to 12%; flooring - 11 to 17%; framing timber -15 to 18%; joinery - 12 to 16%; and weatherboards - 15 to 18%. The common drying methods include air drying wood under shed, forced-air, and kiln drying. Depending on existing conditions, 25mm and 50mm coconut boards take 4 to 11 weeks and 16 to 21 weeks to air dry, respectively to attain equilibrium moisture content of 17% to 19%. Drying schedules have been worked out (Tables 8 and 9) for kiln drying coconut wood to avoid drying defects such as collapse, twist, wrap and check.

Table 8: Kiln drying schedule of 25 mm sawn coconut lumber

Table 9: Air and kiln drying schedule of 50 mm sawn coconut lumber

Pressure Treatment

Coconut is not naturally durable when used in situations favorable to attack by decay fungi and wood boring insects particularly in ground contact and exposed to the weather. The low natural durability can be overcome by the application of suitable wood preservative treatment, for which appropriate prescriptions and dose rates have been developed. Choice of treatment depends on hazard level and cost which can be borne.

Treatment with pressure tank is the most effective method among of all; because borate not just covers all surface area but also penetrate to the whole inside area of Coco wood. So it is much more effective than soaking and spraying. Another advantage is we can do mass product of treated wood in such a short time.

The best preservatives for coco wood are pressure treatment method and then dry kiln process after it. And we will have anti termite’s coco wood in minimum shrinkages problem.

Table 10: Recommended treating processes for coconut wood

Diagram of treatment process

Table 4: Mechanical and related properties of cocowood

Table 5: Comparison of mechanical and related properties of cocowood with some common conventional wood in green condition

Table 6: Uses of coconut timber for building construction

Table 7: Coconut timber derived products and recommended characteristics of raw materials

III. Benefit of cocowood

1. It is replanted wood, not rainforest wood. We only cut the unproductive coconut trees (age up to 25-30 years). We try to reduce the use of rainforest wood, which is very dangerous to ecology balance of earth.
2. Indonesia has a lot of coconut trees farm, largest country in the world. We don’t have supply problems.
3. Its natural sensuous beauty, attractive clear-grained appearance and lasting integrity could be variety touch for your furnishing.
4. We have an anti treatment method that is very effective to prevent fungi and termites to live; also wasted chemical is friendly to environment. We have dry kiln method that could prevent the risk of shrinkage in climate change.