Domain

Explanation

Recycling?

• Yap … Re-Cycling
• Repeating the cycle of usage of materials

Why?

• Materials made into products are conventionally assumed to be of unidirectional use, i.e. once things are no longer useful, they are dumped, treated as wastes and presumed useless
• In land-scarce, resource-deprived and product-hungry civilizations like Singapore, materials are especially precious
• This is not only due all materials being imported or as entreport trade, waste materials have to be safety, compactly and effectively disposed off either as landfill or burnt for power
• To save these resources, preserve the materials at hand & towards environmental excellence, waste materials are being carefully studied, researched & processed into new materials that would begin the next cycle of usage
• This is the essence of recycling

Why wood?

• The top 3 wastes are:

1. Organic wastes
2. Paper
3. Wood

• Environmental engineering targets both organic & inorganic wastes, while paper recycling has gained sustainable rhythm
• Hence, wood wastes are the next logical recycling target
• Wood wastes can be classified as follows:

1. By usage: logistics, domestic (furniture)
2. By species of wood: tropical hardwood, monsoon hardwood, equatorial hardwood, temperate deciduous hardwood, mixed hard-softwood & coniferous softwood
3. By location of origin: industrial (more toxic), commercial (more uniform), domestic (more organic), construction (hybrid)
4. By state of wood: quality (good), deteriorated (needs segregation), rotten (avoid)

• Wood wastes as raw materials for recycling are abundant in quantity, but required careful management, segregation & transportation to preserve quality wood for recycling
• Unlike other organic wastes, wood is more durable & with proper processing, wood can be rejuvenated for use again
• The criteria to recycling wood is processing

Properties of wood?

• Wood varies from origin, species, usage, location & properties
• In general, wood is orthotropic material - it is strong, stiff & durable along some directions & vice versa along others
• I'm sure we know that wood come from trees which grow through height extension & width expansion
• Hence, wood has strong fibers that run along the length (height) of the trees with relatively weaker connections between fibers along the width direction
• Also, wood is organic & changes with the weather - when wet, it heaves, expands & absorbs (becomes structurally weaker & easily deteriorated); when dry, it shrinks, contracts & compacts (structurally stronger & less deteriorated)
• The bark of trees protects the underlying wood, allows moisture to enter & leave as well as permits the heaving & shrinking (volume changes) of the wood
• Good wood engineering & recycling would amplify the useful properties of wood while limiting its detriments

Attributes of good wood recycling?

• The objectives of wood recycling processing are (i.e. what we want to recycled wood to become):

1. To convert wood wastes into useful, strong, durable & stable wood
2. Strong: high internal bond, toughness, hardness, bending strength, nail holding strength, durable
3. Fire retardant: resistant to being burnt (definition: visible flame for at least ten consecutive seconds), FSB fire rating of half-hour (domestic) & one-hour (industrial)
4. Low moisture content, retention & absorption: lower moisture means smaller volume changes, causing less damage to external protection
5. Resistant to pest & chemicals: put to termites' test & chemical corrosion
6. Cost-effectiveness: higher productivity, low resource wastage, environmentally-friendly

• In the words of an insider, "to prosper is near to impossible, to survive is probable"
• Mind you, wood recycling is capital-intensive for speed, efficiency & safety, as the wastes are highly irregular, contaminated & always rotting
• As such, it is expensive to start - supplies of wood wastes as raw materials can be wildly fluctuating, demands irregular & prices unpredictable (due to the state of world affairs)
• In order to have sustainable wood recycling, it requires either the government provides subsidies/supports or good commercial marketing & environmental-consciousness of the public

What's being done to the wood wastes?

• Using the German technology of Werzalit, LHT production process is as follows:

1. Various types of wood wastes are segregated, selected & collected
2. Different proportions of woods (by weight, volume, species, origin & state) are mixed & shredded into wood chips
3. Wood chips are stored for processing
4. Wood chips are cooked & boiled (cleaning)
5. Boiled wood chips are sent for metal separation
6. Separated wood chips are reduced to the required size & dried thoroughly (moisture is enemy no. 1 for wood)
7. The dried wood chips are stored in silos to await customer order for recycled wood specifications
8. Once order is in, the wood chips are mixed with "glue" or MUF
9. The mixture is sent to the pressing station for molding into the final product - LHT Technical Wood
10. It is then allowed to stabilize during storage