Name: 你知道木頭其實可以「融化」嗎？！ (Can You Melt Wood?)
Uploaded: 2025-08-20T21:01:10.000Z
Duration: 6 min 2 s

情態副詞

Early in our school days, we learned about the basic states of matter.

早在學生時代，我們就瞭解了物質的基本狀態。

程度副詞

If you heat a solid enough, it melts into a liquid.

如果把固體加熱到足夠熱，它就會融化成液體。

And if you heat that liquid some more, it boils off as a gas.

如果再加熱液體，它就會沸騰成氣體。

但並不是所有事情都要遵守這些規則。

If you heat up a wooden log enough, instead of melting, it catches fire and burns.

如果把木頭加熱到足夠熱，它不但不會融化，反而會起火燃燒。

Like when we get a nice, cozy fire during winter instead of a wet pile of mush.

就像在冬天，我們能烤出溫暖舒適的爐火，而不是一堆溼乎乎的肉泥。

But why doesn't wood follow the same rules as water, or butter, or crayons?

但為什麼木材不像水、奶油或蠟筆那樣遵循同樣的規則呢？

Let's break down why wood doesn't melt, except when it does.

讓我們來分析一下為什麼木材不會融化，除非它真的融化了。

All molecules everywhere are vibrating all the time.

世界各地的所有分子無時無刻不在振動。

And they vibrate faster when you add energy from heat.

而當你增加熱能時，它們會振動得更快。

A solid substance becomes a liquid when its molecules vibrate fast enough to break out of their orderly arrangement.

當固態物質的分子振動速度足夠快，從而打破其有序排列時，它就會變成液態。

Those molecules start to slide past each other, and the solid loses its shape to become a liquid.

這些分子開始互相滑動，固體就會失去形狀，變成液體。

The temperature at which this happens is called the melting point.

發生這種情況的溫度稱為熔點。

And the transition between states of matter, like solid and liquid, is known as a phase change.

物質狀態（如固體和液體）之間的轉變被稱為相變。

Even in a mixture of a bunch of different chemicals, they all have their own melting points.

即使是一堆不同化學物質的混合物，它們也有各自的熔點。

For example, when ice cream melts, it's because the water ice is melting.

例如，當冰淇淋融化時，是因為水冰正在融化。

Part of the reason wood doesn't melt is because it's also made up of a mixture of chemicals.

木材不會融化的部分原因是它也是由化學物質混合而成的。

These include water, as well as the plant materials lignin and cellulose.

其中包括水以及植物材料木質素和纖維素。

Some of these substances have their own melting points, but others, like cellulose, don't actually have melting points at all.

其中有些物質有自己的熔點，但有些物質，如纖維素，實際上根本沒有熔點。

Cellulose is made of really long chains of carbon, hydrogen, and oxygen.

纖維素是由碳、氫和氧組成的長鏈。

The amount of heat needed to disentangle these chains and melt cellulose is so high that they hardly ever melt.

分解這些鏈條和熔化纖維素所需的熱量非常高，是以它們幾乎不會熔化。

Instead, the chemical bonds holding the chains together start to break apart.

相反，將鏈條連接在一起的化學鍵開始斷裂。

And the cellulose breaks down into different, smaller chemicals before it gets hot enough to melt, per se.

而纖維素在熱到足以融化之前，就會分解成不同的、更小的化學物質。

The molecules in cellulose still vibrate when you heat them up, like when you hold a match or lighter under some firewood.

纖維素中的分子在加熱時仍會振動，就像把火柴或打火機放在木柴下一樣。

But since it's so tough for those molecules to slide past each other, they end up vibrating themselves to pieces.

但是，由於這些分子很難相互滑動，它們最終會把自己震成碎片。

So when you heat up wood, giant molecules like lignin and cellulose start to break into smaller molecules, including water, carbon dioxide, formic acid, acetic acid, methane, methanol, hydrogen gas, and several others.

當你加熱木材時，木質素和纖維素等大分子開始分解成小分子，包括水、二氧化碳、甲酸、乙酸、甲烷、甲醇、氫氣等。

Some of those new molecules are flammable gases.

As they form, they escape from the wood like air out of a balloon.

當它們形成時，它們就會從木材中逸出，就像氣球裡的空氣一樣。

And on their way out, they catch fire and burn, generating more heat.

在它們出來的時候，它們會著火並燃燒，產生更多的熱量。

And fun fact, the popping sounds you sometimes hear in a campfire happen when some of these gases get trapped inside a log and then explode out all at once.

有趣的是，你有時在篝火中聽到的啪啪聲，就是這些氣體被困在原木中，然後一下子爆發出來的聲音。

Not all of the new chemicals are gases, though.

不過，並非所有新化學物質都是氣體。

Any that don't burn off or escape as smoke end up as ash or charcoal.

沒有燃燒掉或以煙霧形式逃逸的，最終會變成灰燼或木炭。

The heat from the flames breaks down even more of the large molecules in the wood.

火焰的熱量會分解木材中更多的大分子。

And that releases even more gases, which burn and generate more heat, which breaks down more molecules.

這樣就會釋放出更多的氣體，這些氣體燃燒後產生更多的熱量，從而分解出更多的分子。

And on and on until all the fuel is spent.

如此循環往復，直到耗盡所有燃料。

Because the lignin and cellulose break down into other chemicals at high temperatures, burning a log isn't considered a phase change in the same way melting is.

由於木質素和纖維素在高溫下會分解成其他化學物質，是以燃燒原木並不像熔化那樣被認為是一種相變。

A phase change like melting has to be reversible.

像熔化這樣的相變必須是可逆的。

If you've ever stuck melty ice cream back in the freezer for a while, you know that it's still ice cream afterwards.

如果你曾把融化的冰淇淋放回冷凍室一段時間，你就會知道它之後還是冰淇淋。

If sometimes a little grainy and ice-crystally.

如果有時有點顆粒狀和冰晶狀的話。

But while you might be able to refreeze water into ice, you can't unburn a log, right?

不過，雖然你可以把水重新凍成冰，但你卻無法讓木頭重新燃燒起來，對嗎？

What if you didn't have to melt a whole piece of wood?

如果你不需要融化整塊木頭呢？

What if you could melt just one of the many chemicals that make up a log?

如果你能融化構成原木的眾多化學物質中的一種，會怎樣呢？

It turns out, that is a thing we can do, under the right circumstances.

事實證明，在適當的情況下，我們可以做到這一點。

And scientists and manufacturers can use it to stick two blocks of wood together, without using glue or nails.

科學家和製造商可以用它將兩塊木頭粘在一起，而無需使用膠水或釘子。

For some time now, construction workers and furniture makers have been using glues or even melted plastics to join two pieces of wood together.

一段時間以來，建築工人和傢俱製造商一直在使用膠水甚至融化的塑膠將兩塊木頭連接在一起。

But many of those adhesives give off toxic fumes, and some of them can cause cancer.

但是，許多粘合劑都會釋放有毒氣體，其中一些還會致癌。

So, researchers have been looking for some safer, more environmentally-friendly alternatives.

所以研究人員一直在尋找一些更安全、更環保的替代品。

Wood welding takes advantage of the different compounds that are already inside the wood.

木材焊接利用了木材內部已有的不同化合物。

The technique uses the lignin at the surface of the wood as a type of glue.

這種技術利用木材表面的木質素作為一種膠水。

Normally, the lignin in wood is solid and not very glue-like at all.

通常情況下，木材中的木質素是固體，根本不像膠水。

To turn it into an adhesive, a wood welder vibrates one piece of wood on top of another, while applying pressure.

為了將其轉化為粘合劑，木材焊接機會在施加壓力的同時，將一塊木頭放在另一塊木頭上進行振動。

At just the right frequency, the heat and friction from the vibration melts the lignin at the wood's surface, as well as a little bit of another chemical called hemicellulose.

在合適的頻率下，振動產生的熱量和摩擦力會融化木材表面的木質素，以及另一種叫做半纖維素的化學物質。

The vibrations only need to last for a few seconds.

That's long enough to heat the surface to above lignin's melting point, which is about 170 degrees Celsius.

這段時間足以將表面加熱到木質素的熔點（約 170 攝氏度）以上。

And it's also short enough to keep the temperatures below the point where lignin starts to break down into those smaller chemicals, around 280 degrees Celsius.

它的時間也足夠短，可以將溫度控制在木質素開始分解成這些較小化學物質的溫度以下，即 280 攝氏度左右。

The welding process also works if you screw a wooden dowel rod into a hole in a different wood block, like making a hammer or a wood lollipop.

如果將木釘杆擰入另一塊木塊上的孔中，焊接過程也同樣有效，比如製作錘子或木棒棒糖。

In either case, once the lignin cools down, it solidifies just like glue and bonds the two pieces together.

無論哪種情況，木質素冷卻後都會像膠水一樣凝固，將兩塊木板粘合在一起。

Some studies show that wood-welded joints can even end up stronger than those joined with regular wood glue.

一些研究表明，木材焊接接頭甚至比用普通木膠連接的接頭更牢固。

And wood welding hasn't taken over large-scale production yet, but some researchers are looking into bringing it into applications such as furniture manufacturing.

木材焊接還沒有大規模生產，但一些研究人員正在研究如何將其應用到傢俱製造等領域。

So with some careful physics, we get wood that melts just when we need it to, and we still get to enjoy our campfires.

通過一些細緻的物理方法，我們得到的木材在我們需要的時候就會融化，而且我們仍然可以享受我們的篝火。