经济学人下载:三维压制 第三世界的发展空间

Science and technology
科学技术

3D printing
三维压制

A third-world dimension
第三世界的发展空间

A new manufacturing technique could help poor countries as well as rich ones
一项新的制造技术能够对贫困国家有所帮助，就像对那些富有国家的帮助一样。

EVERY summer, Seattle holds a raft race in Green Lake, a park that is the eponymous home of the water the rafts must cross.
每年夏天，西雅图都会在绿湖举行一场木筏比赛，参加比赛的木筏必须渡过这个湖，这里的公园因其湖水而闻名。

Entries for the Milk Carton Derby have to be made from old plastic milk bottles.
参加这场同城牛奶盒比赛的木筏必须是由旧的塑料牛奶盒制成。

The result is a wonderfully Heath-Robinson collection of improvised craft.
结果，你就会看到一场奇妙的希思-鲁宾逊简易工艺展。

But this year one stood out: the entry from the University of Washington's engineering department actually looked like a boat.
但是今年，有一个参赛的木筏特别引人注目：这个木筏是华盛顿大学工程系做的，看起来真的像一只船。

The students who built it, Matthew Rogge, Bethany Weeks and Brandon Bowman, had shredded and melted their bottles, and then used a 3D printer to print themselves a plastic vessel.
制造这个木筏的学生—马修罗格、伯斯尼威克斯和布兰登伯曼，把他们收集的塑料盒切碎后再熔化，再使用一种三维压印技术压印成一种塑料容器。

No doubt the Milk-Carton-Derby rules will be tightened next year—though in the end, the team came only second.
毫无疑问的是，同城牛奶盒比赛的规则明年会更加严格—虽然最后，这个队只赢得了第二名。

But they did come first in a competition that mattered more.
但是，他们在比赛中首次出现的意义却更重大。

On October 19th they won $100,000 in the 3D4D Challenge, organised by a charity called techfortrade.
在10月19日，他们在由一个称为技术为了贸易更美好的慈善组织组织的三维-四维挑战赛中赢得了十万美元的奖金。

3D printing is all the rage at the moment.
三维压印目前正是风靡一时。

Several varieties of the technique exist, using a wide range of materials as the ink.
利用几种不同的现有技术，再加上大范围的原料—称之为墨水就可以操作了。

One of the most popular methods, though—and the one used by the team—works by extruding a filament of molten plastic.
尽管，最流利的一种方式—就是那个参加比赛的队伍使用的，只是挤压成一条熔化后的塑料细丝。

In the case of the team's printer, this plastic was high-density polyethylene from milk bottles.
就这个参赛队伍的印刷技术来说，这种塑料是由牛奶盒提炼出的高密度聚乙烯。

The print head makes repeated passes over the thing being printed, leaving a plastic trail as it does so.
打印头重复地打压着半成品，当它重复这样的过程后，只留下一条塑料丝。

It thus builds up a three-dimensional structure.
最后，就生产出了一个三维产品。

3D printing is now taken seriously by manufacturers as an alternative to cutting, bending, pressing and moulding things.
制造商们正在认真考虑三维压印技术，想用它来替代切割、弯曲和压制成型机器。

It is also a popular hobby among those of a geeky disposition.
而且，它在那些古怪的配制中也算比较受欢迎了。

What it has not been used for so far is to help people in poor countries improve their everyday lives.
只是，到目前为止它还没被应用于贫困国家，帮助那里的人们改善他们的生活。

Mr Rogge, Ms Weeks and Mr Bowman intend to employ their prize money to do precisely that.
罗格先生，威克斯女士和伯曼先生打算用他们的奖金去实现这个目标。

They plan to form a firm that will, in partnership with a charity called Water for Humans, custom-build composting toilets and rainwater collectors.
他们打算与一家称为为人类提供生活之水的慈善组织合作，创建一家专门生产自动堆肥厕所和雨水收集容器的公司。

The partnership will look for suitable local entrepreneurs in poor countries and will train them how to build, use and maintain the printers.
他们的合伙人将会在那些贫困国家中寻找当地合适的企业家，并且会训练他们怎样组装、使用和保养压印机器。

Once the technology is established for toilets and water collectors, other products will be introduced.
一旦这种技术应用于厕所和集水箱，那么将会产生一系列的其它附属产品。

The local partners will know what products are needed and how much people are prepared to pay for them—and therefore what is worth making.
当地的合作者瘵会了解，这里需要什么样的产品，这里的人们愿意花多少钱来购买—因此这是值得试试的。

The operation will thus run on a commercial basis.
这种运作将会基于一种商业操作模式。

But the software that controls the printers will be open-source and available to all, as will many of the designs for things the printers can make.
但是，控制压印机器的软件将会成为公共资源，所有人都可以使用，就像当时设计这种压印机器时的设想一样。

That way, the technology can spread.
这样的话，这种技术将能很快传播开来。

A trial will begin soon in Oaxaca, Mexico.
墨西哥的瓦哈卡将会很快进行这种试验。

The crucial point about the team's printer is that it combines size and cheapness.
威克斯小组的压印机最关键的一点是，它的大小正合适而且价格很便宜。

Printers used by hobbyists are not expensive, but they are small.
供业余爱好者使用的压印机并不贵，而且很小巧。

Many would find it hard to make anything larger than a coffee cup.
许多人发现这个机器做出的东西都没一个咖啡杯大。

Those used by engineering companies cost serious money—and even they might balk at printing an object the size of the Milk Carton Derby boat.
那些工程公司使用的压印机成本很高—甚至他们也无法压制出像同城牛奶盒比赛中那样大的木筏。

The team's printer is built around a second-hand computer-controlled plasma cutter.
那个参赛队伍的压印机是由一台二手电脑控制的空气等离子切割机做出来的。

This directs the movement of an extruder that melts flakes of plastic into a thin stream which can be squirted out as required.
电脑控制着挤压机里的一切运作—即先熔化塑料，再挤压成细细的液体状，当需要时就可以喷射出来进行压制。

It is able to create things with dimensions of up to 2.5 metres by 1.2 metres by 1 metre.
这种机器可以生产出长2.5米，宽1.2米，高1米的物品。

Appropriately, many of its parts were themselves manufactured on a desktop 3D printer.
产品的许多部分还是来自于原材料，只是经过了一台台式三维压印机的处理而已。

The ink is cheap, too. High-density polyethylene is as common as muck—literally, for a lot of it ends up on refuse tips.
墨水也很便宜。高密度聚乙烯很常见，就像随处可见的泥土一样—就是这个意思，因为垃圾堆中有大量这种材料。

Chop it up, though, and it is grist to the mill.
但是，一定要记得剁碎它，这对压印机很重要。

Mr Rogge estimates that if he and his colleagues had printed their boat from commercial plastic filament it would have cost them $800.
罗格先生估计，如果他和他的同事利用商业塑料丝来制作这条船的话，那么成本会高达800美元。

Instead, 250 clean, empty milk bottles set them back just $3.20.
相反，他们用250个干净的，空牛奶盒只花了3.2美元。

Some technical questions remain.
不过，还有一些技术问题。

High-density polyethylene shrinks when it cools.
高密度聚乙烯遇冷会收缩。

That stresses the object being printed and can sometimes tear it apart.
这个不足也反应到了压制出来的产品上，产品有时都能完全扯开。

The students are therefore working on a second prototype that prints things faster, allowing the layers of plastic to cool almost simultaneously.
因此，这些学生们正在努力制作第二个样品，以提高压制速度，而且确保让塑料层几乎能同时冷却下来。

They are also experimenting with making things from other types of waste plastic that suffer less from shrinkage.
他们也在试验用其它类型的废塑料制作产品，以减少收缩性。

And until a production version of the printer is ready and priced, it remains to be seen how competitive its output really will be with mass-produced items.
在压印机生产出来的成品已经完全没有问题，而且定出合理的价格以前，这种产品与大批量生产的成品的竞争力谁高谁低还有待观察。

Mr Rogge doubts, for example, that a 3D-printed bucket—even one made from milk bottles—will ever be cheaper than one made in a factory.
罗格先生还不确定，比如说，一个三维技术压制出来的水桶—即使原材料是牛奶盒—的价格会低于工厂生产出来的水桶价格。

Boats, though, could be a hit.
虽然，木筏可能会是个创举。

One of the judges at the 3D4D Challenge noted that many small vessels in West Africa are made from trees, such as teak, that are becoming scarce.
在三维-四维挑战赛中的一位评委说，在西非，许多小容器就是由树木，比如柚木制成的，而这种木材也越来越少了。

Making them from waste plastic instead would be an environmental twofer: rare species would be conserved and less rubbish thrown away.
如果用废塑料制作这些容器将会对环境是一举两得：珍稀物种得到了保护，而且还减少了垃圾