位置:首页 > 英语听力 > VOA英语听力下载|VOA news > voa标准英语|美国之音常速英语下载|在线收听
VOA常速英语: 面罩生产商
日期:2020-06-17

My name is Eric Bubar.I'm the associate professor of physics at Mary Mount University in Arlington, Virginia.What I've been doing to help out with the Covid-19 response is creating 3-D printed PPE.So, the design I'm using is something called the face shield. I have two designs, this one and this one. These are actually not my designs. They are open sourced. They're created by other individuals. So, this was created by a company named Prusa Research. They're very well known in the 3D printing industry for having very reliable 3D printers. And then this is the Verkstan design made from a Swedish design firm.What is 3-D printing?It's a way to do manufacturing. It's called additive manufacturing in some circles. And what you do is you take some plastic in the form of a filament, and you extrude it through a very, very hot nozzle. That nozzle melts the plastic and it lays down a little bit of plastic in whatever shape you want. As soon as the plastic hits the,what we call the built plate, it kind of cools off and solidifies. Then the little nozzle will go up just a little bit and draw another layer on top of that, and build up whatever 3-D shape you can imagine. So, if you look very closely at this 3-D print,you can see that there are different layers. So, a 3-D printer builds up whatever shape you want, layer by layer by layer.

So altogether, this one takes probably about four hours to fabricate one, whereas this one, the 3D Verkstan, this 3D print takes about 40 minutes to print one of these little headbands. And then, the shield itself is a very thick overhead transparency that takes about, maybe,five minutes to hole punch, three hole punch to get it to pop onto these little pegs. So, this one takes, maybe, 45 minutes to create one. So, currently the shields are being used by a variety of different healthcare professionals, in hospitals, in community health centers, in elder care facilities. People like that these 3D printed shields are sanitizable so they can reuse them. They can clean them very easily. And regarding changes that we might make to these face shields, we're always open to more feedback. And we've gotten some feedback that some providers would like a little bit more length on the bottom of it, so that it kind of interfaces with their sternum a little bit better, so that it kind of blocks off any transition into the bottom. And some providers want a visor over the top. So, on this Prusa design, you can see that this is open. This is meant to ventilate air so that it doesn't fog up, but it does allow some particulates can get down in there, so, maybe, some visor to cover that portion up. Those are the two big pieces of feedback that we've gotten that were trying to come up with adaptations for and adjustments. But currently what we're trying to do is stick with designs that are recommended by NIH print exchange. These are the ones that have been approved for clinical use.
 1/2    1 2 下一页 尾页