leetcode 木材加工

If you’ve ever gone to the hardware store to buy lumber to build that DIY desk or home theater center, you’ve probably come across your fair share of warped and twisted boards before you finally landed on a decent-looking 2×4. Here’s why that is.

如果您曾经去过五金店购买木材来建造DIY桌子或家庭影院中心，那么在最终找到外观不错的2×4面板之前，您可能会遇到相当一部分翘曲和扭曲的木板。 这就是为什么。

木材如何制成 (How Lumber Is Made)

To really understand why lumber sometimes twists, bows, and warps, it’s important to first learn how lumber gets made.

要真正理解为什么木材有时会扭曲，弯曲和翘曲，重要的是首先要了解木材的制作方法。

Lumber comes from logs that are run through a set of industrial-sized saws and cut down into more manageable pieces. The above graphic is a great example of the different shapes and sizes that can be accomplished using a single log and different types of cutting methods.

木材来自原木，这些原木通过一组工业尺寸的锯锯切成更易于管理的碎片。 上图是使用单个圆木和不同类型的切割方法可以实现的不同形状和尺寸的一个很好的例子。

Trees are naturally full of moisture on the inside, so when logs get cut up into smaller pieces, those pieces need to dry out. Depending on where the lumber is being made, it will either be air dried or kiln dried.

树木的内部自然充满水分，因此当将原木切成小块时，这些树需要干燥。 根据木材的生产地，可以风干或窑干。

Air-dried lumber typically begins outdoors and is laid out with spacers between pieces to allow airflow all around. Once the moisture content goes down, it’s sometimes brought indoors to dry further and acclimate the lumber to indoor conditions. However, sometimes it’s left outdoors to stay acclimated to outdoor conditions, making it better suited for decking, fencing, and patio furniture.

风干的木材通常开始于户外，并在各块之间放置垫片，以使空气流通。 一旦水分含量下降，有时会将其带入室内进一步干燥，并使木材适应室内条件。 但是，有时它会留在户外以适应室外条件，使其更适合于甲板，栅栏和露台家具。

Kiln-dried lumber is dried using a kiln (obviously), but is more expensive to do. However, it’s a lot faster than air drying and it takes out more moisture, so kiln-dried lumber is usually less susceptible to twisting and warping.

窑干木材用窑炉干燥(显然)，但是这样做的成本更高。 但是，它比风干要快得多，并且可以吸收更多的水分，因此窑干的木材通常不易扭曲和翘曲。

Once the lumber is dried, it’s then fed into planers, which are unique types of saws that shape the wood into the perfectly rectangular shape that you’re familiar with. From there, it’s sorted into specific sizes and shipped off to your local hardware store for customers to purchase.

木材干燥后，将其送入刨床，这是独特类型的锯，可将木材塑造成您熟悉的完美矩形形状。 从那里将其分类为特定的大小，然后运到您当地的五金商店供客户购买。

扭曲和翘曲如何发生 (How Twisting and Warping Occurs)

As mentioned above, there are definitely pros and cons to each method of drying, and depending on what you’re going to use the lumber for, you may want to opt for a specific type of dried lumber. But either method can be performed wrong, and that’s where major twisting and warping can occur.

如上所述，每种干燥方法绝对有优缺点，并且根据您打算使用的木材的种类，您可能希望选择一种特定类型的干燥木材。 但是，任何一种方法都可能执行错误，这就是发生严重扭曲和变形的地方。

First off, there’s no way to completely prevent twisting and warping in lumber, even if you do everything right. Wood acts as a sponge, expanding as it takes in moisture from an environment with high humidity. And then it shrinks and hardens as it drys out while acclimating to a lower humidity. This causes twisting and warping to varying degrees.

首先，即使您做得正确，也无法完全防止木材扭曲和翘曲。 木材起着海绵的作用，当它吸收高湿度环境中的水分时会膨胀。 然后随着干燥变干而收缩并变硬，同时适应较低的湿度。 这会导致不同程度的扭曲和翘曲。

However, by properly drying out the wood, you can at least significantly reduce the chance of lumber getting warped or twisted. One of the reasons why you see all sorts of warped boards at the hardware store is that they likely weren’t fully dry yet when taken out of the kiln. So while they were being shipped to the hardware store, the lumber finished drying out, but in a different environment, which caused the twisting and warping.

但是，通过正确干燥木材，至少可以大大减少木材翘曲或扭曲的机会。 您在五金店看到各种翘曲板的原因之一是，从窑炉中取出后，它们可能还没有完全干燥。 因此，在将木材运送到五金店的过程中，木材完全变干，但是处于不同的环境中，这导致了扭曲和翘曲。

如何避免扭曲和翘曲 (How to Avoid Twisting and Warping)

Again, you can’t always avoid twisting and warping, but there are a few things you can do to lessen the chances of it happening, both during the buying process and after you bring it home.

同样，您不能总是避免扭曲和变形，但是在购买过程中以及将其带回家后，您可以采取一些措施来减少发生的可能性。

First off, look for quartersawn lumber when sifting through it all at the hardware store—you’ll know a board is quartersawn when you see decorative rays show through on the surface (pictured above). Quartersawn lumber is usually more stable than lumber cut using other methods.

首先，在五金店筛选时要寻找四分之一锯材-当您看到装饰光线从表面穿过时，您会知道一块四分之一锯材(如上图所示)。 四分之一锯材通常比使用其他方法砍伐的木材更稳定。

However, even after you find a really straight piece of lumber, you’ll still want to care for it a little bit after you bring it home. Let it sit for a couple weeks in your garage or shop, making sure to put a couple of spacers underneath so that air can get to the underside of the boards. This allows the lumber to acclimate to your environment, and if you notice that it starts to warp and twist, you can easily return it and get your money back, which is a lot easier to do before you’ve cut it all up.

但是，即使找到一块非常直的木材，将其带回家后仍需要稍微照顾一下。 让它在您的车库或商店中放置几个​​星期，并确保在其下面放置一些垫片，以便空气可以进入木板的下面。 这样可以使木材适应环境，如果您发现木材开始翘曲和扭曲，则可以轻松地将其退回并退还您的钱，这在切掉所有木材之前要容易得多。

If you want to avoid having to constantly sift through lumber in order to find good boards, you might want to try your local lumberyard, which likely has higher-quality lumber than a big box store like Lowe’s or Home Depot—these larger stores are usually more concerned about quantity than quality.

如果您要避免为了寻找好的木板而不得不不断地筛选木材，则可以尝试使用当地的木材场，这种木材场的木材质量可能比Lowe's或Home Depot之类的大型商店要高，这些大型商店通常更关注数量而不是质量。

Image from Core77, Mike Mozart/Flickr, Luke Gilliam/Flickr

图片来自Core77 ， Mike Mozart / Flickr， Luke Gilliam / Flickr

翻译自: https://www.howtogeek.com/303017/why-does-lumber-sometimes-look-twisted-and-warped/

leetcode 木材加工