How Carpet Is Made
So, you’re curious about how things are made. Good for you -- it pays to know
how carpeting is constructed. Because that knowledge can help you decide if carpeting
is a flooring solution for the way you live.
Just remember this: when selecting carpet, thicker is not always better. What you
need to look at is the construction of the carpet.
You want a tight twist in
each yarn, not loose and frayed at the end. Like the hair commercial on TV, you
don’t want split ends in your carpet either!
A firm, dense pile is also
the mark of a quality carpet. How to check the
density? Bend a corner of the carpet and see how much backing shows. The
more backing you see, the less dense and durable the carpet.
And for high traffic areas, consider lower profile carpets that won’t have
the potential to matte
and crush.
But we’re getting ahead of ourselves. To start at the beginning, check out
our construction story that follows—and happy learning!
Today’s healthiest carpets get plenty of fiber.
Fiber is the basic material
that a carpet is made up of. Over ninety percent of all of the carpet made today
is made up of synthetic fiber. The rest is natural fiber, most commonly wool. First,
let’s look at the most common synthetic fibers.
Synthetic fibers are usually
made up of one of three materials: nylon,
polypropylene or
polyester. All three are
created by similar chemical processes using oil and natural gas.
You can rely on nylon.
70% of carpet today is made of nylon and, compared to the other fibers below,
it performs the best overall. Nylon is the leader in: appearance retention, fade
and heat resistance, soil and stain resistance, and color and styling. The highest
performance nylon is Type 6.6, which has a tighter molecular construction, making
the carpet more resistant to stain penetration.
Go slow, long word ahead.
The next most common material used in carpet manufacturing is polypropylene, also
referred to as olefin. Introduced in the late 1950’s in Italy , polypropylene
BCF has seen fast growth over the last twenty years, and today represents more than
thirty percent of the total fibers used in the carpet industry.
While polypropylene is not as resilient or resistant to abrasion as nylon, it is
naturally stain and fade resistant. Its natural resistance to moisture means that
it must be dyed before being extruded, resulting in a more limited range of color
options. Polypropylene is most often used in
loop pile carpet constructions.
Does polyester suit you?
The third type of material commonly used in carpet manufacturing is polyester. Polyester
was introduced to the carpet industry in the mid 1960’s, and has been well
accepted for its bulkiness, color clarity, and good stain and fade resistance. While
not as resilient as nylon, Polyester fiber carpet constructed with today’s
new technologies can be a good performer.
The dyed-in-the-wool original.
The above three materials make up the majority of synthetic fibers. The other type
of fiber used in carpet construction is staple fiber. While some synthetics are
used in the creation of staple fibers, the original staple fiber used in the making
of carpet is wool.
The wool used in today’s carpet comes primarily from New Zealand, Argentina,
and the United Kingdom. Since wool is a natural fiber, it ranges in color from off-white
to black, with many earthen tones between.
Berber, now considered a type of carpet construction, actually comes from the name
of a group of North African sheepherders called the Berbers. The Berbers were known
to produce very coarse wool, with characteristic color flecks in their yarns.
Although wool doesn’t stand up to abrasion and moisture as well as synthetics,
it cleans well and is known to age gracefully. Wool is the most expensive
carpet fiber, and represents less than one percent of the U.S. carpet market.
The production of carpet, a 3-part epic.
There are basically three steps to manufacturing carpet. The first step is what
is called tufting. Tufting begins
with the process of weaving the synthetic or staple fiber into a primary backing
material. The primary backing
material is usually made of woven polypropylene, and its main value is to provide
a base cloth to hold the yarn in place while the tufting happens.
The tufting machine looks like a really big sewing machine. It has anywhere from
800 to 2000 needles working in concert to pull the yarn through the primary backing
material. The typical tufting machine sits about 12 feet wide, and as its needles
penetrate the backing, a small hook called a looper grabs the yarn and holds it
in place. This process results in what is called loop pile construction.
Loop pile products hold their appearance exceptionally well. Since there are no
exposed yarn tips, only the sides of the yarn are exposed to wear and stress. Generally
speaking, low profile loop carpet stands up to heavy traffic best.
Cut to the next scene.
In some carpet styles the looper then rocks back against a knife, where the small
loops of yarn are cut, creating what we call a
cut pile carpet. The length of these cut pieces of yarn is referred to as
the pile height, and
is basically the distance between the looper and the primary backing.
These precision cuts are controlled by a computer, and are sometimes programmed
to cut only some of the loops. This method of selectively cutting, called cut and
loop construction, creates a recognizable pattern on the surface of the carpet.
Now let’s pause in our construction story to identify and
explain some terms and construction variables that you will encounter while
making a carpet purchase decision.
Pile height, or nap,
is the length of the tuft measured from the primary backing to the yarn tips. It’s
usually shown as a fraction, or sometimes its decimal equivalent. Usually shorter
pile heights are more durable than longer pile heights.
The stitch rate of a
carpet is the measure of how close the yarns are together. Stitch rate is measured
in penetrations, or tufts, in a given length of carpet, usually an inch. The stitch
rate is controlled by how fast the carpet is moved through the tufting machine.
Seven to eight tufts per inch is a good number, while three or four is pretty poor.
Face weight is determined
by the actual amount of fiber per square yard, and is measured in ounces. A typical
carpet may have a face weight of 35 to 45 ounces for example.
Finally, density is a measure
of how tightly the yarn is stitched into the primary backing. Higher density carpet
will typically wear better than low density carpet.
The second step of carpet manufacturing is to dye for.
Now the carpet is taken through one of two dyeing processes. The first method of
dyeing is called yarn dyeing,
or sometimes pre-dyeing, where the color is applied to the yarn prior to tufting.
The advantages of all yarn dyeing methods include good side-by-side color consistency,
large lot sizes, and uniformity.
The second method involves applying color to the yarn after the carpet
has been tufted. This method is called
carpet dyeing. There are several carpet dyeing methods in use, each producing
a unique end result.
The first technique, often referred to as
Beck, or batch dyeing, involves stitching the ends of the carpet together,
and then running the tufted carpet loop through large vats of dye and water for
several hours. The Beck process is ideal for smaller production runs, and heavier
face weight products.
Continuous dyeing
is a similar process to Beck dyeing, but involves running the carpet through several
processes in addition to just the dye application. Continuous dyeing applies the
color directly to the carpet face by spraying or printing. This process is also
used to create multicolor or patterned effects in the carpet.
Screen printing
is another common method of carpet coloring, where color is applied through anywhere
from one to as many as eight silk-screens.
The major benefits of carpet dyeing, that is dyeing the carpet after the tufting
process, are greater color flexibility, and lower cost.
And the third and final manufacturing step is the finishing process.
This process is typically a single production line that completes the final stage
of the carpet construction.
In the finishing process, a coating of latex is applied to both the tufted, dyed
carpet’s primary backing, and also to secondary backing. Secondary backing
is typically made of a woven synthetic polypropylene material. The two parts are
squeezed together in a large heated press, where they are held firmly to preserve
their shape.
Shearing, one of the last
stages in the manufacture of carpet, is the process of removing all of the little
loose ends and projecting fibers that might have been created during the tufting
process. It also helps achieve the yarn’s tip definition of the finished carpet.
Finally, each carpet is carefully inspected for color uniformity and other manufacturing
defects before it is rolled, wrapped, and shipped.
That’s the story on how carpet is made. We hope it helps you be a more savvy
shopper. If anything, now you can throw the word “ polypropylene” around at the party to celebrate
your home’s beautiful new carpeting.