Fiber Shapes

Over the years, brand name fiber manufactures and carpet mills that make their own in-house fibers have developed various shapes to achieve different performance characteristics for the different types of carpet.

This is a review of the evolution of the various fiber shapes. Fiber shapes have been re-engineered and improved; today we have four basic shapes that have survived the test of time. There are several different types of synthetic carpet fibers made, mainly olefin, polypropylene, polyester and its cousins, nylon 6 and nylon 6.6. You can learn more about the types of fibers in our article on fiber types. This paper focuses more on the actual shape of the fiber and how the shape affects performance.

A key principal in fiber performance is called light refraction. Carpet fibers are engineered to magnify color as light rays pass through the fiber. There is not as much color in the fiber as appears because as light passes through the fiber it magnifies the color making the fiber look more bright and brilliant.

Some fibers are softer, scratch easier, are distorted and damaged easier than other fibers. If the fiber is damaged it does not magnify the light as well causing the carpet to look worn, dirty and “uglied out.” “Uglied out” is a condition when the carpet looks matted, soiled, and dingy and you want to replace it because it does not look good. Often a carpet is replaced not because the carpet is worn out but because it is uglied out.

This can happen for a couple of reasons, one being the carpet is a low quality low performing carpet and just wears out quickly. Another reason would be that the carpet is not properly maintained and the fibers are damaged to a point that they do not properly magnify light properly.

Round Fibers:

Carpet Fiber Shapes
The first synthetic carpet fibers were round in shape, we quickly learned the round shape magnified scratches and soil. Carpet made with round shaped fibers looked much dirtier and more worn than they really were. This shape was quickly replaced with other shapes that had improved performance characteristics.

Trilobal Fibers:

Carpet Fiber Shapes

The trilobal fiber was invented to help defuse the magnification of soil and scratches that occurs with the round fiber.

Trilobal fibers are mainly used in residential carpet where the customer wants full and fluffy carpets compared to shorter harder commercial carpet. The industry says one of the better characteristics of a trilobal fiber is to add bulk and luster. You can get a more luxurious feel and look by using a trilobal fiber. Because the lobes of the fiber create bulk, you do not need to use as much raw material in the manufacturing process and carpets made with trilobal fibers tend to be less expensive than carpets made with other fiber shapes. This is because the other shapes require more material to create the same look and feel.

The biggest problem with trilobal fibers is the lobes or legs of the fibers can fold, bend and break causing the carpet to look gray and dingy. The light rays are blocked causing a dulling effect that makes the carpet look dirty and worn when it may not be. This wear is called “traffic lane gray” or “uglied out” and cleaning may temporarily improve the look of the carpet but will quickly flatten out looking worn and dirty again.

Delta and Modified Delta Shape:

Fiber Shapes

The delta fiber shape was engineered to have the strength and resilience of the round fiber shape and help hide soil like the trilobal shape. The delta shape gives you some bulk and luster like the trilobal but the lobes can still fold over, break off and trap soil. For this reason, the delta fiber was re-engineered and called a modified delta.

The modified delta shape is mainly used in commercial carpet because it does not create the bulk and luster achieved with the trilobal shape. It takes more fiber to create the same look. Most commercial carpets are manufactured with lower and tighter loops so they do not need to create the illusion of bulk and luster.

Fiber Shapes

Carpets manufactured with the delta or modified delta shape usually perform better than carpets made with the trilobal shape. Quality commercial carpets tend to cost more because more material is required to manufacture quality carpet. The more material the more expensive the product costs and in most cases with proper maintenance will outperform other carpets.

You want the fiber to keep its shape and not trap soil. Commercial carpets get 100’s and 1,000’s of foot traffics per day where a residential carpet may be walked on 30, 50 or 100 times a day. Using a residential type fiber in a commercial application tends to show early signs of wear and tear.

Four -Hole Hallow Filament Fibers:

Fiber Shapes of Carpet

Most commercial carpet mills agree that the four hole hallow filament fiber is the best performing fiber in the industry. It is a four-sided fiber, with rounded corners and has four holes running through the center.

It performed well because it does not have the peaks and valleys that fold over and trap soil. The square shape is easier to clean because there are not crevasses’ for the dirt and soil to get stuck in. Independent laboratory tests show this fiber shape releases soils easier when vacuumed or cleaned.

Carpet made with this fiber may cost a bit more upfront than carpet made with other fibers but in most cases it will last longer and is easier to clean. This means your cost per year will be reduced and carpets with this fiber shape should in the end save you money over time.

Carpet Traffic and Wear Patterns

Gary the Carpet GuyAs I travel the world inspecting, repairing, cleaning and teaching others how to care for the carpet, one of the biggest concerns I see on a regular basis is traffic or wear patterns. The following is my opinion based on 30 plus years of working with carpet on how carpet traffic and wear patterns are created.

Wear patterns are created as people walk back and forth in the same path. The carpet in the path is walked on more than the carpet along the edges. The uneven amount of wear in one area alters the way the carpet looks compared to carpet along the edges. For example, in commercial facilities areas like hallways, the pivot points at intersections and around corners, under office chairs or in front of the copier, water cooler and vending machines get more traffic than the edges of the rooms. In residential applications the path down the center of a hallway, areas in front of the sofa or next to the beds are often more worn than the edges of the rooms.

There are two different conditions created by wear:

  1. Color change caused by pile or nap variance known as “Watermarking, Pooling or Rivering”
  2. Color change caused by pile or nap distortion known as Traffic Lane Gray or Ugly-Out

Understanding what creates wear patterns can help you determine the type of carpet to select and better understand the life cycle expectation of the carpet in your home or facility. Carpet fiber, construction, backing, design, maintenance and several other things affect the way a carpet will look and wear, which we will discuss in another paper on carpet construction and performance.

We often work with property owners and facility manager who confuse wear patterns with soiling and think the cleaning crew is not keep the carpet clean. In most cases even if you cleaned the carpet every day it would not change the appearance of the carpet. Often the carpet will still look dirty after being properly cleaned. It is not dirty; it is the color variance in the appearance of the carpet. This change in the carpet alters the way the carpet fibers magnify the light that passes through the fibers. Carpet is engineered to magnify color as light passes through the fiber. This is called light refraction. This illustration is an example of how the principle of light refraction works.

How Wear Patterns Show on Your Carpet

Any modification to the way light is refracted through the fiber will alter the way the carpet looks. Distortions in light often create shadows which make the carpet look splotchy and darker and the effect is often confused for soil.

1. Color change caused by pile or nap variance known as “Watermarking, Pooling or Rivering”

Watermarking, Pooling and Rivering often confuse people because one section of the carpet will look lighter and other sections of the carpet will look darker. Looking across the carpet the dark side will look dirty and the lighter side seems to be clean. Usually customers think the dark side is dirty and should be as light as the light side. When a carpet cleaner cannot make the carpet the same color the customer thinks they did not do a good job and that the dark side is still dirty.

When you talk to carpet experts about pile variance, most are familiar with the Portland Airport carpet which provides a clear example of the light refraction effect. I took these pictures while in the Portland Airport and you can see from one angle the pile is light and when you look from the opposite direction the spot looks darker.

Carpet Traffic and Wear Patterns

This color variance in this carpet is not soiling, the carpet fibers are laying in different directions affecting the way the light is refracting through the fibers.

Recently my son Matson and I looked at this carpet which is the best example of “Rivering” I have seen in the thirty-something years I have been in the carpet industry. You can see how the carpet pile changes direction right down the middle of the hallway.

Carpet Traffic and Wear Patterns

Several years ago I looked at a carpet because the Interior designer on the project thought the carpet was defective. The project used carpet tiles and the installers’ quarter turned the carpet. The designer envisioned the carpet tile would look like broadloom but the installation method recommended quarter turning the tiles. The facility was upset with how the carpet looks and thought the carpet should be replaced.

Because one of my specialties is fixing carpet issues including manufacturing related problems, the carpet manufacturer and the facility owners wanted me to determine what the issue was. It was surprising to the designer and facility management that there is not a color issue with this carpet. The carpet dye of each tile is the exact same color, the only difference is the direction the carpet is laid.

Carpet Traffic and Wear Patterns

The color difference is caused by the way the light is refracting off the carpet nap that is laying in opposite directions. It is common for owners or facility managers to think the carpet is dirty, when in reality it is how the carpet looks. This type of wear is not considered a manufacturing defect; it is “the natural characteristic of a luxurious carpet.”

2. Color change caused by pile or nap distortion known as Traffic Lane Gray or Ugly-Out

As carpet is stepped on, the foot twists and turns which can cause fibers to unravel, flair and bloom. The more the fiber bundle is damaged or altered the more obvious the wear pattern will be. There are a lot of factors that determine how quickly the fiber bundles will distort. Some of the main things affecting performance are fiber type, denier, twist, heat-set, number of ply’s per bundle, traffic level, maintenance etc.

Carpet Traffic and Wear Patterns

These pictures show how the fiber bundles can be damaged. As the bundles unravel, it alters the way the light passes through the fiber making the wear patterns appear darker, soiled and dirty.

These pictures show how the appearance of the carpet changes as the carpet wears. You can see how the worn section looks dirty when compared to the unworn area, it is obvious where the sofa was in this house.

Carpet Traffic and Wear Patterns

These pictures were taken right after my son cleaned this carpet. He pre-treated, power scrubbed and rinsed this area six times and the carpet still looked soiled. The carpet is not dirty. This is a perfect example of how wear and tear and fiber distortion change the appearance of the carpet. If you look at the close-up photo you can see how the fibers on the right side of the picture are flatter, lying down and pointing to the left. The fibers on the left side of the picture have not been walked on and you see how they are still fairly round and upright.

The worst condition is a combination of both fiber or nap variance and distortion. We have seen situations where the fibers lay in different directions as they are also unraveling and blooming. In all three of these situations there is not a lot that can be done to reverse the change. Selecting a carpet that is manufactured with better components and engineered for your application combined with proper maintenance is the best way to avoid premature replacement due to appearance.

Carpet Traffic and Wear Patterns

These before and after pictures are among the best examples I have seen. It is hard to believe this is the same carpet. Look closely at the picture on the right, you can see how thin the fibers look and that the fibers are pointing in all directions. This carpet was in bad shape; the wear patterns were so noticeable that the homeowner was going to have to replace the carpet because it looked so bad.

Hopefully this information is helpful and provides answers you have been looking for. Please call us if you have any carpet related questions or need help resolving installation, performance, warranty or maintenance problems.


Gary the Carpet Guy
Cary Woodfield started his carpet career in 1978 when his family bought a carpet cleaning franchise. As his career advanced he became a leading expert specializing in understanding and solving carpet problems. Cary was the LDS Church’s carpet expert for 10 years and has served as a member of the Utah State and WSCA-NASPO Carpet Committees.

As his reputation grew Cary started traveling around the world teaching, specifying, inspecting, cleaning and fixing problems. Cary enjoys working with clients like Carpet Manufactures, Facility Managers, Schools and Universities, Government Agencies, Hospitality and the Health-Care Industry. Cary’s main focus is lifecycle expectations, total cost of ownership, RFP’s, specifications, carpet performance and maintenance.

Employee Background Checks – How Far Should You Go?

In May of every year, I’m reminded of an article that I penned over a decade ago. That’s because it’s the anniversary of the senseless and tragic murder of a beautiful young woman at the hands of an in-home service worker, in this case a so-called carpet cleaner. I think that article is worth revisiting . . . so read on . . .

The service industry is made up of many trustworthy, hard working individuals who are dedicated to protecting the health and safety, as well as valuable furnishings of many people. As such, service workers develop very special relationships with our customers. We have access to the personal areas of their homes and offices. They trust us so much that they literally open their homes or offices to us so that we may perform services for them with little or no supervision. And many times, we employers must depend on subcontractors to help us provide those services.

Occasionally, you see headlines or hear radio or TV news reports: “Carpet Cleaners Rob Homeowner.” Unfortunately, sometimes, it’s worse. For instance, a few years back, two armed robbers were caught ransacking a residence by homeowners and wound up shooting the husband. This pair of thieves had previously spent hours in the home, just as most of us do in our profession as cleaners or restorers. In this case, they worked for a service that catered to wealthy homeowners. The carpet cleaner-robbers had a clever scheme. One guy actually “cleaned,” while the other cased the contents, alarm systems, doors and windows. So by the time they finished cleaning, they both knew a lot about that house and its security.

These clever thieves returned several months after the “cleaning” job to rob the home; but this time, they were surprised by the unsuspecting homeowner. When it was finally determined who employed the robbers, the homeowner sued the service employer. It turned out that both men had criminal records and felony convictions before they were hired. The company was found guilty of “negligent hiring.” The cleaning company owners had to pay $11 million in damages.

Carpet Cleaner Murders Woman
“Carpet Cleaner Murders Woman” was the headline that described the tragic, totally unnecessary loss of Kerry Spooner-Dean, a lovely young pediatrician from California.

“Carpet Cleaner Murders Woman” was the headline that described the tragic, totally unnecessary loss of Kerry Spooner-Dean, a lovely young pediatrician from California. Kerry was a newly married wife and a highly productive member of her community with a bright future ahead of her. In May of 1998, she innocently responded to a “$5.99-per-room” carpet-cleaning ad. The verdict was $11.22 million. The jury assessed 72% responsibility for this murder to the company that subcontracted the murderer, a parolee with eight convictions for violent felonies.

Needless to say, this bait-and-switch company is gone forever . . .

Unfortunately, so is Kerry Spooner-Dean.

The 9-11-01 tragedy has reinforced the need for employee screening in large companies, such as janitorial businesses, that have regular access to buildings. In contrast, smaller “Mom-and-Pop” firms still are reluctant to spend resources on background checks. However, it may be even more important for smaller businesses to do the checks, since employees often have multiple responsibilities in these companies. Even a minor employee infraction can hurt a firm’s reputation and bank account. And risking an unsuspecting customer’s welfare or life is just plain gross negligence. When you tally up the expense and time it takes to recruit, interview, hire and train an employee, it doesn’t make sense to “cut corners” when verifying background details.

Most franchise operations have taken a pro-active lead in background checks before hiring. If you have a small business and are hiring someone you know, such as a close relative or your neighbor’s son, whom you’ve known intimately all his life, it may be tempting to skip the background check. Similarly, in a small community where everyone knows everybody else and employment turnover is low, it may not seem quite as crucial. But to be legal, employers must be consistent.

Having served as an expert witness in the Kerry Spooner-Dean trial, I strongly recommend mandatory background checks for all potential service employees.

It’s been said that, “The closest a person comes to perfection is when filling out an employment application form.” How true. But the only way to way to verify the truth is to do the checks. At a minimum, employers should check out information on an application form and verify basic information on a resume. To check references effectively, employers have to do much more than casually call the people on a list that the candidate supplies. Believe me, the effort is worth it.

To improve your reference verification results, employers must first decide who to contact. Remember, you’re not limited to the names a candidate gives you. You often can find excellent reference sources through industry contacts or certification organizations, through professional associations, and through any other network that applies (civic clubs, Chamber of Commerce, Better Business Bureau). By doing research, you may reach sources that are more accurate and objective. People with no vested interest in your prospect’s future tend to be more open.

The key to protecting your company is doing your best to verify information provided by candidates. Be sure to keep written documentation of your efforts, including whoever you talk to, the dates and the questions you ask, while making every reasonable effort to check out employee statements.

Employers are many times “caught between a rock and a hard place” when it comes to investigating a potential employee. If they do too little, they can be sued when criminal acts occur. If they do too much, they may be violating federal and state laws by making prohibited inquiries. To avoid appearing discriminatory, treat every candidate equally. Don’t, for example, investigate random candidates or applicants who make you suspicious. Investigate them all in the same manner.

Keep in mind, too, that state and federal laws regulate the kinds of information employers can use when making employment decisions. Most states follow federal guidelines, but there are variations, with California being the most complicated and New York a close second. Check state requirements before proceeding.

The Fair Credit Reporting Act of 1971 (plus significant amendments in the late 1990s), the Privacy Act of 1974, and the Americans with Disabilities Act of 1990 oversee the majority of federal protections for worker privacy and rights. Research the issues or talk to an employment lawyer or a veteran human resources consultant before beginning.

If you do decide to hire an outside firm, most third-party background checks now are completed within a few minutes through searches of computerized public databases. When questionable findings are discovered, the investigating company may need to follow up just as you would, with further information gathering at slight additional cost.

Several years ago, third party background checks cost a company as much as $100. However, as technology has improved, prices have become very affordable. Today, it costs roughly $6-10 for a professional pre-employment screening. Reports may range from simply verifying social security numbers to full investigations, much of which is obtained from public records, including:

  • Court records of criminal convictions
  • Driving records and vehicle registrations (if driving company vehicles is required)

Jud and Jenny Savelle of Bishop Clean Care in Albany, GA perform background checks on their potential employees going back as far as 10 years. Before hiring a new bookkeeper several years ago, the former Bishop owner discovered that an applicant had 17 convictions for forgery. In another case, she interviewed a young man whose criminal record check revealed an 8-page rap sheet. This hiring procedure kept her from making some very costly “hires.”

One word of caution: be sure that you are familiar with local and state ordinances and laws. Seems that some liberal politicians and legal entities have more regard for the criminal’s rights than they do for the safety and even lives of citizens. Consult with a qualified legal advisor in your jurisdiction to avoid potential liability.

The task of finding, hiring and retaining good, honest employees is very important for a business, and the well being and safety of customers. Employing the wrong people can, and will take a toll on the company’s reputation and its ability to generate income. If you don’t check references well, you will inevitably hire the wrong candidate or possibly let some of your best candidates slip by. Both mistakes can be very costly. Invest the time and the money, to perform background checks on prospective employees. It may save your reputation or even your business in the end.

Moreover, the tragic death of Kerry Spooner-Dean should remind us all of our responsibilities as employers, not just to our companies, but to all consumers as well. She, and other victims of service workers, never should be forgotten.