In this installment we’ll talk about streaks and lines in the carpet. These are conditions which occur at the point of manufacture which would be categorized as visible defects. The things you see when you unroll the carpet, in most cases, or that your customer notices after the carpet has relaxed and been vacuumed several times. Actually, many of these are things that should be caught at the point of manufacture. Anything lineal in the face of the carpet, be it in the length of the carpet or in the width, are things that are in the manufacture of the carpet itself. The exceptions would be dark soil lines which show up after the carpet has been put into use but we’ll talk about those later.

Most common will be lines in the carpet that are high or low. For example, one low line running the length of the carpet is the result of too much tension on the yarn which is being starved at that particular needle and pulled down too far. The tension can come from various devices, depending on the machine and the construction of the carpet, but tension is what will pull the yarn down causing a low line. This type of defect cannot be repaired. Opposite that is a high line, this is also a yarn tensioning condition but when too much yarn is being fed. High lines can often be repaired by trimming them to the same height as the rest of the carpet yarns surrounding them using a duck billed napping shears.

Lines that run the length of the carpet which alternate, that is high/low, high/low, etc. are called gauge lines. These are lines caused by machine set up, adjustment and yarn tensioning. They are often referred to as “corn rows” because they look like rows of corn in a field. These lines usually show up after the carpet is installed and relaxed and they cannot be corrected.

Short rows of yarn that may look low, slightly higher and more congested are mends in the carpet. Mending is done when a yarn breaks and leaves a void in the carpet, this occurs at the tufting machine. A good mend will be virtually indistinguishable, a bad mend will show up as a flaw and cannot be corrected.

Zigzag lines running the length of the carpet are low lines, which we described before as a tensioning issue. The lines zig zag because the tufting machine is a staggered stitch or step over stitch tufter and as such the yarn is not tufted in a straight row. The yarn is staggered intentionally to hide streaks or to make a pattern in the carpet. Therefore if the yarn is improperly tensioned it will make the high or low line appear as a zig zagged line. This is quite unique when you see it but if you understand how carpet is tufted you’ll know what this type of line is.

There are also lines or streaks in carpet from an errant yarn, a yarn that has been scuffed or damaged, heat set differently or processed differently. Streaks from this type of inconsistency are not noticeable until the carpet is dyed. After the color has been added to a carpet it will show all the flaws inherent in it.

Another type of low line that runs in short lengths across the face of the carpet is a shift mark. Shift marks are caused by the yarn being starved or pulled down as the needle bar doing the tufting is shifting back and forth. Shift marks are indicative of a step over stitch construction. These marks cannot be corrected.

All of the conditions we’ve just described are inherent in the carpet and are visible defects. They can be seen at the time of manufacture, and should be, but often are not picked up and the product ships with the flaws in it. There are other defects that have to do with tensioning and lines in the carpet but those described in this issue are the most common. There are also lines that will manifest themselves in the carpet after it’s installed.

The most common “line” in the carpet after installation is crush marks. These are caused by the weight of the carpet upon itself. This is not a defect and can almost always be eliminated by steaming the carpet correctly, if it’s nylon. If the carpet is polypropylene crush marks will be permanent. This is not a defect but a handling, storage or shipping condition.

Another type of streak or line in the carpet is from oil or some topically introduced substance. An oil line will create a dark line in the carpet that will start as a faint line and grow increasingly darker with use. A clogged jet or over application of a soil retardant can also cause a dark line. Yes, too much soil retardant is a soil attractant. These types of streaks or lines can almost always be serviced and removed completely without any damage or detrimental effect to the carpet if you know what you are supposed to do and do it properly. Improper servicing for removal of this type of line can permanently damage the carpet. This is a brief description and explanation of the most common kinds of lines in carpet. If you have a specific problem or question give me a call and I’ll help you out.