Carpet And Rug Construction

Understanding carpet construction

The look and performance of a particular carpet is determined by its construction, which may be loop, cut or combinations of the two.  In corridors, lobbies, offices, classrooms, hotel rooms, patient care facilities and other public areas, loop piles of low, dense construction tend to retain their appearance and resiliency and, generally, provide a better surface for the rolling traffic of wheel chairs or food carts.  Cut pile or cut and loop pile carpet are very good choices for administration areas, libraries, individual offices and boardrooms.

Various types of high performance backing systems have additional advantages, including higher tuft binds, added stability, imperviousness to moisture and resistance to edge raveling.  Consideration should be given to the functional needs of a particular area.

Understanding carpet construction assists in specifying elements that will provide the best performance in a particular location. Commercial carpet is primarily manufactured by tufting or weaving.  Each process will produce quality floor coverings, but tufted carpet accounts for 95 percent of all carpet construction.  Both tufting and woven manufacturing are efficient and employ advanced technologically to provide capability for a myriad of patterns and floor covering. 

Tufted: Tufting is the process of creating textiles, especially carpet, on specialized multi-needle sewing machines.  Several hundred needles stitch hundreds of rows of pile yarn tufts through a backing fabric called the primary backing. The needles push yarn through a primary backing fabric, where a loop holds the yarn in place to form a tuft as the needle is removed. The yarn is caught by loopers and held in place for loop-pile carpet or cut by blades for cut-pile carpet.  Next, secondary backings of various types are applied to render a variety of performance properties.

Here are some key steps in the tufting process:

  • Yarn comes from cones on creel racks (or from big spools called beams) into the machine.
  • The primary backing feeds into the machine.
  • Yarn and primary backing come together in the machine (full shot of machine)
  • Yarn is fed through needles on a needlebar of a tufting machine. Needles repeatedly penetrate or tuft into the primary backing.
  • The tufted carpet is mended and inspected.
  • Carpet is rolled onto large rolls for the next step (whether it’s to be dyed or to be backed.)

Woven:  Woven carpet is created on looms by simultaneously interlacing face yarns and backing yarns into a complete product, thereby eliminating the need for a secondary backing. A small amount of latex-back coating is usually applied for bulk.  Principal variations of woven carpet include velvet, Wilton and Axminster.

Carpet construction types

Twist and Velvet carpet types

Traditional woven carpets such as axminster and wilton have been manufactured for over 200 years. The looms on which the carpets are woven have altered considerably over the years but the construction principle of interlocking the pile yarns with backing yarns is little changed.

Twist and velvet carpets have a different appearance and texture.

Axminster and Wilton carpet have pile and backing yarn woven together for strength and stability.

This image shows a twist carpet on the left and a velvet carpet on the right.

 

Axminster construction

Axminster construction

In an axminster gripper weave, cut tufts of yarn are inserted at the point of weaving by means of grippers. For each tuft to be inserted along the width of the carpet, there is a corresponding metal gripper which rises from the bed of the loom to grip the appropriate coloured end of yarn from the vertical yarn carrier. A knife blade slices the tuft to the correct length, the gripper then returns to the bed of the loom and places the tuft in the appropriate position, the weft shots of the backing yarns then bind it into place.

In an axminster gripper weave, cut tufts of yarn are inserted at the point of weaving by means of grippers.

For each tuft to be inserted along the width of the axminster carpet, there is a corresponding metal gripper which rises from the bed of the loom to grip the appropriate coloured end of yarn from the vertical yarn carrier. A knife blade slices the tuft to the correct length, the gripper then returns to the bed of the loom and places the tuft in the appropriate position, the weft shots of the backing yarns then bind it into place.

A beater bar pushes each row of tufts and weft shots tightly against one another to form the carpet. The “beatup” (rows) can vary from as low as 5 to 14 rows per inch, or even higher if required. Different coloured ends of yarn (according to design) can be selected from the yarn carrier, which is raised or lowered by means of a jacquard (punched card) mechanism. Many different colours can be used in this weaving method. More modern looms have electronic jacquards which enable them to produce very complicated designs with almost infinite pattern repeats.

Wilton construction

Wilton construction

A traditional wilton weave carpet is one in which the pile threads run continuously into the carpet and are raised above the surface of the integral backing by means of wires or hooks. Wilton carpets are often cut or loop products and different yarn types can be used to produce different surface textures. Wilton weaving is not as versatile as axminster for the production of patterned carpets, due to continuous yarns that create waste yarn on the back of the carpet.

A traditional wilton weave carpet is one in which the pile threads run continuously into the carpet and are raised above the surface of the integral backing by means of wires or hooks.

Wilton carpets are often cut or loop products and different yarn types can be used to produce different surface textures. Wilton weaving is not as versatile as axminster for the production of patterned carpets, due to continuous yarns that create waste yarn on the back of the carpet.

Brintons wilton carpets are woven on looms designed and built by our own engineers in our own factory. They differ from traditional wilton looms as they have no “dead” or wasted yarns in the back. These advanced design looms weave two carpets as a sandwich, know as "face-to-face", which is then sliced into separate rolls. As with traditionally woven wilton carpet, Brintons face to face looms produce a durable woven product, which is hard wearing and dimensionally stable. The carpet does not suffer from the delamination and stability weakness often associated with tufted carpets.

Facts on Backings 

All carpet has some type of backing system or chemistry that helps keep the tufts in place. Backing systems are made from a variety of materials and may also come with various kinds of protective treatments (such as anti-microbial or anti-stain) or beneficial properties (such as anti-static).

The methods and chemicals used depend upon the performance requirements of the backing and the carpet. These decisions will be based upon the specifier’s performance considerations and the manufacturer’s recommendations. Performance considerations are especially important for demanding environments. It’s important that the specifier identify the highest priority needs for how the carpet will perform, whether that is wear and tear, moisture-resistance, or heavy foot traffic. The manufacturers’ end use recommendations help determine which product will meet the established performance expectations.

Carpet backing systems contain the following elements: a primary backing, a chemical adhesive, and often a secondary backing. In the most common system, the yarn is secured into the primary backing by synthetic latex, and a secondary backing (or cushion) is attached with a bonding agent or adhesive to provide further pile-yarn stability and to add dimensional stability to the carpet structure.

Whether a carpet has a secondary backing depends upon the end use of the carpet and the location of the installation. Carpet for high performance end use generally has a primary backing and a secondary backing or often an added cushion attached to the primary backing.

Below are listed some of the common types of carpet constructions and their main features:

Cut Pile Saxony

Cut Pile Saxony Carpets

  • Generally made in solid colors
  • Surface has a smooth appearance
  • Generally made with nylon, wool or polyester fibers
  • Good performance and in appearance
  • Works well with traditional or formal room settings
Textured Saxony

Textured Cut Pile Saxony Carpet

  • Surface appearance is textured
  • Stylish, casual appearance
  • Won't show vacuum cleaner marks or footprints
  • Very popular carpet style today
  • Good choice for active areas of the home
Frieze

Frieze Carpet

  • Very textured, knobby surface appearance
  • Extremely durable, and excellent wearing
  • Yarns very tightly twisted
  • Will cost more than textured cut pile carpets
  • Great for active areas of the home
Cut and Uncut

Cut & Uncut Patterned Carpet

  • Intermixed loops and cut pile, creates a patterned design
  • Loops are shorter than the cut pile creating a carved appearance
  • Usually constructed in multi-color designs
  • Helps hide footprints and traffic patterns
  • Great choice for a variety of room settings
Mutli-level loop

Multi-Level Loop Carpets

  • Has several different heights of loops
  • Generally multi-colored
  • Very durable, casual appearance
  • Offered in many unique looking designs and patterns
  • Helps hides traffic patterns
  • Great for family rooms, basements, etc.
Level loop

Level Loop Carpets

  • Loops are same height and generally multi-colored
  • Usually made from polypropylene (olefin) carpet fibers
  • Often called Indoor-Outdoor or Commercial Carpet
  • Casual appearance, but extremely durable
  • Great for family rooms or basements