By Olivia Cahoon
From flooring and tile to backsplashes and countertops, digital printing technology helps manufacturers print directly to surfaces. One market taking advantage of this technology is the carpet industry.
Traditional carpet manufacturing is a lengthy process often limited by design and cost. While print shops use dye-sublimation (dye-sub) for area rugs and mats, digital inkjet carpet printers help manufacturers mass produce customized carpets for design collections as well as individual end users.
To handle thick, robust carpet materials, inkjet printers should demonstrate a stable and robust system with durable printheads. Additionally, ink type and substrate are selected based on the application’s needs such as soft-ness, resilience, and recyclability.
Above: The Zimmer COLARIS-Carpet Printer works with an open ink system, which uses ink from several manufacturers and types. According to the company, there are 25 unites in operation worldwide.
Traditional Carpet Manufacturing
Carpet decorating existed for hundreds of years, but it wasn’t industrialized until the 19th century when technology became available for mass production. Today, carpet is traditionally decorated with several methods including tufting, weaving, and screen printing.
Tufting is the most widely used carpet construction method that requires colored yarn for loop, cut, level-cut loop, and additional constructions and styles. In this process, hundreds of needles push looped yarn into a support fabric. An added backing material fixes the pile yarn and ensures the fabric’s stability. Colors and patterns are applied with several methods such as piece or spinneret dyeing. While this process is the most popular for carpet construction and decoration, tufted loop pile carpet has a greater potential of snagging and running.
Weaving is another popular carpet construction method that uses colored yarn and different weaving technologies. Most often, pile yarns are interlaced in one of several techniques that each present a different appearance. Compared to tufting, woven carpets are generally more expensive but also have a better appearance. This method also uses less pile weight.
While tufting and weaving incorporate colored yarns for construction and decoration, screen printing is available to decorate plain carpet. This process uses flat or rotary screens in combination with pre-mixed colors to print on low-pile constructions, mainly loop pile velour. According to Thomas Kloebl, sales manager carpet, Zimmer Austria Inc., screen printing is an outdated technology in the carpet manufacturing industry.
Revolutionize the Floor
In the 1970s, digital printing emerged in the carpet industry. At this time, Zimmer created the ChromoTronic Carpet Printing Machine that used computer controlled jets—not traditional screens—to print patterns.
Shortly after, Zimmer developed the ChromoJet, a valve-based digital press that works with pre-mixed spot colors. “Up to now more than 300 installations—from two to five meters—are in operation around the world as well as many sample printers,” offers Kloebl.
Today, digital inkjet carpet printers are available to create endless colors and complex patterns. “Digital printing is a quickly emerging technology used for many flat surface applications,” adds Kloebl.
However, this technology didn’t come to be without difficulty. According to Kloebl, the main challenge was and is to use tiny droplets from inkjet printheads to obtain a good penetration on pile products. “Zimmer is a pioneer and specialist in this field and developed several technologies to get maximum penetration.”
While digital carpet printing expanded in use and technology, improvements are continuously made in speed and penetration on high-pile carpets as well as to minimize water usage, energy, and space.
The latest developments are underway for printing on woven polyester and wool carpet rugs. “This is the perfect combination of quality and flexibility,” says Kloebl. “We have three lines already in operation in the Middle East.”
With a bright future ahead, digital printing is expected to revolutionize the carpet industry by decreasing stock and granting unlimited design access. “Digital printing and dyeing is the future in carpet design. No limitation in color, size, pattern, or design sampling. Furthermore, only griege goods—raw fabric before undergoing dying or bleaching—will be in stock,” notes Kloebl.
Behind the Carpet
In digital carpet printing, carpet is typically printed to directly rather than a transfer method. For a quality design, digital inkjet carpet printers require several features to handle thick and rugged materials of varying sizes.
“Carpet needs a stable and robust system starting at unrolling and ending at roll-up,” comments Kloebl. To do so, precise feeding throughout the line is essential for consistent quality products.
Printheads are also important for satisfactory results and to avoid challenges. When selecting a carpet printer, Kloebl suggests manufacturers ensure the printheads are robust and can also be repaired. Additionally, carpet, mat, and rug printing requires special software to match the carpet industry’s needs.
Ink types for carpet printing are selected according to the final application. For example, rugs, promotional carpets, and mats need bright colors while contract carpet and carpet tiles require enhanced light fastness properties.
Reactive, acid, disperse, and direct sublimation inks are all options when it comes to digital carpet printing. Zimmer suggests acid for polyamide, wool, and silk. Disperse is ideal for polyester. Reactive works well for cellulose and cotton fabrics.
Certain substrates are typically better suited for carpet printing than others. Similar to ink, substrates should be selected based on the application. For rugs and mats, Kloebl sees a strong trend toward polyester and cationic polyester for its affordable price, softness, and recyclability. For carpet and carpet tiles, nylon is preferred due to its resilience and stability. Wool, acrylic, and cotton do not currently play a significant role.
Depending on the fiber used, carpet printing requires a post-printing process. With the Zimmer COLARIS sys-tems, nylon, wool, and cationic polyester is first washed before printing and then steamed, washed, and dried. “For some applications and qualities we can skip the post-washing process,” admits Kloebl.
Polyester carpets also require a pre-washing or foam impregnation. After printing, drying and high temperature fixation is used followed by reductive washing and drying again.
Dedicated digital carpet printers are few and far between—two vendors standout as pivotal players in the market.
Released in 2014, Hollanders Printing Systems offers the ColorBooster 250 Carpet Edition. The 2.5-meter wide format device is designed for carpet printing with dye-sub transfer and direct-to-textile options. It includes the proprietary Hollanders media handling system, on-board remote support system, and options for built-in humidity and temperature control.
Available by Zimmer, COLARIS is a family of high-performance, high-quality printing machines for textile and carpet materials. Devices range from 1,800 to 4,200 millimeter printing widths. The COLARIS-Carpet Printer is a digital technology working with a number of process colors that are mixed directly on the carpet surface. Available since 2016, 25 units are currently operating around the world with nearly 40 million square meters produced each year.
COLARIS works with an open ink system, which uses ink from several manufacturers and types. “Therefore, we can choose inks depending on fastness requirements but logistics and prices must also be considered,” says Kloebl.
Established in 1375, carpet manufacturer Mohtasham Carpet celebrates an annual production capacity of 1,869,000 square meters completed by 300 employees. Its manufacturing footprint amounts to 47,4000 square meters with carpet production machinery like loop machines, shaggy devices, and weaving machines with up to 1,200 reeds. The manufacturer also employs a team of in-house designers for products intended for the end user market.
In 2018, Mohtasham Carpet became the first carpet manufacturer to install the Zimmer COLARIS solution for printing on woven polyester. This is a bold move for the company as Iran’s carpet sector does not traditionally favor synthetic fibers, and so carpet production is slow on incorporating polypropylene fibers and polyester yarn.
With the COLARIS, Hossein Rahimi, managing director, Mohtasham Carpet, says the company intended to create a carpet that is easily recyclable with weft and pile yarns as the same polyester material. Additionally, Mohtasham Carpet needed a simpler method to produce custom designs.
“For carpets, your hand is always closed because of color limitations,” says Rahimi. “For a machine-made woven carpet, you can only use ten colors. To make a new color, you have to weave two together.”
To house its printing line, Mohtasham Carpet installed a 3,500 square meter building to its 11,000 square meter facility. The company exports $10 million worth of carpets each year to markets in Australia, Europe, and South Africa.
Satisfying Traditional Needs
The modified COLARIS solution is complete with a custom penetration booster system to ensure ink saturation on woven white PET carpet—pushing ink into carpet fibers before drying, heat fixation, washing, and drying.
Ink saturation is a critical component to carpet manufacturing as it mimics the look of venerated handmade carpet. This feature is crucial to the Iranian carpet printing market. “Iran has the biggest tradition in carpets. The Iranian people are very picky when it comes to penetration and the backside of the carpet, and often people buy the carpet from the backside,” explains Rahimi.
Iran’s carpet history is vast, particularly in its notoriety for producing hand-woven carpets. While the domestic market is strong, rising popularity for Iranian hand-woven carpets amounts to roughly a third of the world’s market.
In addition to its popularity, Iran’s woven carpets are highly regarded compared to tufted carpets. “A woven carpet has a lot of advantages compared to a tufted carpet. It is more stable, with only a minimal latex finish on the back,” explains Rahimi. With a tufted carpet, the pile is stitched into a pre-woven backing and then a secondary backing is adhered.
The Home Market
While the COLARIS helps Mohtasham Carpet meet demands for the export market, it also aids in serving the domestic Iranian market.
Today’s Iranian customers demand fast-changing fashion, more so than ever. With high demands in the domestic market, Mohtasham Carpet predominantly provides carpets directly to the end user.
The COLARIS production line helps the carpet manufacturer print on demand. With this technology, Rahimi says the company can accept orders for one carpet while saving money. “When we have an order from another country, they might come with a different color of yarn. If we do this order for a small quantity, we have to order the specific yarn, change the creel of the machine, and we likely waste some of the yarn as well.”
In addition to satisfying international and domestic markets, Mohtasham Carpet’s digital equipment presents new opportunities. The hospitality sector, which currently employs contract carpeting, often sees architects using woven carpet due to its longevity. “A printed, customized logo can now be applied to these carpets,” adds Rahimi.
To further boost sales of its new technology, Mohtasham Carpet invested $500,000 in television commercial advertising in Iran. Rahimi says the manufacturer’s marketing receives positive feedback and a number of inquiries regarding production and operation timelines.
“We are confident that the product will come out nicely. You have a learning phase and then acceptance from the market. This is not always easy due to competitiveness but it will help this market and make it a little faster,” says Rahimi.
Carpets Take All
Digital printing devices allow carpet manufacturers to create custom designs while cost effectively producing traditional weaves. As with any new technology, it’s important for manufacturers to determine which ink types and substrates best fit the carpet’s end use before selecting a digital printing device.
Oct2019, Industrial Print Magazine