Non-contact precision spray is a revolutionary application method that enables textile manufacturers to satisfy growing demand from consumers and brands for more sustainable practices at every level of the supply chain.
The primary goal of every retailer or brand and textile manufacturer is to deliver higher, more consistent quality to end customers, and in addition to its environmental benefits, precision spray supports that goal. This disruptive technology dramatically cuts chemical waste and energy consumption while improving fabric performance, making it the future standard for textile finishing, remoistening, and moistening for sanforizing and compacting.
TexCoat™ G4 Precision Spray Valve Technology
BW Converting’s sustainability focused technologies include its TexCoat G4 precision spray system, which applies the precise amount of finishing chemistry for woven and knit fabrics achieving optimal required performance.Finishing chemistries suitable for spray include durable water repellents (DWR) both PFAS and PFAS-free recipes, softeners, anti-microbials, flame retardants, resins and many other technical finishes.
Precise Chemistry Control
The key to the consistent quality and environmental benefit gained by converting to spray technology is that it’s non-contact. Precision spray eliminates the need to empty, clean, and replenish the pad for changeovers when switching fabric or chemistry.
Components of a typical spray system from BW Converting include the chemistry supply unit, better known as the pump station, which doses the finish chemistry to the spray unit. It’s then controlled by the operator interface, which is programmed for the precise amount of pickup and width and weight of the fabric. The system’s algorithms then calculate coverage and controls the application via the spray valves.
The precise amount of “add-on” is applied to the fabric.
If the chemical mix is the same from batch to batch, TexCoat G4 can change the amount of pickup, from 20% for one fabric for instance, to 30% for the fabric behind it. Regardless of the fabric characteristics, it’s not necessary to stop the production line.
Any chemistry that is not attached to the fabric is returned and filtered back into the pump station. Finishing lines that run continuously are more efficient and ensure higher quality.
This is true for any production process, whether it’s weaving, manufacturing, dyeing or finishing. Uninterrupted production also amounts to substantial savings in chemistry, water, and energy.
Zero Chemical Waste in Changeovers
When a recipe change is required, the finish chemistry is unloaded, and the system goes through an automated cleaning cycle that circulates fresh water through the system supply lines, valves, and reservoir tank that holds the chemistry and is then ready for the reloading of the new chemistry. This total changeover process only takes about six minutes. Chemistry can range from softeners, anti-microbial, DWR (C6 and C0), flame retardants, wicking agents, and more, for fabrics such as knitted and woven and for single or dual-side applications.
Single or Dual-side Application
While pad application is a tried-and-true technology in finishing applications, one of the downsides is that the fabric is saturated when dipped and squeezed. Some finish applications don’t require saturation and in fact, are less desirable. Precision non-contact spray allows for single-side application where it is not only unnecessary but also not desired to coat both sides of the fabric. An example of single-side coating being an optimal solution is performance fabrics that require DWR on one side and wicking on the other or latex back coating and polymerization.
Wet-On-Wet Applications
With wet-on-wet finishing, the fabric is dipped and squeezed in the first pad before it is dipped into the chemical bath to get the proper application. With wet-on-wet pad based applications, the quality of the fabric suffers from dilution or “tailing effect” where wet fabric dipping into the chemical bath, dilutes the recipe and results in uneven application from meter to meter. Contact-free precision spray is unaffected by this phenomenon and results in consistent finish application from the beginning to the end of the batch saving at least 50% in chemistry and energy savings from 30-35%.
Wet-On-Dry Applications
Wet-on-dry finishing is primarily found in woven fabrics. Dry fabric is dipped and squeezed in a single pad with a pickup or add-on of 60%-70% depending on the fabric construction. Immediately after padding, the fabric enters the stenter frame where the water is evaporated and the chemical finish is cured (if required). TexCoat G4 can apply the same amount of chemical solids using approximately 50% of the amount of water. This allows a significant reduction in the amount of heat in your stenter frame, and/or a higher process speed, depending on the requirement. As an example, there are textile manufacturers who process fabric with pad technology at 60 MPM.
Using TexCoat G4, the same fabric and finish can be processed at 120 MPM, doubling the stenter output. TexCoat G4 is great for the environment and an excellent tool for business.
