"Curing" is the chemical process of converting monomers and comonomers (crosslinkers) to polymers. Monomers are the basic molecular chemical components of the ChemStik® technology. Polymers are the macro-molecular chemical products produced by the polymerization of monomers. It is analogous to cellulose and wood. Cellulose is the "monomer" that forms wood. Similarly, protein is the monomer that forms muscle. Nature invented polymerization...we have just expanded on that concept. At GTT, we use monomers and crosslinkers to make our polymeric finishing treatment.
"Dry Curing" is a water-free, solvent-free method of polymerization. We use two different methods for dry curing (though others are also possible): thermal curing and plasma curing. Thermal curing is accomplished by passing ChemStik-treated fabric through a heated zone. The heat that the fabric is exposed to causes polymerization to occur. Plasma curing is done using free radicals produced by the plasma to induce polymerization.
Once cured, the treated fabric remains stable and durable for the life of the fabric. True polymerization causes bonding of the polymer to the fabric. This greatly improves the laundry durability and abrasion resistance of the treated fabric. Our finishing treatment will not wash off, rub off or wear off. Check out our videos for proof of performance and durability.
Crosslinkers are monomers with two polymerizing ligands, often on opposite ends of the molecule. They are useful for connecting and strengthening two polymeric layers or for bonding a polymer to the fiber, especially synthetic fiber - since those are also polymers. If you think of polymers as the wooden beams that form a wall frame... crosslinkers are the braces between the beams that are added for strength and support. Crosslinked polymers are shown in the above illustration.
We use both monomers and crosslinkers in our ChemStik® formulation - along with other important components to provide you, the customer, with the best possible finishing treatment and one that has unsurpassed laundry durability. The importance of crosslinkers has long been known in polymer chemistry: the industrialization of rubber for use in tires and other applications was made possible by the process of "Vulcanization", which is the crosslinking of rubber's naturally-occurring polymers by the addition of sulfur.
As it turns out, Nature is particularly fond of crosslinked polymers. As an example, see the animated picture, below, of a double helix, crosslinked biopolymer commonly known as DNA. It is the basis of all life.
The GTT dry technology can be applied to one or both sides of a fabric. In this way, fabric can be treated so that one side is hydrophobic, while the other side is hydrophilic. Ths is just one unique capability of dry finishing technology.
For rain repellence, it is best to use a fabric treated on both sides, as rain often has a velocity and momentum that causes penetration into the fabric, perhaps reaching the hydrophilic side. However, there are unique applications in which this "dual-functionality" is desired.
In addition, the pressure pod may be pressure-tuned to achieve the desired degree of monomer penetration into the fabric and therefore a controlled amount of hydrophobicity with fabric depth.
The video below shows a thin, polyester fabric that is treated to be hydrophobic on one side and hydrophilic on the other. This demonstrates the uniqueness of the GTT dry finishing technology - this would be impossible to do using conventional "wet" finishing.
Thermal Dry Finishing also means that fully-cut-and sewn apparel may be sprayed with the GTT chemistry and then thermally cured. This treatment has also been shown to last at least 100 wash/dry cycles. The athletic shirt shown left was purchased retail and was originally hydrophilic. With the GTT finish, the hydrophilic finish was overcome and made hydrophobic.
The same can be done with athletic or outdoor footwear, outerwear, hats, scarfs, gloves and socks. A key advantage of treating fully-finished apparel is that the seams and sewn joints are also treated for the best performance.
For footwear, high pressure curing causes deep penetration of the fabric for controlled water repellency and moisture management.
The GTT treatment can be applied over fluorocarbon finishing that has worn off or washed off for extended durability.
Water-free finishing is needed for smart textiles. Imagine embedding electronics into apparel, awning covers, footwear, or medical textiles for safety, visibility, or biometrics - would you want to then pull those sensitive electronics through a water bath and then dry out the fabric in an oven? Water-free finishing makes smart textiles possible.
The video below shows how a single-sided, PFC-free DWR finish can be used to enhance the water-shedding properties of laminated polyester fabric. Here, the GTT finish is applied directly onto the poly-urethane lamination.