The pre-treatment on the fabric is necessary to improve the quality of the printing result. In particular, depending on the type of ink used, the pre-treatment chemical liquid can help the ink to adhere to the textile surface as if it were a glue, or apply the solution that will help the chemical reaction that binds the ink to the fabric permanently.
The preparation can be applied on the fabric in different ways, the most classic and common of which is the impregnation with a padding foulard: this is because the pre-treatment is spread evenly on both sides of the fabric, with the certainty that there will be no parts or spots where the ink cannot adhere or react.
The drying of a fabric occurs for several reasons: after the washing stage, especially when printed with acid or reactive ink, where the final washing phase is mandatory. Or it can be useful for drying post-treatment chemicals that are applied to a fabric before the heat fixation phase. Even the drying stage, like that of pretreating a fabric, can take place in different ways.
For example, on our easyCOAT/DRY machine we use cylinders heated with diathermic oil to have precise temperature control (very important if particularly delicate fabrics are used), temperature uniformity and constant maintenance of the same. It is important that drying reaches the point where the fabric retains its natural moisture.
With post-treatment or textile finishing we mean the application of a chemical treatment on the fabric, after the printing phase, to increase or add certain characteristics depending on the intended use of that fabric.
In particular, those listed below are the main treatments that can be applied with a padding foulard system:
Treatment that reduces the formation and proliferation of bacteria and other microorganisms on fabrics. Anti-bacterial textiles can be bactericidal (total elimination of bacteria) and bacteriostatic (if their excessive proliferation is inhibited). Active ingredients that prevent the growth of microorganisms are termed anti-microbials.
Mainly used as post-treatment for:
Treatment on fabric able to stop the spread of a virus. For a fabric to be “antiviral” it must be able to deactivate a virus that settles on it. For an anti-viral to be considered effective it is not enough that it deactivates a virus, but it is necessary to ensure that the antiviral fabric is able to stop the virus in a much shorter time than the same untreated fabric. The antiviral activity also depends on the degree of coverage of the fibers with the antiviral active ingredient. However, it is difficult to cover the entire surface of the fibers: the effectiveness of the antiviral finishing is therefore increased by increasing the dosage of the antiviral product. The effectiveness of the antiviral is reduced with each wash the fabric is subjected to. Also in this case, to improve the duration of washing, it is necessary to increase the dosage of the antiviral product during the finishing phase.
Like the anti-bacterial treatment, it is used for
It is known that UV rays can be harmful and dangerous for the skin, especially if a person is particularly sensitive or overexposed. In this case, the garment treated with an anti-UV finishing works as a screen that protects against ultraviolet rays responsible for the greatest damage to the skin. The protection factor of textile products refers to UV rays and is called UPF: UV Protection Factor. The use of an anti-UV treatment is especially necessary for light and light fabrics, or when you need to make clothing that is light with a good level of protection.
Mostly used for
A fabric is considered stain resistant if it has both water-repellent and oil-repellent characteristics. For water-soluble stains, silicone-based chemicals are used, for greasy stains, synthetic resin-based products are used.
It is used in particular on fabrics for:
Treatment that prevents water from penetrating the fabric and passing through it, even in case the water falls from above (stronger than the anti-drop treatment). Depending on the requirements of the product, it can be resistant to high temperatures, washing in water or dry cleaning.
It is mainly used for
Cellulose-based fabrics, in particular conditions of humidity and environmental heat, can develop permanent damages due to the depolarization of cellulose and the creation of molds and other organisms that feed on this substance. To avoid such damage it is sufficient to apply antiseptic chemicals or bacteriostatic products.
Ideal for fabrics exposed to humidity and adverse weather conditions, such as
Treatment that ensures that the fabric does not absorb drops of water poured slowly onto it. It differs from waterproof fabric finishing because it is “weaker”.
Mostly suitable for
Fabrics treated with this type of finishing prevent unpleasant odors to be released fron the fibers with which they have been in contact for more or less prolonged time.
It can be used for
The fabric can be chemically treated with thermosetting or other synthetic resins, which modify the internal structure of the fiber, to prevent it from creasing and creasing over time with use.
Treatment which reduces the amount of pollen sticking or adhering to the fabric. The amount of pollen that will be able to adhere to the fibers of the fabric can still be removed easily.
Suitable and specific for
With anti-dirt we mean a type of dirt other than the oily or watery one mentioned in the stain resistant treatment; even dirt caused by dusty stains can be difficult to wash. Through particular chemical finishing, certain surface irregularities of the fiber can be improved so as to prevent dirt from adhering and being easily removed.
Synthetic fibers (polyester, acrylic and polyamide), due to their hydrophobic character, have a reduced conductivity towards electricity, so much so as to maintain the electricity charges for a long time once rubbed with other bodies, or accumulated in the presence of magnetic fields. This involves, in some cases, the formation of small sparks and real electric discharges that cause the annoying phenomenon that can be perceived in all respects. The chemical products that give the synthetic fibers an antistatic effect form on the surface a thin film with a higher electrical conductivity than that of the fiber itself which avoids the creation of this problem.
Mainly used in home textile products such as
Very specific and particular treatment that prevents the fabric from absorbing blood. There are different types of treatment, from the most basic to the most complex characteristics based on the type of use that the finished textile product will have.
Treatment that absorbs and facilitates the evaporation of body sweat that is created in contact with the skin. This happens especially with particularly water-repellent fabrics that do not have the ability to absorb sweat and which often also become electrostatic.
Fabric which, even if completely immersed in water, does not modify its chemical, physical, size and shape characteristics.
The flame retardant prevents the spread of a flame. This is a very technical finishing. Based on the intended use of the fabric, it is very important to establish the characteristics and the level of flame resistance that the finished product must have.
This treatment is used for
Finishing treatment that increases the softness and the touch of a fabric.
Used very frequently on all fabrics,
For most of the chemical finishing treatments listed above, drying alone is not enough. To ensure that the product remains permanently on the fabric, it is necessary to polymerize, that is, to fix the resins contained in the chemical solution with a high temperature so that they remain bound to the fibers. Every chemical finishing has its own specifications for curing.
Curing is also necessary in digital printing with pigment inks, because this ink is fixed to the fabric through a binder (acrylic resin) which acts as an adhesive support between the dye and the fabric.