Speciality Finishing Agents

Speciality finishing agents give the cloth a function other than handle: antistatic, hydrophilic, water and oil repellent, shade-deepening, filling and flame retardant. The twenty-five products in the Derin Kimya range fall into nine effect groups.

What do speciality finishing agents solve?

Softeners and silicones set the handle of the cloth. A speciality finishing agent adds a function that has nothing to do with handle: it dissipates static, repels water and oil, takes up perspiration, deepens the shade, adds weight, or changes how the fabric burns. What these products share is not a chemical class but a place in the process; they all go onto the cloth in finishing, mostly on the pad-stenter line.

The twenty-five products in this family fall under nine effect headings.

Products by effect group

Antistatic and surface slip

Synthetic fibres carry no moisture, so the charge built up by friction stays on them. The result is sparking, dust pick-up, and cloth clinging to the machine in the sewing room. An antistatic finish opens a conductive path on the fibre surface and dissipates that charge. DK HYDROSTATIC 3M does this job; DK HYDROSTATIC 3MD adds surface slip to the same effect.

Hydrophilicity

Polyester and polyamide do not absorb water. In sportswear, moving perspiration to the surface so it can evaporate requires a wettable fibre. DK HYDROSTATIC 6M is the finishing agent that makes the fibre hydrophilic. The control is the drop test, and the acceptance limit comes from the customer specification.

Water, oil and soil repellency

The logic here is the reverse of hydrophilicity: surface energy is lowered so a droplet stands on the cloth instead of spreading into it. DK HYDROFOB 12 S gives water repellency. DK FLC 33, DK FLC K and DK FLC CONC are fluorocarbon-based finishes that repel oil and soil alongside water.

Curing decides the outcome in this group. If the film does not form properly the effect is gone after the first wash, so the stenter regime and the pick-up count as part of the recipe.

Colour deepening

On deep shades such as black and navy, light reflected off the fabric surface makes the colour read washed out. A colour deepening agent forms a film of low refractive index on the surface and cuts that reflection, so the shade reads fuller and deeper. DK SOFT 346 A and DK FINISH DARK are used for this.

Speciality handle silicones

These products belong to the silicone family but are formulated towards a specific handle. DK SOFT CASHMERE is used for an extra-soft handle and DK SOFT SILK 4700 for a silky one. DK NANOSIL 4G is a nano-structured micro silicone emulsion. DK SOFT AVS 40 is a softener carrying aloe vera.

Body, weight and stiff handle

Some jobs call for a cloth that is full or even stiff rather than soft; shirting, lining, curtain and technical fabrics belong here. DK PVA 40+ and DK FINISH HS are used as body-building agents, while a second DK FINISH HS is listed as a stiff-handle finish. DK FINISH UP adds weight. DK FINISH TIGHT reduces yarn slippage in wovens.

Crease resistance

A crease-resist finish builds bridges between cellulose chains and improves how the cloth recovers after creasing. It is paid for in tear and abrasion strength, which is why the recipe usually runs with a polyethylene emulsion or a silicone. DK FINISH BRA is the product in this group.

Antibacterial finishing

Antibacterial finishes limit bacterial growth on the cloth; the intended outcome is usually odour control and a hygiene claim. BIO CLEAN PST, BIO CLEAN V 70 and BIO CLEAN B 50 are general-purpose products. BIO CLEAN PES is listed for synthetic fibres and BIO CLEAN PST S as a silver-ion type.

Flame retardancy

A flame retardant finish changes how the fabric ignites and how flame spreads across it. DK FINISH FR is a durable grade. In this group the performance is always defined against a test standard, and the acceptance criterion comes from the end use.

What does regulation say about antibacterial and flame retardant finishes?

These two groups differ from the rest on one point: they are subject to product regulation, and that regulation varies by market. An antibacterial claim falls under biocidal product rules in many countries; which active may be used in which product type, and which claim may appear on the label, differs from country to country. For flame retardancy the acceptance criterion follows the end use, and in some product groups it is a legal requirement. The registration and documentation status of Derin Kimya products is given on their product pages: pending from the client.

What to watch when building the recipe

Speciality finishing agents are rarely applied on their own. Most of the time they share a pad liquor with a softener, a silicone and a catalyst, and two points decide the result.

The first is ionic compatibility. A cationic antistatic and an anionic finishing agent can precipitate in the same trough, so the mixture is trialled at small scale before the lot runs.

The second is effects cancelling each other out. A hydrophilic finish and a water-repellent finish work against each other on the same cloth, and a softener can shorten the wash durability of a repellent finish. Where a recipe is asked for more than one function, which one takes priority is settled at the start.

Dosage and curing figures for Derin Kimya products are given on the product pages: pending from the client.

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