Sodium Lauryl Sulfate K12

Product Overview

Sodium Lauryl Sulfate (SLS, trade name K12, C12H25OSO3Na) is the classic wetting agent for nickel plating and the standard foaming anionic of electroplating pretreatment. Its job in a nickel tank is specific and easy to verify: hydrogen is evolved at the cathode during plating, and without a wetting agent the gas sticks to the work as bubbles, leaving pinholes and pits in the deposit. K12 lowers the surface tension of the bath so hydrogen releases in fine streams instead of clinging bubbles, and it keeps the nickel surface fully wetted so brightener and leveler action is even. On the cleaning side of the line it is the foaming engine of soak and electrocleaners. Market grades: needle/powder K12 at 90-93% active for bath dosing, and paste at 30-70% active for cleaning blends. The differences that matter in plating are active content (pay on real active, not on bag weight), sulfate salt content, and whether the lot is chloride-free enough for sensitive baths. QLQ supplies the low-salt needle grade with COA so dosing stays predictable.

Product Identity (Encyclopaedia Card)

What it is and what it does. Sodium lauryl sulfate (K12) is the anionic surfactant used as the wetting, emulsifying and foaming agent in cleaners, in pickling inhibitors and in some plating wetting systems.

• White to pale yellow powder or needles; one of the most widely used anionic surfactants in the industry.
• Reduces surface tension so that cleaners reach the bottom of recesses and blind holes.
• Strong foamer - it needs care in spray and in high-agitation equipment.

Typical Use in a Plating / Finishing Line

Safety, Handling & Storage

Quality Documents Shipped With Every Batch

Buyer Questions We Answer Every Week

How It Works in the Bath: K12 Anti-Pitting Dose

Nickel baths run at 45-60°C with air or cathode agitation and always evolve some hydrogen at the cathode. Surface tension of an un-wetted nickel bath is high enough for hydrogen bubbles to sit on the surface and grow; when they finally release they leave a pit that the deposit cannot fill. K12 at the right level stops this:

Consumption is mainly drag-out (K12 is not destroyed by electrolysis), so a rack line loses roughly 5-15 g per 1000 dm² plated and additions follow surface-tension measurement or a foam-height check, not guesswork.

Where Else K12 Is Used on the Line

Quality Checks Before Use

How QLQ controls it: lots are checked for active content, chloride and surface-tension response against a retained reference, and every drum is Hull-cell verified in a working nickel bath before release. Because pitting complaints are nearly always traceable to wetting, the batch number on each bag lets a shop and QLQ agree in minutes whether the K12 lot - or something else - caused the defect.

Common Problems & Fixes (Workshop Table)

Handling & Safety

• Health: K12 powder irritates eyes and airways; wear goggles, gloves and a dust mask when weighing. Wash spills off skin promptly.
• Dosing: make a 5-10% stock solution in warm water and add by surface-tension control; never dump powder straight into a hot nickel tank (it can float, foam and locally over-dose).
• Hydrolysis note: K12 is a sulfate ester - in very hot, strongly acidic baths it hydrolyzes slowly. For acid baths above 50°C consider the sulfonate analog (sodium dodecyl sulfonate), which is hydrolysis-stable.
• Foam management: keep an anti-foam spray or a low-foam backup wetter near rack lines; a foam-over during a production run costs brightener and floor time.
• Storage: sealed bags in a dry store; K12 absorbs moisture and the active content of a badly stored bag drifts. Shelf life sealed: 12+ months.

What It Does on Iron, Zinc Alloy, Copper and Stainless Steel Parts

FAQ

Pinholes ruining your nickel finish? Send QLQ engineering a Hull cell panel and bath data - our chemists help plating shops in 10+ countries trace pitting to wetting, filtration or contamination. Contact us.