Foaming trigger sprayer, plastic, 28/410, black

Foam pump sprayer turns a liquid formulation into dense foam without propellant gas. When the lever is pressed, it does not atomise the liquid into a mist but mixes it with air and dispenses it as foam that spreads easily. Suitable for products applied over larger areas: bathroom and kitchen foam cleaners, foaming hand soaps, pet shampoos, upholstery cleaning agents, and foam shoe care products.

Foam stays on a surface longer than liquid, runs less on vertical surfaces, and can be dispensed more economically than pouring. For a cosmetics or household-product manufacturer, it is a straightforward way to turn an aqueous surfactant solution into a product with a more pleasant application experience. The sprayer has a 28/410 neck finish and is suitable for both cosmetic and technical formulations.

How foam is formed and what this means for the formulation

When the lever is pressed, the formulation is drawn up through the dip tube and forced through the foamer mesh, where the liquid stream is mixed with air. The sprayer does not create foam on its own — the formulation composition is decisive. Key points:

• Surfactants are essential – foam is only produced by a solution with a sufficient content of foaming surface-active agents, for example Cocamidopropyl Betaine, Sodium Coco-Sulfate, or Decyl Glucoside. Pure water, a hydrolat, or a surfactant-free solution will come out as a thin stream, not foam.
• Low viscosity – the formulation must be as fluid as water or only slightly thicker. The mechanism struggles to draw up gel cleansers and thickened shampoos, the foam is thin or does not form, and the mesh clogs.
• No oils or undissolved particles – oils, exfoliating particles, or undissolved powder will block the mesh. Oil-based formulations also destabilise foam.
• Surfactant concentration determines foam quality – too much surfactant produces dense foam but makes rinsing harder and can leave a film on surfaces in the case of cleansers. Test several concentrations and choose the one at which the foam is stable and rinses off easily.

Use with a bottle

The sprayer is designed for bottles with a 28/410 neck finish. Compatible bottles and ready-made bottle-and-sprayer combinations are available in the Handymade range. The transparent dip tube is long enough to reach the bottom of taller bottles. For a shorter bottle, cut it to length with a sharp knife or scissors so that the end touches the bottom without bending. A bent dip tube draws in air, producing uneven foam.

Do not fill the bottle to the brim. The nominal volume is the amount the bottle is designed for. The total capacity up to the brim is greater, but part of it is taken up by the sprayer head and dip tube, so the formulation would overflow when closing. Fill only to the nominal volume, not to the neck. With your own bottle-and-sprayer combination, verify the seal integrity, consistency of the dose, and the behaviour of the formulation after the filled package has been standing for several days.

Good to know

• Suitability for cosmetics – the sprayer is made of polypropylene (PP) and is suitable for use with cosmetic products. The declaration of conformity and technical documentation are available with the product.
• Before first use – rinse the sprayer with clean water, or pump a small amount of ethanol or isopropyl alcohol through it and allow it to dry. This removes any residues from manufacturing and transport.
• Cleaning and reuse – when changing the formulation or before storing, pump clean water through the mechanism. Dried surfactant in the mesh is the most common reason a sprayer stops foaming. A clean mechanism with a smoothly operating lever can be reused.
• Essential oils and solvents – polypropylene tolerates standard aqueous surfactant solutions and most cleaning formulations. For formulations with a higher proportion of essential oils, limonene, or organic solvents, verify in advance that the material does not soften and that the seal does not begin to leak.
• Chemically aggressive formulations – strong acids, alkalis, or chlorine-based cleaners can damage the spring and seals of the mechanism. For such formulations, carry out a storage test in the filled package and monitor dosing over several weeks.

Frequently asked questions