LIQUID DISHWASHER RINSE AID

MANUFACTURING PROCESS

Overview

Liquid Dishwasher Rinse Aid is a low-foaming, surfactant-based wetting and sheeting agent designed to reduce water spots and speed up drying on dishes, glassware, and cutlery after the final rinse cycle in automatic dishwashing machines.
Its formulation typically contains nonionic surfactants, alcohols, citric acid, solvents, hydrotropes, dyes, and preservatives.

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1. RAW MATERIALS

Main Ingredients

• Nonionic Surfactants (Low Foam): Alcohol ethoxylates, secondary alcohol ethoxylates, modified EO/PO surfactants

• Acid Agent: Citric acid or organic acid blend (for pH control & water spotting reduction)

• Solvents: Isopropyl alcohol, ethanol, propylene glycol

• Hydrotropes: Sodium xylene sulfonate, sodium cumene sulfonate

• Defoamer (Optional): Silicone-based antifoam

• Chelating Agents: GLDA, EDTA or MGDA

• Colorant & Fragrance (Optional)

• Preservative: Phenoxyethanol, CMIT/MIT or benzisothiazolinone

• Water: Deionized or softened water

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2. EQUIPMENT REQUIRED

• High-speed mixer or propeller mixer

• Stainless steel mixing tank (with heating option if needed)

• pH meter

• Conductivity meter

• Filling machine

• Storage tanks and filtration system (optional)

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3. MANUFACTURING PROCESS (STEP-BY-STEP)

Step 1 – Water Charging

• Add deionized water (approx. 60–80% of batch) into the mixing vessel.

• Start the mixer at medium speed.

Step 2 – Acid & Solvent Addition

• Dissolve citric acid completely in water.

• Add solvents (IPA, ethanol, or propylene glycol).

• Mix until fully uniform.

Step 3 – Surfactant Addition

• Slowly add low-foam nonionic surfactants.

• Maintain mixing at 25–35°C to avoid excessive foam.

• Mix thoroughly until a clear or slightly hazy solution forms.

Step 4 – Hydrotrope Addition

• Add Sodium Xylene Sulfonate (SXS) or Sodium Cumene Sulfonate (SCS) to stabilize clarity and improve solubility.

Step 5 – Chelating Agent

• Add GLDA / MGDA / EDTA, mix until completely dissolved.

Step 6 – Defoamer (Optional)

• If needed, add silicone defoamer in small quantities (0.05–0.2%).

• Mix slowly to avoid destabilizing the silicone droplets.

Step 7 – Preservatives & Additives

• Add preservative, dye, fragrance (if used).

• Mix gently to ensure full dispersion.

Step 8 – pH Adjustment

• Adjust pH to 2.5 – 4.5 depending on formulation type.

• pH is critical for water spot reduction.

Step 9 – Top-Up & Final Check

• Add the remaining water to reach final batch volume.

• Continue mixing until the product is perfectly homogeneous.

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4. QUALITY CONTROL PARAMETERS

• Appearance: Clear or slightly blue transparent liquid

• pH: 2.5 – 4.5

• Viscosity: Low (20–60 cps)

• Density: 1.00 – 1.04 g/mL

• Foam Level: Very low (low-foam surfactant system)

• Stability: No separation at 45°C / 24 hours

• Spotting Performance: Must leave glass streak-free

• Conductivity: Used for batch consistency

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5. PACKAGING

• HDPE or PET bottles (250 mL – 1 L)

• Bulk packaging for industrial use (5 L – 20 L)

• Ensure the product is acid-compatible and UV-stable

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6. APPLICATION

• Used in the final rinse of automatic dishwashers

• Typical dosage: 2–4 mL per rinse cycle

• Ensures fast drying, spot-free shine, and improved sheeting action