Alkaline Cleaning Chemicals

Alkaline cleaning chemicals are high-pH formulations that remove oils,ngreases, and shop soils from metal parts by saponifying and emulsifying them.nIn industrial manufacturing this family covers two opposite jobs on the pH scale:ncaustic and silicate-based alkaline cleaners that strip organic soils, and mineralnacids that dissolve scale, rust, and oxide. Most parts-cleaning lines run both innsequence u2014 an alkaline wash, then an acid descale or pickle u2014 because neither removesnthe other's soil.

Caustic soda (sodium hydroxide) is the workhorse alkali for industrial parts cleaning.nIt is dosed to build the bath pH that saponifies oils and lifts shop grime. Caustic isnaggressive on aluminum and zinc, so specify it for ferrous parts, or pair it with anninhibitor and a silicate buffer when cleaning soft metals. Buying it in beads simplifiesndosing and storage versus liquid caustic for shops that mix baths on demand.

Hydrochloric and phosphoric acid handle the descaling side. Hydrochloric acid picklesnmill scale and rust fast, but it attacks the base metal if a part soaks too long, soncontrol concentration and dwell time. Phosphoric acid works more slowly, leaves a mildnphosphate film that aids paint adhesion, and is preferred where some flash-rust protectionnbetween steps is wanted. The trade-off is speed against substrate loss: fast picklingncosts metal.

• Alkaline soak and spray washing of ferrous parts before paint or plating
• Acid descaling and pickling of mill scale, rust, and heat-treat oxide
• Phosphate conversion pretreatment for paint adhesion and corrosion resistance
• Surface activation and metal brightening ahead of coating or assembly
• Bath make-up and pH control in industrial parts-washer and immersion lines

• Sodium hydroxide u2014 PubChem
• Hydrochloric acid u2014 PubChem
• Phosphoric acid u2014 PubChem