Alkaline Degreasing Additive For Oxidation
LW-31A Alkaline Degreasing Additive For Oxidation is suitable for pretreatment of anodic oxidation process to aluminum and its alloys. It can effectively remove natural oxide film, oil stain, burr, floating sands on the surface of the sand-blasted aluminum profiles and at the same time, it can simplify the production processing steps and obtain a clean, uniform, delicate and soft metal surface.
1. Comparisons of LW-31A alkaline degreasing process with traditional process:
Process | Traditional alkaline etching pretreatment process | LW-31A Process |
Complexity of Production Process | The production efficiency is affected by complex processes. The number of standard treatment process baths before oxidation is 10, Before aluminum profiles enter into alkaline etching bath, the degreasing process is requested and with degreasing additive consumed, what is more, after alkaline etching process, the surface ash is serious and needs to be treated in nitric acid + sulfuric acid neutralization bath. This kind of ash is difficult to be removed, special neutralization and ash removal additive should be added to the bath, so the cost of degreasing and neutralization ash removal is high. | Simple process with 6 baths before anodization: weak acid rinsing → rinsing → alkaline degreasing LW-31A→ rinsing - sulphuric acid neutralization → oxidation. In this process flow, there is no need to prepare special acid degreasing bath or add acid degreasing additive before LW-31A bath. Only configure the 10-20 g/L dilute sulfuric acid or other acid containing rinsing bath is ok. After LW-31A degreasing process, there is no ash or only a little ash on profiles surface, which can be neutralized by ordinary sulphuric acid, thus, the neutralization cost is very low.
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Acidic Waste Water Amount | A large amount of acidic (fluoride-containing) waste water is produced and the amount of waste water produced in the production of per ton aluminum profiles are 5-8 tons. It accounts for most of the acidic waste water produced by the whole oxidation line. | Very little acid waste water is produced, on the contrary, about 2-3 tons of alkaline waste water is produced per ton of aluminum profiles, which saves a lot of waste water treatment costs. |
Aluminum Loss | The loss of aluminum is large. The average loss of aluminum is 10-15kg per ton of aluminum profiles. If the annual output is 10000 tons, the waste weight of extrusion billet is 100-150 tons per year. | Compared with the traditional alkaline etching process, the aluminum loss is lower, the average aluminum loss is about 1-5kg / T, and the annual saved cost of raw materials is very considerable. |
Waste Residue Amount | A large amount of waste residue is produced, which increases the production cost. More than 70% of the oxidized waste residue is produced by alkaline etching bath.
| Strictly controlled according to the process requirements, there is no waste residue produced in the alkaline degreasing process, which saves the cost of waste residue treatment. |
Workshop Environment | Alkaline etching bath will produce a lot of alkali fog when it works, it is not only deteriorates the working environment of the workers, but also destroys the workshop equipment, oxidation and electrophoresis process, and increases the management cost.
| No alkali fog and alkali odor produced which achieves a friendly workshop environment. |
Environmental Protection of Formula | F- containing | F- free |
Comprehensive Cost | The average consumption of sodium hydroxide per ton of aluminum profile is 20-30kg, and the consumption of alkali etching additive is 2-3kg. The comprehensive production cost is relatively high. | The average consumption of sodium hydroxide per ton of aluminum is 5-10 kg, and the consumption of LW-31A is 1-2 kg. The comprehensive production cost is low. |
2.Bath Make-up:
Name | Quantity | Unit |
LW-31A | 10-12 | g/L |
Sodium hydroxide (NaOH) | 10-20 | g/L |
Water | Balance | |
3. Operating Conditions:
Name | Quantity | Unit |
Temperature | 45-55 | ℃ |
Time | 3-5 | min |
PH | 10-13 |
4. Solution Maintenance:
1、Analyse the bath solution PH value and the content of aluminum ion and NaOH every day. Control the free alkali at 10-20 g/L .
2、Replenish LW-31A by 1-2kg (normally 1.5kg) per ton aluminum profiles in normal production. Replenish sodium hydroxide according to the bath solution analysis results and the surface effect.
3、Under normal process conditions, when the aluminum ion reaches 30-40g/L, the bath solution parameters can be automatically balanced and stable operation.
5.Packaging and Storage:
Package: Plastic barrel (25kg/barrel,1000kg/barrel)
Storage: Suggested to store in cool, dry and well ventilated place; away from fire and heat source.
