Zeolite Detergent Grade

Zeolite 4A type

Although washing habits differ from country to country,there is a trend towards easier handling (compact powders, tablets). First and foremost, however, the consumer continues to demand a clean wash combined with maximum protection of the items laundered. The resulting requirement to continuously improve the performance of detergents is leading to the use of new or optimised raw materials.To a large degree, the aforementioned challenges dominated the development of detergents in the 1980s and 90s.

Zeolite Detergent Grade, originally designed as a phosphate substitute for purely ecological reasons, increasingly had to meet the demands imposed by modified detergent composition and production technologies. In particular, the trend towards compact detergents increased the demand for builder systems with a high adsorption capacity for liquid components, especially for surfactants.

Zeolite detergent grade introduced approximately 42 years ago, proved to be a good carrier for surfactants and in the 90s advanced to become the builder leading to compact and supercompact detergents. Nevertheless, the market demanded further improvements. The manufacturers of zeolites detergent grade responded to the demand for higher standards of performance and processing by developing new grades of zeolite. These include the zeolites of types P, X and AX, which have all recently been introduced into the market.

In the early 70s, a systematic quest for phosphate substitutes led to research into synthetic zeolites as builders for detergents.All detergent zeolites are characterized by a high aluminum content. According to Lowenstein’s rule, not more than half the Si atoms in the crystal lattice can be replaced by Al atoms. In the case of detergent zeolites, an Si/Al ratio of 1 or virtually 1 is achieved.

This in turn results in a maximum content of Na+ ions, which are necessary to neutralize the AlO2- units. Since Na+ ions are able to move in the zeolite pores, they can easily be exchanged for calcium ions, and sometimes other ions.

Chemical Formula of Zeolite 4A :

Water can be softened either by complexing (e.g. phosphates), ion exchange (e.g. zeolites), or precipitation (e.g. sodium carbonate). In the case of complexing agents and ion exchangers, the water softening additionally prevents the formation of poorly soluble inorganic salts, which are a key factor in the formation of textile incrustations.

Detergent builders also contribute towards the inhibition of greying and the removal of dirt. Beyond these tasks that relate purely to the wash, builders also perform important functions in the production process. In spray-dried detergent powders, they make a key contribution to the structure of the washing powder (hence the name “builder”).

In non-tower processes, they serve as a carrier for liquid components. When the first heavy-duty detergents were marketed at the beginning of this century, the first builders they contained were sodium carbonate and sodium silicate. From the 30s onwards, the more effective phosphates performed the role of builders. The introduction of phosphate-reduced (1976) and later phosphate-free detergents (1983) marked the beginning of the era of builder systems containing zeolites (sodium alumino silicate).

Before Zeolite A was first used as a builder in detergents, a number of questions needed to be answered concerning its behavior in the laundering process. Results showed that, despite its insolubility, Zeolite 4A does not lead to the excessive incrustation of fibers. This is due to its specific, optimized particle shape (rounded corners and edges) and particle size (mean value of 3.5 μm).

Due to the slower kinetics of ion exchange as compared to phosphate, it emerged that Zeolite A was not capable of completely suppressing the precipitation of calcium carbonate, especially at high washing temperatures and elevated water hardness. In view of this fact, it was necessary to add a soluble builder. Whilst Zeolite Detergent Grade had first been combined with sodium triphosphate, the addition of polycarboxylate subsequently proved to be significantly more effective.

The polycarboxylates are able to delay the formation and precipitation of poorly soluble calcium carbonate, by inhibiting crystal growth even when applied at low concentrations in the substoichiometric range (threshold effect) and through their dispersive action. This finding led to what has since 1983 been the dominant builder system for phosphate-free detergents and which is comprised of Zeolite 4A, polycarboxylate and sodium carbonate.

Several tests by independent consumer test organizations have demonstrated an excellent performance for these phosphate-free detergents in comparison to phosphate-containing products.Tested under critical conditions, the phosphate-free builder system containing zeolite even proved superior to the earlier sodium triphosphate system.

Systems containing phosphates require precise dosage which must be monitored exactly in relation to the water hardness, otherwise significant fiber incrustation will occur caused by phosphate precipitation. By contrast, zeolite-based systems even at low dosages and elevated water hardness tend to cause only low textile incrustation and deposits on washing machine parts. This robust performance under a wide range of conditions and the high degree of flexibility in formulation terms facilitated the development of the zeolite-based low dosage compact detergents.

Alongside its main function (that of softening water) zeolite also has other proven effects in the laundering process. Zeolite detergent grade for instance promotes the inhibition of greying through heterocoagulation with dirt particles. Furthermore, zeolites can remove dyes from the washing liquor by heterocoagulation and adsorption. In conjunction with the relatively low sodium concentration associated with zeolite as compared with soluble builders, this leads to a reduced risk of dyes discoloring other items. Zeolite is the builder of choice for special products termed “color detergents”.

Generally, zeolites detergent grade possess a number of advantages over other builders during the production of detergents. For example, zeolites display very high product stability, regardless of the particular process employed (spray drying, granulation, extrusion, etc.).

They prove inert when exposed to elevated temperatures, mechanical influences, or alkalinity. Partial decomposition or chemical conversion, as can occur with sodium triphosphate or specific layered silicates depending on the process design, has not been reported with zeolites. This makes zeolites particularly flexible materials for the production of detergents. Additionally, zeolites are used as effective flow aid for powder handling.

Specification

A further salient feature of zeolites is their high adsorptive capacity for liquid components, e.g. surfactants. This property facilitated the development of the surfactant-rich compact detergents which have now been on the market since the late 80s.

Properties of detergent zeolites in the laundering process

• minimized fiber damage via special particle morphology
• minimized incrustations due to the optimized particle size distribution
• high water softening capacity
• robust performance under a wide range of conditions
• inhibition of greying
• inhibition of dye transfer

Zeolite A is used in detergent production and storage

• the high adsorption capacity for liquid components
• high stability during processing
• effective flow aid for powder handling

Within the framework of this banner of “Code of Good Environmental Practice”, self-imposed obligation, detergent manufacturers aim to achieve the following targets by 2002:

• 5% of energy saved per wash
• 10% of product saved per capita
• 10% of packaging saved per capita
• 10% reduction in poorly degradable organic ingredients per capita

The relative humidity is not more than 90% of the indoor humidity. This zeolite should be far away from water, acid and alkali. Air isolation and sealing is quite necessary for storage.

We has been actively involved in development and production of zeolite products for more than 20 years. We continue to provide verious kind of zeolite products for our customers

ADVAN® 4A Zeolite are widely used as catalysts in the refining of crude oil into finished petroleum products.Zeolites are also increasingly finding use in the production of petrochemicals, often replacing environmentally unfriendly catalysts. Unlike more hazardous acid catalysts that have been used in the past, zeolites are non-hazardous, regenerable, and non-corrosive.