What are the ecological requirements of environmentally friendly pretreatment agents?

In textile pretreatment, relevant ecological requirements must be met when manufacturing and selecting pretreatment agents. Otherwise, even if the quality of the applied auxiliaries is high, the safety and ecology of the product will still be unqualified.

Ecological requirements for environmentally friendly pretreatment agents

As a kind of important textile auxiliaries, the ecological requirements of pretreatment agents are the same as other textile auxiliaries, and there are roughly the following eight items:

(1) High biodegradability

The biodegradability of the pretreatment agent refers to the property that it is oxidized and decomposed by microorganisms under certain conditions to generate harmless substances such as carbon dioxide, water and inorganic substances. Generally, the average biodegradation degree of the environmentally friendly pretreatment agent is required to be above 90%, and the initial biodegradation degree is above 80%.

(2) Low toxicity

The toxicity of pretreatment agents includes acute toxicity, repeated exposure toxicity, carcinogenicity, irritation, allergy, mutagenicity, fish toxicity, and aquatic bacteria and algae toxicity. Acute toxicity, fish toxicity and toxicity to aquatic bacteria and algae are expressed by LD50 (unit: g/kg), LC50 (unit: mg/L) and ECO50 (unit: mg/L), the value is greater than 100 (unit) Indicates safety, greater than 1 (unit) indicates availability, and less than 1 (unit) indicates strong toxicity. Acute toxicity, repeated exposure toxicity, carcinogenicity, irritation, allergy and mutagenicity, etc., are usually detected by Ames test (salmonella microsome test with and without enzyme activity).

(3) Low formaldehyde or no formaldehyde

For textiles that come into direct contact with the skin, it is necessary to ensure that the amount of formaldehyde produced by free and hydrolysis of the pretreatment agent does not exceed 30 mg/kg, while for other textiles, the formaldehyde content cannot exceed 300 mg/kg.

(4) Can not contain environmental hormones

Environmental hormones are chemical substances that are extremely harmful to human health and the ecological environment, also known as endocrine disrupting substances. At present, there are 70 kinds of environmental hormones banned in the international market. Among them, various hormones such as alkylphenols, phthalate plasticizers, chlorinated phenols, polychlorinated dioxins, etc. are all related to pretreatment agents.

(5) The content of extractable heavy metals cannot exceed the allowable limit

The toxicity of heavy metals to human body and aquatic organisms is more and more recognized and valued by people. The EU stipulates that the extractable heavy metal content in the pretreatment agent cannot exceed the following values (excluding the amount of heavy metals that are part of the molecular structure of the pretreatment agent, the unit is mg/kg): Ag 100, AS 50, Ba 100, Cd 20, Co 500, Cr 100, Cu 250, Fe 2 500, Hg 4, Mn 1 000, Ni 200, Pb 100, Se 20, Sb 50, Sn 250, Zn 1 500.

(6) 24 kinds of carcinogenic aromatic amines or 24 kinds of carcinogenic aromatic amines produced by cracking under specific (ie reducing) conditions, the content of which should not exceed the allowable limit of 30 mg/kg (Eco-Tex Standard 100 requires no more than 20 mg/kg) ).

(7) Can not contain adsorbable organic halide

Adsorbable organic halides include halogen-containing carriers, chlorinated hydrocarbon solvents, chlorine-containing bleaches, preservatives, halogen-containing pesticides, and halogen-containing fungicides.

(8) It cannot contain other harmful chemical substances, such as phosphate, polyphosphate, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, volatile organic compounds and banned pesticides.