Hidrojen peroksit ile ağartılmış ve optik beyazlatılmış pamuklu kumaşlarda görülen sararmanın incelenmesi

Abstract

In order to eliminate the undesirable yellowness of white fabrics, home blueing is often resorted to. A small amount of ultramarine applied to the cloth eliminates the yellowish tint of the fabric. When optical bleaching agents are imployed a part of the blue radiation emanated by these substances under the action of ultra-violet rays is used for the neutralization of yellowness, and the remaining part is added to the light reflected from the specimen. Most widely used are bleaching agents from the stilbene series, especially such derivatives as 4,4'-diamino,2,2*-stilben-sulphonic acids, for instance direct white : <^ y-M CO HN^ y~cH -HC~( ^NHCPHAK^ ^> HO3S SO^H Of great importance are optical bleaching agents on the basis of cyanuric chloride, for instance blanckophor B *çy HQ,S SCfeH Y R R These substances are characterized by intensive fluorescence and high substantivity towards cellulose fibre. Almost 90% of these substances used for treating cellulose fibres are derivatives of stilbene triazine. The behavior of these substances, their stability and strength depend on the form of radicals R and R'. At present, in many countries white textile goods are treated with these substances, and a number of firms produce a large variety of optical brightening agents. Some investigators advise the use of a combination of some optical and chemical bleaching agents, i.e., combined chemical and optical bleaching. Others recommend to combine the use optical brightening agents with the treatment of fabrics with precondensation products of synthetic resins or with various finishing agents. A great disadvantage of optical brightening agent is that fluorescence is considerably reduced under the influence of many external factors and their resistance to light is low. This study is concerned with the yellowing that takes place on cotton fabrics after peroxide bleaching and optical brightenings. A wide range of optical brightening agents and some softeners have been tested and the yellowing on textiles has been observed. The following parameters have been investigated in order to detect yellowing possibilities. 1- The behavior of optical brightening agents in different concentrations. 2- The behavior of softeners. 3- The influence of pH of the bleaching bath. 4- The fabric processing conditions. xm In order to eliminate the undesirable yellowness of white fabrics, home blueing is often resorted to. A small amount of ultramarine applied to the cloth eliminates the yellowish tint of the fabric. When optical bleaching agents are imployed a part of the blue radiation emanated by these substances under the action of ultra-violet rays is used for the neutralization of yellowness, and the remaining part is added to the light reflected from the specimen. Most widely used are bleaching agents from the stilbene series, especially such derivatives as 4,4'-diamino,2,2*-stilben-sulphonic acids, for instance direct white : <^ y-M CO HN^ y~cH -HC~( ^NHCPHAK^ ^> HO3S SO^H Of great importance are optical bleaching agents on the basis of cyanuric chloride, for instance blanckophor B *çy HQ,S SCfeH Y R R These substances are characterized by intensive fluorescence and high substantivity towards cellulose fibre. Almost 90% of these substances used for treating cellulose fibres are derivatives of stilbene triazine. \/ H0£ i^H \/ k it Xll The behavior of these substances, their stability and strength depend on the form of radicals R and R'. At present, in many countries white textile goods are treated with these substances, and a number of firms produce a large variety of optical brightening agents. Some investigators advise the use of a combination of some optical and chemical bleaching agents, i.e., combined chemical and optical bleaching. Others recommend to combine the use optical brightening agents with the treatment of fabrics with precondensation products of synthetic resins or with various finishing agents. A great disadvantage of optical brightening agent is that fluorescence is considerably reduced under the influence of many external factors and their resistance to light is low. This study is concerned with the yellowing that takes place on cotton fabrics after peroxide bleaching and optical brightenings. A wide range of optical brightening agents and some softeners have been tested and the yellowing on textiles has been observed. The following parameters have been investigated in order to detect yellowing possibilities. 1- The behavior of optical brightening agents in different concentrations. 2- The behavior of softeners. 3- The influence of pH of the bleaching bath. 4- The fabric processing conditions. xm In order to eliminate the undesirable yellowness of white fabrics, home blueing is often resorted to. A small amount of ultramarine applied to the cloth eliminates the yellowish tint of the fabric. When optical bleaching agents are imployed a part of the blue radiation emanated by these substances under the action of ultra-violet rays is used for the neutralization of yellowness, and the remaining part is added to the light reflected from the specimen. Most widely used are bleaching agents from the stilbene series, especially such derivatives as 4,4'-diamino,2,2*-stilben-sulphonic acids, for instance direct white : <^ y-M CO HN^ y~cH -HC~( ^NHCPHAK^ ^> HO3S SO^H Of great importance are optical bleaching agents on the basis of cyanuric chloride, for instance blanckophor B *çy HQ,S SCfeH Y R R These substances are characterized by intensive fluorescence and high substantivity towards cellulose fibre. Almost 90% of these substances used for treating cellulose fibres are derivatives of stilbene triazine. \/ H0£ i^H \/ k it Xll The behavior of these substances, their stability and strength depend on the form of radicals R and R'. At present, in many countries white textile goods are treated with these substances, and a number of firms produce a large variety of optical brightening agents. Some investigators advise the use of a combination of some optical and chemical bleaching agents, i.e., combined chemical and optical bleaching. Others recommend to combine the use optical brightening agents with the treatment of fabrics with precondensation products of synthetic resins or with various finishing agents. A great disadvantage of optical brightening agent is that fluorescence is considerably reduced under the influence of many external factors and their resistance to light is low. This study is concerned with the yellowing that takes place on cotton fabrics after peroxide bleaching and optical brightenings. A wide range of optical brightening agents and some softeners have been tested and the yellowing on textiles has been observed. The following parameters have been investigated in order to detect yellowing possibilities. 1- The behavior of optical brightening agents in different concentrations. 2- The behavior of softeners. 3- The influence of pH of the bleaching bath. 4- The fabric processing conditions.