Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2002-01-07
2003-11-18
Gupta, Yogendra N. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
Reexamination Certificate
active
06649581
ABSTRACT:
The present invention relates to a cleaning process applicable to any laminated or nonlaminated, woven or nonwoven, thermoplastic material or flexible thermoplastic film and to an alkaline composition for said cleaning.
The present invention relates more particularly to a cleaning process applicable to any thermoplastic material made of impact polystyrene or of [sic] flexible thermoplastic film made of woven polypropylene or laminated or nonlaminated polyethylene and to an alkaline composition for said cleaning. These materials are encountered in the composition of numerous packaging types, for example in the form of big bags for the transportation of mainly food, chemical or cosmetic raw materials (milk powder, coffee, cocoa, condiments, carbon black, zinc oxide, and the like). These bags are known under the names of “flexible container”, FIBC (Flexible Intermediate Bulk Container) or “big bag” and are commonly used in industry.
After use, these materials can vary widely in condition, extending, for the most extreme cases, to the sometimes significant presence of mold, and their use in the food field therefore renders them particularly sensitive to the propagation of microorganisms or microbes (aerobic mesophilic flora,
Escherichia coli
, yeasts, molds, and the like). Unfortunately, as their composition shows poor resistance to high temperatures, the application of a conventional treatment, which consists in boiling them to obtain a sterilization compatible with contact with foodstuffs, irreversibly modifies their physical properties (shape, volume, sturdiness, conducting structure) and, when they are in the form of flexible containers, this treatment also damages the components of use to their users which they comprise, such as printing, logos, labels or document holders. It has in fact been observed, with certain containers made of polypropylene or polyethylene which have been subjected to an excessively severe treatment, that significant shrinkage occurs and that stacking is rendered difficult.
U.S. Pat. No. 3,908,680 has disclosed a process intended essentially for cleaning and for bleaching contact lenses which consists in bringing the lens into contact with a first aqueous solution and then with a second aqueous solution, one being acidic and the other basic, each of these solutions comprising a peroxo compound which releases active oxygen, in bringing the lens into contact with an ionic detergent, and in rinsing the lens with water. However, this process relates to the field of contact lenses, which is far removed from the fields of applications of the present invention. Furthermore, the contact lenses are not subjected to mechanical washing using an alkaline composition of detergent type.
Furthermore, European Directive 94/62/EC of December 94, relating to packaging and packaging waste, and French Decree No. 98-638 of July 98, relating to the taking into consideration of environmental requirements in the design and manufacture of packaging, provide measures and encourage solutions targeted at reusing all types of packaging, including those comprising the materials in question in their composition. This is because the latter are, for the most part, commonly discarded after a single use as, despite strong demand, the absence of a cleaning process which is effective without being too aggressive currently prevents any reuse of them.
The aim of the present invention is to provide a cleaning process and a cleaning composition which meet this demand without harming the qualities which characterize these materials when they are used.
A first subject matter of the present invention is a process for cleaning laminated or nonlaminated, woven or nonwoven, thermoplastic material or flexible thermoplastic film, for example in the form of big bags for the transportation of mainly food, chemical or cosmetic products, characterized in that it comprises, at a temperature sufficiently low to prevent any shrinkage and deformation of the abovementioned material or film, at least one stage of washing in an alkaline medium in a bath in the presence of an alkaline washing composition comprising at least from 5 to 18% of sodium hydroxide, from 3 to 12% of sodium carbonate, from 10 to 28% of sodium perborate and from 0 to 10% of surfactant(s), preferably from 2 to 10% of surfactant(s). The remainder of the alkaline composition is composed of a neutral support powder comprising a fragrance and/or various specific substances, such as a wetting agent, and/or of water, when the composition is in the liquid form. A single washing in an alkaline medium may be acceptable depending upon the use which will be made of the material or film, in particular in the field of chemistry.
According to another distinguishing feature, the stage of washing in an alkaline medium is followed by a stage of washing or sterilizing in a bath in the presence of a bleaching and disinfecting agent, and/or a stage of neutralization of the alkaline medium by an acidic product. These stages may prove to be necessary according to the field of application of the thermoplastic material or film, such as, for example, in the food-processing field.
Another subject matter of the present invention is a process for cleaning and sterilizing laminated or nonlaminated, woven or nonwoven, thermoplastic material or flexible thermoplastic film, for example in the form of big bags for the transportation of mainly food, chemical or cosmetic products, characterized in that it comprises at least the following stages at a temperature sufficiently low to prevent any shrinkage and deformation of the abovementioned material or film:
a stage of washing in an alkaline medium in a bath in the presence of an alkaline washing composition,
a stage of washing or sterilizing in a bath in the presence of a bleaching and disinfecting agent, and
a stage of neutralization of the alkaline medium by an acidic product.
According to one distinguishing feature, the two washing stages are carried out at a temperature of between 20 and 70° C.
According to another distinguishing feature, the two washing stages are each carried out over a duration of between 10 and 30 minutes.
The neutralization stage is advantageously carried out at an ambient temperature or under cold conditions.
The process advantageously comprises a pretreatment by wetting with cold water and/or followed by a post-treatment stage consisting of rinsing with water at an ambient temperature or under cold conditions. The entire treatment can be followed by spin-drying and/or by drying.
According to one distinguishing feature, the washing in an alkaline medium is carried out with an alkaline washing composition with a pH of between 10 and 14 and the neutralization of the medium is carried out with an acidic product with a pH of between 2 and 6.
According to another distinguishing feature, the concentration of the alkaline composition is from 15 to 155 grams per kilogram of dry material to be cleaned.
The bleaching and disinfecting agent is advantageously a solution of chlorine, of permanganate or hydrogen peroxide.
The chlorine solution advantageously comprises sodium hypochlorite, chlorine and active chlorine.
According to one distinguishing feature, the concentration of bleaching and disinfecting agent is from 0.25 to 6% of the volume of the bath or from 1.5 to 37 grams per kilogram of dry material to be cleaned.
According to another distinguishing feature, the neutralization product is sodium hydrogensulfite or a sodium hydrogensulfite and sulfur dioxide composition. According to one characteristic, the concentration of neutralization product is from 1 to 25 grams per kilogram of dry material to be cleaned.
Yet another subject matter of the invention is an alkaline composition for the washing of laminated or nonlaminated, woven or nonwoven, thermoplastic material or flexible thermoplastic film, characterized in that it comprises at least from 5 to 18% of sodium hydroxide, from 3 to 12% of sodium carbonate, from 10 to 28% of sodium perborate and from 0 to 10% of surfactant(s), preferably fr
Lalle Jean-Yves
Lalle Marie-Jeanne
Gupta Yogendra N.
Petruncio John M
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