CS199139B1 - Method of pretreating textile substrates for emery sheets - Google Patents

Description

The invention solves the pretreatment of textiles intended for the application of emery abrasive, ensuring the impermeability and reduced water absorption of the base fabric.

The previous pretreatment consists in peeling the fabric with hardening solutions, for example glue, starch, followed by drying on one side, for example by means of a trowel-rubber pad, followed by drum drying. The curing process is carried out from the opposite side to which the emery layer comes on. The coating pastes are a mixture of glue, starch, kaolin, powder obtained by evaporation of sulphite lyes β with small admixtures of soap, wetting antimicrobial and hygroscopic preparations and colored pigment. The purpose of this pretreatment is to prevent leakage of the glue solution when gluing the emery layer to the other side of the fabric. In order to achieve the required reduction in leakage rates, a simultaneous 2 to 3 times repetition of the coating is required, which significantly reduces productivity. In some cases, additional starching or sizing by peeling or coating is still necessary after the coating. In some fabrics, the initial flap may be omitted and the ee will proceed directly to the incision. On the whole, however, the current variants of the pretreatment of emery textiles are a common principle of mechanical leakage prevention, ie. we want to maximize the fabric filling. Also, checking is normally done by assessing transparency

pre-treated fabrics. The disadvantage of the described method can be seen in the necessity of repeated repetition, coating.

In contrast, the method according to the invention focuses on the chemical or physico-chemical pathway of preventing or reducing the penetration of aqueous textile adhesive systems. The invention also uses preparations which it applies to fibers or textiles. It is based on the fact that the base fabric is hydrophobically treated by kinking with a hydrophobic dispersion and by applying a hydrophobic paste or only by applying a hydrophobic paste on a paraffin or wax base with the addition of aluminum or zirconium salts and / or optionally based on aluminous or zirconium soaps chromateearyl chloride. Alternatively, the dispersion also includes a paste of variously combined mixtures of said materials, for example a mixture of aluminum and zirconyl soaps and the like. Optionally, binders and stiffeners such as starch, starch derivatives, cellulose derivatives, dextrin, glues, acrylic, polyethylene, polyvinyl acetate, polyacrylonitrile polymers can be added. , fillers and loaders such as kaolin and finely ground limestone, and finally anti-rot and antifungal agents such as borax, blue vitriol, salicylic acid, etc. Only some or some of these substances may be used in amounts of 20 to 50 g / kg of dispersion or paste.

The hydrophobic dispersion suitable for treating backing fabrics comprises 10 to 180 g / kg of dispersed paraffin or wax and 1 to 15 g / kg of aluminum or zirconium salts, optionally additionally or only 5 to 150 g / kg of aluminum or zirconium soaps or 5 to 90 g / kg of chromstearyl chloride.

The hydrophobic paste contains 20 to 300 g / kg of dispersed paraffin or wax paste with an addition of 1 to 20 g / kg of aluminum salts such as sulfate, formate, acetate, aluminum alum or an equal amount of zirconium salts such as zirconium chloride, ammonium nitrocarbonate. In addition, the paste comprises an aluminum or zirconium soap formed from 7 to 60 g / kg of sodium or potassium soap and from 10 to 80 g / kg of aluminum sulphate or aluminum alum or ammonium zirconium carbonate. The hydrophobic paste may comprise either only aluminum or zirconium soap or only paraffin, wax and aluminum or zirconium salts. The hydrophobic coating paste is alternatively composed of 5 to 90 g / kg of chromstearyl chloride and optionally 10 to 180 g / kg of dispersed paraffin or wax. Preferably, 3 to 40 g / kg of concentrated waterglass solution can be added to the hydrophobic paste.

In general, hydrophobizing agents based on other bases can be used, for example most of the so-called permanent Si stable water-repellent treatment. However, from an economic point of view and in terms of the resulting desired properties of the backing fabric, the use of these more expensive formulations appears unsuitable. The hydrophobising agent is applied to the fibers or fabric either on both sides of the entire fabric mass by kinking on the foil and subsequent drying, or one-sided, i.e. by mixing the hydrophobising agent into the coating paste for the gravel coating method, textile. Alternatively, the coating can be applied gradually from both sides. Alternatively, a combination of the above two methods may be used, i.e., most commonly, first by cloning with an impregnation containing a bydrophobizing agent and subsequent one-sided coating with a paste containing a hydrophobizing agent in addition to conventional hardeners and fillers.

The main aim and advantage of the process according to the invention is the saving of 1 and 2 closing abutments, possibly the possibility of omitting the final starching or sizing, or the initial starching, the method of physically chemical modification of the textile surface, ie achieving a certain water repellency, reducing the sorption of aqueous solutions. mechanical filling, which may, however, be considerably less also in the case of pre-treatment in the prior art. Therefore, it is advisable to use hydrophobizing agents which also contribute to the filling effect, emulsions of paraffins, waxes, aluminum soaps, etc.

The upper limit of dosing of the hydrophobizing agents into the float finish or coating paste is governed by the spread of the glue solution during application of the emery, and at the same time the gluing strength, i.e. the anchoring of the emery on the textile base, must be taken into account. The maximum usable concentration of hydrophobic preparations should be determined by experiment, it varies considerably depending on the material composition, method of production and content of waxes and fats, as well as preparation, fabric softeners and similar products contained in fibers.

The process according to the invention opens the possibility of using viscose staple fabrics for emery, sheets or strips, since it regulates the amount of glue solution that penetrates into these highly hydrophilic fibers. If the fabric is oversaturated with the glue solution, the final product becomes too brittle. Similarly, in the case of nonwoven fabrics containing a viscose fleece, the absorbency of the fabric is expediently reduced by the process according to the invention, while the productivity in the pretreatment is increased. At the same time, it is advantageous here to combine a hydrophobizing agent * with a binder based on acrylates, polyvinyl acetate, polyethylene, polyacrylonitrile and the like in the flocculation bath, which contributes to the stability of the fabric during the application of emery and subsequent drying. In addition to these typical fields of application of the process of the invention, it can also be advantageously applied in the pre-treatment of conventional cotton fabrics intended for emery sheets or strips, avoiding 1 to 2 coats or preliminary optional starching or sizing. A special case of use is the pretreatment of sandpaper for underwater sanding, in which reducing the absorbency of the textile backing is no longer only an auxiliary property in the next manufacturing operation, i.e. the application of emery, but is an essential utility of the final product.

Example 1

The cotton fabric is wrapped on a foulard with a bath of 35 g / l paraffin-based, degraded glue and aluminum salts and 40 g / l degraded starch. This is followed by drying on a drying fixation frame. The fabric is then unilaterally wiped with a paste containing in aqueous medium the following components per kilogram of paste: 220 g of kaolin, 80 g of starch, 50 g of paraffin-based preparation, degraded glue and aluminum salts, e.g. product Depluvin T, 15 g glue, 15 g dried sulphite liquor, 3 g industrial salt, 10 g aluminum sulphate. One coat with this paste is sufficient to achieve satisfactory * emery application behavior. In a number of cases, for more compact and heavier fabrics, this single coating can be carried out with a conventional coating paste if previous bathing containing a paraffin-based, degraded glue and aluminum salt composition at a dosage of 40 to 100 g / l has been performed. is indicated at the beginning of this example.

Example 2

The nonwoven fabric containing viscose fleece, cotton warp, and PAD binder silk is fed to a foulard bath containing 100 g / l of paraffin-based composition, degraded glue and aluminum salts, known as MS. product Depluvin T and 60 g / l aqueous polyvinyl acetate dispersion, commercial product. Disapol TK 163 Cs. production. This is followed by drying and subsequent thermofixation of the PAD fraction on the drying fixation frame. Apply one or two coats of composition:

. a) as shown in Example 1,

b) or a coating paste containing aluminum or zirconia soaps as a hydrophobizing agent. The composition of the paste per kilogram is 200 g of kaolin, 30 g of starch, 50 g of carboxymethylcellulose, commercial product Lovosa čs. production, 20 g of glue, 5 g of industrial salt, 10 g of sodium soap, 14 g of aluminum sulphate or 10 g of alum, or 13 g of ammonium zirconium carbonate are used instead of the last two substances,

o) or a coating paste containing aluminum soaps in combination with a paraffin dispersion as hydrophobizing components. The composition of the paste is the same as in Example 1 except that the paste contains 7 g / kg of sodium soap,

(d) or pastes of a composition referred to in alternatives (a) to (c), containing in addition 5 g / kg waterglass of 40 ° Bé,

e) or a coating paste containing chromstearyl chloride as a hydrophobizing agent. The composition of the paste per kilogram is 180 g of kaolin, 90 g of starch, 20 g of glue, 3 g of industrial salt, 40 g of a concentrated solution of arylate chromate in isopropyl alcohol and 5 g of hexamethylenetetramine to blunt the acid resulting from subsequent drying.

Alternatively, the coating is carried out with two coatings of the conventional composition, i.e. without the hydrophobizing agent.

Example 3

The cotton fabric is rolled onto the foulard by a bath of the same composition as Example 1 and additionally containing 15 g of sodium soap, 20 g of aluminum sulphate and optionally 15 g of alum. Alternatively, instead of the last two, 26 g of ammonium zirconium carbonate are used, or a ready-mixed mixture of paraffin, aluminum bolts and zirconium stearate, commercially known as Dichtfest Z 141, a product of the GDR, is used at a rate of 60 g per liter bath. This is followed by coating with a hydrophobic paste according to one of the possibilities given in Example 2. '

Example 4

The non-woven fabric containing viscose fleece and viscose viscose rayon is rolled onto a foulard bath containing 150 g / l paraffin-based glue and degraded glue and 30 g / l aqueous dispersion containing 50% polyvinyl acetate · Drying on drying frame follows · One or two wipes alternatively for thinner textiles by three coatings in the ways described in example 2 ·

Example 5

The nonwoven fabric described in Example 4 is covered with a bath of 30 g / l chromstearyl chloride, a concentrated solution in isopropyl alcohol, with the addition of compounds which suppress the acidic environment resulting from subsequent drying, i.e. 30 g / l sodium formate and 80 g / l urea. eventually 7 g / l hexamethylenetetramine · Klocation and drying is followed by coating with one of the methods given in example 2 ·

Claims (5)

A method of pretreating a backing fabric for emery sheets or sheets, providing impermeability and reduced absorbency of the backing fabric prior to bonding the abrasive powder, characterized in that the backing fabric is hydrophobically peeled by hydrophobic dispersion and hydrophobic paste only or with hydrophobic paste only. addition of substances with bonding, stiffening, weighting, antifouling, filling and antifungal properties or with the addition of any of the following: 3. The pre-treatment method according to claim 1, characterized in that it is garmented with a hydrophobic dispersion and coated with a hydrophobic paste based on paraffins or waxes and salts of aluminum or zirconium and / or aluminum or zirconium soaps. 3. Substrate pretreatment method. fabric according to claim 1, characterized in that it is garbled. hydrophobic dispersion and rubs with a hydrophobic paste based on chromstearyl chloride. The fourth ground fabric pretreatment method according to claim 1 or 2, characterized in that the hydrophobic klocu- dispersion containing 10 to 180 g / kg or dispersed paraffin wax and from ¹ to 1 5 ^{g / kg} of aluminum net> oz ^{and h} rkonylovýc my ^d El and ^/ no ^b 5 to 15 ^{0 g / kg} salt ^{i h} l ⁱ it ^to at or zirconium p ^{of manufacture} then ^{possibly 20} and ^from the ^{150 g / kg of} L ^ix St ^l as ^t nose ^t m ^and a ^binding, ^ now running ^ RNI, ^{pl nus} sentation, zatežkávacímí., Prot ^ n ^ obnými and protip ^ dreamy 'as lowly ^{b, d} Eriva ^and TU starch ^d Eriva ^the ce ^l u ^l oz ^y, dextran, ^{glues, poly} mer ^y akrylátev ^ potyetytenové, ^{the poly} vinyl acetate ^and tov ^s, pol ^y afcrylonitrilcv ^s, kaolin. ^of finely ground limestone, borax, blue skaHce, ^alkyl salicylic Selina like. - 5. A method of pretreating a backing fabric as set forth in claim 1 or claim 2, wherein the backing fabric is coated. . r ^s h ^yd ro ^f Pers onal c paste containing? ²⁰ and ^{about 300 g / kg} dispersed ^p ara ^fi nu or wasps ^to USP ^CMD and ^the EM ¹ and ^{20 g /} k ^g SOH ^hl in ^Cart with or zirconium, on ^{of ex} and ^d aluminum sulphate or zlrkonylchlor carbonate or ^ u ^'s amonnozirkonylov it and ^/ or zirconyl hli.nit ^Star or ^Star my ^dl ov ^yl ene as ^of from 7-60 ^{g / kg} of ^d n ^{b eh} of no race of ^{d l} n of ^eh my ^d la al ^{0-80 g /} k ^g siíranu aluminum or alum, alumina or carbonate amonnozirkonylového, taking into hydrofobrá passport ^{ype Rida} p ^{of manufacture} then ^possibly from ²⁰ to ^{150 g / kg} of substances with vlastnostei a binding, tužicíni, filling, as ^you from ^{ka i} mI vac ^for hnilotmými and prot ^ ^IPL ísnovým ^well as the sparsely-derivatives. ^šk ro u ^{b, d} er ^{even sulfates} celluloses ^{y, d} extrin, .klih ^y polymers acre ^yl acrylates ^{s, p} ol ^y e ^the Lenovo, ^{the poly} vinyl acetate, polyacrylonitrile, kaolin, finely ground limestone, borax, bluestone, salicylic acid and the like 6. The pretreatment method according to claim 1 or 3, characterized in that it is flocculated with a hydrophobic dispersion or not coated with a hydrophobic paste. containing from 5 to 90 g / kg chromstearylchloridu the addition of compounds to suppress the acidic environment during drying eg. 0.5 to 10 g / kg-hexametytente Tramín and ^{possibly d} and n ^{of 10} to ^{180 g / kg of di} er s ^{p g p} ylated ara ^fi nu or wax ^EXAMPLE £ doses ^{of 20} and ^{of the 150 g / kg of acrylate} e ^K vlasteostmi pojteími., benefiting p ^{l nothing} zatěžWvscími., anti-fouling and protlplíaňovými such as starch, starch derivatives, cellulose derivatives, dextrins, glue polymers of acrylate, polyethylene, polyvinyl acetate, polyacrylonitrile, kaolin, finely ground limestone, borax, blue vitriol, salicylic acid and the like. . A method of pretreating a backing fabric according to items 1 to 3, 5 and 6, characterized in that 3 to 10 g / kg of concentrated waterglass solution is added to the hydrophobic coating paste.