DE1990729U - Phenolic resin bonded abrasive fabric - Google Patents

Description

DR-WALTERNiEtSCH.; ■ Ä *

Patent attorney file: 2105 Gbm

2 Hamburg 70 0Λ £ 1Πΐ77 * 9 * ί1

Schloßstraße 112-Posifadi 10914 Π Μ · D 1 UII ' ^LJt

Long distance call; 652-97 07-. ' . - - · -.-.-. Applicant: REICHHOLD CHEMIE AKTIENGBSELLSCHAET

■ Hamburg - 7-Qi Iversstr. 57 ■ '. \

Inventor: Hermann Singer and. Dietmar Wunderlich ",". both in Hamburg

Pheno Ihar z-bonded abrasive fabric sheet, __ ..

In the German utility model 19Ql j34O there is a phenolic resin bond Abrasive fabric web from finished, if necessary with the use of abrasive fabrics equipped with fillers Abrasive grain layer protected, which is characterized is that this is an intermediate plastic layer (2) between the carrier fabric (1) and the phenolic resin binder layer (4) from cured mixtures consisting of.

a) Epoxy resins based on / from bisphenol Aj.

b) at least one '. Epoxy resin based on Bisph.enol-A.,: Xvelches by reaction with castor oil, is internally plasticized and .. \ - ^; - "- ■■ ...-.-" ■, -

c) hardeners .-: "'". ^:: ; _:

As a further development of this phenolic resin-bonded S eh le.if fabric web according to utility model 1 9-01 340, it was found that an x ^ esentially improved abrasive fabric web is obtained if the abrasive grain carrier contained is made of regenerated cellulose fibers, in particular of the polynosic fiber type and where. -. "■ - ..- ■". ■ "-.- ■" ■ - _: a) the warp thread sized and finished, and the: size and first finish without a boundary layer adhered. ^: . tend to be connected. . / .; ■ "■■ '.. ^; ■' ---. - ■" -., - ■ _: ;; "■■■■ -"..; ~ '2 ■

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b) the weft thread has an initial finish. "".

In the present innovation, the abrasive grain carrier fabric prepared in this way is used then with an intermediate plastic layer (2) between the carrier fabric (1) and the phenolic resin binder layer (4) provided "as already described in the German utility model 1-901? 40", otherwise can use all embodiments of this utility model the present innovation will be improved ... .

For the production of high-quality abrasive fabrics, which are used in many ways in the form of abrasive belts for machine grinding in the metal and woodworking industry, cotton fabrics are primarily used ... ) in question with a thread count per cm of 34/20;, 5 from cotton yarns of strengths 20/28 m / g ι the fabric weight - the desized fabric. is, about 235 g / m, a The warp direction has a breaking load of approx. 2; 5 kp / cm with an elongation at break of 17 $ ..., while the corresponding tensile strength values for the weft direction are at a breaking load of 10 kp / cm and an elongation at break of 8 % lien text Flächengebildeh according to DIN 53-857 · -The obtained result was divided by .3, of the 5 cm wide Prüf'streif s at 1 cm-.umzurechnen to.)

Since abrasive fabrics: ready-made as abrasive belts in their direction of use, that is, the warp or longitudinal direction of the fabric _{} may} only have a very low elongation, otherwise there is a risk "that the abrasive belts will be under the influence of the during the grinding process

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If the tensile stress that occurs is excessively long and runs down from the contact disk of the grinding machine, it is necessary to subject such fabrics to a stretching process during the finishing process in the wet state, which is fixed by incorporating finishing agents after the fabric has dried. A finished abrasive backing fabric based on the above-mentioned cotton fabric type has ζ. Β- the following properties: (for comparison, the corresponding raw fabric is listed again in the right column).

Finished raw fabric

Fabric (desized)

Medium basis weight 40 g / m ² 236 g / m ² Tear strength in
Warp direction kg / cm 23 kp / cm Elongation at break . '. ■ .. ■ ", 12, 5% 17th $ Tear strength in. _:
Weft direction - 20th 6 kg / cm 10 kp / cm Elongation at break $ 8th

It can be seen that the greater elongation originally present in the warp direction compared to the weft direction during the Tearing process through the stretching and finishing process is essential was decreased while the; Elongation, in the weft direction has increased significantly - in other: words: The stretching and finishing process resulted in the Warp direction existing stretch "partially in the weft direction relocated. An Easermaterial based on cotton possesses ideal precautionary tongues to keep it in when it is wet Warp direction_ to move forward strongly. In the case of cotton fibers or -weave namely takes the stretch at the beginning of the tearing-.

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Process already with little force to then hardly to increase with further tensile stress, d. H. it is possible, cotton fibers and, accordingly, cotton fabrics largely in the warp direction by a wet stretching process to equip with low stretch. '

Disadvantageous for the use of abrasive raw fabrics on the The basis of cotton is that it is relatively complicated must be subjected to prepared dry and wet finishing processes before they are: equipped in the actual sense, d. h «can be interpreted. The reason for this lies in the fact that one is responsible for the manufacture of sole fabrics Highly absorbent carrier fabric is required, as only these meet the requirements for perfect adhesion of the finish and Have binders on the fabric.

Cotton, however, contains growth-related substances of a waxy and fat-like nature, which; cause a considerable disturbance of the wettability and absorbency of the fabric and only through intensive, costly treatment pretreatment, such as desizing, alkaline decoction: and cupping - each in connection with numerous flushing processes - can be removed. .. - - "- - ^:: '- ; ..":; _: . "

There has been no lack of attempts. Abrasive fabrics made from cellulose materials, d ,. H. on the basis of regenerated Cellulose manufacture. As far as it is low-value Abrasive cloth sheets for hand sanding processes, this has already been practiced with great success for years. It but so far it has not yet succeeded perfectly, cellulose tissue for high-quality abrasive grain backing cloth webs :, the. to the

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Manufacture of sole fabric tapes suitable for machine grinding are to be used. This / is related to the fact that cellular wall fabrics of the conventional type compared to cotton fabrics have a greatly reduced wet strength compared to the corresponding strength values in the dry state. Furthermore, their swelling value - better water retention capacity - is significantly higher than with cotton fibers. It is also known that in the case of wool fiber types there is largely proportionality between the action of force and the elongation that occurs; it is therefore not possible, during the wet finishing, to fix the cellulose fabric with little stretch by mechanical stretching. - -: -'-.- ; '■■■■■■■ ■ / - ■ / "■ - ■ - .." ..

The latest developments in the Field _of the ZeIlstoffasern however, have led to rayon materials like approach in their dry in their Naßreißverhalten very to that of cotton. It can even be stated that the dry strength of such cellulose materials is significantly higher than that of cotton, while their elongation behavior during the tearing process in the dry as well as in the; wet condition largely corresponds to that of cotton fibers. At this stage in the development of cellulose fibers, it is a question of fibers made from regenerated cellulose, in particular from the Pplynosic group, which represents a certain term within cellulose technology ; the Association International Polynosis (AjP) set certain requirements "of a technical nature that must be met by polynosian fibers.) It would be of general advantage to

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position cellulose tissue made from regenerated cellulose wool, in particular the Polynosic Group, to be used as abrasive raw cloth, as these are much less complicated because of their natural cleanliness in-the wet equipment ... are to be treated as normal Cotton fabric.

A disadvantage is ₃ that the conventionally warp thread-sized abrasive backing fabrics, due to the conventional sizing, have an anti-adhesive character compared to the conventional finishing binders to be applied later and therefore have to be conventionally unconditionally desized. In addition, soft abrasive carrier fabrics made from regenerated cellulose, in particular from the Polynosic group, have a much greater absorbency than desized cotton fabrics and thus take on significantly more finishing agent, which in turn makes the finishing process more expensive.

Furthermore, the tear resistance of normally finished abrasive raw fabrics becomes on the basis of regenerated cellulose, especially Polynpsic fibers, greatly reduced.

It has now been found that the disadvantages outlined above can be avoided if, in accordance with utility model 1 901 J54O, an abrasive grain backing fabric made of regenerated cellulose fibers, in particular of the polynomial fiber type, is used, where _:

a) the warp thread sighted and finished and the Size and first finish are firmly bonded without a boundary layer and;

b) the weft thread has an initial finish.

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A special embodiment of the abrasive grain carrier fabric web is characterized in that / the warp thread is provided with a core size (core size - see ADHÄSION magazine, volume I96I; No. 10 - pages 505-512, and No. 11 - pages 564-577 and NoV 12 - pages 617 - 622 in the article on "Sizing agents for the textile industry" by Erich P. Prieser.) _; ^ _:

In a further embodiment, the abrasive grain backing fabric web for the abrasive fabric web according to the invention is characterized in that the first finish on the warp thread and weft thread is made by first finishing with an initial finishing agent which contains organic solvent emulsified in the aqueous medium, soaking at temperatures of 15-45 ° C swelling agent and about -65 - 200 ⁰ C, a solvent for the warp yarn located on the sizing, is has been placed. -. VJ -._ .. ■■ .- "."".."."'-

An abrasive grain carrier fabric web produced in this way as - The starting material for the new abrasive cloth web has the large one Advantage that the abrasive fabric finish adheres firmly with firmly connected to the core sized warp thread and the weft thread is. .- "" ■; "■ .-" ~.:;: Y. . '. -

In the manufacture of the present web of abrasive grain backing fabric for the abrasive grain fabric web according to the innovation the advantage. that in the first finish there are no large amounts to first finishing agent "must be applied because the warp thread already core-settled -is .., -In addition, the new arrangement in the first finished abrasive grain backing fabric a high elasticity of this - achieved. .

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As a finish for deli. Warp thread b ^ w. prefers keraschlicht is for example useful: degraded starch and starch derivatives ^ Synthetic resins based on isocyanates, homo- and / or copolymeric acrylic compounds. (Butyl, methyl acrylates) ,, Polyvinyl alcohol, - polyvinyl acetate,: acrylic-nitrile-butadiene-styrene ~ copolymers In the form of solutions or dispersions and appropriate wetting agents, e.g., naphthalene sulf onates, acrylic derivatives or xthoxy adducts.

Preferred core sizes are polymers based on acrylates and their derivatives as well as acid-degraded starch products and fatty acid condensation ethoxy adducts. As ..A finishing for the warp thread and for the weft thread come into question, for example: animal hide glue and / or reactive and non-reactive copolymeric acrylate solutions. Or, aqueous dispersions, polyisocyanates , polystyrene, 'N-Methsrloi compounds of urea and its derivatives _s Aldehydes and its derivatives _s sulfone compounds ^ phenol-formaldehyde reso! Resins ^ polyvinyl alcohol, acetate and chloride in the form of. Dispersions and solutions * Spoxyd and polyester resins as well as strong, starch derivatives and ethoxy adducts ₃ where both organic solvents emulsified in the medium are! contain; which at temperatures of 15-45 ° C is a swelling agent and above 65-200 ⁰ C is a solvent for the size on the warp thread. Suitable organic ^{emuigierbare:} solvents are for example toluene, Xyloly Ä'thylacetat, white spirit, Triehloräthylen, perchlorethylene .. Preferred app returmittel are self-crosslinking acrylate copolymers, copolymers of butyl and .insbesondere Sthylacryiat base and MethyImethacrylat barren in-dispersing solvent-dissolved form. :.

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The use of the preferred first finishing agents provides the following particular advantages, since the crosslinking acrylate dispersions, as the first finishing agent for the phenolic base resins to be applied later, have good adhesive properties, and this also avoids embrittlement of the fabric. In addition, the web of abrasive grain backing fabric can be provided with the same initial finish on both sides of the web : as is achieved by a dipping process or a double-sided coating process. This first finished abrasive grain backing fabric web according to the innovation is processed into an abrasive fabric web by further finishing j as described in detail in the utility model 1 901 3 ^ -0 »- ■ _. ■■".'_;.:"■;

Example 1 -.-- ■■ "::.

A warp yarn of strength Nm28 / 30 made of regenerated cellulose fiber (Polyncsic type) is made up of in a sizing trough with a formulation ₃

80 parts by weight of ■; .. - ■ ^: starch. -. - -

Kthoxyadduct 917 parts by weight of water

core-sized and dried on a cylinder drying machine and then woven into a raw abrasive fabric. The raw abrasive cloth produced in this way is without desizing with an initial finish "consisting" of

50 parts by weight of animal hide glue ■ - '■ ".-. (300 sheets, 100 mp)

100 parts by weight of a copolymeric acrylate dispersion 50 parts by weight of kaolin ^; ':. . .

3 parts by weight of naphthalene sulfonate. Λ 797 parts by weight of water - "V" λ - ■ .- .. "■ ..-.. ^: . - ^; -" - ^: - "_ ;; io _;

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impregnated and dried and fixed with simultaneous stretching with a lateral penetration of about 11 ^ 5 %. It is then coated on the front in accordance with utility model 1 901 J540, Example Ij, and then treated further in the manner described there. Compared to the known abrasive fabrics, the abrasive grain fabric produced in this way is characterized by excellent elasticity and good grain bonding. - - -. ^: ν. "■" ■ ".-.-

A warp yarn made of regenerated cellulose fibers (Polynosic type) of Nm 26 is placed in a sizing trough with a liquor _s consisting of .-. ■ '■' .. ^-:; ■ ■ - / ''

120 parts by weight of reactive, copolymeric acrylate

Dispersion

5 parts by weight of water-soluble copolymer made from - ..-. "... ■■■■■ - .." ■ -50 % acrylic acid, 70 % butyl acryl at 875 parts by weight water

is arbitrated _s and then in the air duct at l40 dried and fixed / after weaving the abrasive raw tissue without desizing is immediately with a "finishing solution consisting of" ■■ C / ■■ '■■: ^"■:; . -

120 parts by weight of reactive copolymeric acrylate, - ■. ■ "'■"' "■■ ':.-Dispersion'-

5 parts by weight of a, Copolyraerisates from 30 % ; .. "..."':"-■" .- acrylic acid and 70 % butyl acrylate

20 parts by weight of toluene βθ parts by weight of kaolin .-..

.20 parts by weight of dimethyloldihydroxyethylene urea 2: parts by weight. Magnesium chloride

^: 773 wt parts of water _..-:: .-.

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impregnated and stretched; dried at 140 ° G - thereby the fabric of breadth jumps; after around 11.5 ^. a., and fixed, Then it is according to the utility model 1 901 3 ^ -0., Example J5., Coated on the front and then in the there described type further treated. It becomes an abrasive grit fabric obtained with excellent grain adhesion.

The resulting Abrasive grain fabric stretched on a belt sander and tested in the test grinding process.

During this test grinding process, a Abrasive fabric with a conventionally sized, then not desized, and then conventional finished abrasive backing fabric by test grinding compared. :

With a constant pressure load; the grinding was carried out from a defined iron pipe. In addition, the surface of the abrasive fabric was visually inspected after the test grinding process in terms of sanding and grain breakage. The benchmark for value is the grinding time achieved up to. complete breaking out of the abrasive grain. The adhesive strength of the abrasive cloth finish was also tested by applying a phenolic resin intermediate layer and laminating this sample to sheet metal using the same phenolic resin. The sample was cured and, after air conditioning, the peel strength and the peel point were determined. . . .. ". _: .

2105 Obm

Belt grinder peeling grain breakout from attempt Fabric according to:

Peeled off

Conventionally sized abrasive cloth, not desized and conventionally impregnated

Newly sized sole fabric with a size and finish according to the invention , impregnated and coated with a second finish, as described in German utility model 1 901 340

1 minute

β kg

12 minutes

15 kg

between plain and
finish

between phenolic resin and
finish

The tests show that the abrasive grain fabric web after present innovation in several respects is surprisingly improved.

The abrasive grain fabric web according to the requirement is provided by the Drawings clarified.

FIG. 1 shows the abrasive grain carrier 8, where 1 is the learning element and illustrates the first finished warp thread and illustrates 2 the first finished weft thread.

Figure 2 shows the structure of the newly treated Abrasive grain fabric, with 8 illustrating the soil grain carrier shown in FIG. 1 and with the innovation according to the invention Fabric finish is provided. The abrasive grain binders β., consisting of the base binder 4 and the size binder 5 are clearly reproduced. As an abrasive grain coating For example, 3 is silicon carbide in those used in the grinding tools industry obliclian grit gradations useful. aside from that is the modern filler-free molding compound in addition

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applied as an intermediate layer .9 / _s- reproduced. This intermediate layer 9 significantly / improves the technical properties of the _{abrasive fabrics 3} because, due to their viscoplastic properties, they form the suitable transition from flexible carrier fabrics to the hard synthetic resin bond of the abrasive grain carriers. The molding compound used according to the invention as applied, filler-free coating compound © "is designated with the number 9. - -" ■: .. "" - '■ - ■ ·: .- .. .- .. ■■ "." -

Claims (1)

- - - Protection claims 1, phenolic resin-bonded abrasive fabric web according to Nutzrauster 1 901 340, characterized in that the abrasive grain carrier it contains consists of regenerated cellulose fibers, in particular of the polynosic fiber type, and where -,. "■ - ■■■■■■■ -." .. "■ -..- ■ a) the warp thread sized and finished and the size and first finish without: boundary layer firmly adhering connected is b) the weft thread has an initial finish. 2. Abrasive fabric web according to claim I _5, characterized in that the warp thread is provided with a core size. That the 5th abrasive fabric web according to claim 1 or 2, characterized in that: contains in the warp and the weft Erstappretur located by padding with a Erstappreturmittel ,, which imwässrigen medium-emulsified organic solvent which comprises at temperatures from 15 to 45 ⁰ C a swelling agent and above 65 - 200 ⁰ C a ® »- solution ^ b ^ ir * 'for the size located on and in the warp thread is arranged.