DD300635A5 - Process for producing glass fiber bundles - Google Patents

Abstract

The invention relates to a process for the production of glass fiber bundles for glasfaserverstaerkte concrete elements. The object of the invention is achieved by using a binder of the substance system lignin / phenol / formaldehyde for impregnation of the fiber bundles as sizing agent and drying the impregnated fiber bundle below the curing temperature of the binder. Preferably, a binder having a lignin content of 40 to 45%, a phenol content of 20 to 24%, a formaldehyde content of 16 to 30% and a sodium hydroxide content of 7 to 11%, based on the total mass, is used as the size. The use concentration of the binder is adjusted to a solids content of 0.1 to 30% based on the total binder mass. The fiber bundles impregnated with the binder are dried at 80 to 130 ° C. {Production process; Glasfaserbuendel; glass fiber reinforced concrete elements; Lignin / phenol / formaldehyde binders}

Description

Field of application of the invention The invention relates to a method for producing glass fiber bundles for glass fiber reinforced concrete elements. Characteristic of the known state of the art Among other things, glass fibers are used to produce reinforced concrete elements. For this purpose, the Glasseidenspinnfäden immediately after emerging from the nozzle with a sizing or Schmalz to a glass fiber strand

bound. The strand or fiberglass bundle is cut into staple fibers, with the sizing continuing to hold the individual fibers together. The cut fiber bundle pieces are then mixed into the concrete. In the mixing process the fibers should spontaneously separate and distribute evenly.

According to DD-WP 282678 there is a process for the preparation of isolable inorganic glassy fibers with a Sizing based on polydimethyldiallylaminium chloride alone or in combination with waterglass in contact with Water spontaneously disintegrate. Similarly, the use of one or more substances from the group of concrete plasticizers, air-entraining Concrete additives proposed as size for glass fiber filaments and glass fibers. In a third solution proposal, water-soluble film-forming polymers and non-ionic surface-active polymers are used Compounds or water-soluble film-forming polymers, cationic surface-active compounds and nonionic

surface-active compounds and optionally further typical additives used.

It has also been proposed a sizing which in an aqueous medium between 1.0 and 40.0 parts by mass in% of one or

more of the cationic surfactants from the homologous series of the quaternary amines and / or the quaternary amine oxides.

The sizes described have a high material price. In addition, they are, especially the surfactants, physiological

not safe.

Object of the invention

The aim of the invention is a process for the inexpensive production of spontaneously isolatable glass fiber bundles with a physiologically harmless and inexpensive binder.

Explanation of the essence of the invention

The object of the invention is to use as sizing agent for the manufacture of glass fiber bundles a binder which has a high degree of physiological safety, cheaper than currently used sizing materials. According to the invention, this object is achieved in that a binder of the substance system lignin / phenol / formaldehyde used for impregnation of the fiber bundle as the size and the impregnated fiber bundle below the

Curing temperature of the binder is dried. Preferably, a binder with a lignin content of 40 to 45%, a phenol content of 20 to 24%, a formaldehyde content of 16 to 30% and a Natriumhydroxidgehe.lt of 7 to 11%, based on au? the total mass, applied. The application concentration of the binder is adjusted to a solids content of 0.1 to 30%, based on the total binder mass. The impregnated with the binder fiber bundles are preferably dried at 80 to 130 ⁰ C.

It has been found that the binder in only dried and uncured state on the one hand reliably surrounds the glass fibers also when cutting the staple fibers and does not allow premature singling and spontaneously dissolves on the other side in the alkaline medium. It is well suited for the production of glass fiber reinforced concrete elements. The aqueous medium surrounding the cement or CSH matrix has a pH above 7. In contrast to the surfactants, the material is 10 to 100 times cheaper. In addition, it is physiologically harmless.

To improve the wetting and sheathing of the fibers, it is possible to add to the binder 0.1 to 0.4% of adhesion promoter and / or crosslinking agent in the form of polyethylene dispersion, surfactants or similar substances.

Ausführungcbelsplele

Bolsplel 1

A lignin-phenol-formaldehyde binder in the composition of 45 g of sulfate lignin, 22 g of phenol, 8 g of alkali, 24 g of formaldehyde and 138 g of water is diluted by addition of water to a solids content of 5% of the total mass.

The solution is absorbed by immersing glass fiber bundles on this and dried at 120 ° C for about 2 hours. The result is a firmly adhering coating which dissolves in 0.5% potassium hydroxide at room temperature within 3 seconds of the fiber.

Example 2

To the binder in the composition according to Example 1 is added a polyethylene dispersion in the amount of 0.2 parts by weight in% solid content. The binder solution is applied to glass fiber spun yarns and dried at 135 ° C for about 1.5 hours. The glass fiber bundle can be cut into 3 mm pieces without the shearing forces occurring during cutting canceling the fiber bond. In 2.5% sodium hydroxide solution, the fibers spontaneously separate.

Claims (7)

1. A process for the production of glass fiber bundles of elementary fibers by merging the elementary fibers into fiber bundles, impregnating the fiber bundles with a polymeric size and drying the impregnated fiber bundles strands, characterized in that as-sizing a binder of the substance system lignin / phenol / formaldehyde used and with the binder impregnated fiber bundle is dried below the curing temperature of the binder. 2. The method according to claim 1, characterized in that the size of a binder of the substance system lignin / phenol / formaldehyde with a lignin content of 40 to 45%, a phenol content of 20 to 24%, a formaldehyde content of 16 to 30% and a sodium hydroxide content of 7 to 11%, based on the total mass, is applied. 3. The method according to claim 1, characterized in that the application concentration of the binder to a solids content of 0.1 to 30%, based on the total binder composition, is set. 4. The method according to claim 1, characterized in that the size contains a bonding agent. 5. The method according to claim 1, characterized in that the size contains a crosslinking agent. 6. The method according to claim 1, characterized in that the size 0.1 to 0.4% of polyethylene dispersion, based on the total mass of the binder added. 7. The method according to claim 1, characterized in that the impregnated with the binder fiber bundles dried at a temperature of 80 to 130 ⁰ C wild.