DE2050996A1 - Process for creating warm hoods for block molds - Google Patents

Description

DR. E. WIEGAND DIPL-ING. W. NIEMANN 2050996

DR. M. KOHLER DIPL-ING. C. GERNHARDT

MÖNCHEN HAMBURG

phone-. 555476 8000 MONCHEN 15, ¹⁶ * ⁰ ^ ^upper

TEtEGRAMMERKARPATENT NUSSBAUMSTRASSE 10

W. 4o o7o / 7o

Foseco Trading AG
Chur, Graubünden (Switzerland)

Process for creating heat hoods for block molds

The invention relates to the creation of thermal hood liners in block shapes. For the sake of simplicity the expression "hoods for block molds" is used in the description, but it is clear that that thereby also G-ießaufätze or head attachments for such Block forms are encompassed as the invention is equally applicable to the creation of thermal hood liners (hot topping linings) in pouring attachments or head attachments is applicable.

There are many ways of attaching warming hood panels or other elements in the headboard

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known of the block forms. Procedures in which special Apparatus or devices, e.g. clamping plates, nails, rods, rods, anchors or bolts, are used are usually troublesome, and no such particular method has achieved any widespread use Recording.

Various adhesive systems for attaching liner panels to block mold walls have been proposed, however, none of these consistently give satisfactory results mainly due to the inability of the adhesive to is satisfactory under the conditions normally encountered in steel mill operations Exerting an effect delivered.

The walls of block molds are often uneven and contain cracks, depressions or scars and burn cracks (crazing), so that when a sheet of lining material, usually compared with the block mold wall is flat, is pressed against the wall, a contact is created only in a few places. Hence will the surface of the plate carrying an adhesive layer the wall only glued at a few points of contact. Moreover, the surface of the walls of the block form is common not coherent, but consists of loosely adhering particles of iron oxide or refractory residues of materials, which have been used as linings, or from particles of anti-shrinkage agents used in previous Ingot casting operations were used. Lining panels can not be used on the walls using known Adhesive systems can be attached without first brushing the walls to remove the residue.

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In addition to this nonuniformity of minor To extent, the walls of block molds are seldom flat. Usually they have a bulge, and the lining panel must be adapted to this bulge in use. So a flat lining plate must have this shape deformed and some adhesive fastening system must be able to cope with the inclination of a resilient or resilient lining panel be able to resist returning to shallow training.

Known adhesives suffer from several disadvantages; Non-refractory adhesives tend to be their desired Y / effect inadequate to perform if they both before as well as heat occurring during casting become and in a lot they are prone to burn or even explode; refractory adhesives tend to Leaving behind a residue adhering to the block mold walls after the block has been stripped off. Yfenn the structure To avoid deteriorating backlog in the course of successive operations, the backlog must removed. .

Thus the use of known adhesives created a need for a more thorough one Cleaning the block molds than using a blower wind or a wire brush as would normally be done in practice is achieved. This additional cleaning is both time consuming and time consuming uncomfortable.

According to a first aspect of the invention there is therefore a method of creating heat hoods on block molds provided by gluing or adhering preformed lining panels for thermal hoods in block forms, the

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is characterized in that at least one of the surfaces to be glued together, one Applying a soft layer of flame retardant material, arranging the lining panels in the block form or puts it in place and presses it against the wall of the block mold, thereby deforming the soft layer, wherein the soft layer on the surface of the block mold by means of an intermediate layer of an adhesive is made to adhere. This middle or intermediate thin layer does not pose a fire hazard and works in a satisfactory manner.

According to a particular embodiment of the invention a method is provided for creating thermal hoods on block molds, in which © a lining element for heat hoods on the walls of the block mold by means of a deformable sealing material to which both the Lining board as well as the wall with the help of an adhesive be glued, is attached. This deformable sealing material represents in this case the. just the flame-retardant soft layer described.

The method according to the invention overcomes the disadvantages inherent in the known adhesive systems. Sore and strong or vigorous attachment of the lining panels for heating hoods on molded block walls the possibly existing roughness of the walls and their Arching enabled.

It should be noted that this effect could not be obtained by mere use of a thick layer of a certain organic adhesive because one such a thick layer poses a considerable risk of fire. represents. When using a soft layer of lower

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Flammability with a thin layer of adhesive is coated, can have good adhesion as well a good mechanical fit can be obtained at the same time

Preferably, the soft layer is applied to the lining panel of a heating hood first, although it can also be glued to the wall of the mold or a grit attachment, the panel then being glued to this layer. The soft layer preferably has a thickness that is on the order of | Unevenness or unevenness of the mold wall lies and ζ · Β. 0.8 mm to 1.5 mm. The soft layer can be formed in very different ways and a wide variety of materials can be used in its construction. The material can be soft and elastic, for example like polyurethane foam, non-vulcanized neoprene sheets (skin) or sponge polypropylene, or it can be non-elastic, for example like a paste-like or putty-like mass or mastic. In some cases, for example for certain cementing or mastics, the material of the soft layer may itself be sufficiently tacky to hold itself to the plate prior to mounting a of the plate to the wall, wherein an intermediate, however, in other cases, for example with polyurethane foam, Adhesive layer can be used. The soft layer can in some cases be made of a material similar to the material from which the lining panel for the thermal hood is formed. The outer lining panel for the heat hood is usually 0.5 to 5 cm thick, although thinner lining panels or facing panels are also known and can also be attached according to the method according to the invention.

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Xm use allows the presence of the soft layer the absorption or interception of the irregularity in the: Block form wall and also in many cases it encapsulates Particles of scale, gehmutz or the like., And the soft layer is firmly adhered to the solid wall of the form itself. the Adhesion or bonding between the plate and the mold wall is brought about by pressing the plate onto the mold wall. if the pressure is released, the movement of the plate is absorbed by the wall in the soft material and the Adhering surfaces are not pulled away from each other.

The soft shiqht does not have to be over the whole Surface of the plate or the block mold wall extend, but they can be in the form of a number of separate or individual areas, e.g. in the form of strips or pearls from the soft layer.

An absorption of the adhesive or the material the soft layer itself in the plate to a minimum To reduce * it is often advantageous to coat the panel with a suitable primer coat or finish to provide.

A number of other considerations should be made when selecting the material for the soft layer will. Preferably the soft layer is:

(a) capable of absorbing vibration or impact j

(b) easily deformed when pressure is exerted on the lining panels for the thermal hood installed in the Block shape are applied, a larger contact area is achieved,

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with the soft layer facing the micro irregularities and geometric irregularities of the block shape adapts;

(c) able to maintain its functional softness State under extreme conditions of humidity and temperature that occur during their storage can}

(d) of sufficiently high tensile and shear strengths to the weight of the lining panels of the thermal hood to wear at room temperature and at elevated temperatures;

(e) a sufficiently high internal shear strength at elevated temperatures: i.e. at temperatures which occur during the casting of steel, so that the viscosity of the material is not deteriorated to a sufficient extent to allow the bond to occur weaken by flow between the block form and the lining panel;

(f) Compatible with any adhesive used to bond the soft layer to the panel or to the mold wall is used; for example, the material of the soft layer should not cause the adhesive to create a easily peelable skin. or forms an easily peelable film; it is also not intended to absorb the adhesive or otherwise the adhesive properties adversely affect the same;

(g) suitable to be sufficiently thermally degraded and in this way to enable the residue to be easily removed from the mold after use, however the extent of degradation should be such that the adhesion between the liner and the mold is not affected until a bear solidified out

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Head metal inside the warming hood (hot top) itself formed -has}, ββ should not be at any stage be ignited.

Materials that have been specially shaped for use as a soft layer include, for example, extru-

Dated sheet or web materials or tapes of compositions * which contain one or more powdered fillers, e.g. powdered calcium carbonate or precipitated chalk or trays, and binders, e.g. plasticized synthetic resins, non-drying alkyd resins, mixed vegetable oils or mixtures which have been added with any of these components . Alternatively, the binder a drying vegetable oil, such as linseed oil (eg · stand oils, blown © oils or physically blown oils (bodied blown oils) may be, to which an antioxidant has been added. The viscosity range of the oils used, for example, 4o can be up 3ooo poise at 25 ⁰ C The oils can also contain other additives, such as viscosity stabilizers, oxidation and polymerization catalysts, compounds or fillers (e.g. bentontones) and polyisobutylenes (to increase elongation) Kraft paper, asbestos, glass wool or slag wool, to improve the tensile and shear strength of the composition, and the filler may have been coated in advance, such as a resin or stearate, to prevent excessive absorption by the resin binder.

Any adhesive used to attach the soft material to the panels of the thermal hood lining or is used on the block form, should preferably:

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(a) a pressure sensitive material with a near • be sticky degree;

(b) sticky or sticky and not under the Exposure to extreme humidity and temperature conditions;

(c) a flexible / elastic film when dry result;

(d) be effective at temperatures between -15 and + 4QO ^{0 C;}

(e) Compatible with the soft layer material and the base coat, if used; ·

(f) so deteriorated or carbonized during the casting process (charred) so that no undecomposed part of the adhesive remains on the block mold wall, to be detrimental to subsequent lining or casting operations.

The base coat and / or size (if used) is applied to the base plate of the heating cap (which can be insulating or exothermic, flexible or stiff) to prevent excessive absorption of the adhesive by the mass of the heating cap (hot topping composition) z ^f u impede. The base coat or size should be flexible or elastic when dried, and should preferably be non-flammable and make the surface of the thermal hood lining element essentially impermeable or other commonly used paint filler), this filler or pigment helping to level or level the surface of the lining board for the heat hood so as to produce a smoother surface.

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offer to which the glue is applied and then the layer off The base of the base coat (primary) can e.g. be an aqueous emulsion of polyvinyl acetate or of poly-2-ethylhexyl acrylate. A diluted emulsion of the glue that is used can be used if desired. One a suitable, commercially available size is "POLITONE" from Dunlop Chemical Products Division.

In the practical implementation, the base coat and the soft layer preferably on the surface the lining panels for the heat hood, which are to be glued to the block mold wall, applied, this being in the form of a series of stripes or pearls or the layers can obscure the entire front surface of the element. A particularly preferred one Arrangement is one in which a number of parallel strips spaced apart with a width of 12.7 to 50.8 mm (1/2 to 2 inches) each with the spacing between the strips about Is 12.7 to 5o.8 mm (1/2 to 2 inches). Most preferably, the soft layer is at least along each one Edge of each panel that is deepest in use is attached.

In a very convenient embodiment of the invention, the soft material is in the form of strips of an extruded composition having an adhesive layer applied to both surfaces. The adhesive / soft material sandwich can then be made with the application of a sheet of conventional Release paper to be protected on any surface. The sandwich comprising glue and soft material is applied to the primed surfaces of the heating

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hood element is applied after removing one of the release papers · The second release paper is removed immediately before fixing the panel in the block form. By applying pressure to the lining plate of the heating hood, it is made to adhere strongly to the mold wall and the soft material is deformed in order to compensate for any surface irregularities in the mold wall. The soft material can flow in some cases and to Terkapselung any loose particles which may stick to the mold wall tend, and permit penetration of the adhesive between ä the particles themselves. The operation can be successful in block forms at temperatures ranging from -15 to + 4-0O ⁰ C can be applied. It is of course not necessary to use release papers when applying the adhesive / soft material sandwich material directly to the thermal dome plate. Heat hood plates of particular suitability for use according to the invention are those as described in German patent specification ....... (patent application P 2o 15 266.3).

The invention is explained in more detail below using an example

example

A mastic composition has been adopted for use as soft materials from the mixture of 2 parts by weight of precipitated chalk and 1 part by weight of a non-drying alkyd resin manufactured. This composition became ribbons of 12.7 mm in width and 1.587 mm in thickness (1/2 inch or 1/16 inch) extruded. Any face of the tape was with a 50% τ / aqueous emulsion of poly-2-ethylhexyl acrylate applied as a coating and allowed to dry. A suitable coating weight is in the range

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from 5 to 50 g of emulsion per 9.29 dm (square foot), a coating weight of from 0.1 to 30 g per 9.29 dm being preferred will. Each area was then protected with a strip of silicone treated release paper. Isolating Heat hood panels were then used to hold the adhesive sandwich made by removing the backsides (i.e. those surfaces that are removed from the cast metal when used as heat hood insulators) with a Primer consisting of an emulsion of partially hydrolyzed polyvinyl acetate containing china clay filler, have been deleted. The release paper was removed from one face of a strip of the adhesive / Mssfcix sandwich removed, whereupon the sandwich is then along the bottom edge or bottom edge of the back of one of the Isolation plates was applied. Additional strips were then placed parallel to the first strip and on the plate at a distance of 12.7 mm («1/2 inch) over the entire Surface of the plate applied. The remaining panels were prepared for use in a similar manner. The panels were then easily secured in place in the head of a block mold by simply adding the second release paper removed and the plates pressed into position.

It can be seen that although above three separate components (primer, adhesive and soft material) have been referred to, it is sometimes possible is to incorporate two or all of these components into a composite material. For example it may be possible to use a soft material, which is also sufficiently adhesive to perform the effect of sticking to the heating hood plate. It is also possible to incorporate an impermeable layer during the manufacture of the warming hood element and

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thereby the need to apply a primer coat to avoid.

As can be seen, according to the invention, a method for the advantageous production of heating hoods for Block molds as described above are created, and also the materials for carrying out this Procedure provided. In particular, the invention also encompasses the strips of soft material of those described Kinds coated with a pressure-sensitive adhesive on each side, as well as block molds or heating hoods- I Plates, sockets or the like. Glued such strips exhibit.

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Claims (8)

Patent claims 1. Method for creating thermal hoods in block molds by gluing pre-formed warm hood lining panels to the block form, characterized in that at least one of the surfaces that interfere with each other are to be glued, a soft layer of a flame-retardant material provides, the lining panels brings it into position in the block mold and presses it against the block mold wall, the soft layer is deformed, whereby the soft layer is made of the surface of the block form with the help of an intermediate layer glued with an adhesive. 2. The method according to claim 1, characterized in that one heat hood lining plate to the Walls of a block shape over a deformable sealing material on which both the plate and the wall are glued by means of an adhesive, attached. 3. The method according to claim 1 or 2, characterized in that that the soft layer is first placed on the lining panels and the panels so treated then in the block form £ n brings its position. 4. The method according to any one of claims 1 to 3> thereby characterized in that the soft layer is made from a material selected from the group consisting of polyurethane foam, unvulcanized Forms neoprene sheet or fur, sponge polypropylene, putty or mastic. 5. The method according to any one of claims 1 to 4, characterized in that before applying the soft Layer on the lining board the face of the 109819/1189 Lining board that is to come into contact with the soft layer, with a primer coat or with a size, for example with a pigment or filler-containing emulsion of a polymeric film-forming Materials. 6. The method according to any one of claims 1 to 5, characterized in that there is an intermediate layer an adhesive for adhering the soft layer to one or both of the surfaces to which it is attached is to be applied, whereby the adhesive consists of a (( Polymer consists of 2-ethylhexyl acrylate. 7. The method according to any one of claims 1 to 6, characterized in that the soft layer is made a mixture of a powdered filler such as precipitated chalk or sebum and a flowable one Binders consisting of plasticized synthetic resins, non-drying alkyl resins or vegetable oils forms. 8. Strip of soft material, which consists of a mixture of a powdery filler and a flowable binder consisting of plasticized "synthetic resins, non-drying alkyd resins or Vegetable oils, which is formed on;} each side with a pressure sensitive adhesive for use in the method of claim 1. 9. Strip according to claim 8, characterized in that the pressure-sensitive adhesive is made from poly-2-ethylhexyl acrylate consists. 109819/1189 ORIGINAL INSPECTED