SU69189A1 - The way to get pencil mines - Google Patents

Description

In the production of color and copying rods, solid fats, water and a binder are added to a dried mineral consisting of a mixture of naphols, fillers and pigments, after which the mixture is stirred under heating, without subjecting it to roasting.

The mixture is then passed through the rolls and mixed again. In some hours, the beam x in the mixer prior to pressing sets the entire amount of fat, in others only part of the fat is added, and the rest is injected after drying.

In all cases, only saturated fatty acids are used: stearin, stearates, Japanese wax and paraffin, salomas, etc.

Almost exclusively talc and kaolin are used as filler for pencil mines that are not fired during production.

Talc and kaolin have little plasticity in a mixture with water and are almost devoid of binding ability. Therefore, to obtain sufficient strength: Blend rods to: the compressible mass are added binders, for example, a solution of starch, dextrin of traganth, etc., and large quantities of saturated fatty acids: stearin, stearate, wax, paraffin, salomas, etc. .

Sometimes clay is used to make pencil mines.

The rods obtained by pressing pure clay, sealed in water, or clay mixed with a dye, possess, directly after drying, great strength, almost the same as that of calcined rods. The line of dried clay rods is not inferior in softness to that of pressed talc. Despite these valuable properties of clay, it is usually not used in the production of quarantine mines that are not subjected to roasting, because of the hygroscopicity of the rods and their easy soaking in water.

The hardness of the obtained rods is insignificant and fluctuates within narrow limits of soft gradations, as a result of which rods of only large diameter must be produced.

183

In order to eliminate the above disadvantages, the authors developed a method of obtaining pencil mines without roasting based on any fillers using drying oils of drying oils as binders for a mixture of fillers and pigments. This method makes extensive use of clays to produce mines of varying hardness and high strength. A small amount of drying oil or drying oil is added to the finely ground mixture of clay and pigment, the resulting mass is mixed with water and mines are pressed, after which they are dried and fattened with non-drying fat.

When, for one reason or another, the use of clay as a filler is unacceptable, for example, in the production of luminous crayons from light composition on an inorganic basis or in the production of pencils of very light shades, and kaolin, talc or materials are used as fillers, pigment and drying oil or drying oil are added to an aqueous solution of starch or tragante and mines are pressed from the resulting mass, as indicated above.

In some cases, for example, to obtain strong rods of small diameter, a water-soluble thermoplastic resin, such as phenol-formaldehyde and water, is added to the mixture of fillers, pigment and drying oil or drying oil, and mines are formed from the mixture obtained by the above method.

The advantages of the proposed method are as follows.

Due to the ability to widely apply clay, which has a much greater degree of dispersion than talc and kaolin, there is no need for wet mixing of the components of the mixture.

The process of mixing and rolling the mixture can be reduced to hours instead of 6-7 hours according to the old method, since according to the proposed method, a mixture enters the mixer containing all components of the mass, ready for pressing, with the exception of water.

1.84

The time spent on the wire pouring and drying of the rods can be shortened several times, since during the operation of the proposed method no cracks or fractures appear even during rapid drying.

Example 1. Plastic clay ,. as little colored as possible, for example, Russian watches, dried until complete removal of the capillary-connected water, placed in a dry drum and rotated for six to eight hours. The drum is opened, 4-5% of linseed or other drying drying oil is added and it is continued to rotate for another 3-4 hours. The crushed mass in the form of a fine free-flowing powder is placed in a blender, 18-20% water is added by weight of clay, mixed until a homogeneous mass is obtained within an hour, the mass is passed through 2-3 times through rollers and again mixed in a mixer for 30- 40 minutes. Of. the resulting mass is pressed mines in the usual way. After laying, the rods are left on. air for 2-3 days, after which they are transferred to the dryer without heating or to a moderately heated dryer and, depending on the thickness of the rod, dried for 2-3 days, after which the rods are held at. temperature of about 70 ° or higher depending on the desired hardness of the finished rods. The dried stems are greased in a bath of salomas or a mixture of salomas with mineral oil or other suitable fats.

Example 2. Getting color copy and black lead min. Simultaneously with clay, pigments or graphite, soot, etc. are dried. The mixture of dry clay with pigment or graphite is processed in the drum for 20 hours, after which the linseed oil or some drying oil is added and rotated for another 5b hours. The mass is then transferred to a mixer and is carried out as indicated in the example. In the production of black lead rods, they are dried at temperatures up to 160 ° and above. The drying time is determined by the desired gradation and

set for each batch of pencils by laboratory method.

Subject invention

Claims (4)

1. A method for obtaining pencil mines without roasting on an organic binder, characterized in that drying oil or drying oil is used as a binder. 2. A method according to claim 1, characterized in that a small amount of drying oil or drying oil is added to the dehydrated, finely ground mixture of pigment and filler, for example clay, the crawled mass is mixed with water and pressed mines, after which the latter are dried and fattened with non-drying fat. 3. Acceptance of the method according to paragraphs. 1 and 2, characterized in that an aqueous solution of starch or tragante is added to the mixture of the writing and filler, for example kaolin or talc, and the drying oil or drying oil and mines are formed from the resulting mass according to the above method / in paragraph 2 of the method. 4. Acceptance of the method of paragraphs. 1 to 3, characterized by the fact that a water-soluble thermoplastic resin and water are added to the mixture of the filler, pigment and drying oil or linseed oil, and mines are formed from the mixture obtained in paragraph 2 of the method.