KR100349180B1 - Moldings made of plastic wastes and a method of manufacturing thereof - Google Patents

Abstract

PURPOSE: The formed one for a floor material and a construction material using the waste plastic and its preparation method are provided, wherein the formed one has the strength and appearance suitable to a floor material and a construction material. CONSTITUTION: The formed one comprises the lower layer consisting of 3-90 wt% of the waste plastic and 10-97 wt% of the steelmaking slag; and the upper layer consisting of 3-90 wt% of the waste plastic and 10-97 wt% of the powered stone. The method comprises the steps of melting 3-90 wt% of the waste plastic at 160-200 deg.C, adding 10-97 wt% of the steelmaking slag to the molten plastic and mixing the mixture mechanically to obtain the primary molten mixture; melting 3-90 wt% of the waste plastic at 160-200 deg.C, adding 10-97 wt% of the powdered stone to the molten plastic and mixing the mixture mechanically to obtain the secondary molten mixture; and injecting the primary molten mixture into a mold, putting the secondary molten mixture on the primary molten mixture, and press molding them. Preferably the press molding is carried out at a pressure of 5-50 kg/cm2.

Description

Moldings made of plastic wastes and a method of manufacturing uses

The present invention relates to the utilization of waste plastics, and more particularly, to a molded article and a method for manufacturing the waste plastics for use as sidewalk blocks or building interior materials.

Recycling of waste plastics will be one of the most necessary technologies in the 21st century in terms of preserving the natural environment and utilizing resources, and with this trend, researches on using waste plastics are being conducted in various ways.

Looking at the recycling technology of the waste plastic mainly developed to date, mainly the pulverization technology of waste plastic resin and how to use the waste plastic of a single resin. For example, recent European patent EP 654496 (95/5/24), AU 935235 (94/3/31), US 5300267 (94/4/5), DE 4207972 (93/7/15), All are techniques for the use of a single waste plastic. In addition, international patents WO 9510402 (95/4/20) and JP 6155463 (94/6/3) have been proposed regarding shredding techniques of mixed waste plastics for recycling some mixed waste plastics.

On the other hand, steelmaking slag occurs in the steelmaking process of the steel mill, a large amount is being discarded because no effective utilization method has yet been proposed.

The inventors of the present invention have found that the use of the characteristics of steelmaking slag, crushed stone and waste plastic can be recycled while exploring the utilization method of the above-mentioned waste plastic and came to propose the present invention.

An object of the present invention is to provide a molded article having strength and appearance by appropriately mixing waste plastic as a binder and steel slag or crushed stone as a reinforcing material.

Another object of the present invention is to provide a method for producing a molded article having a two-layer structure having excellent strength and appearance.

The present invention for achieving the above object relates to a molded article composed of weight percent, waste plastic: 3-90%, steelmaking slag: 97-10%.

The present invention also relates to a molded product composed of waste plastic: 3-90% and stone powder: 97-10% by weight.

In addition, the two-layer structure consists of a lower layer composed of waste plastic: 3-90%, steel slag: 97-10%, and an upper layer composed of waste plastic: 3-90%, stone powder: 97-10%. It relates to a molding to be formed.

Molding method of the present invention for achieving the above another object, in the method for producing a molding using waste plastic, 3-90% by weight of the waste plastic is melted in the temperature range of 160-200 ℃, here 97- Adding 10% by weight of steelmaking slag and then mechanically mixing to obtain a first molten mixture; Melting 3-90% by weight of waste plastic at a temperature in the range of 160-200 ° C., adding 97-10% by weight of stone powder and mechanically mixing to obtain a second molten mixture; And injecting the first molten mixture into a mold, and then injecting the second molten mixture onto the injected first molten mixture followed by pressing.

Hereinafter, the present invention will be described in detail.

The present invention is characterized by producing a molding using waste plastic waste as a binder and using stone crushed material and steelmaking slag as reinforcing agents.

First, the waste plastic used in the present invention can be used not only industrial waste plastic, but also general municipal waste plastic. At this time, the waste plastic may be used any one kind of polyethylene (PE), polypropylene (PP), polystyrene (PS), or a mixture thereof, and waste plastics in which other materials such as resins and inorganics are mixed. If mixed waste plastics are used, they can be used as they are. However, if you want to obtain better characteristics, the mixture can be mixed according to the method suggested by the inventors in Korean Patent Application No. 97-49238. The compatibility of waste plastics can be secured. In addition, the waste plastic may be used by melting it by heating above a predetermined temperature, or by dissolving it as a binder.

The steelmaking slag used as a reinforcing material in the present invention may be generally slag generated in a steelmaking process of an ironworks. For example, converter slag and electric furnace slag. Generally, steelmaking slag is crushed for extraction, and the particle size is crushed to about 8 mm or less. In the present invention, the steelmaking slag may be used.

Stone powder used as a reinforcing material in the present invention, such as steelmaking slag is a crushed stone powder that occurs when used in the general industry as a natural stone. There are various kinds of calcite such as calcite, but the type does not matter, and when various kinds of stone powder are mixed and used, the appearance is better. In addition, the particle size is not particularly limited because it can be used in various ways depending on the thickness of the molding obtained according to the present invention. For reference, the stone powder generated in the general industry is treated after being classified after the particle size in the size of about 30-40 mesh, just use it.

When the above-mentioned binder waste plastic and reinforcing steelmaking slag or stone powder are mixed at an appropriate ratio, a molded product having excellent strength and appearance can be obtained.

According to the invention, the molding is composed of waste plastic: 3-90% by weight (hereinafter referred to simply as '%'), steelmaking slag: 97-10%, or waste plastic: 3-90%, stone powder: 97 It is -10%. The reason for controlling the components as such, when the waste plastic is contained less than 3% of the binder role is insufficient and the molding does not show the strength. If the waste plastic exceeds 90%, the content of steel slag or stone powder is so small that the strength increase and other physical properties are inferior.

Molded products made of the waste plastic and steelmaking slag are inexpensive and have excellent strength characteristics, but have a disadvantage in that the appearance is not beautiful. In addition, the waste plastic and the stone powder have a beautiful appearance by showing the color and texture of the stone, but the disadvantage is that the production cost increases because the stone powder is expensive.

Therefore, the present inventors have a two-layer structure of the lower layer composed of waste plastic: 3-90%, steelmaking slag: 97-10%, and the upper layer composed of waste plastic: 3-90%, stone powder: 97-10%. Moldings have been developed. At this time, the thickness of the lower layer and the upper layer can be varied depending on the application of the molding, and also can be varied according to the particle size of the steelmaking slag and stone powder. Forming as thin an upper layer as possible can provide an inexpensive molding.

Hereinafter, the manufacturing method of the molding of this invention is demonstrated.

First, it is preferable to melt 3-90% by weight of waste plastic in the temperature range of 160-200 ℃. The reason is that below 160 ℃, the uniform melting of waste plastic resin is not made. Especially, when mixed waste plastic is used, polypropylene does not melt and exists as a lump, which affects the physical properties. This is due to the thermal decomposition of resins with good melting points, such as polyethylene.

97-10% of steelmaking slag is added to the molten waste plastic as described above, and mechanically mixed to obtain a first molten mixture. In this case, there is no special method of mixing, and the mixing may be performed as uniformly as possible.

In addition, as described above, 97-10% of the stone powder is added to the molten waste plastic and then mechanically mixed to obtain a second molten mixture.

The first molten mixture is injected into a mold, and then the second molten mixture is injected onto the injected first molten mixture. In this case, the injection may be injected at an even thickness.

After injection as described above and press molding, a molded article having a two-layer structure is obtained. At this time, the molding pressure is preferably molded at a pressure of 5-50 kg / ㎠. The reason for this is that less than 5 kg / cm 2, the strength is insufficient, and more than 50 kg / cm 2, the manufacturing cost increases due to meaningless overpressure.

In order to obtain the molded product of the first melt mixture or the second melt mixture in the continuous method as described above, in the process of injecting into the mold, only the first melt mixture is injected and molded, or only the second melt mixture is injected and molded. .

And, if you want to further increase the strength of the molded product produced by the present invention, glass fiber, carbon fiber or rock wool may be further added as a reinforcing material.

Molded article prepared according to the present invention is not a phenomenon such as brittleness which is a disadvantage of the existing natural stone can greatly improve its life. Therefore, it can be used as a flooring material and building wall material, such as a building floor or sidewalk block using the existing natural stone, it can be variously applied as long as the characteristics of the other.

Hereinafter, the present invention will be described in detail through examples.

Example 1

A waste plastic mixed molding made of the composition of Table 1 was made, and no additives such as a compatibilizer or a crosslinking agent were added. This waste plastic molding was cut to a size of about 5 mm and then dried in a windy location for at least one day. After drying the dried plastic in the amount shown in Table 2, and heated to a temperature of 200 ℃ molten steel, 0.1-2mm steel slag (T.Fe: 15-24%, CaO: 40-50%, SiO ₂ : 5-10%, MnO: 3-7% and the like) were added and mechanically mixed to obtain a first melted mixture. In addition, a calcite powder, which is a 30-40 mesh stone powder, was added and mechanically mixed to obtain a second molten mixture.

The second molten mixture was injected into the bottom of the mold with an even thickness of about 2-5 mm, and the first molten mixture was evenly injected into the thickness of about 2 cm, and then molded by applying a pressure of 10 kg / cm 2. The bending strength and the compressive strength of the molding thus obtained were measured and the results are shown in Table 2 below.

Plastic type Polyethylene Polypropylene Polystyrene Etc weight% 40-60 15-25 15-25 Within 10%

Waste Plastic (wt%) 5 10 15 20 25 30 35 Existing concrete brick Bending strength (㎏ / ㎠) 0.3 1.3 1.4 1.5 2.9 1.8 1.5 - Compressive strength (㎏ / ㎠) 0.6 4.3 4.5 4.7 7.8 4.2 2.7 0.4-0.8

As shown in Table 2, the molded article having a two-layer structure according to the present invention was found to have superior compressive strength than the existing concrete brick.

As a result of the present inventors visually confirming the molding, the molding showed black color on the side with steel slag, but the side of natural calcite exhibited the same pattern and color as natural calcite and has the atmosphere of natural stone. Excellent.

As described above, the present invention can contribute to resource recycling and nature conservation by utilizing plastic and steelmaking slag, and it is effective to provide flooring and building wall materials at low cost.

Claims (3)

Waste formed by weight of two layers of waste plastic: 3-90%, steel slag: 97-10%, and lower plastic: 3-90%, stone powder: 97-10%. Molded flooring and building wall using plastic. In the manufacturing method of the molding using waste plastic, Melting 3-90% by weight of waste plastic at a temperature in the range of 160-200 ° C., adding 97-10% by weight of steelmaking slag, and then mechanically mixing to obtain a first molten mixture; Melting 3-90% by weight of waste plastic at a temperature in the range of 160-200 ° C., adding 97-10% by weight of stone powder and mechanically mixing to obtain a second molten mixture; And Injecting the first molten mixture into a mold, and then injecting the second molten mixture onto the injected first molten mixture, followed by pressing for molding, for flooring and building wall materials using waste plastics. Method of Making Molded Products. The method as claimed in claim 2, wherein the press molding is performed at a pressure of 5-50 kg / cm 2.