JPH047104A - Manufacture of recycled waste plastics - Google Patents

Abstract

PURPOSE:To manufacture a recycled waste plastics at low cost through simple facilities by a method wherein recovered waste plastic, which is crushed into coarse particles and fine particles, is employed as filler and waste plastic, which is turned into fine powder, is employed as forming resin and both are mixed together and, after that, formed under heat and pressure. CONSTITUTION:Recovered items are selected in advance into thermosetting resin and thermoplastic resin and preferably used in separate processed. However, the state of one resin mixed somewhat with the other resin is allowable. After the ores and metals in the recovered items are removed by utilizing the difference is specific gravities and the like, the recovered items are crushed with a crusher so as to classify in resin having the particle size of 5 mm or less or concretely into coarse grained resin having the particle diameter of 3 - 1 mm and fine grained resin having the particle diameter of 1 - 0.5 mm so as to prepare a filler. Further, the particle size of the forming resin is preferably 3 mm or less, especially 0.5 mm or less and more preferably 0.1 mm or less. The mixing range is 70 - 10 wt.% of filler and 30 - 90 wt.% of forming resin. Next, the mixture is heated up to the predetermined temperature and then pressed so as to be formed into a predetermined shape.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides useful recycling methods using so-called waste plastics such as thermosetting resins and thermoplastic resins that are treated as industrial waste and household waste. The invention relates to a method for manufacturing materials.

[Conventional technology] Conventionally, methods for recycling waste plastic include, for example, A simple recycling method that heats and melts the waste plastic material and turns it into pellets or film sheets, ■ A composite recycling method that heats and melts the waste plastic mixture and molds it into pellets or plates, ■ Turns it into granules. A recycling method is known in which crushed waste plastic is mixed with fibrous materials such as hemp thread, sawdust, etc., and the mixture is compressed into a plate shape and used as a building material.

[Problem to be solved by the invention] Among the conventional waste plastic recycling methods described above, in the method of heating and melting waste plastic, the properties of each waste material must be clearly understood in advance before classification and collection. However, there is a problem in that sorting and collecting waste plastic is technically complicated and difficult.

In addition, even if expensive equipment is used to sort and collect waste plastic, and even if waste plastic is time-consuming and sorted, recycling requires advanced manufacturing technology, and in addition, recycling requires stable quality. There was a problem in that it was difficult to secure materials.

Furthermore, the method of heating and melting waste plastics has the problem that a large amount of smoke and toxic gases are generated when the waste plastics are heated and melted.

Furthermore, when a fibrous material is used, there is a drawback that the cost of recycled material is high.

Therefore, in the past, only a portion of thermoplastic resin was reused as fire-resistant aggregate or supplementary material for road repair, or a portion of flammable waste plastic was reused as solid fuel. , most waste plastics are 6,000/m3
Currently, waste is incinerated or disposed of in landfills at a cost of around 100,000 yen.

The present invention was made to solve these problems, and an object of the present invention is to provide a method for manufacturing recycled material from waste plastics at low cost using simple equipment and means.

[Means for solving the problem] The method for producing recycled waste plastic material according to the present invention includes:
The collected waste plastic is crushed into coarse particles and fine particles as a filler, the same (pulverized into fine powder is used as a molding resin, and a mixture of the two is heated and pressure molded. A solid recycled material is obtained.

[Function] In this invention, the fine powdered waste plastic whose particle size has been adjusted becomes molten and softened by heating, and serves to bind the coarse and fine particles of waste plastic, so that the entire mixture is formed by pressure molding. becomes a strong unity.

In another aspect of the present invention, the mixed foamable raw materials are foamed and expanded by heat treatment, and the waste plastic filler consisting of coarse particles and fine particles is pressurized from the inside, so that the whole becomes a strong one body. Become a thing.

[Example] First, the general manufacturing process of the present invention will be described. In the first step, collected waste plastics are sorted and crushed to prepare filler and molding resin.

In other words, it is preferable that the recovered materials, which are raw materials, be sorted in advance into thermosetting resins such as phenolic resin, urea resin, and melamine resin, and thermoplastic resins such as polyethylene, vinyl chloride resin, and expanded polystyrene, and used in separate processes. . However, there is no problem even if they are mixed to some extent.

If ores or metals are mixed into the recovered products, there is a risk of breaking the crusher, so it is better to put these raw materials into a large water tank and remove them using the difference in specific gravity.

A well-known crushing device such as a rotary shear crusher or a reciprocating shear crusher can be used. Separate the particles into coarse particles with a particle size of 3 to 1 mm and fine particles with a particle size of 1 to 0.5 mm and fill them using a conventional method such as a wind sieve type separation method that utilizes the difference in the resultant force from the own weight, or a mechanical sieve. Prepare as material.

If the particle size of the filler exceeds 5 mm, the surface of the product (recycled material) will become too rough, reducing its commercial value. However, when producing large recycled materials such as those used for concrete blocks, coarse particles of about 30 mm can also be used.

In addition, by using coarse particles and fine particles, the thermoplastic binder is uniformly dispersed during molding to create a pressurized close-packed structure, and it is difficult to obtain a close-packed structure with either one (, Furthermore, the melting and dispersion range of the thermoplastic binder is large, and a long time is required for processing.

Next, the molding resin can be used as is in the coarse or fine particles, but it is
Collect as fine particles less than mm in size.

The molding resin is melted during the heating process and acts as a binder to bind the coarse particles and fine particles, so the length of 0.5 m
A particle size of 0.1 mm or less is preferred.

In the second step, the filler and molding resin are weighed in the desired ratio and mixed uniformly. This mixing ratio is 7
The range is 0 to 10% by weight, and 30 to 90% by weight,
The mixing ratio is determined depending on the purpose of use, such as large products, small products, frames, construction materials, etc.

In addition, if the filler content exceeds 70% by weight, the surface of the recycled material becomes rough and reduces the product value, and if it is less than 10% by weight, the strength of the recycled product decreases significantly and is easily deformed during use ( Become.

For mixing, a commonly used concrete mixer, mortar mixer, Eirich mixer, etc. may be used, and the mixing is carried out for approximately 10 to 15 minutes until the two are evenly mixed.

Next, in the third step, the mixture is heated to a predetermined temperature and then pressure molded into the desired shape, or pressure molded while heating to form the desired shape, or formed into the desired shape from the beginning. The filled material is heat treated to obtain a product.

That is, the mixture is placed in a perforated steel box or the like and heated with hot air or steam at 140 to 180°C for about 5 hours.
The mixture is pressurized at 300 to 1000 g/cm 2 using a general-purpose pressure molding machine and molded into a plate, rod, cube, or castable pouring mold of a predetermined size.

Alternatively, the molding may be performed while heating with a hot press equipped with a heating device.

The purpose of the above heating is to melt the particulate molding resin in the mixture and make the mixture into a high-strength solid.The heating temperature and heating time vary depending on the type of waste plastic used as the raw material.For example, polyethylene resin is heated to 180℃. , 5 hours, and for phenolic resin, 140℃ for 5 hours, for expanded polystyrene, 130℃ for about 2 hours, and in the case of hot press, be sure to understand the softening start temperature, hardening completion temperature, and time. do.

In addition, the molding pressure may generally be as low as 100 to 200 g/cm, but especially for products such as construction plates (recycled products).
If you need strength of 500-800g 7cm
“Or press with more.

Note that demolding after molding is easy because a gap is created between the molded product and the mold due to the difference in expansion and contraction by allowing the mold to cool or air-cooling. Furthermore, although the molding resin becomes molten by heating, it does not burn and decompose (the granular filler only softens, so no harmful gases are generated).

After visually inspecting waste plastics discharged from a certain factory and removing impurities such as inorganic materials, fireproof materials, solder alloys, and wires, the phenolic resin is sorted and separated, and then crushed using a rotary shear crusher. Then, it was sieved using an automatic sieve into the filler with particles of 3 to 1 mm and 1 mm or less, and the molding resin of 0.5 mm or less, and each of the above was weighed at 10.60.30% by weight. was added to the Eirich mixer and mixed for 15 minutes.

This mixture was placed in a large perforated box and heated to 140°C with hot air.
, heated for 5 hours 50X50X1.000mm
Approximately 2.2 kg is poured into the horizontal formwork (L), a 25kg weight is placed on the upper part of the formwork, and the molding is performed at a pressure of approximately 30g/cm2. After cooling naturally, the frame is removed and used for gardening. Manufactured square timber.

The strength (compressive strength) of the product is 200k as shown in Table 1.
g/cm2.

FIG. 1 is a sectional view showing the molding machine used in this example. In the figure, 1 is the mold, 2 is the granular filler in the mixture, 3 is the fine powder molding resin in the mixture, and 4 is the upper part. The frame 5 is a weight placed on the upper frame.

19 liters of waste plastics in city garbage are visually sorted into phenolic resin products and polyethylene resin products, and then put into a large water tank and subjected to shower flushing, separate flushing, specific gravity classification, etc.
Remove ores, metals, inorganic substances, and other impurities by one of the methods, crush with a rotary shear crusher, and use an automatic sieve for 3 to 30 minutes.
1 mm, a phenol resin filler of 1 mm or less, and a 0.
About 5.0 kg of polyethylene resin for molding of 5 mm or less was weighed to 20 and 50.30% by weight, respectively, and put into a mold of a large hot press heated with steam, and 1
After heating at 80° C. for 5 hours, the mixture was molded at a pressure of about 50 kg/cm” to produce a castable mold.

The compressive strength of this recycled material is 210 k as shown in Table 1.
g/cm'.

1. Select one type of waste material from our own raw material bags made of nylon, polyethylene, etc., wash it in a water tank, and heat it to 180-190℃.
, melted for 5 hours, cooled, and crushed into pieces of 3 mm or less using a general-purpose crusher, and classified into fillers of 3 to 1 mm, 1rr+m or less, and molding resins (binder) of 3 mm or less, respectively. 20. Weighed to 30.50% by weight, 180°C, 5
After heating for a period of time, it was pressure-molded using a cold press at a pressure of 30 kg/cm2.

The compressive strength of this recycled material was 220 kg/cm''.

A recycled material was produced in the same manner as in Example 3 by weighing out the 3-1 mm filler and the 3 mm or less binder prepared in Example 3 to 20.80% by weight, respectively.

The compressive strength of this recycled material was 320 kg/cm'', but it was deformable and elastic when pressed, making it suitable for use as a square shed for gardening.

In addition, useful uses of the recycled materials of each example are listed in Table 1.

In addition, in the conventional example shown in Table 1, the particle size of the raw materials was not adjusted, and 70% by weight of sawdust was simply blended with 30% by weight of molding resin that had been ground into fine powder, heated at 180°C for 5 hours, and then cooled. It is produced by pressure forming to 30 kg using a press, and its compressive strength is extremely low at 40 kg/cm''.

1. Shrink and sinter the Styrofoam waste materials (fish containers, etc.) at 130℃ for around 90 minutes, and crush them into pieces of 10 mm or less using a rotary shear crusher.
Pulverize to 3 mm or less to use as a filler. Styrofoam, which is a purchased raw material, was blended with this in the following blending ratio, mixed with water, filled in a closed frame, and heat-treated at 130°C for 2 hours.

In this manufacturing method, water for water kneading becomes steam by heating and fills the sealed frame, which facilitates temperature transfer and contributes to the expansion and bonding of unfoamed polystyrene raw materials, resulting in so-called internal expansion pressure molding. .

(Blending ratio) Waste sintered polystyrene -10mm 40% by weight//
-3mm 25 tt
Purchased raw material 1.5 mm $ 35 N This recycled material is very light with a specific gravity of about 0.3, and if it is about 50 mm thick, it can be used as a precast formwork material, and it is stronger than commercially available Styrofoam. It performed well as a filling material (core) during construction of incinerator air blowouts, sand extraction holes, etc.

In this case, the core does not need to be removed after construction and is dried (at 200°C).
There is an advantage that the pores are opened by combustion extinguishing (before and after), and demand is expected.

[Effects of the Invention] As described above, according to the present invention, since the equipment and manufacturing method for manufacturing recycled materials are simple, a large amount of waste plastic can be used effectively, eliminating the need for incineration or landfill disposal. In addition, by adjusting various conditions such as the type of waste plastic, blending ratio, heating temperature, and pressure during manufacturing, we can produce products of different quality and shape, as well as cutting,
This has the effect of making it possible to obtain recycled materials suitable for a variety of purposes, such as those in various shapes, by cutting or the like.

Furthermore, the obtained recycled product has no directionality, can be processed freely, and can be manufactured using simple home-made equipment, making it possible to easily and inexpensively produce recycled materials that can be used for multiple purposes.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a molding machine used in the present invention. 1...Formwork 2...-Filling material 3...Molding resin 4...Kamiazusa 5...Omoshi agent Patent attorney Kubo 1) Akira Hou

Claims (1)

[Claims] 1. After mixing a filler made from crushed waste plastic into coarse and fine particles and a molding resin made from crushed waste plastic into fine powder, the mixture is heated and pressure-molded. A method for producing recycled waste plastic material, characterized by: 2. The method for producing recycled waste plastic material according to claim 1, wherein the filler is 70 to 10% by weight and the molding resin is 30 to 90% by weight. 3. Using a filler with a particle size of 5 mm or less,
3. The method for producing recycled waste plastic material according to claim 1, wherein the molding resin has a particle size of 3 mm or less. 4. A method for producing recycled waste plastic material, which comprises mixing the filler whose particle size has been adjusted by crushing waste plastic with an unfoamed raw material, and then heating and foaming the mixture in steam and press-molding it from the inside. .