JPH1029222A - Environment-friendly type injection molded body and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reuse hard-to-regenerate waste by a method wherein a molding material prepared by mixing reusable shredded paper pieces, which are obtained by shredding hard-to-regenerate plastic film laminate paper or resin coated paper and their products, with pellet resin is injection-molded into predetermined moldings. SOLUTION: Waste plastic film laminate paper or resin coated paper 16 and their products are shredded with a shredder or the like into square shredded paper pieces 10 having one side of 1.0-5.0mm in the thickness of 0.18-2.0mm. On the other hand, pellet resin 30 having the melt flow rate of 5-50 is prepared so as to be fixed with the shredded paper pieces 10 and then charged in the hopper 42 of a screw type injection molder 40. The charged mixture is plast plasticized through the rotation of a screw 46, heated with heaters 44 and injected in a mold 48.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of mixing waste paper or paper products, especially plastic film laminated paper or resin-coated paper, which is difficult to recycle, and recycle shredded paper pieces shredded from the product with a pellet resin. Molding material
The present invention relates to an injection-molded article that is injection-molded into a predetermined shape. Further provide a production method to increase the content of paper,
The present invention relates to the provision of an environmentally friendly injection molded article that is easier to process, more specifically, easier to incinerate.

[0002]

2. Description of the Related Art In recent years, the problem of waste has become a major social problem, and in turn, a global environmental problem. In view of these problems, reduction of waste, promotion of recycling, and development of easily processable products have been actively performed. Conventionally,
While the printing industry is working hard on these countermeasures, most of the printed waste paper and its products that do not contain waste resin etc. are reused as raw materials for recycled paper. Since film-laminated paper or resin-coated paper and its products cannot be reused as a raw material of recycled paper, they have to be landfilled or incinerated.

On the other hand, the development of easily recyclable, easily decomposable and easily incinerated products has been promoted when disposing of easily processed products, that is, products. Conventionally, paper and resin are mixed, and first, a paper-containing pellet is produced by an extruder and a pelletizer, and the pellet is used as a paper-containing injection-molded product by an injection molding machine. In other words, in this step, it is necessary to temporarily extrude the paper-containing pellet into an extruder, and since the paper is exposed on the surface of the paper-containing injection-molded product, the limit of the paper content is limited. Judgment at a level that does not impair
As low as 5%, the calories burned are high, and there have been problems such as damaging the incinerator and lowering the combustion efficiency.

Further, the conventional manufacturing process of a paper-containing injection molded product for easy incineration and the characteristics of the product will be described in detail with reference to FIGS. A piece of paper (58) cut with a miller or the like and a new pellet resin (30) are mixed and charged into a hopper (42) of an extruder (50) shown in FIG. Next, the mixture is melt-kneaded with a screw (46) of an extruder (50), passed through a die (53) to extrude a rod-shaped paper-containing resin (56), and cooled in a cooling tank (52). ) Is a pelletizer (5
Pelletized in 4). This paper-containing pellet resin has a paper content of 35% when judged at a level that does not impair the molded product.

[0005] The paper-containing resin pellets produced here were made into a paper-containing injection-molded product such as a measuring cup (20) shown in FIG. 3 by a screw-type injection molding machine (40) shown in FIG. In this step, in order to make a paper-containing injection-molded product directly with a screw-type injection molding machine (40) without using an extruder (50), the kneadability of a shredded paper piece (58) and a pellet resin (30) is required. However, even if it is made, the paper content is less than 20%, which is far from the purpose of easy incineration.

Next, the ease of incineration of a paper-containing injection molded product will be described. Generally, the calorific value (burning calories) of a mixture of paper and plastic is about 3500 kc for 100% paper.
al / kg, paper content 70%, about 5000 kcal /
kg, paper content 60%, about 6000 kcal / kg,
At a paper content of 40%, it is said to exceed about 7500 kcal / kg, and at 100% plastic, it exceeds 10,000 kcal / kg. When the calorific value of the mixture increases, that is, when the content of plastics increases, in the incineration, the refractory bricks and the like of the incinerator are damaged, and unburned molten resin flows out. In such cases, the combustion efficiency is deteriorated. From such a thing,
The calorific value of the incinerated material is desirably 6500 kcal / kg or less. In recent years, heat recovery by waste incineration has been recommended from the viewpoint of energy saving. In this case, the higher the calorific value of the waste, the higher the heat recovery efficiency and the better fuel. Therefore, it is said that the calorific value of the waste as fuel for the incinerator with a boiler is optimal around 6500 kcal / kg.

[0007] From such a background, it is an object to obtain an easily incinerated paper-containing injection-molded product having a high paper content.
Further, development is being conducted with the aim of obtaining an injection-molded product in which the resin content is reduced by increasing the paper content, thereby saving petroleum resources, and by reducing the weight, transportation energy is saved.

[0008]

However, as described above,
In the prior art, it is difficult to recycle waste plastic film-laminated paper or resin-coated paper and its products, and the production cost of paper-containing easily incinerated injection-molded products is high. In addition, there were many problems that the paper was exposed, water leakage and destruction were likely to occur, and the calorie burned was high and the incineration property was lacking. The present invention solves the problems of the prior art, and it is possible to reuse an unnecessary plastic film laminated paper or resin coated paper and its product, which is difficult to recycle, and to make the reused product more easily incinerated. It is an object to provide a processable injection-molded article and to reduce the production cost by shortening the production process of the injection-molded article. That is, an object of the present invention is to provide an ultimate environmentally friendly injection molded article and a method for producing the same.

[0009]

In order to attain the above object, the present invention relates to a method for regenerating shredded plastic film-laminated paper or resin-coated paper cut into small pieces. An environmentally friendly injection molded article characterized by being injection molded into a predetermined molded article using a molding material obtained by mixing with a pellet resin.

In the invention according to claim 2, the shredded recycled material has an area of 1.0 mm ^{2 to} 25.0 mm ² and a thickness of 0.18.
A method for producing an environmentally friendly injection molded article characterized in that the content of paper is increased by using the molding material having a size of from 2.0 mm to 2.0 mm.

[0011] In a third aspect of the present invention, there is provided a method for producing an environmentally friendly injection molded article, wherein the pellet resin has a melt flow rate (MFR) of 5 to 50.

[0012]

Embodiments of the present invention will be described below. As shown in FIG. 1, the environmentally friendly injection molded article using the recycled shredded paper piece of the present invention and the method for producing the same are obtained by milling waste plastic film laminated paper or resin coated paper (16) or a product thereof using a miller or the like. One side is 1.0mm
５5.0 mm, desirably 1.0 mm to 3.0 m on one side
m and a thickness of 0.18 mm to 2.0 mm, desirably 0.28 mm to 1.68 mm. The shape is not limited to a quadrangle, but may be a triangle, a circle, or the like. On the other hand, the melt flow rate (MFR) is 5 to 50, preferably 20 to 3
A pellet resin (30), which is 0, is prepared, dry-blended (mixed) with the shredded paper piece (10), and put into a hopper (42) of a screw-type injection molding machine (40).

The charged mixture is supplied to a heater (4
By the rotation of the screw (46) heated by 4), it is plasticized and injected through a sprue into a mold (48) which has been clamped.

Here, in order to obtain an injection molded article having a high paper content, the form of the shredded paper piece (10) was examined first. The thickness of the shredded paper piece (10) is 0.18 mm or less, 1.0
If it is less than mm square, biting into the screw (46) of the screw type injection molding machine (40) becomes poor, and it is difficult to increase the paper content. In addition, shredded paper pieces (1
0) When the thickness is 2.0 mm or more and 5.0 mm square or more,
Although the shredder is difficult to shred, the cut surface of the shredded paper piece (10) is exposed on the surface of the injection-molded product, causing problems such as water content, and the fluidity of the resin plasticized in the screw (46). Worsened, screw-type injection molding machine (4
0), there is a problem that it is difficult to pass through a gate or a nozzle. Therefore, the thickness is desirably 0.28 mm to 1.68 m.
m, a high-quality injection-molded article having a high paper content was obtained by using a piece of cut paper (10) having a square shape of 1.0 mm square to 3.0 mm square.

Similarly, in order to obtain an injection-molded article having a high paper content, the form of the pellet resin (30) was examined. It is necessary that the resin is in the form of pellets. In the plasticizing step, the screw (46) does not back,
This is a condition for preventing difficulties in weight reduction. When the resin has a melt flow rate (hereinafter, referred to as MFR) of 5 or less, it is difficult to surround the resin around the shredded paper piece (10) and form it, and this is a problem particularly at the filling tip. On the other hand, if the MFR is 50 or more, burrs occur on the product, and the commercial value is lost. Therefore, it is desirable that the MFR of the pellet resin (30) is high, and the use of the pellet resin (30) having a MFR of 5 to 50, preferably 20 to 30 allows the shredded paper piece (1) to be used.
Resin is well taken in around 0), and a high-quality injection-molded article without exposing the shredded paper piece (10) on the surface of the obtained injection-molded article and free of burrs can be obtained. The temperature of the resin at the time of heating is 185 ° C. or less, preferably 165 ° C.
° C or less is desirable, and there is also a result that the higher the MFR, the harder the shredded paper piece (10) is exposed on the surface of the injection molded product.

[0016]

[Table 1]

From the relationship between the MFR of the pellet resin (30) and the paper content of the injection-molded article, the results of the above confirmation experiments were as shown in Table 1. As shown in Table 1, when low-density polyethylene (LDPE) with MFR11 is used as the pellet resin (30), a high-quality injection-molded product has a paper content of less than 70% and a low-density MFR30. When polyethylene (LDPE) was used, it was confirmed that the paper content was limited to less than 80% in order to obtain good quality and high quality injection molded products. That is, M of the pellet resin (30)
It was confirmed that the higher the FR, the better the quality of the injection molded product.

Further, as the type of the pellet resin (30),
It is desirable to use a resin having high heat-fusibility with the plastic film or the resin coating film (14) of the shredded paper piece (10) shown in FIG. That is, in the plasticization process, the pellet resin (30) and the shredded paper piece (1
The resin layer is uniformly formed on the outermost surface of the injection-molded product by the thermal fusion with the plastic film or the resin coating film (14) of 0), and a higher-quality injection-molded product having a high paper content can be obtained. . For example, when the plastic film or the resin coating film (14) is polyethylene, a combination of low density polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (L-LDPE) resin as the pellet resin (30) Is more desirable.
When the plastic film or the resin coating film (14) is polypropylene, a combination of a random polymerized polypropylene, a block polymerized polypropylene, and a homopolymerized polypropylene resin is more preferable as the pellet resin (30).

As described above, the easy-to-process, environmentally friendly injection molded articles of the present invention having a high content of recycled shredded paper pieces include, for example, various sheet products such as daily necessities, stationery, building materials, decorative articles and the like. Or, it includes a base material sheet or plates used therefor, or an injection molded article used as a food spoon, a small spoon, a storage container for various products, and the like.

[0020]

Next, the present invention will be described in detail with reference to examples.

Example 1 A measuring cup of a powder detergent shown in FIG. 3 was prepared under the following materials, injection molding conditions and the like.

Resin used Petrocene 248 (manufactured by Tosoh Corporation) (LDPE: MFR = 50) Recycled shredded paper sheet Polyethylene double-sided laminated paper Recycled shredded paper sheet and pellet resin ratio 70 to 30 (weight ratio) Resin content of recycled shredded paper sheet Ratio of paper to paper 26.4 to 73.6 Size of recycled shredded paper pieces Approximately 2.0 mm square, approximately 1.0 mm thickness Injection molding conditions Resin temperature 160 ° C-150 ° C-150 ° C Injection screw diameter 30mmφ Original pressure 1400 kg / cm ² injection speed 55% pressure 90% (primary) 40% (secondary) weighing 40mm

The measuring cup produced here was of good quality, with the paper pieces not being exposed on the surface and the resin being uniformly formed on the outermost surface. The paper content was calculated to be 51.6%, and the calorific value was estimated to be about 6600 kcal / kg, which was the optimum fuel for an incinerator with a boiler.

[0024]

As described above, the present invention has the following effects. That is, the present invention is a waste paper and paper products, especially a plastic film laminated paper or resin coated paper that is difficult to recycle and recycled shredded paper pieces shredded from the product, mixed with pellet resin to form a molding material, Since it is an injection-molded article that is injection-molded into a predetermined shape, there is an effect of reusing waste that is difficult to regenerate. Further, by providing a production method for increasing the content of paper, there is an effect of providing an environment-friendly injection molded article having easy processing properties, specifically, more easily incinerated property. In addition, the use of the recycled shredded paper pieces eliminates the steps of extrusion and pelletization in the conventional manufacturing process of a high-content injection molded article of paper, and has the effect of reducing production costs. In addition, the injection molded article of the present invention has a high paper content, is light in weight, and has a small amount of resin. Therefore, it is also effective in saving transport energy and petroleum resources. That is, by providing the ultimate environmentally friendly injection molded article and its manufacturing method, there is an effect of greatly contributing to environmental conservation.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is an explanatory view showing a manufacturing process of an injection-molded article in a cross section.

FIG. 2 is a perspective view illustrating a recycled shredded paper piece used for the injection molded article of the present invention.

FIG. 3 is an explanatory view showing a measuring cup showing an example of the injection molded body of the present invention in a cross section.

FIG. 4 is a cross-sectional view of an extruder for explaining a conventional method.

[Explanation of symbols]

10 mm shredded paper piece (10) 12 mm paper base paper (12) 14 mm plastic film or resin coated film (14) 16 mm plastic film laminated paper or resin coated paper (16) 18 mm shredder (18) 20 {Measuring cup (20) 22} Easily incinerated injection molded product (22) 24} Plastic (24) 30} Pellet resin (30) 40} Screw type injection molding machine (40) 42} Hopper (42) 44 ‥‥ heater (44) 45 ‥‥ power unit (45) 46 ‥‥ screw (46) 48 ‥‥ mold (48) 52 ‥‥ cooling layer (52) 53 ‥‥ die (53) 54 ‥ ‥ Pelletizer (54) 56 ‥‥ Resin containing bar-shaped paper (56) 58 ‥‥ Paper piece (58)

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29K 511: 12

Claims (3)

[Claims] 1. A molding material obtained by mixing a regenerated shredded piece of plastic film-laminated paper or resin-coated paper shredded into small pieces and a pellet resin is injection-molded into a predetermined molded body using a molding material obtained. An environmentally friendly injection molded article characterized in that: 2. The shredded recycled material has an area of 1.0 mm ² to 2 mm.
5.0 mm ^2, the manufacturing method of environmentally friendly injection molded body according to claim 1, wherein the use of said molded timber is the thickness 0.18Mm～2.0Mm. 3. The method for producing an environmentally friendly injection molded article according to claim 1, wherein said molding material having a melt flow rate (MFR) of said pellet resin of 5 to 50 is used.