JP2002086529A - Method for recycling used pet product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mold a new product by reusing only a regenerated raw material obtained through a recycling process following the recovery of a used PET product and a used resin product molded of a plastic resin other than PET. SOLUTION: The regenerated raw material 22 obtained by mixing and drying the grinds 14 of the used PET product and the grinds 18 of the used resin product molded of the plastic resin other than PET at a ratio of 3:7-4:6, is loaded into an injection molding machine 24 and injected into a molding frame 38 for the product disposed in the injection molding machine 24 at 280-285 deg.C molding temperature which are higher than the melt point of PET and in such a manner that the intermediate part of the heating cylinder 28 of the machine 24 is set at a high temperature and both end parts thereof are set at a low temperature. Thus the molding of the product is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recycling used products such as PET bottles formed of PET (polyethylene terephthalate).

[0002]

2. Description of the Related Art In recent years, a recycle mark having a substantially triangular number 1 is printed on the outer peripheral surface of a container.
PET bottles for beverages molded by PET, and PP in which the numbers in the recycling mark are 2, 4 to 7
(Polypropylene), a large number of detergent containers formed of styrene, and the like have been found.

[0003] PET bottles for beverages whose number in the recycling mark is 1 are PET which is flexible and brittle.
Due to the material characteristics of the material, it was formed into a tubular shape by an injection mechanism instead of an injection molding machine that formed by performing a series of operations of material chip supply, heating plasticization, injection into a mold, cooling and solidification, and unloading of molded products A material is placed in a molding die, a gas, a liquid, or the like is blown into the tubular material, and a blow molding machine that forms a hollow product by the blowing pressure or the like is used.

[0004] Also, plastic bottles for beverages need to be molded using new PET for the convenience of human use for beverages, and used PET bottles are collected by a collection company and lids and labels are excluded. And some are recycled as fibers by mixing recycled and new materials,
Or they are recycled as fuel, but most are simply incinerated as garbage, and they have never been recycled to produce products.

[0005] The number in the recycling mark is 2,
The used materials such as detergent containers 4 to 7 are collected, and the recycled materials crushed by removing the lid and the label are mixed with the new materials, and the recycled products are molded by an injection molding machine, a blow molding machine or the like. Some of them have been recycled.

[0006] In addition, products whose number in the recycling mark is 3 are not used recently because dioxin is generated at the time of incineration and disposal because the raw material is vinyl chloride.

[0007]

Conventionally, PET such as used PET bottles in which the number in the recycle mark is 1 is used.
The problem was that most of the products were incinerated and not recycled.

Also, when recycled as fibers, not only from recycled materials from used PET products, but also by mixing with new PET materials, the products are recycled, and products are recycled only from recycled materials. The inability to do so was a problem.

[0009] There is also a strong demand for a method of recycling PET products such as used PET bottles that have been incinerated, and recycling them as new products.

The present invention addresses these needs and, in view of the above drawbacks, uses only recycled materials produced by collecting used PET products and used resin products molded from plastic resins other than PET. It is an object of the present invention to provide a method for recycling used PET products that can form a new product.

[0011]

DISCLOSURE OF THE INVENTION The present invention relates to a used PET.
A recycled raw material obtained by mixing and drying a PET crushed piece obtained by crushing a product and a resin crushed piece obtained by crushing a used resin product formed of a plastic resin other than PET at a ratio of 3: 7 to 4: 6, Pour into injection molding machine and set molding temperature to PE
Within the range of 280 degrees to 285 degrees, which is higher than the melting point of T, set the heating cylinder of the injection molding machine at a high temperature at the middle and at both ends at a low temperature, and place it in the product mold installed on the injection molding machine. It is characterized by injecting and molding a product.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for recycling used PET products according to the present invention will be described below in detail with reference to FIGS.

First, a PET crushed piece 14 obtained by crushing a PET bottle which is a collected used PET product 12 and a used resin product 16 formed of a plastic resin other than the collected PET, such as polypropylene and styrene. Resin crushed pieces 18 obtained by crushing a detergent container are prepared.

In the present embodiment, the PET cover, which is the collected used PET product 12, is made of PET, fixed to the upper end of the PET bottle, the resin portion of the upper peripheral portion, and the label attached to the outer periphery are simultaneously pulverized to make PET. It can be used as a crushed piece 14.

Further, the resin lid fixed to the upper end of the detergent container, which is the collected used resin product 16, the resin portion at the upper peripheral edge, and the label attached to the outer periphery are also simultaneously pulverized to obtain resin pulverized pieces. 18 can be used.

The pulverized PET pieces 14 and the pulverized resin pieces 18 do not need to be formed into pellets.
m or less, and about 3 mm is optimal.

Next, the PET crushed pieces 14 and the resin crushed pieces 1
And 8 are dried and agitated and mixed by the mixer 20 at a ratio of 3: 7 to 4: 6 to produce a recycled raw material 22.

The mixing of the PET crushed pieces 14 and the resin crushed pieces 18 assists the flexibility and fragility, which are the material properties of the PET crushed pieces 14, by the high strength, which is the material property of the resin crushed pieces 18. In addition, the used PET product 12 and the used resin product 16 are simultaneously recycled.

This mixing ratio is a range in which the quality of the injection-molded product is good, and if the mixing ratio is outside this range, the product quality is remarkably deteriorated.

The crushed pieces 14 and 18 may be sufficiently dried beforehand through a drier (not shown) or the like before stirring and mixing.

Next, the recycled material 22 is charged into an injection molding machine 24.

In the present embodiment, the injection molding machine 24 is an injection molding mechanism that has been used conventionally, and its outline will be briefly described below.

An injection nozzle 30 is provided at one end of a heating cylinder 28 having an injection screw 26 inserted therein, and a hopper 32 for charging a material at the other end. A plurality of heaters 34 and 35 are provided on the outer peripheral surface of the heating cylinder 28. , 36, 37 are wound.

In this embodiment, the heaters 34, 35, 3
6, 37 are wound around at least four points of the heating cylinder 28, and each heater 34, 35, 36, 37 is
The temperature is individually adjusted within the range of 280 to 285 degrees higher than the melting point of T, and the heaters 34 and 37 at both ends of the heating cylinder 28 are used.
Is set to 280 degrees (low temperature), and the heaters 35 and 36 in the middle of the heating cylinder 28 are set to 285 degrees (high temperature).

The reason why the upper limit temperature of the intermediate portion (high temperature portion) of the heating cylinder 28 is set to 285 degrees is to reduce energy consumption, and the lower limit temperature of both ends (low temperature portion) of the heating cylinder 28 is set to 280 degrees. The reason for this is to take into account the fact that the melting point (about 250 degrees) fluctuates depending on the component composition of PET, and to perform good and reliable injection molding.

Next, the regenerated raw material 22 is melted in the heating cylinder 28 of the injection molding machine 24 and injected from the injection nozzle 30 into the product mold 38 installed in the injection molding machine 24. Then, the product mold 38 is released from the mold to form a product, for example, a daily product such as a bucket.

At this time, the injection nozzle 30 of the injection molding machine 24
The injection pressure of the regenerated raw material 22 injected from the
Adjust according to the size of the product to be molded.

Thus, according to the recycling method of the present invention, a new product can be formed using only the used PET product 12 and the used resin product 16,
In addition, by setting both ends of the heating cylinder 28 of the injection molding machine 24 to a low temperature and setting an intermediate portion to a high temperature, the recycled material 22
The T crushed pieces 14 and the resin crushed pieces 18 are reliably and uniformly melted, and the product quality can be improved.

In the figure, 40 is a crusher, 42 is a mixer 2
0 indicates a heater section.

In this example, the used PET product 12 is not limited to a PET bottle, and the used resin product 16 is not limited to a detergent container.

The heater 3 wound around the heating cylinder 28
4, 35, 36, and 37 are four places, but it is obvious that there are five or more places.

[0032]

According to the method for recycling used PET products according to the present invention, a crushed piece of used PET products,
A recycled raw material obtained by mixing and drying a crushed piece of a used resin product molded with a plastic resin other than T at a ratio of 3: 7 to 4: 6 is put into an injection molding machine and installed in the injection molding machine. Injecting into the finished product form and molding the product, a new product can be molded using only used PET products and used resin products, and is excellent in recycling.

The molding temperature is set higher than the melting point of PET.
Within the range of 80 degrees to 285 degrees, the heating cylinder of the injection molding machine is
By setting the intermediate portion at a high temperature and the both end portions at a low temperature, the crushed PET pieces and the crushed resin pieces, which are the recycled materials, are reliably and uniformly melted, and the product quality can be improved.

[Brief description of the drawings]

FIG. 1 is a simplified front view showing a recycling process of a used PET product of the present invention.

FIG. 2 is an enlarged vertical sectional view showing a heating cylinder of the injection molding machine.

[Explanation of symbols]

 12 Used PET Products 14 PET Crushed Pieces 16 Used Resin Products 18 Resin Crushed Pieces 22 Recycled Materials 24 Injection Molding Machine 28 Heating Cylinders 34, 35, 36, 37 Heaters 38 Product Formwork

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F206 AA24 AR061 JA07 JF51 JL02 JN43 JQ46 4F301 AA14 AA15 AA25 AD02 AD05 AD06 BB04 BC15 BD05 BF12 BF25 BF32

Claims (1)

[Claims] 1. PET obtained by grinding used PET products (12)
A crushed piece (14) and a crushed resin piece (18) obtained by crushing a used resin product (16) formed of a plastic resin other than PET.
And a recycled material (22) obtained by mixing and drying at a ratio of 3: 7 to 4: 6 into an injection molding machine (24), and setting the molding temperature to PE.
Within the range of 280 degrees to 285 degrees higher than the melting point of T, the heating cylinder (28) of the injection molding machine (24) is set at a high temperature in the middle and at both ends at a low temperature. A method for recycling used PET products, which comprises injecting into a product form (38) installed in the product and molding the product.