JP2008137163A - Method and apparatus for separating wall trim material made of thermoplastic resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a separation method capable of efficiently, easily and inexpensively separating a wall trim material made of a thermoplastic resin into a thermoplastic resin layer and a base material paper layer to respectively use the separated layers as reusable regenerated raw materials. <P>SOLUTION: The wall trim material made of the thermoplastic resin is heated to a temperature higher than the softening temperature of the thermoplastic resin layer and the softened thermoplastic resin layer is peeled from the base material paper layer by a physical method. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to recycling of waste materials of thermoplastic resin wall coverings, and more particularly to a separation method and apparatus for thermoplastic resin wall covering materials.

  Thermoplastic resin wall coverings are composed of a thermoplastic resin layer and a base paper layer laminated on a decorative surface, and are widely used as wall coverings. In recent years, the demand for recycling of thermoplastic resin products has become stronger, and the recycling of wall covering materials is also demanded. However, most of the waste material from thermoplastic resin wall coverings, such as defective products discharged from manufacturing factories and processing processes, redesigned products, and long-term stock disposal products, is used for landfill and incineration. Currently it is being processed. In order to solve this problem, various methods for recycling wall covering materials have been proposed. Among them, a thermoplastic resin that does not contain a base paper as an impurity in the thermoplastic resin when used in a subsequent process. Methods for separating the layer from the base paper layer have been studied.

  For example, Patent Document 1 discloses a method of separating and recovering a vinyl chloride resin layer by swelling a vinyl chloride resin layer using an organic solvent. However, this method requires a large-scale processing apparatus such as a solvent removal apparatus and a solvent recovery apparatus, resulting in poor processing efficiency and high equipment costs and running costs. Moreover, in the method using an organic solvent, there exists a problem that the kind of resin layer to isolate | separate will be limited to vinyl chloride resin.

  Patent Document 2 discloses a method of cutting and peeling one layer of a laminate using a rotating body having a cutting blade. However, this method requires fine adjustment of the distance between the cutting blade and the feed plate rotor surface, and is difficult to adapt to laminates with unknown or non-uniform substrate thickness. When the interval between the body surfaces is wide, the recovery efficiency is deteriorated, and when the interval is narrow, there is a problem that a high-purity recovered product cannot be obtained. Moreover, the special rotary body which provided the cutting blade on the surface is required, and an installation expense and a maintenance expense will become expensive.

JP 09-59423 A JP 2003-88772 A

  The present invention is intended to solve the above-mentioned problems, and a thermoplastic resin wall covering formed by laminating a thermoplastic resin layer and a base paper layer is composed of a thermoplastic resin layer and a base paper layer. In addition, the present invention provides a method and an apparatus that can be efficiently and easily separated at low cost and are recycled as a material that is easy to handle in the recycled raw material market.

  The present inventors have intensively studied to solve the above problems. The present invention heats the thermoplastic resin wall covering to a temperature higher than the temperature at which the thermoplastic resin layer softens, and further scrapes the softened thermoplastic resin layer from the base paper layer by a physical method. A method and apparatus for separating a base paper layer.

The present invention heats the thermoplastic resin wall covering to a temperature higher than the temperature at which the thermoplastic resin layer softens, and softens the thermoplastic resin layer, whereby the peel strength between the thermoplastic resin layer and the base paper layer is increased. The thermoplastic resin layer softened and softened very easily can be scraped and separated from the base paper layer by a physical method.
Furthermore, the separated thermoplastic resin layer and base paper layer are recycled material materials that can be easily reused, and can be effectively used as resources.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these drawings.
FIG. 1 shows an embodiment of a thermoplastic resin wall covering applied to the present invention. The wall covering material has a structure in which a thermoplastic resin layer a and a base paper layer b are laminated.
FIG. 2 shows an embodiment of a separating apparatus for separating the plastic resin wall covering material c into the thermoplastic resin layer a and the base paper layer b. The means 3 for continuously feeding the wall material c made of thermoplastic resin, the means 1 for heating above the temperature at which the thermoplastic resin layer a is softened, and the flat blade edge having a blade edge thickness of 1 mm or less. It is a separating apparatus comprising a means 2 for physically scraping, and a means 4 for taking up the base paper layer b after scraping off the thermoplastic resin layer a.
FIG. 3 shows an embodiment of a flat plate as scraping means. Hereinafter, each will be described in detail.

  The present invention can be applied to both non-foamed and foamed thermoplastic resin wall coverings c. Examples of the thermoplastic resin layer a include, for example, polyethylene, ethylene-vinyl acetate copolymer (hereinafter referred to as “EVA”). ), Ethylene- (meth) acrylate copolymer, olefin resin such as chlorinated polyethylene, vinyl chloride resin, polyester resin, (meth) acrylic resin, thermoplastic elastomer (olefin, styrene, urethane) It can be applied to a wall covering material made of a thermoplastic resin such as polyester. Of these, application to olefin resins, vinyl chloride resins, and thermoplastic elastomers is preferable in terms of ease of use of recycled materials. Addition of plasticizer, stabilizer, chelator, filler, foaming agent, foaming aid, UV absorber, colorant, flame retardant, antioxidant, processing aid, lubricant, etc. in the thermoplastic resin layer a An agent may be added.

  Examples of the base paper layer b include pulp paper, flame retardant paper (a sheet obtained by treating a pulp-based sheet with a flame retardant such as guanidine sulfamate and guanidine phosphate), inorganic materials such as aluminum hydroxide and magnesium hydroxide, and Any of inorganic paper mixed with glass fiber may be used.

  Although not shown in FIG. 1, the surface of the thermoplastic resin layer a, which is the decorative surface of the thermoplastic resin wall covering c, is improved in scratch resistance, chemical resistance, contamination resistance, weather resistance, and the like. Therefore, a fluororesin coating may be applied, or a PMMA resin film, a polyolefin resin film, an eval film, or the like may be laminated.

  In the present invention, as a heating method capable of heating the thermoplastic resin wall covering c above the temperature at which the thermoplastic resin layer a is softened, high-pressure steam, hot water, hot oil, electric heater, far-infrared rays, high-frequency and microwaves are used. A general heating means 1 such as an oven, a roll, or a plate using an electromagnetic wave such as a flame or the like as a heating source can be used. In the present invention, the thermoplastic resin layer a employs a dry method in which the thermoplastic resin layer a is not in direct contact with a heating source such as high-pressure steam, hot water, or hot oil but is softened in contact with the heating means. No device for removing moisture or solvent from the thermoplastic resin layer a and the base paper layer b is required.

When heating is performed by the heating unit 1, it is necessary to set the heating temperature to be equal to or higher than the temperature at which the thermoplastic resin layer a is softened. Since the temperature at which the thermoplastic resin layer a softens varies depending on the constituent resin components, the heating temperature is appropriately set. For example, when the thermoplastic resin layer a is made of a vinyl chloride resin, the heating temperature is preferably 130 ° C. or higher, and preferably 150 ° C. or higher. In the case where the thermoplastic resin layer a is made of an olefin resin such as polyethylene or EVA, the heating temperature is 100 ° C. or higher, preferably 120 ° C. or higher.
When the set temperature is higher than the temperature at which the thermoplastic resin layer a is softened, the thermoplastic resin layer a is softened and easily separated. If the temperature is lower than the temperature at which the thermoplastic resin layer a is softened, the peel strength between the thermoplastic resin layer a and the base paper layer b is strong, and the frictional resistance with the scraping means 2 increases, so that the scraping becomes insufficient. The thermoplastic resin layer a remains on the base paper layer b, and a sufficient separated state cannot be obtained.
Moreover, since the organic compound and the water | moisture content contained in the thermoplastic resin wall covering material c can be removed by heating, the thermoplastic resin layer a and the base paper layer b obtained by separation are each used as a recycled material raw material. High quality.

  In the present invention, as a method of physically scraping the softened thermoplastic resin layer a from the base paper layer b, scraping means 2 provided with a flat plate, high-pressure gas blowing (air knife) or the like as a scraping jig is used. I can do things. As the flat plate, a material made of a metal having moderate elasticity and a heat-resistant synthetic resin such as nylon can be used, and as the high-pressure gas, an incombustible gas such as air or nitrogen gas can be used. By using a flat plate or high-pressure gas having an appropriate elasticity, high recovery efficiency can be obtained without considering the thickness of the base paper layer b and thickness variation.

  FIG. 3 shows a flat plate as an example of the scraping jig. X and Y in the figure indicate the blade edge thickness and the flat plate thickness, respectively. When a flat plate is used as the scraping jig, the cutting edge thickness X made of a material having moderate elasticity needs to be a flat plate having a thickness of 1 mm or less, and the preferable cutting edge thickness X is 0.5 mm or less, more preferably 0.2 mm or less. It is. When the blade thickness X is greater than 1 mm, the frictional resistance with the softened thermoplastic resin is large, and when scraped off, the thermoplastic resin remains on the base paper layer and the recovery efficiency deteriorates. The flat plate thickness Y is not particularly limited, but a range having an appropriate elasticity depending on the material is preferable. In order to obtain a good peeled state, it is preferable to appropriately set the angle between the thermoplastic resin wall covering c and the flat plate. As a favorable angle, the angle between the plane in the flow direction of the base paper layer b after separating the thermoplastic resin layer a from the contact point between the blade edge and the thermoplastic resin layer a and the flat surface is preferably 90 degrees or less. Is 45 degrees or less.

In the present invention, each of the heating means 1 and the scraping means 2 may be a single device or may be an integrated form.
As an integrated form, for example, when an oven is used as the heating means 1, scraping can be performed in the oven. Further, it is also possible to directly scrape the heated roll and the thermoplastic resin wall covering material c passing on the plate with a flat plate, high-pressure gas or the like. Further, when a flat plate or an air knife is used as a scraping jig, the unheated thermoplastic resin layer a is scraped if a flat plate or a high-pressure gas (air knife) heated to a temperature at which the thermoplastic resin layer a is softened is used. You can also.

  In the present invention, the feeding means 3 and the take-up means 4 are provided before and after the above means. In many cases, defective products discharged from manufacturing factories and processing processes, redesigned products, and disposal products of long-term inventory are in the form of scrolls wound around paper tubes or iron cores. And by installing the take-up means 4, it becomes an efficient device capable of continuous operation. As the feeding means 3, the scroll is placed on a plurality of rolls, the shaft is passed through a paper tube or iron core, the ends of the paper tube or iron core are fixed, and the tension by brake control or tension control. A general means having an adjusting portion can be used. As the take-up means 4, a general means having a pinch roll portion and a take-up portion capable of speed control can be used. Although there is no restriction | limiting in particular in taking over speed, 3 m / min or more is preferable from a viewpoint of productivity. The take-up speed is appropriately adjusted depending on the scraping jig, the heating temperature, the material of the thermoplastic resin layer a, and the like.

  Further, in the present invention, in order to make the shape of the scraped thermoplastic resin layer a constant and to facilitate handling in a subsequent process used as a resource, processing such as pulverization and granulation can be performed. . As a pulverization method, a general pulverizer equipped with a fixed blade, a rotary blade, and a screen can be used. As granulation methods, a thermoplastic resin layer separated by a Banbury mixer, kneader, two rolls, etc. is heat-kneaded, sheeted and then cut by a pelletizer, or separated by a single screw extruder or a twin screw extruder. The obtained thermoplastic resin layer a is heated and kneaded and hot cut with a dice head, or formed as a strand and cut in-line, or the thermoplastic resin layer a separated with a super mixer, a Henschel mixer or the like is stirred at high speed There is a method of mixing by heating, discharging to a cooling mixer and granulating. By making these pulverizing means and granulating means 5 in-line with the separation apparatus of the present invention, a more efficient apparatus can be obtained. Furthermore, by performing the granulation treatment at a preset temperature of 130 ° C. or higher, preferably 150 ° C. or higher, the resin temperature becomes higher by 10 to 30 ° C. or higher than the preset temperature due to shear heat generation, and moisture and chemical foaming contained in the thermoplastic resin layer a. Since undecomposed materials and / or volatile organic compounds such as residues can be removed, the resulting granulated product has a higher quality as a recycled material material.

  In addition, when granulating, resin, plasticizer, stabilizer, chelator, filler, foaming agent, foaming aid, ultraviolet absorber, colorant, flame retardant, antioxidant, processing aid, lubricant, etc. By blending the additives as appropriate, it is possible to produce a compound suitable for various processing uses as a subsequent step.

  For molding using the thermoplastic resin layer a separated and recovered according to the present invention as a material, a molding apparatus for thermoplastic resin such as a normal calender molding machine, extrusion molding machine, injection molding machine, press molding machine, blow molding machine or the like is used. The molded body that can be used can be used for applications such as building materials (flooring materials, wall covering materials, waterproofing materials, etc.), civil engineering materials, interior materials such as automobiles and railway vehicles, daily necessities, toys, miscellaneous goods and the like.

  Next, the present invention will be described in more detail with specific examples, but the present invention is not limited to these examples.

Judgment on the quality of each evaluation item was in accordance with the following criteria.
[Separation performance: Visual judgment]
The separation performance of the thermoplastic resin layer and the base paper layer was evaluated according to the following criteria.
Evaluation criteria ○: The thermoplastic resin layer and the base paper layer are separated.
X: The thermoplastic resin layer remains in the base paper layer. Or it is inseparable.
[Formability: Visual judgment]
In the case of calendar molding, the flow around the bank was evaluated, and in the case of extrusion molding, the flowability of the resin at the T-die outlet was evaluated according to the following criteria.
Evaluation criteria ○: Around the bank is good in the calendar, and in the extrusion molding, there is no abnormality in the resin flow and the moldability is good. Also, there is no rough skin or bubbles on the sheet surface.
X: Abnormality is observed around the bank in the calendar and resin flow in the extrusion. Also, there are rough skin and bubbles on the sheet surface.

<Example 1>
The wall material made of non-foamed vinyl chloride resin (hereinafter referred to as “PVC”) was used as the wall material made of thermoplastic resin and heated for 10 seconds on a hot plate set at a temperature of 180 ° C. . Using a stainless steel plate with a blade thickness of 0.5 mm (scraper for wallpaper construction), the PVC on the surface of the PVC wall covering was scraped off. The scraped PVC was pulverized by a pulverizer equipped with a screen having a hole having a diameter of 8 mm, and formed into a sheet of 0.3 mm at 170 ° C. by a calendar molding machine.

<Example 2>
In Example 2, instead of the waste material of the non-foaming type PVC wall covering in Example 1, a scroll of the foaming type PVC wall covering was used. Heated at 180 ° C. using a roll with hot oil as a heating source as a heating means, and scraped with a steel doctor blade (Echo Blade Co., Ltd., bevel type, flat plate thickness 0.15 mm) with a blade edge thickness of 0.06 mm as scraping means What was equipped as a taking jig was used. Further, the feeding means and the take-up means were installed and taken up at a speed of 5 m / min. The rest is the same as in Example 1.

<Example 3>
In Example 3, the heating temperature 180 ° C. in Example 2 was replaced with 140 ° C., and separated at a speed of 3 m / min. The rest is the same as in the second embodiment.

<Example 4>
In Example 4, instead of the waste material of the PVC wall covering in Example 2, the waste material of the EVA wall covering manufactured using EVA (vinyl acetate content 20%, MFR = 1.5 g / 10 min) was used. Using. Moreover, it calendar-molded at 150 degreeC. The rest is the same as in the second embodiment.

<Example 5>
In Example 5, instead of the calender molding machine in Example 4, an extrusion molding machine was used to form a sheet of 0.5 mm. The rest is the same as in Example 4.

  The evaluation results of Examples 1 to 5 are shown in Table 1. As is clear from Table 1, all showed good separation performance, and the molding using the obtained thermoplastic resin layer showed good moldability.

<Comparative Example 1>
In Comparative Example 1, the heating temperature of 140 ° C. in Example 3 was not heated (25 ° C.). Other than that is the same as Example 3.

<Comparative example 2>
In Comparative Example 2, the heating temperature 180 ° C. in Example 5 was set to 60 ° C. Other than that is the same as Example 3.

The evaluation results of Comparative Examples 1 and 2 are shown in Table 1. As is apparent from Table 1, scraping was impossible at unheated (25 ° C.) and heating temperature of 60 ° C., and the wall covering was broken. The moldability was not evaluated.

  The thermoplastic resin layer and the base paper layer separated according to the present invention can be recycled as reusable raw materials, and the separated thermoplastic resin layer can be used alone or mixed with a virgin material. It can be used with various molding machines, and the molded body can be used for building materials (floor materials, wall coverings, waterproofing materials, etc.), civil engineering materials, interior materials such as automobiles and railway vehicles, daily necessities, toys, sundries, etc. Can be widely used for applications.

It is an expanded sectional view of the thermoplastic resin wall covering relating to the present invention. It is explanatory drawing which shows one Example of the separation apparatus regarding this invention. It is explanatory drawing which shows one Example of the flat plate which is a scraping jig regarding this invention.

Explanation of symbols

a: thermoplastic resin layer b: base paper layer c: thermoplastic resin wall covering 1: heating means 2: scraping means 3: feeding means 4: take-up means 5: pulverizing means and / or granulating means X: Flat blade edge thickness Y: Flat plate thickness

Claims (2)

A thermoplastic resin wall covering made by laminating a thermoplastic resin layer and a base paper layer is heated to a temperature higher than the temperature at which the thermoplastic resin layer softens, and the softened thermoplastic resin layer is then made by a physical method. A method for separating a wall material made of thermoplastic resin, characterized by scraping off the layer. An apparatus for separating a thermoplastic resin wall covering formed by laminating a thermoplastic resin layer and a base paper layer into a thermoplastic resin layer and a base paper layer, and continuously connecting the thermoplastic resin wall covering. Means for automatically feeding out, means for heating above the temperature at which the thermoplastic resin layer softens, means for physically scraping the softened thermoplastic resin layer with a flat blade edge having a blade edge thickness of 1 mm or less, and further scraping the thermoplastic resin layer An apparatus for separating a wall material made of a thermoplastic resin, characterized by comprising means for pulling a base paper layer after being taken.

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