CN1237127A - Method for recycling packaging liner material, pellets formed therefrom and articles injection molded from the pellets - Google Patents

Abstract

Package-cushioning materials are recycled by the steps of: drying waste copolymerized PE + PS form, pulverizing the dried foam fusing the pulverized foam, forming the fused foam into ingots, extruding the ingots, and cutting the extrudate into pellets. The pellets can be injection molded into articles at a temperature of 160-200 degrees Celsius.

Description

Process for recycling packaging liner material, and pellets formed therefrom and articles injection molded from the pellets

field of invention

The present invention relates to the recycling of packaging cushioning materials, such as material forming PS (polystyrene) foam or forming PE (polyethylene) plus PS copolymerized material.

Description of prior art

At present, environmental pollution has formed a serious problem, so people have paid great attention to how to effectively collect used packaging liner materials and dispose of most recycled materials or products for environmental protection purposes, by reducing the amount of waste that was originally intended to be buried or incinerated. The amount of synthetic packaging material and the saving of natural resources used to manufacture new plastic products.

Generally, only waste PS is collected and recycled and mixed with new high-quality polystyrene (HIPS) to make windows and picture frames. However other packaging liner materials like copolymerized PE+PS foam and PE foam are excluded from recycling because PE+PS and PE are found to be difficult to process in the recycling industry. It is known that PE and PS resins cannot be mixed properly, and it was generally believed that a mixture of PE and PS resins was not possible.

Copolymerized PE+PS foam products and PE foam products are more difficult in the recycling process, because PE+PS and PE foam or PE foam are not commonly used, and the melting point of PE is higher than that of PS. Therefore, co-polymerized PE+PS foam scrap and PE foam are not often collected for recycling. However, considering the environmental problems caused by the incineration of plastic waste as a means of disposal, more research is necessary in developing recycling methods for these waste plastics.

Due to its higher reliability and effectiveness in transportation, the use of PE+PS packaging liner material has been becoming more and more common, which should be attributed to the impact absorption, elasticity of copolymerized PE+PS. Better physical properties such as durability of repeated use, but also due to the advantages of reducing transportation costs due to the fact that it occupies less volume when the packaging is increased. Therefore, since PE+PS is used more and more as a packaging liner material, it is necessary to develop a new method for recycling the copolymerized PE+PS.

Brief description of the invention

The present invention is disclosed to solve the above-mentioned problems and one of the objects of the present invention is to provide a method of recycling packaging cushioning materials. Another object of the present invention is to provide a method for recycling foam packaging cushioning materials comprising copolymers of polyethylene (PE) and polystyrene (PS). Yet another object of the present invention is to provide a pellet formed from a method of recycling a foam packaging cushioning material comprising copolymerization of PE and PS; and to provide an injection molded article formed from the pellet.

According to the object of the present invention, it provides a method for processing waste packaging cushioning material of copolymerized polyethylene (PE)+polystyrene (PS) foam, comprising recycling the foam into PE+PS pellets . The recycling preferably comprises comminuting the waste co-polymerized PE+PS foam; melting the comminuted PE+PS; forming a billet from the melted foam; extruding the billet; cutting the extrudate into pellets.

Waste copolymer PE+PS foam should be dried to remove moisture before entering the recycling process. Appropriate pigments can be added during the extrusion step to obtain a wide range of colors from white to black.

Products can be injection molded from pellets at a temperature of 160-200°C to prevent discoloration.

Brief description of the drawings

For a fuller understanding of the nature and objects of the present invention, reference should be made to the following detailed description together with the accompanying drawings;

Figure 1 is a flow diagram of recycling packaging liner material consistent with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

The recycling method of the present invention will be described in detail with reference to FIG. 1 . Synthetic packing dunnage is used to protect items from damage during shipping. The used packing liner material is then typically separated from the item and disposed of after the item has been shipped.

In the recycling industry, these discarded plastic packaging liners are collected and sorted into various waste types, namely paper, vinyl, PS (polystyrene) foam and co-polymerized PE (polyethylene) +PS (polystyrene) foam. The scrap PE+PS foam undergoes a continuous process of a series of steps, or steps 20, called shredding 30 → melting 40 → billet formation 50, extrusion 60 (following another melting step), and subsequent cutting into recycled PE+PS pellets 70.

The recycled PE+PS pellets 70 are then injection molded at 80 to form functional parts 90 for supply to manufacturers.

The waste PE+PS foam is preferably dried by a drying process 100 prior to the recycling process 20 .

And when the recovered PE+PS gum is extruded through the extrusion process 60, if necessary, some pigments (such as titanium, carbon or their mixtures) can be added to form colors from white to black.

In the injection molding process 80, the recycled PE+PS resin may be injection-molded at a temperature of 160-200° C. to prevent burning and maintain its predetermined color.

Therefore, we found that waste PS+PE can be effectively used to produce recycled functional materials through the recycling method of the present invention. Table 1 lists the physical properties of recycled functional materials similar to conventional ABS resin or HIPS resin.

Table 1 Determination of physical properties of various synthetic products according to ASTM test unit Recycled PE+PS resin ABS (VH-0810) New HIPS(HR-1360) 100% recycled new material new material Tensile Strength kg/ ^cm2 418 420 320 Flexural strength kg/ ^cm2 495 600 360 flexural elasticity ratio kg/ ^cm2 15,000 24,000 17,600 Elongation % 14 - - shock 3.2mm kg cm/cm - 19 10 6.4mm kg cm/cm 1.89 - - Melt Index g/10 points 1.89 5.5 3.8 Heat distortion temperature ℃ 78 76 78 hardness R 54.5 100 112

Recycled packaging liner material, mixed recycled pellets and extrusions formed therefrom from the above method have several advantages, according to the invention since the recycled pellets of waste copolymerized PE+PS are 100% The land is used to produce recycled functional materials, thereby reducing the environmental pollution caused by burying or incinerating plastic products, saving natural resources and providing new functional products.

Although the present invention has been described in conjunction with a preferred embodiment, those skilled in the art may make additions, subtractions not specifically described without departing from the spirit and scope of the invention as defined by the appended claims , modify and replace.

Claims (9)

1. the method for the discarded package-cushioning material of the PE+PS foams of processing copolymerization comprises that the PE+PS foams that reclaim the depleted copolymerization form the step of PE+PS pellet.

2. the method that claim 1 limited, wherein recycling step comprises:

A. pulverize the PE+PS foams of depleted copolymerization;

B. the PE+PS foams after fusion should be pulverized;

C. fused PE+PS is formed blank;

D. this blank of extrusion molding; And

E. extrusion material is cut into pellet.

3. the method that claim 1 limited, wherein depleted copolymerization PE+PS foams were carried out dry to remove remaining moisture content before being transformed into pellet.

4. the method that claim 2 limited wherein adds pigment in step D.

5. the discarded package-cushioning material of the PE+PS foams by reclaiming copolymerization forms the pellet that the PE+PS pellet forms.

6. the pellet that claim 5 limited is formed by following steps:

A. pulverize the PE+PS foams of depleted copolymerization;

B. the PE+PS foams after fusion should be pulverized;

C. fused PE+PS is formed blank;

D. this blank of extrusion molding; And

E. extrusion material is cut into pellet.

7. the discarded package-cushioning material of the PE+PS foams by reclaiming copolymerization forms the PE+PS pellet and with the formed goods of this pellet injection moulding.

8. goods that claim 7 limited, being injection-moulded in 160～200 ℃ the temperature range wherein carried out.

9. goods that claim 7 limited, wherein reclaim and may further comprise the steps:

A. pulverize the PE+PS foams of depleted copolymerization;

B. the PE+PS foams after fusion should be pulverized;

C. fused PE+PS is formed blank;

D. this blank of extrusion molding; And

E. extrusion material is cut into pellet.

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