KR101977445B1 - Device for manufacturing bio plastic foam sheet - Google Patents

Abstract

The present invention relates to a bio-plastic foam sheet producing apparatus, comprising a mixing unit for mixing a biomass raw material and a plastic resin to form a base material, a main extrusion unit for receiving and melting and extruding a base material from the mixing unit, A die unit for foaming the mixture discharged from the extrusion unit to form an intermediate foam layer in the form of a sheet and forming an outer layer on the outer surface of the foam middle layer, and a sub extrusion unit for supplying a raw material for forming the outer layer as a die unit, It is possible to solve the problem of deodorization due to the contact with the foam middle layer and to confine the foam gas in the foam middle layer to ensure the foam uniformity.

Description

TECHNICAL FIELD [0001] The present invention relates to a bio-plastic foam sheet manufacturing apparatus,

The present invention relates to a bio-plastic foam sheet production apparatus, and more particularly, to a bio-plastic foam sheet production apparatus using bio-plastic including amorphous polypropylene resin-based natural product herbaceous biomass and environmentally- The present invention relates to a bio-plastic foam sheet production apparatus for producing a bio-plastic foam sheet.

Generally, foamed plastic is excellent in packaging function such as buffering property, waterproof property, hygienic property, heat shielding property, light weight property and formability, and is used for building insulation material, consumer cushioning packing material, concentrated aquatic products box, rich for aquatic aquaculture product, , Packaging materials for home delivery, helmets and surfboard interior materials, and other industrial packaging materials.

In particular, most of the currently used foam sheets are mostly made of a material made of paper in which polystyrene and polyethylene foam or a polyethylene plastic material is coated. The thermoplastic resin, polystyrene, contains styrene monomers that can release environmental hormones, which are carcinogens, when pyrolysis or chemical dissociation occurs. The compound is a kind of 'endocrine disrupter' that enters into the body of an animal or a human body to interfere with or disrupt hormone action. The compound has toxicity comparable to that of cadmium and is a toxic substance which is reported to be harmful to reproductive organs due to infertility in female, infertility and sperm count due to adverse effects on liver, kidney, heart and lungs .

Therefore, recently, studies are being conducted to develop packaging material for food which is harmless to human body by using natural plant material. As society's interest in improving the quality of life and pleasant living environment is heightened, there is a growing need to build a sustainable recycling system for foamed plastics, which has been recognized as being easy to use and discard. In addition, when used as a composite material coated with polyethylene on paper, it can not be recycled and recycled when it is used after disposal, so it is placed in front of the purifying resources and carbon abatement policies that are currently being implemented worldwide. There is a lot of investment going on.

Conventional methods for producing foamed plastics using biodegradable bioplastic raw materials include Korean Patent Laid-Open Publication No. 10-20070099587, a method for producing foamed biodegradable plastics using biodegradable resin derived from a high viscosity reforming plant for high- Biodegradable resin composition derived from a high viscosity reforming plant for high foaming with monomers added thereto, but the biodegradable foamed resin obtained as described above is produced through a polymerization process and lacks cost effectiveness due to high energy and production limitations do. Also, International Patent Publication No. WO 2005/085346 discloses a foamable thermoplastic polymer containing 0.01 to 5 parts by weight of (meth) acrylic acid ester or glycidyl ester based on 100 parts by weight of a polylactic acid-based aliphatic polyester. ) Acrylic acid esters and glycidyl esters only serve as a crosslinking agent for the polylactic acid-based aliphatic polyester, a flexible composition can not be obtained and the biodegradability is low so that the application is limited.

On the other hand, conventional biomass-based foamed plastic has a problem in that it causes problems of bad odor when it is applied to foods and that the foamed gas of the foamed layer is released to the outside, resulting in deformation of the product. In addition, phase separation phenomenon occurs between the blending raw materials due to vibration during the operation of the extrusion equipment for producing the foamed plastic, which is a main cause of nonuniform blending, resulting in non-uniformity of the degree of foaming, .

DISCLOSURE Technical Problem The present invention has been made in order to overcome the problems of the conventional bio-plastic foam sheet and its manufacturing apparatus as described above, and it is an object of the present invention to solve the problem of deodorization due to contact of biomass, And an object of the present invention is to provide an apparatus for manufacturing a bio-plastic foam sheet capable of securing foam uniformity.

It is another object of the present invention to provide an apparatus for producing a bio-plastic foamed sheet capable of uniformly mixing and supplying a blending raw material to vibration during operation.

According to an aspect of the present invention, there is provided an apparatus for manufacturing a biofabric foam sheet, comprising: a mixing unit for mixing a biomass as a raw material of a plant with a plastic resin to form a base material; A main extrusion unit for receiving and melting and extruding the base material from the mixing unit; And a die unit for forming an outer layer on the outer surface of the foamed middle layer so as to prevent the release of the foamed gas contained in the foamed middle layer, .

In the apparatus for manufacturing a bio plastic foam sheet according to an embodiment of the present invention, the main extrusion unit includes a first main extruder for receiving a base material from the mixing unit, a second main extruder for melting the mixture at a temperature different from that of the first extruding unit A second main extruder, and a connection part connecting the outlet end of the first main extruder and the inlet end of the second main extruder.

In the apparatus for manufacturing a biofabric foam sheet according to an embodiment of the present invention, the connecting portion includes a straight tube connected to an end of the first main extruder, and an elbow tube connected to the second main extruder, It is also possible that the tube is provided so as to be detachable in two along the longitudinal direction.

In the apparatus for manufacturing a bio plastic foam sheet according to an embodiment of the present invention, the die unit includes a main extrusion passage for introducing a mixture from the main extrusion unit and forming the foam middle layer, And a pair of sub-extrusion flow paths communicating with the ends of the main extrusion flow path and into which the raw material for forming the outer layer flows into the outer side of the foam middle layer.

The apparatus for producing a bio plastic foam sheet according to an embodiment of the present invention may further include a sub-extrusion unit for supplying a raw material to the sub-extrusion path.

In the apparatus for producing a bio plastic foam sheet according to an embodiment of the present invention, the sub-extrusion unit may include a first sub-extruder and a second sub-extruder that supply different raw materials to the pair of sub- .

In an apparatus for producing a bio-plastic foam sheet according to an embodiment of the present invention, there is provided an apparatus for manufacturing a bio plastic foam sheet, comprising: a first pressure detecting unit for detecting a pressure of a main extrusion passage of the die unit; a second pressure detecting unit for detecting a pressure of the second main extruder; A third pressure detector for detecting the pressure of the first main extruder and a second pressure detector for receiving a pressure signal from the first pressure detector, the second pressure detector and the third pressure detector and controlling the feed rate of the first main extruder and the second main extruder The control unit may further include a control unit.

In the apparatus for producing a bio-plastic foam sheet according to an embodiment of the present invention, when the pressure of the main extrusion passage received from the first pressure detection section is out of a preset value, The output of the motor can be firstly adjusted and the output of the first extruding motor of the first main extruder can be secondarily adjusted.

In the biofabric foam sheet manufacturing apparatus according to an embodiment of the present invention, the mixing unit may include a mixer in which biomass as a raw material of a plant and plastic resin are mixed and mixed, and a mixer discharged from the mixer to the main extrusion unit A plurality of main feeders are provided in parallel with each other at a predetermined interval, and screw vanes 222 having opposite directions are provided on both sides of a center of each screw shaft, and each of the screw vanes 222 A plurality of collecting screws provided in opposite directions to the screw blades 222 of adjacent collecting screws for moving the mixture discharged from the hopper to the center of the screw shaft, a collecting motor for driving the collecting screws, And is provided at the lower center along the axial direction, and in a direction perpendicular to the collecting screw It may be provided containing a plurality of feed screw for feeding the mixture to fall in the middle of the collecting screw to the main extrusion unit, and a feed motor for driving the feed screw.

As described above, according to the apparatus for manufacturing biofabric foam sheet according to the present invention, when it is applied for food, the contact between the biomass and the food is blocked to solve the problem of unpleasant odor and the foam layer is placed in the middle layer, By holding the foaming gas in the middle layer, the foam uniformity can be ensured and the deformation of the foamed product can be minimized.

In addition, even when the blending raw materials are uniformly mixed and supplied to the vibration during operation, a foamed sheet having a uniform degree of foaming and excellent physical properties can be produced.

According to the present invention, it is possible to facilitate the cleaning of the connection pipe connecting the extruders.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side sectional view showing a bio-plastic foam sheet to be produced by the present invention,
FIGS. 2 to 3 are side views showing an apparatus for producing a bio-plastic foam sheet according to an embodiment of the present invention,
FIG. 4 is a plan view showing the apparatus for producing bio-plastic foamed sheet shown in FIG. 3,
5 is a cross-sectional view showing one side of the main feeder shown in Fig. 3,
FIG. 6 is a cross-sectional view taken along line AA in FIG. 5,
Figs. 7 to 9 are perspective views showing the connection portion shown in Fig. 3,
10 is a schematic cross-sectional view showing the die shown in Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows a bio-plastic foam sheet 10 to be produced by the present invention. The foamed biofabricated foam sheet 10 is formed with an intermediate foam layer 11 at the center and outer layers 12 are formed on both outer sides of the foamed middle layer 11.

The middle foam layer 11 is formed by mixing and melting biomass as a raw material of a plant with a plastic resin and foam molding in a sheet form. An outer layer 12 is formed on both outer sides of the foamed middle layer 11 in sheet form.

The outer layer 12 surrounds the outer side of the foam middle layer 11 and prevents the foam gas contained in the foam middle layer 11 from being released. The outer layer 12 is formed in the form of a film to cover the outer side of the middle foam layer 11. The outer layer 12 formed on both sides of the foamed intermediate layer 11 may be formed of different materials or may be made of the same material.

2 to 10, an apparatus for manufacturing a biofabric foam sheet according to an embodiment of the present invention includes a mixing unit for mixing a biomass as a raw material of a plant with a plastic resin to form a base material, A main extruding unit for receiving and melting and extruding the mixture, and a die for forming an outer layer 12 on the outer surface of the middle foam layer 11 by foaming and molding the mixture discharged from the main extrusion unit, Unit 700, and a sub-extrusion unit for supplying raw materials for forming the outer layer to the die unit 700. [

The mixing unit includes a mixer 100 in which biomass as a raw material of a plant is mixed with a plastic resin and a main feeder 200 that supplies a mixture discharged from the mixer 100 to the main extrusion unit.

Examples of the base material to be introduced into the mixing unit include a polyolefin resin in the form of pellets of 2 to 3 mm, a biomass of 7 to 50 mu m ultra fine powder, a fine inorganic filler (2 to 10 mu m powder) for reducing heat and friction coefficient, (20 ~ 50mm slice) and lubricant (0.5 ~ 1mm granules) for compatibility.

Here, the polyolefin resin is provided in the form of a pellet, and the other materials are provided in the form of powder, which may cause phase separation between the materials due to vibration during operation of the apparatus and may not be properly compounded. The main feeder 200 prevents the phase separation phenomenon by forcibly collecting and mixing the materials.

The main feeder 200 includes a plurality of collecting screws 220 provided in parallel with each other at a predetermined interval, a collecting motor 240 for driving the collecting screws 220, And a feed motor 270 for driving the feed screw 260. As shown in FIG.

6, each of the collecting screws 220 has a screw shaft 221 and screw vanes 222 are provided on both sides of the screw shaft 221 in opposite directions to each other. Accordingly, when the screw shaft 221 rotates in one direction, both screw vanes 222 feed the mixture in opposite directions to each other.

The screw vanes 222 are provided in opposite directions to the screw vanes 222 of adjacent adjacent collection screws 220 to collect the mixture between the pair of the collection screws 220. In addition, each screw blade 222 is provided between the screw blades 222 of adjacent adjacent collecting screws 220 to minimize the space between the collecting screws 220, and thus the collecting screws 220 Can be transported without any excess.

The adjacent screw vanes 222 are not provided with the screw vanes 222 at the center of the screw shaft 221 so that the mixture is prevented from being separated from the screw shaft 221, So that they can easily fall into the space between them. The mixture which is collected at the center of the collection screw 220 and falls is fed to the main extrusion unit by the feed screw 260.

The collecting screws 220 are simultaneously rotated by the interlocking chain 250 and receive the power of the collecting motor 240. A driving sprocket (not shown) is provided to move the interlocking chain 250 to the driving shaft of the collecting motor 240 and a driven sprocket 230 is provided at the end of the screw shaft 221 of each collecting screw 220. When the collecting motor 240 is driven, the interlocking chain 250 is moved in an infinite track manner to rotate the plurality of collecting screws 220. At this time, the mixture discharged from the hopper 210 reaches the center of the screw shaft 221 .

The conveying screw 260 is provided along the axial direction of the collecting screw 220 below the center without the screw blade 222 to supply the mixture falling from the center of the collecting screw 220 to the main extrusion unit.

When the main feeder 200 is used, the base material can be prevented from being dispersed and separated from the base material. Thus, the base material can be supplied to the main extruding unit, And the foamed intermediate layer 11 foamed at ultra-fine and high density can be obtained by supplying a high mixture.

The main extruding unit includes a first main extruder 300 for receiving the base material from the mixing unit, a second main extruder 400 for melting the mixture at a different temperature than the first main extruder 300, And a connecting part 500 for connecting the outlet end of the second main extruder 400 and the inlet end of the second main extruder 400.

The first main extruder 300 is a twin extruder having two extruding screws (not shown), and the first extruding motor 310 rotates a pair of the extruding screws. The second main extruder 400 is a single extruder having one extruding screw (not shown), and the second extruding motor 410 rotates the extruding screw. The rotation speed of the first extrusion motor 310 and the second extrusion motor 410 is controlled by the control unit.

The pressure of the second main extruder 400 is set to be lower than the pressure of the first main extruder 300. The discharge pressure of the first main extruder 300 is lowered in the second main extruder 400 so that the shape of the foam middle layer 11 can be prevented from being deformed by the high extrusion pressure. In other words, the second main extruder 400 functions to release the high pressure in the first main extruder 300.

In addition, the base material introduced into the first main extruder 300 starts to foam in a multistage manner while continuously passing through the first main extruder 300 and the second main extruder 400. That is, the first main extruder 300 and the second main extruder 400 have a different blowing agent foaming in the first main extruder 300 and a foaming agent foaming in the second main extruder 400 with different melting temperatures . When the temperature of the first main extruder 300 is set at 150 degrees and the temperature of the second main extruder 400 is set at 180 degrees, the blowing agent is blown at a temperature of 180 degrees with the blowing agent blown at 150 degrees. When the foaming agent to be foamed is mixed into the base material, the foam is primarily foamed at 150 degrees while passing through the first main extruder 300, and secondarily foamed at 180 degrees while passing through the second main extruder 400. To this end, a first main extruder 300 and a second main extruder 400 are provided with a heating mechanism (not shown) and a temperature sensor (not shown), respectively. The temperature sensor sends the temperature signal to the control unit. The control unit controls the operation of the heating mechanism to adjust the temperatures of the first main extruder 300 and the second main extruder 400 to within the set temperature.

The discharge end of the first main extruder 300 is provided with a side feeder 450 for injecting a blowing agent. The side feeder 450 injects the foaming agent into the discharging end of the first main extruder 300 at a constant speed so as to perform foaming in multiple stages in the second main extruder 400 and the die unit 700. The amount of blowing agent varies depending on the content of biomass.

The connection unit 500 includes a straight pipe 510 and an elbow pipe 520. The straight tube 510 is bolted to the end of the first main extruder 300 and the elbow tube 520 is bolted to the end of the second main extruder 400. The straight pipe 510 and the elbow pipe 520 are flanged to each other.

The elbow pipe 520 is provided so as to be separated into two pieces along the longitudinal direction. As shown in Fig. 8, an elbow-shaped transfer passage 523 is formed in the elbow pipe 520. As shown in Fig. The elbow pipe 520 includes a first tubular body 521 and a second tubular body 522 and is bolted to each other and the first tubular body 521 and the second tubular body 522 are combined to form a conveying passage 523 do. The first tubular body 521 is cut in half from the curved section of the conveying passage 523 to one end and the second tubular body 522 is formed with a groove forming a part of the conveying passage 523. [

As described above, the transfer passage 523 of the connection part 500 is divided into two along the longitudinal direction thereof, so that it can be easily cleaned after the extrusion operation. The inside of the transfer tube 523 formed in the first tubular body 521 and the second tubular body 522 can be easily cleaned after the second tubular body 522 is disassembled from the first tubular body 521.

10, the die unit 700 includes a main extrusion passage 720 for introducing a mixture from the main extrusion unit to form an intermediate foam layer 11, and an outer layer 12 on the outer side of the foam middle layer 11, And a pair of sub-extrusion flow paths 730 through which the raw material for forming the sub-extrusion flow path 730 flows.

The main extrusion passage 720 and the sub extrusion passage 730 are formed in the die 710. The main extruding channel 720 receives the mixture from the first main extruder 300 and foam-shapes the foam middle layer 11 into a sheet form. The sub extrusion flow path 730 is provided on both sides of the main extrusion path 720, and the raw material is supplied from the sub extrusion unit.

The sub-extrusion unit of the present embodiment includes a first sub-extruder 610 and a second sub-extruder 620 that supply different raw materials to a pair of sub-extrusion channels 730, respectively. Unlike the present embodiment, one sub-extruder can be used when the same raw material is fed into the pair of sub-extrusion passages 730.

The end of the sub-extrusion passage 730 is connected to the end of the main extrusion passage 720 to form one discharge passage 740. In the discharge flow path 740, the outer layer 12 is formed at the same time while discharging the raw material from the sub-extrusion flow path 730 to both surfaces of the middle foam layer 11 formed from the main extrusion path 720.

The outer layer 12 is simultaneously formed on the outer side of the foam middle layer 11 so that the outer layer 12 covers the outer side of the foam middle layer 11 and prevents the foam gas contained in the foam middle layer 11 from being released. When the foamed gas contained in the foamed middle layer 11 is released, the shape of the foamed middle layer 11 is deformed to deteriorate the function of the foamed material. The outer layer 12 seals the foamed gas to prevent the shape deformation of the foamed middle layer 11 It will be possible to do.

The die unit 700 is provided with a first pressure detecting unit 811 and the second main extruder 400 is provided with a second pressure detecting unit 812. The connecting unit 500 is provided with a first main extruder 300, And a third pressure detecting unit 813 for detecting the pressure.

The first pressure detecting unit 811 measures the pressure of the main extrusion path 720 of the die unit 700 and sends a pressure signal to the control unit. The second pressure detecting unit 812 detects the pressure of the second main extruder 400 And the third pressure detecting unit 813 detects the pressure of the first main extruder 300 and sends the pressure signal to the control unit.

The control unit receives the pressure signals from the first pressure detecting unit 811, the second pressure detecting unit 812 and the third pressure detecting unit 813 and controls the first pressure detecting unit 811, the second pressure detecting unit 812, And controls the feed speeds of the first main extruder 300 and the second main extruder 400 based on the pressure signal received from the pressure detector 813. That is, when the pressure of the main extrusion path 720 received from the first pressure detecting unit 811 is out of the set value, the control unit primarily adjusts the output of the second extrusion motor 410 of the second main extruder 400 And secondarily regulates the output of the first extrusion motor 310 of the first main extruder 300.

If the pressure of the main extrusion passage 720 received from the first pressure detecting section 811 drops below a predetermined value, the output of the second extrusion motor 410 of the second main extruder 400 is first raised, Thereby increasing the pressure of the mixture supplied to the inlet 720. The output of the first extrusion motor 310 of the first main extruder 300 is increased when the pressure of the main extrusion path 720 is not adjusted despite the output control of the second extrusion motor 410. Since the pressure of the second main extruder 400 must be lower than the pressure of the first main extruder 300 as described above, the control unit controls the pressure value received by the second pressure detector 812 and the pressure value of the third pressure detector 813, The pressure of the second main extruder 400 is lower than the pressure of the first main extruder 300 and the output of the second extruder motor 410 of the first main extruder 300 .

When the pressure control of the main extruding passage 720 is adjusted to a set value, the controller controls the first extruding motor 310 and the second extruding motor 300 so as to maintain the pressure of the second main extruder 400 and the pressure of the first main extruder 300 at that time. 2 extrusion motor 410 is maintained.

By controlling the motor speeds of the first main extruder 300 and the second main extruder 400 in this manner, the pressure of the main extruding flow path 720 of the die unit 700 is adjusted to easily set the optimal pressure for the foam molding .

1, the foam sheet 10 manufactured in the die unit 700 is manufactured in the form of a roll while sequentially passing through the tension roller mechanism 91, the cooling roll mechanism 92 and the winding mechanism 93 do.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is obvious that the modification or the modification is possible by the person.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100: Mixer 200: Main feeder
210: hopper 220: collection screw
221: screw shaft 222: screw blade
230: Passing sprocket 240: Collecting motor
250: Interlocking chain 260: Feed screw
270 Feed motor 300: First main extruder
310: first extrusion motor 400: second main extruder
410: Second extruder motor 450: Side feeder
500: connection 510: straight tube
520: Elbow pipe 521: First tube
522: second tube body 523:
610: First sub-extruder 620: Second sub-
700: Dice unit 710: Dice
720: main extrusion flow path 730:
740: Discharge passage 811: First pressure detecting section
812: second pressure detecting section 813: third pressure detecting section

Claims (9)

A mixing unit for mixing a biomass as a raw material of a plant with a plastic resin to form a base material; A main extrusion unit for receiving and melting and extruding the base material from the mixing unit; And a die unit for forming an outer layer on the outer surface of the foamed middle layer so as to prevent the release of the foamed gas contained in the foamed middle layer, Including,
The mixing unit includes:
A mixer in which biomass as a plant material and plastic resin are mixed and mixed; And a main feeder for feeding the mixture discharged from the mixer to the main extrusion unit, wherein a plurality of the main feeders are provided parallel to each other at a predetermined interval, and the main feeder has a constant distance about the center of each screw shaft, Wherein the screw vanes are provided in opposite directions to screw vanes of other collecting screws which are adjacent to the side in parallel with each other, and the plurality of collecting vanes which move the mixture discharged from the hopper to the center of the screw shaft screw; A collecting motor for driving the plurality of collecting screws; A plurality of feed screws provided below the center along the axial direction of the collecting screw and provided in a direction perpendicular to the collecting screw and supplying the mixture falling from the center of the collecting screw to the main extrusion unit; And a feed motor for driving the feed screw,
The main extrusion unit includes:
A first main extruder for receiving a base material from the mixing unit; A second main extruder for melting the mixture at a temperature different from that of the first main extruder; And a connection part connecting the discharge end of the first main extruder and the inlet end of the second main extruder, wherein the connection part comprises a straight tube connected to an end of the first main extruder, And an elbow tube which is detachably coupled to the main body in two longitudinal directions,
The die unit includes:
A main extrusion passage for introducing the mixture from the main extrusion unit to form the foam middle layer; A pair of sub extruding flow paths provided at both sides of the main extruding flow path and communicating with ends of the main extruding flow path and into which the raw material for forming the outer layer flows into the outer side of the foam middle layer; And a sub-extruding unit comprising a first sub-extruder and a second sub-extruder for respectively supplying different raw materials to the pair of sub-extruding channels so as to supply the raw material to the sub-extrusion flow channel, A first pressure detector for detecting a pressure of the main extrusion passage of the die unit to control the pressure of the extruder to be lower than the pressure of the first main extruder; A second pressure detector for detecting a pressure of the second main extruder; A third pressure detector for detecting a pressure of the first main extruder; And a control unit for receiving a pressure signal from the first pressure detecting unit, the second pressure detecting unit and the third pressure detecting unit and controlling a feeding speed of the first main extruder and the second main extruder, And a control unit for primarily adjusting the output of the second extruding motor of the second main extruder and secondarily adjusting the output of the first extruding motor of the first main extruder when the pressure of the flow path deviates from the preset value Wherein the biofabric foam sheet is manufactured by a method comprising the steps of: delete delete delete delete delete delete delete delete

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