JP3844049B2 - Production method of biodegradable cushioning material - Google Patents

Description

[0001]
[Industrial application fields]
The present invention prevents damage and damage even when external impact is applied or dropped by packing between the outer packaging body when transporting and handling packaging equipment such as precision instruments, glass, ceramic products or furniture furniture. In addition, the present invention relates to a biodegradable cushioning material that can be completely decomposed and erased even when discarded after use to prevent disposal pollution, and a method for manufacturing the same.
[0002]
[Prior art]
In order to prevent damage due to external impacts during transportation and handling of precision instruments, in the case of products that have been produced in large quantities in the past, a shape that can enclose precision instruments in advance and a packaging material that uses a highly styrofoam material is formed. However, after being wrapped in the packaging mold material and stored and packaged in an outer packaging box made of corrugated cardboard material, in today's situation where many kinds and small quantities are being produced, a variety of precision instruments are used. Each precision instrument is packaged with a dustproof film or the like in an outer packaging box that can be stored and packaged in common, and then stored in the outer packaging box, and a spherical object made of a highly foamed polystyrene material in the gap between the outer packaging box and A thin piece such as a rod-like object or a plate-like object is filled as a cushioning material for distribution. Furthermore, for glass, ceramic products and furniture furniture, it absorbs and reduces external impacts during transportation and handling to prevent breakage and damage. Also, foam sheet or polyethylene made of materials that retain viscoelasticity such as polyurethane and polyethylene materials. It is packaged with a so-called air cap film or the like in which an air layer is encapsulated between the films and used for distribution.
[0003]
However, these packaging molds, cushioning materials, foamed sheet-like materials, air cap films, etc. are discarded after being subjected to short-term distribution, and these are not only made of synthetic resin materials, but also very bulky, From the standpoint of environmental protection, which will be an important issue in the future, not only does it go against volume reduction and volume reduction, but these wastes can only be incinerated. In addition to preventive measures against dioxins, urgent issues have been raised.
[0004]
In recent years, development of products using so-called biodegradable materials, such as polylactic acid resins and acetate resin materials, which are intended to be decomposed and eliminated by the involvement of microorganisms under natural conditions, has been actively attempted. In addition to the high cost, the biodegradability on the other side is impaired if the practical performance is maintained, and if the biodegradability is fully exhibited, on the other hand, there is a problem that the practical performance cannot be achieved. In particular, there are many problems in the development of materials that can maintain practical performance in a short period of time, such as packaging materials and cushioning materials, and can be quickly disassembled and deleted by disposal.
[0005]
The inventor has conducted extensive research in view of such circumstances, and as a result, biodegradability has been promoted with the degree of reproduction of microorganisms that reproduce using water, temperature, and nutrient sources as a breeding condition, and starch-based starch Is a suitable source of nutrients for microorganisms, and starch and corn starch have long been known in the food industry as extrusion cooking. It can be easily prepared, and by mixing polyvinyl alcohol in the presence of about 5 to 10% moisture and kneading under heat and pressure, the polyvinyl alcohol is homogeneously dispersed, and viscoelasticity and toughness are imparted to the plastic workpiece. It is hoped that the so-called specific surface area of the microorganisms should be made large in order to prevent biodegradation and elimination at the time of disposal. In order to achieve this, it has been determined that an open cell structure is suitable. Further, in the production method, only water-absorbing and hygroscopic and fine powdery starch powder and polyvinyl alcohol powder are used as raw materials. Since a blocking phenomenon occurs in the hopper part that feeds the raw material during extrusion molding, a supply hindrance is caused. Therefore, these raw materials are dispersed and mixed with pellets having a large particle size at a ratio of about 20 to 25% by weight. Therefore, it is possible to prevent blocking and to form an open cell structure along with the spraying of heat and pressure steam by spraying water after water injection and heating and pressure kneading without using a chemical foaming agent. As a result, the present invention has been completed.
[0006]
[Problems to be solved by the invention]
That is, according to the present invention, the composition component is composed of starch, polyvinyl alcohol and residual moisture, and can be packed in the gap with the outer package during transportation and handling to protect the transported goods by absorbing the impact in the external impact, and An object of the present invention is to provide a biodegradable cushioning material that can be quickly decomposed and eliminated under natural conditions after use, and a method for producing the same.
[0007]
[Means for Solving the Problems]
The technical means used by the present invention in order to solve the above-mentioned problem is that the present invention uses biodegradation and elimination under natural conditions when discarded after use. Widening the particle size distribution and ensuring stable supply to the extrusion molding machine for the biodegradable powder raw material blended in a proportion of 70 to 75% by weight and 25 to 30% by weight of polyvinyl alcohol powder, and polyvinyl alcohol powder Create a void in the powder raw material by adding water to the body and homogenizing kneading in the extruder, and widening the particle size distribution, and infiltrate water injection to create pressurized heated steam related to the formation of open cells From the top, blended with a starch powder of 65 to 75% weight, polyvinyl alcohol powder of 15 to 25% weight and water of 10 to 20% weight. Comparatively low temperature in a large biodegradable pellets after forming the particle diameter of the heat-kneading further with 20 to 25% by weight biodegradable material dispersed in a proportion.
[0008]
The biodegradable raw material has a uniaxial or biaxial screw, and a hopper of an extrusion molding machine capable of maintaining a temperature gradient from room temperature to 200 ° C. over its supply unit, compression unit, metering unit, and die unit. 1.0 to 5.0% by weight with respect to the supplied biodegradable raw material in the screw supply section in which the biodegradable raw material supplied at a low temperature is not melted and the internal pressure is small. In addition, water is injected and dispersed in the compression part and metering part, and the injected and dispersed and kneaded water is dispersed and encapsulated as heat and pressure steam, and discharged from the die part at the required size. By making the heated and pressurized water vapor contained in the dispersion scatter, an extrusion molding machine that discharges and forms an open-cell structure having a foaming ratio of about 35 to 70 times, and the discharge formed continuous In order to form the required cushioning material from the foam structure, a cooling floating cage is provided in the immediate vicinity of the die, and a cutter that cuts the open-cell structure to be formed to a required length is disposed and cut. In addition to cooling the open cell structure so that it does not deform and floating so that the cut pieces are not fused together, the fan is blown by a blower fan from at least two directions of the cooling floating cage, and suction collection is performed by a suction duct. The present invention resides in a method for producing a biodegradable cushioning material constituted by a cut cooling part. Further, the composition components are substantially 65 to 75% by weight of starch, 25 to 30% by weight of polyvinyl alcohol and 2% of residual moisture. .5 to 5.0% by weight, and is cut to the required size and length at an expansion ratio of 35 to 70 times with an open cell structure. It consists in construction of a biodegradable cushioning material made Te.
[0009]
[Action]
Since the cushioning material of the present invention is configured as described above, it has the following effects. That is, the composition component is foamed with a starch of 65 to 75%, polyvinyl alcohol of 25 to 30% and a residual moisture of 2.5 to 5.0%, and a foam ratio of 35 to 70 times by open cells. Therefore, the solidification property of the starch is imparted with the viscoelasticity and resilience of polyvinyl alcohol, and it is sufficiently bulky because it is foamed 35 to 70 times, preventing damage to the packaged goods even when external impact is applied. In addition to the effect of absorbing the impact force, the rehabilitation is also exhibited and the packaged goods are protected. And when discarded after use, it absorbs moisture and absorbs immediately under natural conditions to promote dissolution and weakening, and constellation is a good source of nutrients for bacteria and gonococcal degrading bacteria, and has an open cell structure with an extremely large specific surface area. Therefore, the decomposing bacteria propagate over the outer surface and the inside, and are decomposed and eliminated in a short time.
Furthermore, in the production method of the present invention, the biodegradable raw material to be used is composed of 20 to 20 biodegradable pellets having a larger particle size with respect to the total amount of biodegradable powder in which the starch powder and the polyvinyl alcohol powder are blended. Because it uses a material that is dispersed and blended at a 25% weight ratio and has a large particle size distribution, blocking in the hopper of the extrusion molding machine is eliminated and voids are created in the biodegradable raw material. Water that is poured for the formation of is easily penetrated.
In forming the discharge, water injected into the supply unit is dispersed and included as heat-pressurized water vapor by heat-pressure kneading, so that an open-cell structure is formed by instantaneously spouting with reduced pressure accompanying discharge. This open cell structure formed by discharge is cut to a required length in a cooling floating cage provided in the immediate vicinity of the die part and is blown by a blower fan from at least two directions, so that cooling is instantaneously performed. It is made and the mutual fusion | melting cut | disconnected by being moved within this cooling floating cage is blocked | prevented, and the buffer material of required length is formed.
[0010]
【Example】
In the following, the embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram of the cushioning material 1 of the present invention, FIG. 2 is a view showing how the cushioning material 1 is used. Sufficient bulkiness to protect the packaged package 2A from being damaged by external impact during transportation and handling, and practical performance such as damage and failure prevention and restoration performance by absorbing external shock. On the other hand, it is necessary to maintain biodegradability that can be easily biodegraded and erased even under natural conditions during disposal after use to prevent disposal pollution.
Therefore, the buffer material 1 of the present invention is selected as a main component in its composition component, which is a starch that retains physical solidification and foam-forming properties and is a good nutrient source for the propagation of degrading bacteria such as bacteria and bacilli. The composition ratio of the starch is preferably 65 to 75% by weight. That is, when the ratio of the starch is 65% or less, it becomes difficult to foam to a desired foaming ratio for imparting bulkiness, and when the ratio exceeds 75%, the open cell structure formed becomes brittle. It depends. Furthermore, various types of starches are commercially available, but in the case of the present invention, those having a particle diameter of several μm to several μm that are generally marketed can be used sufficiently.
[0011]
Further, polyvinyl alcohol is used in the buffer material 1 in a proportion of 25 to 30% by weight. The polyvinyl alcohol imparts viscoelasticity and restorability to the buffer material 1 and also imparts durability, so-called toughness. At the time of disposal, it is intended to promote dissolution and embrittlement due to its hygroscopicity and water absorption, and the remainder is constituted by 2.5 to 5.0% by weight as residual moisture.
In this case, the polyvinyl alcohol having a particle size of generally several to several hundred μm can be used as the polyvinyl alcohol, but it should be noted that the polyvinyl alcohol component is preferably at least 94% or more, In addition, a component having a maximum content of 0.1% by weight or less such as methyl acetate is desired for preventing corrosion of the molding machine.
[0012]
In addition, since sufficient bulkiness is required for practical use, the foaming ratio is preferably at least 35 times or more, preferably 40 times or more, but it is viscoelastic to use a too high foaming ratio. And the restorability is hindered and weakening is also caused. More importantly, in the formation of the foam structure, when it is discarded, bacteria such as bacteria and bacilli are propagated not only to the outside surface but also to the inside to promote biodegradation elimination. The pores 1B are formed by so-called continuous bubbles.
Of course, since the buffer material 1 is also an important object of the present invention to be non-polluting upon disposal, no chemical gas or chemical foaming agent is used in the formation of the foam structure. In the present invention, a means for spraying pressurized and heated steam is employed.
[0013]
The specific size and length of the cushioning material 1 thus formed are appropriately determined depending on the weight of the package transport 2 and the like, but when the weight of the package transport 2 is about 10 to 20 kg, It is preferable that the length is about 16 to 20 mm and the length is about 60 to 80 mm, and if the weight of the package transport 2 is 5 kg or less, the diameter is about 3 to 6 mm and the length is about 60 to 80 mm.
In practical use, as shown in FIG. 2, an appropriate amount may be filled in the packaging gap 2B formed between the package transport 2 to be distributed and the appropriate outer package 2A.
[0014]
FIG. 3 is an explanatory view of the biodegradable raw material 3 used for manufacturing the buffer material 1, and FIG. 4 is a cross-sectional explanatory view of the extrusion molding machine 4 for manufacturing the buffer material 1. As the material, the starch powder 3A is used, and the starch powder 3A having a particle diameter of several μm to several μm generally available on the market can be used satisfactorily. % Polyvinyl alcohol powder 3B is blended in an amount of 25 to 30% by weight. Polyvinyl alcohol powder 3B in such a case can also be used with a particle diameter of about several to several hundred μm, which is generally marketed, but it should be noted that the polyvinyl alcohol component is at least 94% or more. Should be selected so that the methyl acetate component is at most 0.1% by weight.
[0015]
Thus, in such a blended state, the starch powder 3A and the polyvinyl alcohol powder 3B are finely powdered, and these materials are highly hygroscopic and water-absorbing, so that they are supplied during molding by the extruder 4. There is a risk that blocking may occur in the so-called hopper 4A, resulting in uneven supply or inability to supply.
Therefore, as a means for solving such a problem, it is proposed to construct a wide particle size distribution. For this purpose, the starch powder 3A is 65 to 75% by weight, the polyvinyl alcohol powder 3B is 15 to 20% by weight, and water is 10 to 20 so as not to affect the composition of the buffer material 1 to be formed. In addition, the mixture was heated and kneaded at a relatively low temperature, preferably at a die part temperature of about 160 ° C., and a biodegradable pellet 3C having a particle size of about 1 to 3 mm was formed. The biodegradable pellet 3C is further blended at a weight ratio of 20 to 25%, thereby forming the biodegradable raw material 3.
[0016]
The biodegradable raw material 3 thus formed is formed by using an extruder 4 as shown in FIG. 4. In the present invention, the extruder 4 has special improvements and special manufacturing means. Be taken.
That is, as the basic structure of the extrusion molding machine 4, one having a uniaxial or biaxial screw 4B used in food processing, plastic molding processing or the like is used. In such a case, the screw 4B is generally composed of a supply unit 40B, a compression unit 41B, and a weighing unit 42B. Depending on the material used, a slow compression type, a rapid compression type, a non-weighing unit type, a dalmage torpedo type, and a vent type However, in the present invention, a slow compression type, a rapid compression type, or a non-weighing type is preferable.
A hopper 4A for supplying the biodegradable raw material 3 is provided at a position corresponding to the supply portion 40B of the screw 4B of the cylinder 4C to which the screw 4B is mounted.
[0017]
The extruder 4 according to the present invention has means for dispersing and encapsulating the water injected during the formation of the foamed structure in the biodegradable raw material 3 to be heated and pressurized and kneaded, and causing the eruption 6A at the time of discharge. Adopted. Therefore, a water injection pipe 40D for providing the required water injection 4D is provided at the supply site of the screw 4B to which the biodegradable raw material 3A supplied from the hopper 4A is not heated and not subjected to internal pressure, and by a proper water injection pump 41D. It is considered to be injected. In such a case, the amount of water injected into the biodegradable raw material 3A varies depending on the rotation speed of the screw 4B, the internal pressure related to the heating temperature, and the desired foaming ratio. A weight ratio of 0 to 3.0% is a guide.
Naturally, a die part 4F having a discharge hole of a required diameter is mounted on the tip of the screw 4B through a breaker plate 4E for maintaining the internal pressure.
[0018]
Thus, the biodegradable raw material 3 supplied to the supply part of the screw 4B further includes water injection 4D at a ratio of 1.0 to 3.0% by weight with respect to the weight of the biodegradable raw material 3 supplied in the supply part. In addition, melting for kneading is performed by the transfer force to the compression unit and the metering unit accompanying the rotation of the screw 4B and the back pressure of the breaker plate 4E, and the injected water 4D is heated and pressurized A suitable heater is attached so that the temperature gradient is maintained at a maximum temperature of 200 ° C. or less from the supply unit to the metering unit or the die unit 4F in order to vaporize and disperse.
In such a case, the heating temperature is limited to a maximum of 200 ° C. The decomposition of polyvinyl alcohol is accelerated when the heating temperature exceeds the limit temperature, and further, there is a risk that the corrosion of the extruder is accelerated by the generation of acetic acid gas or the like. Another reason is that excessive melting is performed at a high temperature and the shape retention of the discharge formed product is impaired.
[0019]
Thus, by discharging from the discharge port provided in the die part 4F of the extrusion molding machine 4, the heated and pressurized water vapor contained in the dispersion accompanying the rapid pressure reduction is instantaneously ejected from the outer surface, and the through hole 1B continues. The so-called open cell structure thus formed is discharged and formed.
Furthermore, the open-cell structure formed by discharge needs to be cut to a required length in order to be put to practical use. However, the open-cell structure formed by discharge is soft at high temperature and has hygroscopicity and water absorption. Therefore, in order to cut the open cell structure to a required length, it is impossible to apply mechanical external force or cooling with water having a high cooling effect.
[0020]
Therefore, in the present invention, as shown in FIG. 5, the continuous cell structure cut to a required length is formed in a mesh so as not to leak out in the vicinity of the die portion 4F where the continuous cell structure is discharged and formed. The continuous cell structure discharged from the die portion 4 is cut to a required length by the cutter 5B and the continuous cut from the blower fan 5C in at least two directions of the cage body 5A is provided. The bubble structure is cooled by blowing air, and the cut open cell structure is moved in the cage while sufficient cooling can be achieved to prevent fusion, and thus the open cell structure is cooled. The biodegradable cushioning material is manufactured by the cooling floating cage 5 which collects the suction from the suction duct 5D provided below the cage body 5A.
[0021]
【The invention's effect】
As described above, according to the present invention, the composition of the cushioning material is composed of a starch of 65 to 75% by weight, a polyvinyl alcohol of 25 to 30% by weight and a residual water of 2.5 to 5.0% by weight, and has an open cell structure. In this case, it is foamed at a foaming ratio of 35 to 70 times and formed to the required size and length, so that it can be filled into the gap with the outer package regardless of the size, shape and weight of the package transported goods or It can be used simply by filling the gaps between the packaged packages, and it can deal with a wide range of packaged packages by preparing a single standard package.
In addition, the solidifying property of the constituent component maintains the shape-retaining force, and the polyvinyl alcohol provides viscoelasticity and resilience, and the foaming ratio is 35 to 70 times, thus maintaining sufficient bulkiness. Even when an external impact is applied during transportation or handling, the impact is absorbed and mitigated and damages and failures are prevented as well as preventing damage to the packaged goods.
In addition, when it is discarded after use, the shape is easily collapsed by promoting moisture absorption and water absorption under natural conditions. Due to the open cell structure, the degrading bacteria adhere to and propagate from the outer surface to the inner surface, so that they are biodegraded and erased at an early stage, so that no disposal pollution occurs.
Furthermore, in the manufacturing method of the present invention, since biodegradable pellets having a large particle size are dispersed and used in the biodegradable powder raw material in a proportion of 20 to 25%, smooth supply is made to the extrusion molding machine. In the low temperature, low internal pressure supply section of the extruder, the water injected for the formation of the open cell structure was easily infiltrated into the biodegradable raw material and heated and pressurized and kneaded. Water is heated and pressurized to be steamed and dispersed and contained, and the heated and pressurized steam is spouted by decompression by discharge to form an open-cell structure, and the open-cell structure that is soft at high temperature is placed in the cooling floating cage. This is a novel and highly featured biodegradable cushioning material manufacturing method that can form a cushioning material without deforming or fusing the open cell structure by cutting and cooling while blowing air from two directions. It is.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a cushioning material of the present invention.
FIG. 2 is a view showing how the cushioning material is used.
FIG. 3 is an explanatory diagram of a biodegradable raw material.
FIG. 4 is a cross-sectional explanatory view of an extrusion molding machine.
FIG. 5 is an explanatory diagram of a cooling floating cage.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Buffer material 1A Buffer material 1B Through-hole 2 Package transport 2A Outer package 2B Packing gap 3 Biodegradable raw material 3A Constarch powder 3B Polyvinyl alcohol powder 3C Biodegradable pellet 4 Extruder 4A Hopper 4B Screw 4C Cylinder 4D Water injection 4E Breaker plate 4F Die part 5 Cooling floating cage 5A Cage body 5B Cutter 5C Blower fan 5D Suction duct 6A Spout

Claims (1)

  A biodegradable pellet blended in a ratio of 65 to 75% by weight of a starch powder, 15 to 20% by weight of polyvinyl alcohol powder and 10 to 20% by weight of water and formed by heating and kneading at a relatively low temperature, A biodegradable raw material obtained by further dispersing and blending a biodegradable powder raw material 70 to 75% by weight and a polyvinyl alcohol powder 25 to 30% by weight in a proportion of 20 to 25%; A biodegradable raw material is supplied from a hopper of an extrusion molding machine that has a shaft screw and can maintain a temperature gradient from room temperature to 200 ° C. across its supply unit, compression unit, metering unit and die unit. By injecting 1.0 to 3.0% by weight of water to the biodegradable raw material supplied in the part and discharging it from the die part while heating and press kneading. , An extrusion molding machine for discharging and molding an open-cell structure having a foaming ratio of 35 to 70 times by spraying heated and pressurized water vapor, and a continuous discharge molding in a cooling floating cage provided in the immediate vicinity of the die A cutter that cuts the bubble structure to a required length, a fan that cools the cut open cell structure so that the cut open cell structures do not fuse together, and a fan that blows air from at least two directions of the cooling floating cage; A method for producing a biodegradable cushioning material, comprising: a cut cooling part comprising a suction duct for sucking and collecting a cooled open-cell structure cut into a length.

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