阅读说明：本技术 一种可水溶性淀粉基包装缓冲填充物及其制备方法 (Water-soluble starch-based packaging buffer filler and preparation method thereof ) 是由 陈杰 汪磊 王正梅 李海玉 范叶丽 于 2021-09-16 设计创作，主要内容包括：本发明公开了一种可水溶性淀粉基包装缓冲填充物及其制备方法,所述缓冲填充物包括以下重量份的原料：水溶性淀粉60-80份,去离子水10-40份,聚乙烯醇10-20份,增塑剂0-10份,交联剂0-1份。本发明的可水溶性淀粉基包装缓冲填充物生物降解性高,7秒内即可完全溶解在水中,同时具有优越的缓冲性能,弹性指数大于74％；本发明采用的制备方法简单,使用一步降压发泡的方法,相比与现有的螺杆机熔融挤出法,操作步骤简单、耗时短。(The invention discloses a water-soluble starch-based packaging buffer filler and a preparation method thereof, wherein the buffer filler comprises the following raw materials in parts by weight: 60-80 parts of water-soluble starch, 10-40 parts of deionized water, 10-20 parts of polyvinyl alcohol, 0-10 parts of plasticizer and 0-1 part of cross-linking agent. The water-soluble starch-based packaging buffering filler has high biodegradability, can be completely dissolved in water within 7 seconds, and has excellent buffering performance, and the elasticity index is more than 74%; the preparation method adopted by the invention is simple, and compared with the existing screw machine melt extrusion method, the method using one-step depressurization foaming has the advantages of simple operation steps and short time consumption.)

1. The water-soluble starch-based packaging buffer filler is characterized by comprising the following raw materials in parts by weight: 60-80 parts of water-soluble starch, 10-40 parts of deionized water, 10-20 parts of polyvinyl alcohol, 0-10 parts of plasticizer and 0-1 part of cross-linking agent.

2. The water-soluble starch-based packaging cushion filler according to claim 1, wherein the plasticizer is one or more of glycerol, polyethylene glycol, sorbitol, and urea.

3. The water-soluble starch-based packaging cushion filling of claim 1, wherein the cross-linking agent is a zirconium salt and calcium hydroxide.

4. The water-soluble starch-based packaging cushion according to claim 1, wherein the water-soluble starch is one or more of water-soluble corn starch, water-soluble tapioca starch, and water-soluble potato starch.

5. A method for preparing a water-soluble starch-based packaging buffer filling, comprising the steps of:

(1) mixing 10-40 parts of deionized water, 10-20 parts of polyvinyl alcohol, 0-10 parts of plasticizer and 0-1 part of cross-linking agent at 40-45 ℃, and then gradually adding 60-80 parts of water-soluble starch; in a constant-temperature water bath environment, the blend is fully mixed in a stirrer to obtain a premix;

(2) putting the premix into a screw extruder, and melting and extruding to obtain thermoplastic water-soluble starch;

(3) grinding the thermoplastic water-soluble starch in a blade grinding mill for granulation; drying in a constant temperature chamber to obtain thermoplastic water-soluble starch granules;

(4) and (4) carrying out decompression foaming on the granules obtained in the step (3) to obtain the water-soluble starch-based packaging buffer filler.

6. The method for preparing the water-soluble starch-based packaging buffering filler as claimed in claim 5, wherein in the step (1), the temperature of the thermostatic water bath is 60-80 ℃, the stirrer is an overhead stirrer, the rotation speed of the stirrer is 400-1000rpm, and the mixing time is 0.5-2 h.

7. The method for preparing a water-soluble starch-based packaging buffer filling according to claim 5, wherein in the step (1), after the blend is sufficiently mixed in the mixer, the premix is equilibrated for 24-36 hours in a sealed polyethylene plastic bag.

8. The method for preparing the water-soluble starch-based packaging cushion filler according to claim 5, wherein in the step (2), the screw extruder is one of a single screw extruder, a co-rotating twin screw extruder, a counter-rotating twin screw extruder, a parallel twin screw extruder and a conical twin screw extruder.

9. The method for preparing the water-soluble starch-based packaging buffering filler as claimed in claim 5, wherein in the step (2), the extrusion temperature is three-zone temperature or five-zone temperature, the temperature of the extruder barrel is 100 ℃ and 160 ℃, and the rotation speed of the extrusion screw is 10-50 rpm.

10. The method for preparing the water-soluble starch-based packaging buffering filler as claimed in claim 5, wherein in the step (4), the foaming temperature is 100-160 ℃ and the foaming pressure is 1.5-3.5 MPa.

Technical Field

The invention relates to a packaging buffer filler, in particular to a water-soluble starch-based packaging buffer filler and a preparation method thereof.

Background

The packaging buffering filler is a buffering material which plays a role in reducing article collision and protecting articles in the article transportation process. The conventional packaging buffer filler is foam, pearl wool and a filling air bag. Among them, the most widely used is the foam packing filler. The foam filling is a petroleum-based buffer material, and has the problem of environmental pollution in the use process.

In order to avoid the pollution of petroleum-based buffer materials to the environment, the prior art starts to develop environment-friendly buffer materials, but corn and tapioca starch are mostly adopted as environment-friendly bases, and the water solubility of the corn and tapioca starch is poor, so that the biodegradability in the environment is poor. For example, patent CN 108341994A discloses a starch-based foaming material prepared by using starch as a foaming base material, oxidizing the starch by a hydrogen peroxide/ferrous sulfate oxidation system, uniformly mixing the starch with a foaming plasticizing component and a foaming additive component, and performing extrusion foaming molding by a single screw extruder with a high compression ratio; patent CN 112029153A discloses an environment-friendly starch-based foaming material and a preparation method thereof, wherein the starch-based foaming material is finally obtained by uniformly blending, plasticizing, melting and granulating raw materials in multiple steps; in addition, the bio-plastic is adopted, but the biodegradability of the finished product is not good, for example, patent CN 111961259A discloses an expandable starch bio-plastic for foaming and a preparation method thereof, wherein the expandable starch bio-plastic is prepared by uniformly mixing kneaded materials, plant fiber crushed particles, matrix resin, lubricant and sodium bicarbonate at a high speed, and then adding the mixture into a screw extruder for extrusion and granulation.

In the prior art, the raw materials adopted for preparing the buffer material are insoluble in water, the biodegradability of a finished product is low, and the subsequent solid waste disposal cost is high; the screw extruder melt extrusion method has the disadvantages of complex operation steps, long time and high energy consumption.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a natural, safe, nontoxic, green and environment-friendly water-soluble starch-based packaging buffer filler. Another object of the present invention is to provide a method for preparing a water-soluble starch-based packaging buffer filling with simple operation steps.

The technical scheme is as follows: the water-soluble starch-based packaging buffer filler comprises the following raw materials in parts by weight: 60-80 parts of water-soluble starch, 10-40 parts of deionized water, 10-20 parts of polyvinyl alcohol, 0-10 parts of plasticizer and 0-1 part of cross-linking agent.

Deionized water is used as a plasticizer and a foaming agent of the packaging buffer filler to promote starch plasticization and foam growth; the polyvinyl alcohol is used as a reinforcing agent, so that the mechanical strength and the elasticity of the packaging buffer filler are improved; the plasticizer is used for improving the plasticizing capacity of the deionized water to the starch; the cross-linking agent is used as a moisture-proof agent for packaging the buffering filler and is used for improving the moisture absorption performance of the filler.

Preferably, the plasticizer is one or a mixture of glycerol, polyethylene glycol, sorbitol and urea.

Preferably, the cross-linking agent is a zirconium salt and calcium hydroxide.

Preferably, the water-soluble starch is one or a mixture of water-soluble corn starch, water-soluble tapioca starch and water-soluble potato starch.

The preparation method of the water-soluble starch-based packaging buffer filler comprises the following steps:

(1) mixing 10-40 parts of deionized water, 10-20 parts of polyvinyl alcohol, 0-10 parts of plasticizer and 0-1 part of cross-linking agent at 40 ℃, and then gradually adding 60-80 parts of water-soluble starch; in a constant-temperature water bath environment, the blend is fully mixed in a stirrer to obtain a premix;

(2) putting the premix into a screw extruder, and melting and extruding to obtain thermoplastic water-soluble starch;

(3) grinding the thermoplastic water-soluble starch in a blade grinding mill for granulation; drying in a constant temperature chamber, and controlling the water content within the range of 8-20% to obtain thermoplastic water-soluble starch granules;

(4) and (4) carrying out decompression foaming on the granules obtained in the step (3) to obtain the water-soluble starch-based packaging buffer filler.

Further, in the step (1), the temperature of the thermostatic water bath is 60-80 ℃, the stirrer is an overhead stirrer, the rotating speed of the stirrer is 400-.

Further, in the step (1), after the blend is sufficiently mixed in the mixer, the premix is equilibrated in a sealed polyethylene plastic bag for 24-36 hours.

Further, in the step (2), the screw extruder is one of a single screw extruder, a co-rotating twin screw extruder, a counter-rotating twin screw extruder, a parallel twin screw extruder and a conical twin screw extruder.

Further, in the step (2), the extrusion temperature is three-zone temperature or five-zone temperature, the temperature of the extruder barrel is 100 ℃ and 160 ℃, and the rotation speed of the extrusion screw is 10-50 rpm.

Further, in the step (4), the foaming temperature is 100-160 ℃, and the foaming pressure is 1.5-3.5 MPa.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: (1) the biodegradability is high, the material can be completely dissolved in water within 7 seconds, and the material has excellent buffering performance and the elasticity index is more than 74%; (2) the raw materials are green and safe, crops are used as the raw materials, the finished product can be recycled, and the heat used by safe incineration is only half of that of the petroleum-based buffer material; (3) the preparation method is simple, and the method of one-step depressurization foaming is adopted, so that the operation steps are simple and the time consumption is short.

Detailed Description

The technical solution of the present invention is further explained below.

Example 1

A water-soluble starch-based packaging buffer filling material: 60 parts of water-soluble corn starch, 10 parts of deionized water, 10 parts of polyvinyl alcohol, 2 parts of glycerol and 0.1 part of zirconium salt.

The preparation method comprises the following steps: (1) mixing ionized water, polyvinyl alcohol, glycerol and zirconium salt at 40 deg.C, slowly adding water soluble corn starch into the mixture, thoroughly mixing by overhead type stirrer in constant temperature water bath at 60 deg.C at 400rpm for 0.5 hr to obtain starch mixture, and packaging in sealed polyethylene plastic bag for balancing for 24 hr.

(2) And (3) melting and extruding the balanced hydroxypropyl starch mixture through a screw extruder in a single-screw extruder at the temperature of 100-120-140 ℃ in a three-zone cylinder and the rotating speed of 10rpm to prepare the thermoplastic water-soluble starch.

(3) Grinding and granulating the thermoplastic water-soluble starch by a blade grinder with the inner diameter of 2mm, drying in a constant temperature chamber, and controlling the water content to be 8% to obtain thermoplastic water-soluble starch granules;

(4) the treated thermoplastic water-soluble starch is granulated and foamed by a decompression foaming machine, and the foaming process is as follows: the foaming temperature and pressure are respectively 120 ℃ and 1.5MPa, and the water-soluble starch-based packaging buffer filler is prepared.

Example 2

A water-soluble starch-based packaging buffer filling material: 70 parts of water-soluble cassava starch, 15 parts of deionized water, 5 parts of polyvinyl alcohol and 0.1 part of zirconium salt.

The preparation method comprises the following steps: (1) mixing ionized water, polyvinyl alcohol, glycerol and zirconium salt at 40 deg.C, slowly adding water soluble tapioca starch into the mixture, thoroughly mixing by overhead type stirrer in constant temperature water bath of 65 deg.C at 600rpm for 1 hr to obtain starch mixture, and packaging in sealed polyethylene plastic bag and balancing for 36 hr.

(2) And (3) melting and extruding the balanced hydroxypropyl starch mixture through a screw extruder in a single-screw extruder at the temperature of 120-140-160 ℃ in a three-zone cylinder and the rotating speed of 20rpm to prepare the thermoplastic water-soluble starch.

(3) Grinding and granulating the thermoplastic water-soluble starch by a blade grinder with the inner diameter of 2mm, drying in a constant temperature chamber, and controlling the water content to be 8% to obtain thermoplastic water-soluble starch granules;

(4) the treated thermoplastic water-soluble starch is granulated and foamed by a decompression foaming machine, and the foaming process is as follows: the foaming temperature and pressure are respectively 140 ℃ and 2.0MPa, and the water-soluble starch-based packaging buffer filler is prepared.

Example 3

A water-soluble starch-based packaging buffer filling material: 80 parts of potato water-soluble starch, 25 parts of deionized water, 20 parts of polyvinyl alcohol, 10 parts of glycerol and 0.3 part of calcium hydroxide.

The preparation method comprises the following steps: (1) mixing ionized water, polyvinyl alcohol, glycerol and calcium hydroxide at 40 deg.C, slowly adding water soluble potato starch into the mixture, thoroughly mixing by an overhead stirrer in a thermostatic water bath at 70 deg.C at 800rpm for 1.5h to obtain starch mixture, and packaging in sealed polyethylene plastic bag and balancing for 30 h.

(2) And (3) melting and extruding the balanced hydroxypropyl starch mixture through a screw extruder in a single-screw extruder at the temperature of 140-140 ℃ in a three-zone cylinder and the rotating speed of 30rpm to prepare the thermoplastic water-soluble starch.

(3) Grinding and granulating the thermoplastic water-soluble starch by a blade grinder with the inner diameter of 2mm, drying in a constant temperature chamber, and controlling the water content to be 10% to obtain thermoplastic water-soluble starch granules;

(4) the treated thermoplastic water-soluble starch is granulated and foamed by a decompression foaming machine, and the foaming process is as follows: the foaming temperature and pressure are respectively 160 ℃ and 3.0MPa, and the water-soluble starch-based packaging buffer filler is prepared.

Example 4

A water-soluble starch-based packaging buffer filling material: 40 parts of water-soluble corn starch, 40 parts of water-soluble potato starch, 30 parts of deionized water, 15 parts of polyvinyl alcohol, 5 parts of sorbitol and 1 part of calcium hydroxide.

The preparation method comprises the following steps: (1) mixing ionized water, polyvinyl alcohol, glycerol and zirconium salt at 45 deg.C, slowly adding water soluble starch into the mixture, thoroughly mixing by overhead type stirrer in constant temperature water bath of 65 deg.C at 600rpm for 1h to obtain starch mixture, and placing into sealed polyethylene plastic bag and balancing for 36 h.

(2) And (3) melting and extruding the balanced hydroxypropyl starch mixture through a screw extruder in a single-screw extruder at the temperature of 140-160 ℃ in a three-zone cylinder and the rotating speed of 40rpm to prepare the thermoplastic water-soluble starch.

(3) Grinding and granulating the thermoplastic water-soluble starch by a blade grinder with the inner diameter of 2mm, drying in a constant temperature chamber, and controlling the water content to be 15% to obtain thermoplastic water-soluble starch granules;

(4) the treated thermoplastic water-soluble starch is granulated and foamed by a decompression foaming machine, and the foaming process is as follows: the foaming temperature and pressure are respectively 160 ℃ and 3.0MPa, and the water-soluble starch-based packaging buffer filler is prepared.

Example 5

A water-soluble starch-based packaging buffer filling material: 80 parts of water-soluble corn starch, 40 parts of deionized water, 5 parts of glycerol, 5 parts of polyethylene glycol and 0.5 part of calcium hydroxide.

The preparation method comprises the following steps: (1) mixing ionized water, polyvinyl alcohol, glycerol and zirconium salt at 40 deg.C, slowly adding water soluble corn starch into the mixture, thoroughly mixing with overhead stirrer in constant temperature water bath at 75 deg.C at 800rpm for 1 hr to obtain starch mixture, and packaging in sealed polyethylene plastic bag and balancing for 24 hr.

(2) And (3) melting and extruding the balanced hydroxypropyl starch mixture through a screw extruder in a single-screw extruder at the temperature of 140-160 ℃ in a three-zone cylinder and the rotating speed of 30rpm to prepare the thermoplastic water-soluble starch.

(3) Grinding and granulating the thermoplastic water-soluble starch by a blade grinder with the inner diameter of 2mm, drying in a constant temperature chamber, and controlling the water content to be 20% to obtain thermoplastic water-soluble starch granules;

(4) the treated thermoplastic water-soluble starch is granulated and foamed by a decompression foaming machine, and the foaming process is as follows: the foaming temperature and pressure are respectively 160 ℃ and 3.5MPa, and the water-soluble starch-based packaging buffer filler is prepared.

The foam, specific density, expansion ratio, elastic index and water-soluble time of the buffer fillers prepared in examples 1 to 5 were measured, and the results are shown in Table 1.

As can be seen from Table 1, the water-soluble starch-based packaging buffer filler prepared in the embodiments 1 to 5 of the present invention has the advantages of good foaming effect, uniform cell size, low unit density, and high resilience, and can achieve the water-soluble effect within 7 seconds.