A luggage backrest material with comfort and a preparation method thereof

Abstract

This invention discloses a highly comfortable bag backrest material. The raw materials, by weight, include: a plastic material and a solid filler, wherein the weight ratio of the plastic material to the solid filler is 100:(0.1-5). This invention uses a specific gravity of 1000-1100 kg / m³. 3 TPEE with a melt flow index of 3-8 g / 10 min is used to prepare backpack backrest materials with suitable hardness and density, capable of supporting the weight of the backpack and alleviating pressure on the back. Furthermore, the use of titanium dioxide with a particle size ≥3000 mesh as a solid filler, working in conjunction with TPEE, results in backpack backrest materials with good hardness, demonstrating good mixing and processing performance between the plastic material and the solid filler. Simultaneously, the reaction temperature during processing is 170-180℃, and the foaming pressure is 40-50 MPa, which improves the foaming efficiency of the sheet, forming cells of uniform size and structure, giving the sheet good resilience.

Description

A comfortable bag backrest material and its preparation method Technical Field

[0001] This invention relates to a comfortable bag backrest material, specifically C08J, and primarily relates to the field of polymer foam materials. Background Technology

[0002] As a carrier for large items, bags are suitable for long-distance transportation. Most bags carry heavy loads, which puts significant pressure on the back. Therefore, by incorporating a pressure-bearing backrest material, this pressure can be alleviated. However, existing bag backrest materials lack sufficient pressure resistance and resilience. After prolonged use, the pressure noticeably shifts to the back, reducing comfort and increasing fatigue. Therefore, developing a comfortable backpack backrest material that doesn't increase fatigue during extended use is crucial.

[0003] Chinese invention patent CN201911287200.9 discloses a method for preparing TPEE supercritical continuous extrusion microfoam. High melt strength TPEE material is placed in a continuous extruder for primary melting; N2 gas is injected into the primary melt to form a gas-saturated homogeneous liquid TPEE system, creating numerous gas nuclei. The prepared TPEE foam material can be continuously produced with a smooth, non-bubbling surface and good vertical resilience. However, nitrogen injection is required twice, making the process complex. Chinese invention patent CN202210976997.9 discloses a TPEE foam and its preparation process. TPEE and antistatic PEBAX granules are dried separately in an oven; then melt-blended in a mixer, followed by melt-blending with an epoxy chain extender to obtain a mixed sample; finally, it is placed in a supercritical reactor for supercritical foaming. The prepared TPEE foam material has low density, low compression set, high resilience, and antistatic properties. However, secondary foaming is required, and the cell structure and size formed by secondary foaming are uncontrollable, resulting in inconsistent performance at different locations during use. Summary of the Invention

[0004] In order to improve the comfort of bag backrest materials and reduce the fatigue caused by carrying a backpack for a long time, the first aspect of the present invention provides a comfortable bag backrest material, the raw materials of which include, by weight, a plastic material and a solid filler, wherein the weight ratio of the plastic material to the solid filler is 100:(0.1-5).

[0005] In a preferred embodiment, the weight ratio of the plastic material to the solid filler is 100:(0.5-3).

[0006] During the experiment, the applicant discovered that a weight ratio of TPEE to solid filler additives of 100:(0.5-3) can further improve the comfort of carrying the bag while back, reducing back fatigue during long-term use. The reason may be that at a weight ratio of 100:(0.5-3), the titanium dioxide acts as a skeletal structure interspersed within the foaming pores, providing some support and alleviating the pressure of the bag's weight on the back. However, exceeding the optimal weight ratio range results in increased backrest hardness and reduced fit to the back, which is detrimental to backrest comfort.

[0007] In a preferred embodiment, the plastic material is selected from one or a combination of several of TPEE, OBC, TPU, EVA, PP, PE, and SEBS.

[0008] In a preferred embodiment, the specific gravity of the TPEE is 1000-1100 kg / m³. 3 The melt index at 190℃ is 3-8 g / 10 min for 2.16 kg.

[0009] In a preferred embodiment, the specific gravity of the TPEE is 1070 kg / m³. 3 The melt flow index at 190℃ is 5 g / 10 min for 2.16 kg.

[0010] During the experiment, the applicant discovered that using a specific gravity of 1070 kg / m³ was effective. 3 TPEE material with a melt flow index of 5 g / 10 min can achieve good foaming, giving the backrest material suitable hardness and density. It is speculated that this is likely due to its specific gravity of 1070 kg / m³. 3 TPEE can achieve good foaming in this system, forming foamed boards with a suitable foaming rate of 1070 kg / m³. 3 At a specific gravity, the distance between each cell is appropriate, and the cell size is uniform. When under pressure, the cells have a certain degree of contraction, which alleviates some of the weight load on the back and eliminates some pressure. The applicant further discovered that using a melt flow index of 5g / 10min can further alleviate the pressure buffering. The reason may be that the backrest material prepared from TPEE material outside the preferred melt flow index range has low hardness. Under long-term heavy load, the cells will be compressed and deformed, reducing the performance of the weight buffer.

[0011] In a preferred embodiment, the TPEE has a flow shrinkage rate of 0.5-1% and a tensile modulus of 20-25 MPa.

[0012] In a preferred embodiment, the TPEE has a flow shrinkage rate of 0.8% and a tensile modulus of 23 MPa.

[0013] In a preferred embodiment, the solid filler is a nano-solid filler with a particle size ≥3000 mesh.

[0014] In a preferred embodiment, the nano-solid filler is selected from one or a combination of several of nano-metal oxides, nano-talc, nano-fumed silica, nano-metal compounds, and nano-montmorillonite.

[0015] The nano-solid filler is a nano-metal oxide, and more preferably, the nano-metal oxide is nano-titanium dioxide.

[0016] During the experiment, the applicant discovered that using ≥3000 mesh nano-titanium dioxide as a solid filler additive, combined with SEBS, can improve the hardness of the backpack backrest material, further enhancing its pressure-bearing capacity and comfort. The applicant speculates that this may be because adding rutile titanium dioxide to SEBS, with its dense granular structure, allows it to act as a framework for the plastic material, reducing SEBS shrinkage and increasing the hardness of the matrix. However, the applicant further found that titanium dioxide dispersibility in SEBS is poor. By introducing titanium dioxide with a particle size ≥3000 mesh, the applicant can improve its dispersion in the plastic material. Smaller particles of titanium dioxide can penetrate smaller spaces within SEBS, thus achieving uniform dispersion.

[0017] A second aspect of the present invention provides a method for preparing a comfortable bag backrest material, comprising the following steps:

[0018] (1) Preparation of sheet material from mixed raw materials;

[0019] (2) Pass in foaming gas;

[0020] (3) Foaming is required.

[0021] As a preferred embodiment, the method for preparing the comfortable bag backrest material includes the following steps:

[0022] (1) After drying the plastic material, mix it with solid filler additives, and then extrude the mixture into sheets using a sheet extruder;

[0023] (2) Control the sheet thickness by placing the sheet into a high-pressure reactor and introducing critical gas;

[0024] (3) Set the parameters of the high-pressure reactor, immerse the material in the reactor for a period of time, and then depressurize to obtain the backrest material of the bag.

[0025] In a preferred embodiment, the raw materials in step 1 need to be dried before use, with a drying temperature of 90-100℃ and a drying time of 10-15h.

[0026] In a preferred embodiment, the sheet thickness is 10-20 mm, and the foaming gas is selected from supercritical nitrogen or supercritical carbon dioxide.

[0027] In a preferred embodiment, the parameters in step 3 are: reaction temperature 90-200℃, reaction pressure 15-60MPa, soaking time 2-10h, and depressurization time 1-60s.

[0028] In a preferred embodiment, the parameters in step 3 are: reaction temperature 170-180℃, reaction pressure 43-55MPa, soaking time 5-10h, and depressurization time 30-60s.

[0029] In a preferred embodiment, the parameters in step 3 are: reaction temperature 178°C, reaction pressure 45 MPa, soaking time 6 h, and depressurization time 30 s.

[0030] During the experiment, the applicant discovered that placing the sheet material in an environment of 178°C and 45MPa for foaming resulted in the formation of cells of uniform size and structure, giving the sheet material good resilience. The applicant speculates that this is because, under the optimized foaming temperature and pressure, supercritical nitrogen can smoothly enter the interior of the TPEE plastic material, forming a large number of micron-sized bubbles within the system, thus creating a porous foam material. The applicant further discovered that under the optimized foaming conditions, supercritical nitrogen entering the TPEE material containing solid filler and additives encounters both resistance and driving force. This application achieves high resilience by balancing the resistance inside the plastic material and the external pressure of the system to obtain cells of uniform size and structure.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The comfortable bag backrest material described in this invention has a specific gravity of 1000-1100 kg / m³. 3 The backpack backrest material prepared with TPEE with a melt index of 3-8 g / 10 min has suitable hardness and density, which can bear the large weight of the backpack and relieve the pressure of the backpack on the back.

[0033] (2) The comfortable bag back material of the present invention uses titanium dioxide with a particle size ≥3000 mesh as a solid filler and TPEE to work together to prepare a bag back material with good hardness, so that the plastic material and the solid filler have good mixing and processing performance.

[0034] (3) The comfortable bag back material described in this invention has a reaction temperature of 170-180℃ and a foaming pressure of 40-50MPa during processing, which can improve the foaming efficiency of the board and form cells of consistent size and structure, so that the board has good resilience.

[0035] (4) The comfortable bag back material of the present invention uses TPEE and titanium dioxide solid filler in a weight ratio of 100:(0.5-3) to prepare a bag back material with excellent comfort and can reduce back fatigue during long-term use.

[0036] (5) The comfortable bag back material of the present invention has a simple preparation process. The prepared backpack back material has low foam density, consistent structure size, and suitable density and hardness. While having good pressure bearing effect, the material thickness is not high and it is easy to use. Attached Figure Description

[0037] Figure 1 is a picture of the bag backrest material prepared according to the present invention.

[0038] Figure 2 is a picture of a bag made using the backrest material of the present invention. Detailed Implementation

[0039] Example 1

[0040] A comfortable bag backrest material, the raw materials for which are prepared include, by weight, a plastic material and a solid filler, wherein the weight ratio of the plastic material to the solid filler is 100:1.3.

[0041] The plastic material is TPEE, and the specific gravity of TPEE is 1070 kg / m³. 3 The melt index at 190℃ is 5 g / 10 min for 2.16 kg, the flow shrinkage rate is 0.8%, the tensile modulus is 23 MPa, and it was purchased from DuPont, USA, model 3078.

[0042] The solid filler additive is nano-titanium dioxide with a particle size ≥3000 mesh, purchased from Bohuas Nanotechnology (Ningbo) Co., Ltd.

[0043] A method for preparing a comfortable bag backrest material includes the following steps:

[0044] (1) After drying the plastic material, mix it with solid filler additives, and then extrude the mixture into sheets using a sheet extruder;

[0045] (2) Control the sheet thickness by placing the sheet into a high-pressure reactor and introducing critical gas;

[0046] (3) Set the parameters of the high-pressure reactor, immerse the material in the reactor for a period of time, and then depressurize to obtain the backrest material of the bag.

[0047] In step 1, the drying temperature of the plastic material is 100℃ and the drying time is 12h.

[0048] In step 2, the sheet thickness is 15 mm, and the critical gas is nitrogen.

[0049] In step 3, the reaction temperature is 178℃, the reaction pressure is 45MPa, the soaking time is 6h, and the pressure release time is 30s.

[0050] Example 2

[0051] A comfortable bag backrest material, the raw materials for which are prepared include, by weight, a plastic material and a solid filler, wherein the weight ratio of the plastic material to the solid filler is 100:0.5.

[0052] The plastic material is TPEE, and the specific gravity of TPEE is 1070 kg / m³. 3 The melt index at 190℃ is 5 g / 10 min for 2.16 kg, the flow shrinkage rate is 0.8%, the tensile modulus is 23 MPa, and it was purchased from DuPont, USA, model 3078.

[0053] The solid filler additive is nano-titanium dioxide with a particle size ≥3000 mesh, purchased from Bohuas Nanotechnology (Ningbo) Co., Ltd.

[0054] A method for preparing a comfortable bag backrest material includes the following steps:

[0055] (1) After drying the plastic material, mix it with solid filler additives, and then extrude the mixture into sheets using a sheet extruder;

[0056] (2) Control the sheet thickness by placing the sheet into a high-pressure reactor and introducing critical gas;

[0057] (3) Set the parameters of the high-pressure reactor, immerse the material in the reactor for a period of time, and then depressurize to obtain the backrest material of the bag.

[0058] In step 1, the drying temperature of the plastic material is 100℃ and the drying time is 12h.

[0059] In step 2, the sheet thickness is 17 mm, and the critical gas is nitrogen.

[0060] In step 3, the reaction temperature is 175℃, the reaction pressure is 47MPa, the wetting time is 6.5h, and the pressure release time is 30s.

[0061] Example 3

[0062] A comfortable bag backrest material and its preparation method are described. The specific steps are the same as in Example 1, except that the weight ratio of the plastic material to the solid filler is 100:4.

[0063] Example 4

[0064] A comfortable bag backrest material and its preparation method are disclosed. The specific steps are the same as in Example 1, except that the solid filler is talc powder with a particle size ≥3000 mesh.

[0065] Example 5

[0066] A comfortable bag backrest material and its preparation method are disclosed. The specific steps are the same as in Example 1, except that in step 3, the reaction temperature is 160℃, the reaction pressure is 40MPa, the impregnation time is 8h, and the depressurization time is 45s.

[0067] Performance testing

[0068] 1. Density: The density of the bag backrest materials prepared in Examples 1-5 was tested according to GB / T6343-2009 standard.

[0069] 2. Hardness: The Shore hardness C of the bag backrest materials prepared in Examples 1-5 was tested according to the HG / T2368-2011 standard.

[0070] 3. Drop ball rebound: The drop ball rebound rate of the bag backrest materials prepared in Examples 1-5 was tested according to GB / T6670-2008 standard.

[0071] The test results are shown in Table 1.

[0072] Table 1

[0073]

Claims

1. A comfortable bag backrest material, characterized in that, The raw materials for preparation include, by weight, a plastic material and a solid filler additive, wherein the weight ratio of the plastic material to the solid filler additive is 100:(0.5-3); the plastic material is TPEE, and the specific gravity of TPEE is 1070 kg / m³. 3 The melt index is 5g / 10min for 2.16kg at 190℃; the flow shrinkage rate of the TPEE is 0.8% and the tensile modulus is 23MPa; the solid filler additive is nano titanium dioxide with a particle size ≥3000 mesh; the preparation method of the comfortable bag backrest material includes the following steps: (1) mixing raw materials to prepare a sheet; (2) passing foaming gas; (3) foaming to obtain the material; the raw materials in step 1 need to be dried before use, the drying temperature is 90-100℃ and the drying time is 10-15h; the thickness of the sheet is 10-20mm, and the foaming gas is selected from supercritical nitrogen or supercritical carbon dioxide; the parameters in step 3 are: reaction temperature 178℃, reaction pressure 45MPa, wetting time 6h, and depressurization time 30s.

2. A method for preparing a comfortable bag backrest material according to claim 1, characterized in that, Includes the following steps: (1) Mix raw materials to prepare sheet material; (2) Pass foaming gas through; (3) Foaming is then obtained.

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