Process for reinforcing the puncture resistance of biodegradable bubble film pouches

Abstract

The present application relates to the technical field of polyester degradable plastics, and particularly relates to a bio-degradable bubble film bag puncture resistance reinforcement process. The bio-degradable bubble film bag puncture resistance reinforcement process comprises the following steps: dust and oil removal on the surface of a formed bubble film bag, heat treatment to obtain a pretreated bubble film bag; soaking the pretreated bubble film bag in a Tris-HCl buffer solution, adding dopamine hydrochloride into the Tris-HCl buffer solution, air bubbling and ultrasonic treatment, vacuum drying to obtain a surface-activated bubble film bag; adding a silane coupling agent into an ethanol aqueous solution, stirring, adding nano calcium carbonate and graphene oxide into the ethanol aqueous solution, stirring, filtering, washing, vacuum drying to obtain an activated filler; adding polylactic acid and polylactic acid grafted maleic anhydride into dichloromethane, stirring until uniform, adding the activated filler into the dichloromethane, stirring, adding a leveling agent, continuing to stir, standing and defoaming, low-temperature spraying onto the surface of the surface-activated bubble film bag, roller compounding, heat preservation and natural cooling.

Description

Technical Field

[0001] This invention relates to the field of polyester biodegradable plastics technology, and more particularly to a process for enhancing the puncture resistance of biodegradable bubble wrap bags. Background Technology

[0002] Bubble bags are primarily made from polyethylene bubble film, cut to the required bag size and then processed by a bubble film bag-making machine. They are a widely used transparent flexible packaging material, mainly used for cushioning electronic products, plastic products, metal products, ceramic products, glass products, and other products requiring cushioning protection during logistics and transportation.

[0003] With the introduction of the plastic ban, various new types of biodegradable plastic bags have emerged, among which biodegradable plastic bags are the most representative. Bubble bags contain shock-absorbing bubble wrap. The bubble wrap contains countless tiny air bubbles, making it lightweight and elastic. It has the functions of sound insulation, shock absorption, and scratch resistance. However, during use, because the bubble cavity has a certain load-bearing limit, when a heavy object is pressed on the bubble wrap or when external pressure is applied to the bubble wrap, the bubble cavity may rupture under significant force, reducing the cushioning and protective effect of the object.

[0004] In recent years, due to factors such as online shopping, express delivery and the upgrading of electronic products, the use of bubble wrap has increased rapidly, and the resulting environmental problems have become prominent. The development of biodegradable bubble wrap products has gained recognition. Although biodegradable materials have good degradability, they generally have problems such as poor puncture resistance, insufficient high and low temperature resistance and low mechanical strength, which limits the development of biodegradable bubble wrap. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a process for enhancing the puncture resistance of biodegradable bubble wrap bags.

[0006] The process for enhancing the puncture resistance of biodegradable bubble wrap bags includes the following steps: S1. Remove dust and oil from the surface of the formed bubble wrap bag and heat treat it to obtain a pretreated bubble wrap bag; S2. Soak the pretreated bubble wrap bag in a Tris-HCl buffer solution with pH=8-9, add dopamine hydrochloride, sonicate with air for 1-2 hours, and vacuum dry to obtain surface-activated bubble wrap bag. S3. Add the silane coupling agent to the ethanol aqueous solution, adjust the pH of the system to 5-6, stir for 10-30 min, add nano calcium carbonate and graphene oxide, stir at 60-70℃ for 2-4 h, filter, wash, and vacuum dry to obtain the activated filler. S4. Add polylactic acid and polylactic acid grafted maleic anhydride to the mixed solvent and stir evenly. Add the activated filler and stir for 15-35 minutes. Add the leveling agent and continue stirring for 1-4 minutes. Let it stand to remove bubbles. Spray it onto the surface of the surface activated bubble film bag at low temperature. Roll it into a composite. Keep it at 78-80℃ for 10-30 minutes. Let it cool naturally to room temperature.

[0007] Preferably, in S1, the heat treatment temperature is 40-50℃ and the heat treatment time is 5-15min.

[0008] Preferably, in S2, the mass ratio of the pretreated bubble wrap bag to dopamine hydrochloride is 10-20:1-4.

[0009] Preferably, in S2, the ultrasonic frequency is 50-70kHz.

[0010] Preferably, in S2, the vacuum drying temperature is 40-50℃.

[0011] Preferably, in S3, the mass ratio of silane coupling agent, nano-calcium carbonate, and graphene oxide is 1-2:5-10:1-2.

[0012] Preferably, in S3, the mass fraction of the ethanol aqueous solution is 40-60%.

[0013] Preferably, in S4, the mass ratio of polylactic acid, polylactic acid-grafted maleic anhydride, activated filler, and leveling agent is 10-15:1-2:7-14:0.1-1.

[0014] Preferably, in S4, the grafting rate of maleic anhydride-grafted polylactic acid is 1-3%.

[0015] Preferably, in S4, the mixed solvent is composed of ethyl acetate and ethyl lactate in a mass ratio of 90-95:5-10.

[0016] Preferably, in S4, the coating thickness is 10-30 μm.

[0017] A bubble wrap bag is obtained by the above-mentioned process for enhancing the puncture resistance of biodegradable bubble wrap bags.

[0018] Compared with existing technologies, the present invention has the following advantages: This invention can effectively solve the problems of insufficient puncture resistance and poor resistance to high and low temperatures in biodegradable bubble wrap, achieving a significant improvement in the material's protective performance while maintaining its biodegradability and original buffering function.

[0019] This invention utilizes dopamine hydrochloride to form a uniform polydopamine layer on the surface of bubble film, endowing the surface with abundant active groups. A silane coupling agent is used to modify nano-calcium carbonate and graphene oxide to construct an activated filler that combines rigidity and toughness. On one hand, PLA-g-MAH serves as a compatibilizing bridge, uniformly dispersing the activated filler in the PLA matrix. Through low-temperature spraying and roller pressing composite technology, a functional coating with controllable thickness is formed on the surface of the bubble film bag. On the other hand, the surface activated groups and the polydopamine layer are combined to synergistically enhance the puncture resistance of the bubble film.

[0020] The rigid framework of the nanofiller used in this invention can directly resist puncture by sharp objects. Combined with the chemical bonding between the polydopamine layer and the coupling agent, it enhances the interfacial bonding force. PLA-g-MAH strengthens the compatibility between the filler and the matrix, effectively inhibiting crack propagation. The synergistic effect significantly improves the puncture resistance and high and low temperature resistance without affecting the biodegradability of the material, ensuring that electronic products, precision instruments and other items with high protection requirements are protected from external damage during transportation.

[0021] This invention does not affect the biodegradability and cushioning effect of the material, and uses readily available industrial equipment and mild conditions. It not only has low energy consumption, but also has a simple preparation method, which can be applied on a large scale and is suitable for the transportation protection needs of multiple scenarios, effectively promoting the large-scale application of green packaging in multiple scenarios. Attached Figure Description

[0022] Figure 1 The image shows a comparison of the tensile strength and right-angle tear strength of the bubble wrap bags obtained in Example 5, Comparative Examples 1-2, and the unreinforced molded bubble wrap bags.

[0023] Figure 2 This is a comparison chart showing the puncture resistance and the number of bags that do not break upon dart impact compared to the bubble wrap bags obtained in Example 5, Comparative Examples 1-2, and unreinforced molded bubble wrap bags.

[0024] Figure 3 The image shows a comparison of the puncture resistance of bubble wrap bags obtained in Example 5, Comparative Examples 1-2, and unreinforced molded bubble wrap bags at high temperature (60°C) and low temperature (-20°C). Detailed Implementation

[0025] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0026] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0027] The bubble wrap bags used below are commercially available from the applicant (Hangzhou Lihao New Materials Co., Ltd.), and their material is polylactic acid (PLA) and polybutylene terephthalate (PET). The PLA used below is sourced from Toray Industries, Japan, and its brand name is V751X52. The PLA grafted with maleic anhydride used below was purchased from Xi'an Ruixi Biotechnology Co., Ltd., with a grafting rate of 2.11%. The leveling agent used below, BYK-333, is sourced from BYK, Germany. The mixed solvent used below consists of ethyl acetate and ethyl lactate in a mass ratio of 95:5.

[0028] Example 1 The process for enhancing the puncture resistance of biodegradable bubble wrap bags includes the following steps: S1. Remove dust and oil from the surface of the formed bubble wrap bag, and then place it in an oven at 40℃ for 5 minutes to obtain a pretreated bubble wrap bag. S2. Soak 10g of pretreated bubble wrap bag in 50g of Tris-HCl buffer solution with pH 8, add 1g of dopamine hydrochloride, sonicate with air for 1h at a frequency of 50kHz, remove and drain, and vacuum dry at 40℃ to obtain surface activated bubble wrap bag. S3. Add 1g of KH550 coupling agent to 30g of 40% ethanol aqueous solution, adjust the pH of the system to 5 with glacial acetic acid, stir at 100r / min for 10min, add 5g of nano calcium carbonate and 1g of graphene oxide, stir at 60℃ for 2h at a stirring speed of 500r / min, filter, wash, and vacuum dry to obtain the activated filler. S4. Add 10g of polylactic acid and 1g of polylactic acid grafted maleic anhydride to 90g of mixed solvent and stir evenly. Add 7g of activated filler and stir at 100r / min for 5min. Stir at 1000r / min for 10min. Add 0.1g of leveling agent BYK-333 and continue stirring for 1min. Let stand to remove bubbles. Spray at a low temperature of 30℃ onto the surface of the surface activated bubble film bag with a spray thickness of 10μm. Press with a roller at a pressure of 0.15MPa and place in an oven at 78℃ for 10min. Let cool naturally to room temperature.

[0029] Example 2 The process for enhancing the puncture resistance of biodegradable bubble wrap bags includes the following steps: S1. Remove dust and oil from the surface of the formed bubble wrap bag, and then place it in an oven at 50℃ for 15 minutes to obtain a pretreated bubble wrap bag. S2. Soak 20g of pretreated bubble wrap bag in 100g of Tris-HCl buffer solution with pH 8.5, add 4g of dopamine hydrochloride, sonicate with air for 2h at a frequency of 70kHz, remove and drain, and vacuum dry at 50℃ to obtain surface-activated bubble wrap bag. S3. Add 2g of KH550 coupling agent to 50g of 60% ethanol aqueous solution, adjust the pH of the system to 6 with glacial acetic acid, stir at 300r / min for 30min, add 10g of nano calcium carbonate and 2g of graphene oxide, stir at 70℃ for 4h at a stirring speed of 1500r / min, filter, wash, and vacuum dry to obtain activated filler; S4. Add 15g of polylactic acid and 2g of polylactic acid grafted maleic anhydride to 140g of mixed solvent and stir evenly. Add 14g of activated filler and stir at 300r / min for 15min, then at 3000r / min for 20min. Add 1g of leveling agent BYK-333 and continue stirring for 4min. Let stand to remove bubbles, and spray at a low temperature of 40℃ onto the surface of the surface activated bubble film bag with a spray thickness of 30μm. Apply a 0.3MPa pressure roller to the film and place it in an oven at 80℃ for 30min. Allow it to cool naturally to room temperature.

[0030] Example 3 The process for enhancing the puncture resistance of biodegradable bubble wrap bags includes the following steps: S1. Remove dust and oil from the surface of the formed bubble wrap bag, and then place it in an oven at 42℃ for 12 minutes to obtain a pretreated bubble wrap bag. S2. Soak 12g of pretreated bubble wrap bag in 90g of Tris-HCl buffer solution with pH 9, add 2g of dopamine hydrochloride, sonicate with air for 100min at a frequency of 55kHz, remove and drain, and vacuum dry at 48℃ to obtain surface activated bubble wrap bag. S3. Add 1.5g of KH550 coupling agent to 35g of 55% ethanol aqueous solution, adjust the pH of the system to 5.5 with glacial acetic acid, stir at 240r / min for 15min, add 9g of nano calcium carbonate and 1.5g of graphene oxide, stir at 62℃ for 3.5h at a stirring speed of 800r / min, filter, wash, and vacuum dry to obtain the activated filler; S4. Add 13g of polylactic acid and 1.2g of polylactic acid grafted maleic anhydride to 120g of mixed solvent and stir evenly. Add 8g of activated filler and stir at 250r / min for 8min, then stir at 2500r / min for 12min. Add 0.8g of leveling agent BYK-333 and continue stirring for 2min. Let stand to remove bubbles, and spray at a low temperature of 37℃ onto the surface of the surface activated bubble film bag with a spray thickness of 20μm. Apply a 0.2MPa pressure roller to laminate the coating and place it in an oven at 79℃ for 15min. Allow it to cool naturally to room temperature.

[0031] Example 4 The process for enhancing the puncture resistance of biodegradable bubble wrap bags includes the following steps: S1. Remove dust and oil from the surface of the formed bubble wrap bag, and then place it in an oven at 48℃ for 8 minutes to obtain a pretreated bubble wrap bag. S2. Soak 18g of pretreated bubble wrap bag in 70g of Tris-HCl buffer solution with pH 9, add 3g of dopamine hydrochloride, sonicate with air for 80min at a frequency of 65kHz, remove and drain, and vacuum dry at 42℃ to obtain surface activated bubble wrap bag. S3. Add 1.5g of KH550 coupling agent to 45g of 45% ethanol aqueous solution, adjust the pH of the system to 5.5 with glacial acetic acid, stir at 150r / min for 25min, add 7g of nano calcium carbonate and 1.5g of graphene oxide, stir at 68℃ for 2.5h at 1200r / min, filter, wash, and vacuum dry to obtain the activated filler; S4. Add 11g of polylactic acid and 1.8g of polylactic acid grafted maleic anhydride to 105g of mixed solvent and stir evenly. Add 12g of activated filler and stir at 150r / min for 12min, then stir at 1500r / min for 18min. Add 0.2g of leveling agent BYK-333 and continue stirring for 3min. Let stand to remove bubbles, and spray at a low temperature of 33℃ onto the surface of the surface activated bubble film bag with a spray thickness of 20μm. Apply a pressure roller with a pressure of 0.24MPa and place in an oven at 79℃ for 25min. Allow to cool naturally to room temperature.

[0032] Example 5 The process for enhancing the puncture resistance of biodegradable bubble wrap bags includes the following steps: S1. Remove dust and oil from the surface of the formed bubble wrap bag, and then place it in an oven at 45℃ for 10 minutes to obtain a pretreated bubble wrap bag. S2. Soak 15g of pretreated bubble wrap bag in 80g of Tris-HCl buffer solution with pH 9, add 2.5g of dopamine hydrochloride, sonicate with air for 90min at a frequency of 60kHz, remove and drain, and vacuum dry at 45℃ to obtain surface-activated bubble wrap bag. S3. Add 1.5g of KH550 coupling agent to 40g of 50% ethanol aqueous solution, adjust the pH of the system to 5.5 with glacial acetic acid, stir at 200r / min for 20min, add 5g of nano calcium carbonate and 1.5g of graphene oxide, stir at 65℃ for 3h at a stirring speed of 1000r / min, filter, wash, and vacuum dry to obtain the activated filler; S4. Add 12g of polylactic acid and 1.5g of polylactic acid grafted maleic anhydride to 110g of mixed solvent and stir evenly. Add 10g of activated filler and stir at 200r / min for 10min, then stir at 2000r / min for 15min. Add 0.5g of leveling agent BYK-333 and continue stirring for 2.5min. Let stand to remove bubbles, and spray at a low temperature of 35℃ onto the surface of the surface activated bubble film bag with a spray thickness of 20μm. Apply a pressure roller with a pressure of 0.22MPa and place in an oven at 80℃ for 20min. Allow to cool naturally to room temperature.

[0033] The relative biodegradability of the bubble wrap bag obtained in Example 5 reached 91.74%; and its solvent residue content was 5.13 mg / m³. 2 .

[0034] Comparative Example 1 The process for enhancing the puncture resistance of biodegradable bubble wrap bags includes the following steps: S1. Remove dust and oil from the surface of the formed bubble wrap bag, and then place it in an oven at 45℃ for 10 minutes to obtain a pretreated bubble wrap bag. S2. Add 1.5g of KH550 coupling agent to 40g of 50% ethanol aqueous solution, adjust the pH of the system to 5.5 with glacial acetic acid, stir at 200r / min for 20min, add 5g of nano calcium carbonate and 1.5g of graphene oxide, stir at 65℃ for 3h at a stirring speed of 1000r / min, filter, wash, and vacuum dry to obtain the activated filler; S3. Add 12g of polylactic acid and 1.5g of polylactic acid grafted maleic anhydride to 110g of mixed solvent and stir evenly. Add 10g of activated filler and stir at 200r / min for 10min, then stir at 2000r / min for 15min. Add 0.5g of leveling agent BYK-333 and continue stirring for 2.5min. Let stand to remove bubbles, and spray at a low temperature of 35℃ onto the surface of the pretreated bubble film bag with a spray thickness of 20μm. Apply a 0.22MPa pressure roller to the coating and place it in an oven at 80℃ for 20min. Allow it to cool naturally to room temperature.

[0035] Comparative Example 2 The process for enhancing the puncture resistance of biodegradable bubble wrap bags includes the following steps: S1. Remove dust and oil from the surface of the formed bubble wrap bag, and then place it in an oven at 45℃ for 10 minutes to obtain a pretreated bubble wrap bag. S2. Soak 15g of pretreated bubble wrap bag in 80g of Tris-HCl buffer solution with pH 9, add 2.5g of dopamine hydrochloride, sonicate with air for 90min at a frequency of 60kHz, remove and drain, and vacuum dry at 45℃ to obtain surface-activated bubble wrap bag. S3. Add 1.5g of KH550 coupling agent to 40g of 50% ethanol aqueous solution, adjust the pH of the system to 5.5 with glacial acetic acid, stir at 200r / min for 20min, add 5g of nano calcium carbonate, stir at 65℃ for 3h at 1000r / min, filter, wash, and vacuum dry to obtain activated filler; S4. Add 12g of polylactic acid and 1.5g of polylactic acid grafted maleic anhydride to 110g of mixed solvent and stir evenly. Add 10g of activated filler and stir at 200r / min for 10min, then stir at 2000r / min for 15min. Add 0.5g of leveling agent BYK-333 and continue stirring for 2.5min. Let stand to remove bubbles, and spray at a low temperature of 35℃ onto the surface of the surface activated bubble film bag with a spray thickness of 20μm. Apply a pressure roller with a pressure of 0.22MPa and place in an oven at 80℃ for 20min. Allow to cool naturally to room temperature.

[0036] Referring to GB / T 38727-2020 "Fully Biodegradable Packaging Plastic Films and Bags for Logistics Express Transportation and Delivery", the tensile strength, right-angle tear strength, puncture resistance, and number of unbroken bubble wrap bags obtained in Example 5 and Comparative Examples 1-2, as well as unreinforced molded bubble wrap bags, were measured; and the puncture resistance was measured at high temperature (60°C) and low temperature (-20°C).

[0037] like Figure 1 , Figure 2 and Figure 3 As shown, the bubble wrap bag obtained in Example 5 has the highest tensile strength, right-angle tear strength, and puncture resistance, which are significantly better than the comparative example; moreover, the bubble wrap bag obtained in Example 5 also has the highest number of dart-impact-resistant bags, which are significantly better than the comparative example; this confirms that the strengthening process of the present invention can effectively improve the puncture resistance, high and low temperature resistance, and other properties of bubble wrap bags.

[0038] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. A process for enhancing the puncture resistance of biodegradable bubble wrap bags, characterized in that, Includes the following steps: S1. Remove dust and oil from the surface of the formed bubble wrap bag and heat treat it to obtain a pretreated bubble wrap bag; S2. Soak the pretreated bubble wrap bag in a Tris-HCl buffer solution with pH=8-9, add dopamine hydrochloride, sonicate with air for 1-2 hours, and vacuum dry to obtain surface-activated bubble wrap bag. S3. Add the silane coupling agent to the ethanol aqueous solution, adjust the pH of the system to 5-6, stir for 10-30 min, add nano calcium carbonate and graphene oxide, stir at 60-70℃ for 2-4 h, filter, wash, and vacuum dry to obtain the activated filler. S4. Add polylactic acid and polylactic acid grafted maleic anhydride to the mixed solvent and stir evenly. Add the activated filler and stir for 15-35 minutes. Add the leveling agent and continue stirring for 1-4 minutes. Let it stand to remove bubbles. Spray it onto the surface of the surface activated bubble film bag at low temperature. Roll it into a composite. Keep it at 78-80℃ for 10-30 minutes. Let it cool naturally to room temperature.

2. The puncture resistance enhancement process for biodegradable bubble wrap bags according to claim 1, characterized in that, In S1, the heat treatment temperature is 40-50℃ and the heat treatment time is 5-15min.

3. The puncture resistance enhancement process for biodegradable bubble wrap bags according to claim 1, characterized in that, In S2, the mass ratio of pretreated bubble wrap bag to dopamine hydrochloride is 10-20:1-4.

4. The puncture resistance enhancement process for biodegradable bubble wrap bags according to claim 1, characterized in that, In S2, the ultrasonic frequency is 50-70kHz.

5. The puncture resistance enhancement process for biodegradable bubble wrap bags according to claim 1, characterized in that, In S2, the vacuum drying temperature is 40-50℃.

6. The puncture resistance enhancement process for biodegradable bubble wrap bags according to claim 1, characterized in that, In S3, the mass ratio of silane coupling agent, nano-calcium carbonate, and graphene oxide is 1-2:5-10:1-2.

7. The puncture resistance enhancement process for biodegradable bubble wrap bags according to claim 1, characterized in that, In S3, the mass fraction of the ethanol aqueous solution is 40-60%.

8. The puncture resistance enhancement process for biodegradable bubble wrap bags according to claim 1, characterized in that, In S4, the mass ratio of polylactic acid, polylactic acid-grafted maleic anhydride, activated filler, and leveling agent is 10-15:1-2:7-14:0.1-1.

9. The puncture resistance enhancement process for biodegradable bubble wrap bags according to claim 1, characterized in that, In S4, the coating thickness is 10-30μm.

10. A bubble wrap bag, characterized in that, The biodegradable bubble wrap bag is obtained by using the puncture resistance enhancement process described in any one of claims 1-9.

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