High-strength food box and preparation method thereof

Abstract

The invention discloses a high-strength food box which comprises a box body outer layer which comprises the following components in parts by weight: 90-96 parts of polypropylene and 4-8 parts of stiffening master batch; the box body middle layer is prepared from the following components in parts by weight: 80 to 85 parts of polypropylene, 10 to 15 parts of inorganic filler and 4 to 8 parts of stiffening master batch; and the inner layer of the box body comprises the following components in parts by weight: 40-60 parts of composite polypropylene, 10-15 parts of polyethylene and 10-15 parts of ethylene copolymer. The invention further discloses a blister preparation method of the high-strength food box. Compared with the prior art, the plastic uptake food box solves the problems that an existing plastic uptake food box is insufficient in strength, and a sealing film is not firm in bonding.

Description

Technical Field

[0001] The invention relates to the technical field of food box processing, and in particular to a high-strength food box and a preparation method thereof. Background Art

[0002] Three-layer co-extrusion is a plastic processing technology that uses three extruders to melt different types of plastic raw materials respectively, and then extrude these molten plastics simultaneously through a co-extrusion die to form a film or sheet with a three-layer structure.

[0003] When the sheet obtained by the three-layer co-extrusion process is used for the food box blister molding, the existing three-layer sheet is prone to the problems of insufficient strength and easy deformation. In addition, the existing blister food box is prone to the opening passing through the adhesive film sealing, and the bonding is not strong. Summary of the invention

[0004] The purpose of the present invention is to provide a high-strength food box and a preparation method thereof, so as to solve the problems of insufficient strength and weak adhesion of the sealing film of the existing blister food box.

[0005] In order to achieve the above object, on the one hand, the present invention discloses a high-strength food box, comprising:

[0006] The outer layer of the box body comprises the following components by weight: 90-96 parts of polypropylene and 4-8 parts of rigid masterbatch;

[0007] The middle layer of the box body comprises the following components by weight: 80-85 parts of polypropylene, 10-15 parts of inorganic filler, and 4-8 parts of rigid masterbatch;

[0008] The inner layer of the box body comprises the following components in parts by weight: 40-60 parts of composite polypropylene, 10-15 parts of polyethylene, and 10-15 parts of ethylene copolymer.

[0009] As a further description of the above technical solution:

[0010] The polyethylene in the inner layer of the box body is linear low-density polyethylene particles with a grade of LL 1236.85 manufactured by ExxonMobil.

[0011] As a further description of the above technical solution:

[0012] The ethylene copolymer in the inner layer of the box body is an ethylene 1-hexene copolymer with a grade of 2018MB manufactured by ExxonMobil.

[0013] On the other hand, the present invention also discloses a method for preparing a high-strength food box, comprising the following steps:

[0014] S1, take the outer layer component, the middle layer component and the inner layer component of the box body in the above formula ratio, and add them into a three-screw extruder;

[0015] S2, the outer layer component of the box body, the middle layer component of the box body, and the inner layer component of the box body are melted by a three-screw extruder, and are respectively extruded and extruded to an extrusion die by the main screw and two auxiliary screws of the three-screw extruder to output a three-layer sheet, which includes an outer layer composed of the outer layer component of the box body, a middle layer composed of the middle layer component of the box body, and an inner layer composed of the inner layer component of the box body;

[0016] S3, sending the three-layer sheet into a calender for calendering, and after calendering, pulling it to a slicer for slicing to obtain a sheet to be formed;

[0017] S4, feeding the sheet material to be formed into a blister forming mold, and blister forming the sheet material to obtain a food box.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0019] 1. In the present invention, the sheet material prepared by the three-layer co-extrusion process is subjected to blister molding to obtain a food box. The outer layer of the box body and the middle layer of the box body are mainly composed of PP materials. In order to improve the mechanical properties of the sheet material and increase the strength of the food box, the PP materials of the outer layer of the box body and the middle layer of the box body are added with rigid masterbatch for filling and modification. Since the deformation amplitude of the outer layer material of the box body is greater than the deformation amplitude of the middle layer material of the box body during the blister molding process, the outer layer material of the box body is only improved in mechanical properties by the rigid masterbatch, so that the outer layer material of the box body is not easy to deform and rupture, and the PP material in the middle layer material of the box body is further filled and modified by inorganic fillers, so as to further enhance the mechanical properties of the material and improve the strength of the blister food box. The inorganic filler can be specifically one of talcum powder, nano calcium carbonate, and nano zinc oxide.

[0020] 2. In the present invention, polyethylene and ethylene copolymer are mixed into the polypropylene of the inner layer of the box body, so that the inner layer of the blister food box has improved flexibility and cold resistance, so that it can be used to store food in a cold environment. At the same time, the surface tension and surface energy of the blister food box are improved, and the firmness of the bonding when the adhesive is used to seal the top opening of the food box is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 The present invention is a flow chart of a method for preparing a high-strength food box. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] See also Figure 1 In one aspect, the present invention discloses a high-strength food box, comprising:

[0027] The outer layer of the box body comprises the following components by weight: 94 parts of polypropylene and 6 parts of rigid masterbatch;

[0028] The middle layer of the box body comprises the following components by weight: 83 parts of polypropylene, 12 parts of inorganic filler, and 5 parts of rigid masterbatch;

[0029] The inner layer of the box body comprises the following components in parts by weight: 40-60 parts of composite polypropylene, 10-15 parts of polyethylene, and 10-15 parts of ethylene copolymer.

[0030] The polypropylene in the outer layer and the middle layer of the box body are both PP particles with the brand name CM01 manufactured by Tianjin United. The polyethylene in the inner layer of the box body is linear low-density polyethylene (LLDPE) particles with the brand name LL 1236.85 manufactured by ExxonMobil. The ethylene copolymer in the inner layer of the box body is ethylene-1-hexene copolymer with the brand name 2018MB manufactured by ExxonMobil.

[0031] The composite polypropylene in the inner layer of the box body includes polypropylene A and polypropylene B, and the ratio of polypropylene A to polypropylene B is 1:1. Specifically, polypropylene A is PP particles with the brand name CM01 manufactured by Tianjin United, and polypropylene B is PP particles with the brand name 1080 manufactured by Ningbo Formosa Plastics.

[0032] The addition ratio of each component in the inner layer of the box body is: composite polypropylene: polyethylene: ethylene copolymer = 4: 1: 1. Preferably, the inner layer of the box body includes the following components by weight: 25 parts of CM01 polypropylene, 25 parts of 1080 grain polypropylene, 12.5 parts of LL1 236.85 polyethylene, and 12.5 parts of 2018MB ethylene copolymer, which effectively ensures the modification effect of the inner layer of the box body.

[0033] On the other hand, the present invention also discloses a method for preparing a high-strength food box, comprising the following steps:

[0034] S1, take the outer layer component, the middle layer component and the inner layer component of the box body in the above formula ratio, and add them into a three-screw extruder;

[0035] S2, the outer layer component of the box body, the middle layer component of the box body, and the inner layer component of the box body are melted by a three-screw extruder, and are respectively extruded and extruded to an extrusion die by the main screw and two auxiliary screws of the three-screw extruder to output a three-layer sheet, which includes an outer layer composed of the outer layer component of the box body, a middle layer composed of the middle layer component of the box body, and an inner layer composed of the inner layer component of the box body;

[0036] S3, sending the three-layer sheet into a calender for calendering, and after calendering, pulling it to a slicer for slicing to obtain a sheet to be formed;

[0037] S4, feeding the sheet material to be formed into a blister forming mold, and blister forming the sheet material to obtain a food box.

[0038] Working principle: The sheet prepared by the three-layer co-extrusion process is used to obtain a food box after blister molding. The outer layer of the box body and the middle layer of the box body are mainly composed of PP materials. In order to improve the mechanical properties of the sheet and increase the strength of the food box, the PP materials of the outer layer of the box body and the middle layer of the box body are added with rigid masterbatch for filling and modification. Since the deformation amplitude of the outer layer of the box body is greater than that of the middle layer of the box body during the blister molding process, the outer layer of the box body material only improves the mechanical properties through the rigid masterbatch, making the outer layer of the box body material not easy to deform and crack, and the PP material in the middle layer of the box body is further filled and modified by inorganic fillers, which further enhances the mechanical properties of the material and improves the strength of the blister food box. The inorganic filler can be specifically one of talcum powder, nano calcium carbonate, and nano zinc oxide.

[0039] Polyethylene and ethylene copolymers are mixed into the polypropylene of the inner layer of the box body, so that the inner layer of the blister food box has improved flexibility and cold resistance, so that it can be used to store food in cold environments. At the same time, the surface tension and surface energy of the blister food box are improved, and the firmness of the bonding when the adhesive is used to seal the top opening of the blister food box is improved.

[0040] Example 2

[0041] See also Figure 1In one aspect, the present invention discloses a high-strength food box, comprising:

[0042] The outer layer of the box body comprises the following components by weight: 96 parts of polypropylene and 4 parts of stiffening masterbatch;

[0043] The middle layer of the box body comprises the following components by weight: 82 parts of polypropylene, 13 parts of inorganic filler, and 5 parts of rigid masterbatch;

[0044] The inner layer of the box body comprises the following components in parts by weight: 40-60 parts of composite polypropylene, 10-15 parts of polyethylene, and 10-15 parts of ethylene copolymer.

[0045] The polypropylene in the outer layer and the middle layer of the box body are both PP particles with the brand name CM01 manufactured by Tianjin United. The polyethylene in the inner layer of the box body is linear low-density polyethylene (LLDPE) particles with the brand name LL 1236.85 manufactured by ExxonMobil. The ethylene copolymer in the inner layer of the box body is ethylene-1-hexene copolymer with the brand name 2018MB manufactured by ExxonMobil.

[0046] The composite polypropylene in the inner layer of the box body includes polypropylene A and polypropylene B, and the ratio of polypropylene A to polypropylene B is 1:1. Specifically, polypropylene A is PP particles with the brand name CM01 manufactured by Tianjin United, and polypropylene B is PP particles with the brand name 1080 manufactured by Ningbo Formosa Plastics.

[0047] The addition ratio of each component in the inner layer of the box body is: composite polypropylene: polyethylene: ethylene copolymer = 4: 1: 1. Preferably, the inner layer of the box body includes the following components by weight: 25 parts of CM01 polypropylene, 25 parts of 1080 grain polypropylene, 12.5 parts of LL1 236.85 polyethylene, and 12.5 parts of 2018MB ethylene copolymer, which effectively ensures the modification effect of the inner layer of the box body.

[0048] On the other hand, the present invention also discloses a method for preparing a high-strength food box, comprising the following steps:

[0049] S1, take the outer layer component, the middle layer component and the inner layer component of the box body in the above formula ratio, and add them into a three-screw extruder;

[0050] S2, the outer layer component of the box body, the middle layer component of the box body, and the inner layer component of the box body are melted by a three-screw extruder, and are respectively extruded and extruded to an extrusion die by the main screw and two auxiliary screws of the three-screw extruder to output a three-layer sheet, which includes an outer layer composed of the outer layer component of the box body, a middle layer composed of the middle layer component of the box body, and an inner layer composed of the inner layer component of the box body;

[0051] S3, sending the three-layer sheet into a calender for calendering, and after calendering, pulling it to a slicer for slicing to obtain a sheet to be formed;

[0052] S4, feeding the sheet material to be formed into a blister forming mold, and blister forming the sheet material to obtain a food box.

[0053] Example 3

[0054] See also Figure 1 In one aspect, the present invention discloses a high-strength food box, comprising:

[0055] The outer layer of the box body comprises the following components by weight: 95 parts of polypropylene and 5 parts of rigid masterbatch;

[0056] The middle layer of the box body comprises the following components by weight: 82.5 parts of polypropylene, 12.5 parts of inorganic filler, and 5 parts of rigid masterbatch;

[0057] The inner layer of the box body comprises the following components in parts by weight: 40-60 parts of composite polypropylene, 10-15 parts of polyethylene, and 10-15 parts of ethylene copolymer.

[0058] The polypropylene in the outer layer and the middle layer of the box body are both PP particles with the brand name CM01 manufactured by Tianjin United. The polyethylene in the inner layer of the box body is linear low-density polyethylene (LLDPE) particles with the brand name LL 1236.85 manufactured by ExxonMobil. The ethylene copolymer in the inner layer of the box body is ethylene-1-hexene copolymer with the brand name 2018MB manufactured by ExxonMobil.

[0059] The composite polypropylene in the inner layer of the box body includes polypropylene A and polypropylene B, and the ratio of polypropylene A to polypropylene B is 1:1. Specifically, polypropylene A is PP particles with the brand name CM01 manufactured by Tianjin United, and polypropylene B is PP particles with the brand name 1080 manufactured by Ningbo Formosa Plastics.

[0060] The addition ratio of each component in the inner layer of the box body is: composite polypropylene: polyethylene: ethylene copolymer = 4: 1: 1. Preferably, the inner layer of the box body includes the following components by weight: 25 parts of CM01 polypropylene, 25 parts of 1080 grain polypropylene, 12.5 parts of LL1 236.85 polyethylene, and 12.5 parts of 2018MB ethylene copolymer, which effectively ensures the modification effect of the inner layer of the box body.

[0061] On the other hand, the present invention also discloses a method for preparing a high-strength food box, comprising the following steps:

[0062] S1, take the outer layer component, the middle layer component and the inner layer component of the box body in the above formula ratio, and add them into a three-screw extruder;

[0063] S2, the outer layer component of the box body, the middle layer component of the box body, and the inner layer component of the box body are melted by a three-screw extruder, and are respectively extruded and extruded to an extrusion die by the main screw and two auxiliary screws of the three-screw extruder to output a three-layer sheet, which includes an outer layer composed of the outer layer component of the box body, a middle layer composed of the middle layer component of the box body, and an inner layer composed of the inner layer component of the box body;

[0064] S3, sending the three-layer sheet into a calender for calendering, and after calendering, pulling it to a slicer for slicing to obtain a sheet to be formed;

[0065] S4, feeding the sheet material to be formed into a blister forming mold, and blister forming the sheet material to obtain a food box.

[0066] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-strength food box, characterized in that: include: The outer layer of the box body comprises the following components by weight: 90-96 parts of polypropylene and 4-8 parts of rigid masterbatch; The middle layer of the box body comprises the following components by weight: 80-85 parts of polypropylene, 10-15 parts of inorganic filler, and 4-8 parts of rigid masterbatch; The inner layer of the box body comprises the following components in parts by weight: 40-60 parts of composite polypropylene, 10-15 parts of polyethylene, and 10-15 parts of ethylene copolymer.

2. A high-strength food box according to claim 1, characterized in that: The composite polypropylene in the inner layer of the box body includes polypropylene A and polypropylene B, the ratio of polypropylene A to polypropylene B is 1:1, the polypropylene A is PP particles with the brand CM01 manufactured by Tianjin United, and the polypropylene B is PP particles with the brand 1080 manufactured by Ningbo Formosa Plastics.

3. A high-strength food box according to claim 2, characterized in that: The added ratio of each component in the inner layer of the box body is: composite polypropylene: polyethylene: ethylene copolymer = 4:1:

1.

4. A high-strength food box according to claim 1, characterized in that: The outer layer of the box body comprises the following components by weight: 95 parts of polypropylene and 5 parts of rigidity-enhancing masterbatch.

5. A high-strength food box according to claim 1, characterized in that: The middle layer of the box body includes the following components in parts by weight: 82.5 parts of polypropylene, 12.5 parts of inorganic fillers, and 5 parts of rigidity-enhancing masterbatch.

6. A high-strength food box according to claim 1, characterized in that: The polyethylene in the inner layer of the box body is linear low-density polyethylene particles with a grade of LL 1236.85 manufactured by ExxonMobil.

7. A high-strength food box according to claim 1, characterized in that: The ethylene copolymer in the inner layer of the box body is an ethylene-1-hexene copolymer with a brand number of 2018MB manufactured by ExxonMobil.

8. A method for preparing a high-strength food box according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Take the outer layer component, the middle layer component and the inner layer component of the box body according to any one of the formula ratios of claims 1 to 7, and add them into a three-screw extruder; S2, the outer layer component of the box body, the middle layer component of the box body, and the inner layer component of the box body are melted by a three-screw extruder, and are respectively extruded and extruded to an extrusion die by the main screw and two auxiliary screws of the three-screw extruder to output a three-layer sheet, which includes an outer layer composed of the outer layer component of the box body, a middle layer composed of the middle layer component of the box body, and an inner layer composed of the inner layer component of the box body; S3, sending the three-layer sheet into a calender for calendering, and after calendering, pulling it to a slicer for slicing to obtain a sheet to be formed; S4, feeding the sheet material to be formed into a blister forming mold, and blister forming the sheet material to obtain a food box.

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