A pretreatment device for detecting plasticizers in flexible plastic packaging materials.

Abstract

This utility model discloses a pretreatment device for detecting plasticizers in flexible plastic packaging materials, relating to the field of plastic testing technology. It includes a first processing unit and a second processing unit for sequentially performing embrittlement and crushing treatments on the plastic packaging film. The second processing unit includes a frame and a turntable rotatably mounted on the frame. A grinding cylinder is mounted on the turntable, and a filter screen is installed inside the grinding cylinder to divide its inner cavity into an upper grinding zone and a lower collection zone. Several steel balls are arranged in the upper grinding zone. This utility model, by sequentially performing embrittlement and crushing treatments on the plastic packaging film, enables the embrittled plastic packaging film to be better crushed, resulting in a better crushing effect. Furthermore, the layered design of the grinding cylinder with the filter screen allows for the automatic collection and temporary storage of plastic packaging film fragments that meet the testing size during the grinding process.

Description

Technical Field

[0001] This utility model relates to the field of plastic testing technology, specifically to a pretreatment device for detecting plasticizers in plastic flexible packaging materials. Background Technology

[0002] Plastic flexible packaging is widely used in food, pharmaceuticals, and daily chemical products, offering advantages such as lightness, flexibility, low cost, and good barrier properties. However, to achieve these effects, plasticizers are often added. The addition of plasticizers (such as phthalates and adipates) weakens the intermolecular forces of polymers and lowers the glass transition temperature, thereby improving the flexibility, ductility, and processing performance of plastics. However, high-temperature, high-fat environments and prolonged contact can cause plasticizers to leach out, causing irreversible harm to the human body. Phthalate esters, in particular, have been proven to have significant biotoxicity, especially affecting reproductive development and the endocrine system. To ensure the safe use of plasticizers, it is necessary to accurately test whether the migration amount of plasticizers is within the standard range.

[0003] For the detection of plasticizers in flexible plastic packaging materials, the plastic packaging film is generally processed into fragments manually or using crushing equipment, with the fragment size controlled to ≤0.1cm. The fragments are thoroughly mixed, and 0.2-0.5g of the fragment sample (accurate to 0.0001g) is placed in a centrifuge tube. 10ml of tetrahydrofuran is added, and the sample is extracted by sonication for 30min. After sonication, the sample is extracted and filtered. Another 10ml of tetrahydrofuran is added to the residue in the tube, and the sample is extracted by sonication for 30min. The two filtrates are combined and evaporated under reduced pressure at 45℃ to about 3ml. The solution is then diluted to 10ml with n-hexane and filtered through a 0.45μm filter membrane for detection by gas chromatography-mass spectrometry.

[0004] However, in practice, it is difficult to precisely fragment plastic packaging film, resulting in poor crushing efficiency. Even with existing crushing equipment, it is challenging to break plastic packaging film fragments to a size below 0.1 cm. Consequently, these non-standard-sized fragments can interfere with test results in subsequent operations. Furthermore, fragments of the correct size are difficult to effectively screen from the crushed material. Therefore, a processing device is needed for accurately crushing and screening plastic packaging film fragments. Utility Model Content

[0005] The purpose of this invention is to provide a pretreatment device for detecting plasticizers in plastic flexible packaging materials in order to solve the problems in the prior art. This device achieves precise crushing of the film by sequentially embrittlement and crushing the film, and the ground film can be screened out and temporarily stored by a filter screen.

[0006] To solve the above problems, this utility model provides the following technical solution:

[0007] A pretreatment device for detecting plasticizers in flexible plastic packaging materials includes a first treatment unit and a second treatment unit for sequentially performing embrittlement treatment and crushing treatment on the plastic packaging film. The second treatment unit includes a frame and a turntable rotatably mounted on the frame. A grinding cylinder is provided on the turntable. A filter screen is provided inside the grinding cylinder to divide its inner cavity into an upper grinding zone and a lower collection zone. Several steel balls are provided in the upper grinding zone so that when the turntable rotates, the steel balls are used to crush the embrittled film placed in the upper grinding zone, and film fragments smaller than the filter hole size will pass through the filter screen and fall into the lower collection zone.

[0008] As a further embodiment of this utility model: a material cup is detachably installed in the lower collection area, and the opening of the material cup is located directly below the filter screen.

[0009] As a further aspect of this utility model: the first processing component includes a liquid nitrogen pressure tank and a connecting pipe connected to the joint of the liquid nitrogen pressure tank, the connecting pipe being used to deliver liquid nitrogen to the plastic packaging film.

[0010] As a further embodiment of this utility model: the first processing component also includes a cover that is connected to one end of the connecting pipe. The cover can be disposed on the turntable and is used to cover the grinding cylinder inside it.

[0011] As a further embodiment of this utility model: the frame is provided with a drive source for driving the turntable to rotate.

[0012] As a further embodiment of this invention, the device also includes a crushing device for pre-crushing the plastic packaging film, and the discharge port of the crushing device is located above the grinding cylinder.

[0013] As a further embodiment of this invention, the device also includes a lifting mechanism for supporting the crushing equipment, so as to make the discharge port height of the crushing equipment adjustable.

[0014] As a further embodiment of this invention: the grinding cylinders are configured as multiple cylinders and arranged in a circumferential array on the turntable.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. By sequentially embrittled and crushed the plastic packaging film, the embrittled film can be better crushed, resulting in a better crushing effect. Furthermore, the layered design of the grinding cylinder with a filter allows for the automatic collection and temporary storage of plastic packaging film fragments that meet the required size during the grinding process.

[0017] 2. The material cup design allows for the collection of fragments generated during the grinding process. After collection, the material cup can be removed from the lower collection area.

[0018] 3. By setting up a cover that can be placed on the turntable, the two together form a liquid nitrogen cryogenic grinding device, which realizes the integration of the freezing process and the grinding process on one device, saving space.

[0019] 4. Multiple grinding cylinders are provided, which can crush a large amount of plastic packaging film at a time, thus improving crushing efficiency. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the turntable and multiple grinding cylinders in this utility model. Figure 1 ;

[0023] Figure 3 This is a schematic diagram of the turntable and multiple grinding cylinders in this utility model. Figure 2 .

[0024] In the diagram: 1. Frame; 2. Turntable; 3. Grinding cylinder; 4. Steel ball; 5. Filter screen; 6. Material cup; 7. Liquid nitrogen pressure tank; 8. Connecting pipe; 9. Cover; 10. Crushing equipment; 11. Lifting mechanism; 12. Test tube rack; 13. Test tube; 14. Liquid inlet device; 15. Ultrasonic water bath. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0026] like Figures 1-2 As shown, a pretreatment device for plasticizer testing of flexible plastic packaging materials is used to fragment the plastic packaging film before testing, ensuring that the fragment size meets the desired testing requirements and guarantees testing accuracy. Specifically, it includes the following:

[0027] (1) A first processing component for embrittlement treatment of plastic packaging film. Specifically, the first processing component includes a liquid nitrogen pressure tank 7, and a connecting pipe 8 is connected to the joint of the liquid nitrogen pressure tank 7. When the plastic packaging film is placed in a container, one end of the connecting pipe 8 is connected to the container to deliver liquid nitrogen to the plastic packaging film. After being frozen by liquid nitrogen, the molecular chain movement of the plastic packaging film is hindered, its flexibility is lost, and it is prone to brittle fracture, so it can be better crushed.

[0028] (2) A second processing component for crushing embrittled plastic packaging film. Specifically, the second processing component includes a frame 1, a drive source (such as a drive motor) is installed inside the frame 1, a turntable 2 is rotatably mounted on the frame 1, the output shaft of the drive source is fixedly connected to the center of the turntable 2, and the drive source can drive the turntable 2 to rotate. A grinding cylinder 3 is installed on the turntable 2, and a filter screen 5 is installed inside the grinding cylinder 3 to divide its inner cavity into an upper grinding zone 301 and a lower collection zone 302. Several steel balls 4 are placed in the upper grinding zone 301. When the embrittled plastic packaging film is placed in the upper grinding zone 301, the drive source is started, so that the turntable 2 can drive the grinding cylinder 3 to rotate. Therefore, the steel balls 4 will crush and impact the plastic packaging film in the upper grinding zone 301. By controlling the speed and direction of the drive source output shaft, the plastic packaging film can be crushed more effectively. When the size of the crushed plastic packaging film fragments reaches the set limit of ≤0.1cm, these fragments can pass through the mesh of the filter screen 5 and reach the lower collection area 302 for temporary storage. This means that the combined processing of the first and second processing units allows for the necessary pre-crushing of the plastic packaging film, facilitating accurate subsequent testing.

[0029] like Figure 3 As shown, in order to facilitate the removal of fragments from the lower collection area 302, this application has detachably installed a material cup 6 on the lower collection area 302. In the working state, the opening of the material cup 6 is located directly below the filter screen 5. Therefore, fragments passing through the filter screen 5 can directly enter the material cup 6, and can then be removed from the lower collection area 302.

[0030] Furthermore, this application preferably places the plastic packaging film in the grinding cylinder 3 before subjecting it to embrittlement treatment. Specifically, a cover 9 is connected to one end of the connecting pipe 8, and the cover 9 can be placed on the turntable 2. At this time, the grinding cylinder 3 will be covered inside it. Liquid nitrogen is applied into the cover 9 through the liquid nitrogen pressure tank 7, which acts on the plastic packaging film inside the grinding cylinder 3, making it embrittled.

[0031] Of course, in order to shorten the crushing time of the plastic packaging film in the upper grinding zone 301, this application also adds a pre-treatment crushing device 10. The crushing device 10 is lifted and lowered by the lifting mechanism 11. The crushing device 10 first crushes the plastic packaging film into fragments of 0.8 to 2.5 cm, and then changes its position height through the lifting mechanism 11 so that the discharge port conveys the fragments to the upper grinding zone 301 of the grinding cylinder 3.

[0032] In order to increase the amount of pre-processing in a single operation, this application sets up multiple grinding cylinders 3, which are arranged in a circumferential array on the turntable 2. Therefore, a single rotation of the turntable 2 can crush the fragments in multiple grinding cylinders 3.

[0033] After obtaining the appropriate amount of fragments in the material cup 6, weigh 0.2–0.5 g (accurate to 0.0001 g) and place it into test tube 13. Then turn on the liquid inlet device 14. Test tube 13 is placed on test tube rack 12. By rotating test tube rack 12, organic reagents (such as tetrahydrofuran) can be added to multiple test tubes 13 one by one using the liquid inlet device 14. At the same time, test tube rack 12 can also be lifted and moved up and down by other lifting devices. After the reagent is added to test tube 13, the lifting device can be used to move test tube rack 12 into ultrasonic water bath 15 to perform ultrasonic extraction of plasticizers in the fragments for 30 minutes. After ultrasonic extraction, filter the sample liquid into the corresponding test tube using a liftable filter screen. Repeat the steps of adding tetrahydrofuran reagent and performing ultrasonic extraction in water bath for the test residue. Combine the two filtrates to complete the extraction of plasticizers from the plastic sample.

[0034] The above description provides a detailed account of one embodiment of the present invention. However, this description is merely a preferred embodiment and should not be construed as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the claims of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A pretreatment device for detecting plasticizers in flexible plastic packaging materials, characterized in that, The device includes a first processing unit and a second processing unit for sequentially performing embrittlement and crushing treatment on plastic packaging films. The second processing unit includes a frame (1) and a turntable (2) rotatably mounted on the frame (1). A grinding cylinder (3) is provided on the turntable (2). A filter screen (5) is provided inside the grinding cylinder (3) to divide its inner cavity into an upper grinding zone (301) and a lower collection zone (302). Several steel balls (4) are provided in the upper grinding zone (301) so that when the turntable (2) rotates, the steel balls (4) are used to crush the embrittled film placed in the upper grinding zone (301), and film fragments smaller than the filter hole size will pass through the filter screen (5) and fall into the lower collection zone (302).

2. The pretreatment device for detecting plasticizers in flexible plastic packaging materials according to claim 1, characterized in that, A material cup (6) is detachably installed in the lower collection area (302), and the opening of the material cup (6) is located directly below the filter screen (5).

3. A pretreatment device for detecting plasticizers in flexible packaging materials according to claim 1 or 2, characterized in that, The first processing unit includes a liquid nitrogen pressure tank (7) and a connecting pipe (8) connected to the joint of the liquid nitrogen pressure tank (7). The connecting pipe (8) is used to deliver liquid nitrogen to the plastic packaging film.

4. The pretreatment device for detecting plasticizers in flexible plastic packaging materials according to claim 3, characterized in that, The first processing component also includes a cover (9) connected to one end of the connecting pipe (8). The cover (9) can be disposed on the turntable (2) and used to cover the grinding cylinder (3) inside it.

5. A pretreatment device for detecting plasticizers in flexible packaging materials according to claim 1 or 2, characterized in that, The frame (1) is provided with a drive source for driving the turntable (2) to rotate.

6. A pretreatment device for detecting plasticizers in flexible packaging materials according to claim 1 or 2, characterized in that, The device also includes a crushing device (10) for pre-crushing plastic packaging film, and the outlet of the crushing device (10) is located above the grinding cylinder (3).

7. The pretreatment device for detecting plasticizers in flexible packaging materials according to claim 6, characterized in that, The device also includes a lifting mechanism (11) for supporting the crushing equipment (10) so that the discharge port height of the crushing equipment (10) is adjustable.

8. A pretreatment device for detecting plasticizers in flexible plastic packaging materials according to claim 1 or 2, characterized in that, The grinding cylinders (3) are configured as multiple and arranged in a circumferential array on the turntable (2).

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