阅读说明：本技术 一种成型加工系统及其应用 (Forming processing system and application thereof ) 是由 陈正勇 黄维捷 于 2021-09-18 设计创作，主要内容包括：本发明涉及一种成型加工系统及其应用,所述系统包括设置在挤出模头下游的预处理模块和定型模块,所述预处理模块对由挤出模头挤出的熔体坯进行包含以下处理中的至少一种：保温拉伸、保温结晶。与现有技术相比,本系统在定型之前,先通过预处理模块对熔体坯进行保温拉伸或/和保温结晶,以改善最终成品的耐热性和力学性能。(The invention relates to a forming processing system and application thereof, wherein the system comprises a pretreatment module and a shaping module which are arranged at the downstream of an extrusion die head, and the pretreatment module carries out at least one of the following treatments on a melt blank extruded from the extrusion die head: and (5) insulating, stretching and crystallizing. Compared with the prior art, before the system is shaped, the melt blank is subjected to heat preservation stretching or/and heat preservation crystallization through the pretreatment module, so that the heat resistance and the mechanical property of a final finished product are improved.)

1. A profiling processing system, characterized by comprising a pre-treatment module and a profiling module arranged downstream of an extrusion die (1), said pre-treatment module subjecting a melt blank extruded from the extrusion die (1) to a treatment comprising at least one of the following: and (5) insulating, stretching and crystallizing.

2. The converting system of claim 1, wherein said pre-treatment module comprises a temperature-maintaining stretching device for performing a temperature-maintaining stretching treatment on the melt blank extruded from the extrusion die (1).

3. The forming processing system according to claim 1, wherein the pretreatment module comprises a heat-preservation stretching device and a heat-preservation crystallizing device which are sequentially arranged at the downstream of the extrusion die head (1) so as to sequentially perform heat-preservation stretching and heat-preservation crystallizing treatment on the melt blank extruded by the extrusion die head (1).

4. The profiling processing system according to claim 1, wherein the pre-treatment module comprises a thermal crystallization device for thermal crystallization of the melt blank extruded from the extrusion die (1).

5. The forming and processing system as claimed in claim 2 or 3, wherein the heat-insulating stretching device comprises a tank body (3) for containing a liquid-phase heat exchange medium (7), an overflow supporting mechanism arranged in an inner cavity of the tank body (3) along the length direction of the tank body (3), and an external circulation mechanism for supplying the overflow supporting mechanism with the liquid-phase heat exchange medium (7).

6. The forming and processing system as claimed in claim 5, wherein the overflow supporting mechanism comprises at least 2 hollow supporting rods (13) arranged in the inner cavity of the tank body (3) at intervals along the length direction of the tank body (3), a hollow cavity penetrating through the rod body is arranged inside the hollow supporting rods (13) along the length direction of the rod body, the hollow cavity is communicated with the inner cavity of the tank body (3),

the top of the hollow support rod (13) is provided with an overflow notch (14) which is sunken towards the rod body and communicated with the hollow cavity;

or the top of the hollow support rod (13) is provided with a support head (17) which protrudes outwards relative to the rod body and is communicated with the hollow cavity, and the top surface of the support head (17) is provided with an overflow hole (16).

7. A profiling system according to claim 6, characterized in that said overflow notch (14) is an overflow notch (14) having an arcuate edge (15);

support the inside of head (17) and be equipped with cushion chamber (18), support the top surface and the bottom surface of head (17) equally divide do not be equipped with overflow hole (16) that cushion chamber (18) are linked together, cushion chamber (18) through set up overflow hole (16) on supporting head (17) bottom surface with well cavity is linked together, just support head (17) orientation the upper edge of the cross section of extrusion die head (1) is arc edge (15).

8. The forming and processing system as claimed in claim 3 or 4, wherein the heat-preserving crystallization device comprises a tank body (3) for containing a liquid-phase heat exchange medium (7), a limiting guide mechanism arranged in an inner cavity of the tank body (3) along the length direction of the tank body (3), and an external circulation mechanism for supplying the tank body (3) with the liquid-phase heat exchange medium (7);

the limiting guide mechanism comprises at least 2 rotatable guide wheels (4) which are arranged in the inner cavity of the groove body (3) at intervals along the length direction of the groove body (3).

9. Use of a profiling system according to claim 1 for the production of pipes, rods or wires.

10. Use of a forming and processing system according to claim 9 for the preparation of PGA-based drinking straws;

in the preparation process, a melt blank extruded from an extrusion die head (1) passes through a pretreatment module and is subjected to at least one treatment at 60-100 ℃ comprising the following steps: and (3) performing heat preservation stretching, heat preservation crystallization, and cooling and shaping treatment at 5-30 ℃ through a shaping module.

Technical Field

The invention belongs to the technical field of material forming and processing, and particularly relates to a forming and processing system and application thereof.

Background

With the development of petrochemical industry, a large number of plastic products have been widely used in various aspects of people's production and life, for example, in the food packaging industry (products such as disposable lunch boxes, disposable chopsticks, disposable straws, plastic wrap, packaging bags and the like can be made). However, the traditional plastic products such as polyethylene and polypropylene are difficult to degrade after being discarded, which not only brings great burden to environmental management, but also causes serious 'white pollution' to the environment. At present, the disposal mode of the traditional plastic products is usually treated by burying or burning after being collected, but the soil can be polluted by burying, even the underground water resource can be polluted, which can form huge potential harm to the natural environment and ecology, and the natural environment can be seriously polluted by generating a large amount of harmful smoke and toxic gas by burning. For this reason, in the current stage, aiming at industries such as food packaging, the adoption of degradable plastic products to gradually replace the traditional plastic products is a necessary development trend.

At present, in addition to material modification, improvement of a molding process of a material is also receiving increasing attention from researchers in technical development of degradable materials (for example, polyglycolic acid (PGA), polylactic acid (PLA), polybutylene succinate (PBS), and the like). The improvement of the forming and processing technology of the material is beneficial to improving certain properties (such as mechanical property, heat resistance and the like) of the final formed product so as to meet the requirements of different working conditions and expand the application range of the formed product. For example, PGA and its modified materials are used to produce disposable straws, and the conventional process is to cool the tube blank extruded from the die head with water (usually, the water temperature is set to about 5-40 ℃), then to dry and cut by blowing, and the like, thus obtaining the straw product. In the process, when the PGA is directly water-cooled from the pipe blank extruded from the die head, the material of the pipe blank is rapidly solidified, so that the material of the pipe blank can not be fully crystallized, and the heat resistance of the finally manufactured suction pipe product is poor, when the storage environment temperature exceeds about 40 ℃, because the glass transition temperature of the PGA is only about 40 ℃, the heat resistance is poor under the condition of insufficient crystallization, the suction pipe is easy to soften and deform, and the PGA suction pipe manufactured by the conventional process has difficulty in obtaining practical application opportunities. Therefore, the PGA product (for example, disposable straw) manufactured by the conventional molding process is limited in application range, and is not suitable for popularization and application of green and environment-friendly PGA materials. Therefore, there is a need for improvement of the existing molding process to improve the quality of the final molded product, for example, the existing molding equipment for manufacturing the straw can be modified to produce a disposable straw based on PGA material with good heat resistance.

Disclosure of Invention

The present invention is directed to solving the above problems and providing a molding system and an application thereof.

The purpose of the invention is realized by the following technical scheme:

a profiling processing system comprising a preconditioning module and a sizing module disposed downstream of an extrusion die, the preconditioning module subjecting a melt billet extruded from the extrusion die to a process comprising at least one of: and (5) insulating, stretching and crystallizing.

As an embodiment, the pretreatment module comprises a heat-insulating stretching device for heat-insulating stretching treatment of the melt blank extruded from the extrusion die head.

As an embodiment, the pretreatment module comprises a heat-preservation stretching device and a heat-preservation crystallizing device which are sequentially arranged at the downstream of the extrusion die head, so that the melt blank extruded from the extrusion die head is sequentially subjected to heat-preservation stretching and heat-preservation crystallizing treatment.

In one embodiment, the pretreatment module comprises a thermal crystallization device to perform thermal crystallization treatment on the melt blank extruded from the extrusion die head.

As a preferred embodiment, the heat preservation stretching device comprises a tank body for containing a liquid-phase heat exchange medium, an overflow supporting mechanism arranged in an inner cavity of the tank body along the length direction of the tank body, and an external circulation mechanism for supplying the overflow supporting mechanism with the liquid-phase heat exchange medium.

As a preferred embodiment, a supporting partition plate is arranged at the lower part of the inner cavity of the tank body of the heat preservation stretching device, and the supporting partition plate is arranged in parallel with the bottom plate of the tank body, so that a cavity for liquid phase heat exchange medium to flow can be formed between the supporting partition plate and the bottom plate of the tank body, and the overflow supporting mechanism can be conveniently fixed on the supporting partition plate.

As a preferred embodiment, the overflow supporting mechanism comprises at least 2 hollow supporting rods arranged in the inner cavity of the tank body at intervals along the length direction of the tank body, a hollow cavity penetrating through the rod body is arranged in the hollow supporting rods along the length direction of the rod body, the hollow cavity is communicated with the inner cavity of the tank body,

the top of the hollow support rod is provided with an overflow notch which is sunken towards the rod body and is communicated with the hollow cavity;

or the top of the hollow support rod is provided with a support head which protrudes outwards relative to the rod body and is communicated with the hollow cavity, and the top surface of the support head is provided with an overflow hole.

In a working state, a liquid-phase heat exchange medium flows out of an overflow notch or an overflow hole of the overflow supporting mechanism to form a stable liquid level, so that a floating supporting effect is generated on a melt blank; meanwhile, a liquid-phase heat exchange medium is introduced into the tank body and can heat air in the inner cavity of the tank body, so that the temperature of the air is close to that of the liquid-phase heat exchange medium.

In a preferred embodiment, the overflow notch is an overflow notch with an arc-shaped edge, and the overflow notch is preferably designed to have an arc-shaped edge, so that the edge higher than the liquid surface can limit the section of the melt blank contacted with the liquid surface, and the melt blank is prevented from deviating from the normal travel track.

As a preferred embodiment, the inside of the supporting head is provided with a buffer cavity, the top surface and the bottom surface of the supporting head are respectively provided with an overflow hole communicated with the buffer cavity, the buffer cavity is communicated with the hollow cavity through the overflow hole arranged on the bottom surface of the supporting head, and the upper edge of the cross section of the supporting head facing the extrusion die head is an arc-shaped edge.

As a preferred embodiment, infrared heaters may be disposed on the inner walls of the groove body on both sides of the top of the hollow support rod, and in the operating state, the infrared heaters may perform radiant heating on the melt blank section passing through the top of the hollow support rod.

As a preferred embodiment, the heat-preservation crystallization device comprises a tank body for containing a liquid-phase heat exchange medium, a limiting guide mechanism arranged in an inner cavity of the tank body along the length direction of the tank body, and an external circulation mechanism for supplying the liquid-phase heat exchange medium to the tank body;

the limiting guide mechanism comprises at least 2 rotatable guide wheels which are arranged in the inner cavity of the groove body at intervals along the length direction of the groove body.

As a preferred embodiment, each guide wheel can be fixedly connected with the side wall of the inner cavity of the groove body through a connecting rod, so that the guide wheels are suspended in the inner cavity of the groove body.

In one embodiment, the shaping module comprises a cooling shaping device, and the structure of the cooling shaping device is basically the same as that of the heat-preservation crystallizing device. In practical processing application, the length of the groove body of the cooling and shaping device is usually smaller than that of the heat-preservation crystallization device.

As an implementation mode, the external circulation mechanism comprises a circulation pipeline communicated with the inner cavity of the tank body, a liquid-phase heat exchange medium storage tank arranged on the circulation pipeline, a heat exchanger and a circulation pump, wherein the heat exchanger is used for heating the liquid-phase heat exchange medium to a set temperature.

When the drying device is specifically implemented, the traction mechanism, the drying mechanism and the cutting mechanism can be sequentially arranged at the downstream of the shaping module, wherein the traction mechanism can adopt a conventional belt conveyor which is arranged in an up-and-down symmetrical mode, the drying mechanism can adopt a conventional blowing dryer, and the cutting mechanism can adopt a conventional rotary knife cutting machine.

In the application aspect, the system can be used for preparing pipes, bars, wires and other similar profiles, and the melt blank extruded from the extrusion die head is subjected to heat preservation stretching or/and heat preservation crystallization through the pretreatment module, so that the quality of the final formed product can be improved, and the product with good heat resistance can be prepared.

As a preferred embodiment, the system is used to prepare PGA-based straws;

in the preparation process, the melt billet extruded from the extrusion die head passes through a pretreatment module and is subjected to at least one treatment comprising the following treatments at 60-100 ℃: and (3) performing heat preservation stretching, heat preservation crystallization, and cooling and shaping treatment at 5-30 ℃ through a shaping module.

In the above-mentioned preparation process, the traveling speed of the melt gob can be controlled to about 0.5 to 3m/s, the time for the melt gob to pass through the pretreatment module can be controlled to about 3 to 10s, and the time for the melt gob to pass through the sizing module can be controlled to about 1 to 2 s.

Compared with the prior art, the invention has the following advantages:

1) the system can arrange a heat preservation crystallization device between the extrusion die head and the cooling and shaping device, and can carry out heat preservation crystallization on a melt blank extruded by the extrusion die head under the condition of smaller temperature difference (compared with the temperature of the melt blank just extruded by the extrusion die head), and in the process, the melt blank is cooled relatively slowly in a liquid phase heat exchange medium with higher temperature and can generate good oriented crystallization by itself under the traction action, thereby being beneficial to improving the heat resistance of a final finished product;

2) the system can arrange a heat-preservation stretching device between the extrusion die head and the cooling and shaping device, due to the structural design of the overflow supporting mechanisms in the heat-preservation stretching device, the multi-point floating support can be realized on the melt blank entering the heat-preservation stretching device, and the melt blank section between two adjacent overflow supporting mechanisms can be fully drawn and stretched in the longitudinal direction under the heat preservation effect of heated air (namely, the temperature reduction speed of the melt blank extruded by the extrusion die head is slowed down as much as possible), so that the oriented crystallization of material molecular chains in the melt blank can be realized, and the heat resistance of a final finished product can be improved;

3) the system can arrange a heat-preservation stretching device between the extrusion die head and the heat-preservation crystallizing device, and can perform heat-preservation oriented stretching on the melt blank through the heat-preservation stretching device;

4) the system can be directly used for improving the existing processing equipment, the economic practicality is good, the system is not only suitable for preparing the straw products, but also suitable for preparing other similar section products such as pipes, bars or wires, the production efficiency is high, taking the preparation of the straw as an example, the straw products produced by the system can obtain expected quality through thinner thickness, the production cost of the straw products is greatly reduced, the prepared straw has good heat resistance and mechanical property, the shelf life of the straw products in a relatively high-temperature high-humidity environment can be effectively prolonged, the use safety is improved, and the system has good economic benefit.

Drawings

FIG. 1 is a schematic structural view of example 1;

fig. 2 and 3 are schematic structural views of the limiting and guiding mechanism in the working process in the embodiment 1;

FIG. 4 is a schematic structural view of embodiment 2;

FIGS. 5 and 6 are schematic views showing the structure of one form of the overflow supporting mechanism in embodiment 2;

FIGS. 7 and 8 are schematic structural views of another form of the overflow supporting mechanism in embodiment 2

FIG. 9 is a schematic structural view of example 3;

in the figure: a-a heat preservation crystallization device; b-cooling and shaping device; c-a heat preservation stretching device; d-a traction mechanism; e-a cutting mechanism;

1-an extrusion die head; 2-a melt blank; 3-a groove body; 4-a guide wheel; 5-a connecting rod; 61-tank body bottom plate; 62-supporting the partition plate; 7-liquid phase heat exchange medium; 8-tank body cover; 9-a recycle line; 10-a storage tank; 11-a circulation pump; 12-a heat exchanger; 13-hollow support rods; 14-an overflow gap; 15-arc edge; 16-overflow holes; 17-a support head; 18-buffer chamber.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

Example 1

Referring to fig. 1, a molding system includes a heat-insulating crystallization device a and a cooling and shaping device b disposed in sequence downstream of an extrusion die 1.

Specifically, heat preservation crystallization device a is including being used for splendid attire liquid phase heat transfer medium 7's cell body 3, along the length direction setting of cell body 3 spacing guide mechanism in cell body 3 inner chamber and for the cell body 3 outside circulation mechanism who supplies with liquid phase heat transfer medium 7.

As shown in fig. 2 and 3, the limiting guide mechanism comprises at least 2 rotatable guide wheels 4 arranged in the inner cavity of the tank body 3 at intervals along the length direction of the tank body 3, and each guide wheel 4 can be fixedly connected with the side wall of the inner cavity of the tank body 3 through a connecting rod 5, so that the guide wheels 4 are suspended in the inner cavity of the tank body 3.

A medium inlet is formed in one end, far away from the extrusion die head 1, of the groove body bottom plate 61, a medium outlet is formed in the side wall, close to the extrusion die head, of the groove body 3, an external circulation mechanism comprises a circulation pipeline 9 for connecting the medium inlet and the medium outlet, a liquid-phase heat exchange medium storage tank 10, a heat exchanger 12 and a circulation pump 11, the liquid-phase heat exchange medium storage tank 10 is arranged on the circulation pipeline 9, and the heat exchanger 12 is used for heating the liquid-phase heat exchange medium 7 to a set temperature.

It should be noted here that, in addition to the heating method using the heat exchanger, a heating method such as providing a heating element (e.g., an electric heating rod) in the liquid-phase heat exchange medium storage tank or providing a heating element (e.g., an electric heating rod, an electric heating coil, etc.) on the tank bottom plate 61 may be used to heat the liquid-phase heat exchange medium 7 to a suitable temperature.

As an implementation scheme, the cooling and shaping device b comprises a groove body 3 for containing a liquid-phase heat exchange medium 7, a limiting guide mechanism arranged in an inner cavity of the groove body 3 along the length direction of the groove body 3, and an external circulation mechanism for supplying the groove body 3 with the liquid-phase heat exchange medium 7, wherein the limiting guide mechanism and the external circulation mechanism are arranged in the same manner as the heat-preservation crystallizing device a.

As an embodiment, the liquid phase heat exchange medium 7 may be selected from tap water, deionized water, or purified water, etc.

As an embodiment, the top of the tank body 3 is provided with a reversible tank body cover 8, which can be used to cover the tank body 3 in the working state, so as to seal the tank body 3.

The system also comprises a traction mechanism d, a drying mechanism (not shown in the figure) and a cutting mechanism e which are sequentially arranged at the downstream of the cooling and shaping device b, wherein the traction mechanism d can adopt a conventional belt conveyer which is arranged in an up-and-down symmetrical mode, the drying mechanism can adopt a conventional blow drying machine, and the cutting mechanism e can adopt a conventional rotary knife cutting machine.

Taking the preparation of the PGA-based straw as an example, the specific working principle of the system is as follows: in a normal production state, a PGA melt blank 2 extruded from an extrusion die head 1 is fed forward to a heat-insulating crystallization device a, the PGA melt blank 2 enters a tank 3 containing a liquid-phase heat exchange medium 7 (e.g., tap water) at a temperature of about 60 to 100 ℃, the PGA melt blank 2 is immersed in the liquid-phase heat exchange medium 7, the flow direction of the liquid-phase heat exchange medium 7 in the tank 3 is opposite to the feeding direction of the PGA melt blank 2, the PGA melt blank 2 is cooled relatively slowly in the liquid-phase heat exchange medium 7 at a higher temperature, during the process, the PGA melt blank 2 itself can be crystallized to a certain degree, the PGA melt blank 2 continues to be fed forward under the limiting and guiding actions of a guide wheel 4 in a limiting and guiding mechanism, is guided out by the heat-insulating crystallization device a and fed forward to a cooling and shaping device b, the PGA melt blank 2 enters the tank containing the liquid-phase heat exchange medium 7 at a temperature of about 5 to 30 ℃ (for example, tap water), the PGA melt blank 2 is immersed in the liquid-phase heat exchange medium 7, the flow direction of the liquid-phase heat exchange medium 7 in the tank body 3 is opposite to the feeding direction of the PGA melt blank 2, the PGA melt blank 2 is rapidly cooled and shaped in the liquid-phase heat exchange medium 7, and is continuously fed forwards under the limiting and guiding actions of the guide wheel 4 in the limiting and guiding mechanism, and is guided out by a cooling and shaping device, and then is dried and cut to obtain a finished product.

In the process, the liquid-phase heat exchange medium 7 in the groove bodies 3 in the heat-preservation crystallizing device a and the cooling and shaping device b can select a smaller flow rate, so as to ensure that the PGA melt blank 2 does not disturb to normally advance forwards.

Example 2

Referring to fig. 4, a molding system includes a heat-insulating stretching device c and a cooling and shaping device b disposed in sequence downstream of an extrusion die 1 (in this embodiment, the structural features of the cooling and shaping device b are as in example 1).

As an embodiment, the heat preservation stretching device c comprises a tank body 3, an overflow supporting mechanism arranged in the inner cavity of the tank body 3 along the length direction of the tank body 3, and an external circulation mechanism for supplying a liquid phase heat exchange medium 7 to the overflow supporting mechanism.

As an implementation scheme, the lower part of the inner cavity of the tank body 3 is provided with a supporting partition plate 62, the supporting partition plate 62 can be provided with a hollow groove, the hollow groove communicates the space above the supporting partition plate 62 with the space below the supporting partition plate 62, the overflow supporting mechanism is fixed on the supporting partition plate 62, and further, a plurality of hollow grooves can be arranged and are uniformly distributed on the supporting partition plate 62.

In a working state, a liquid-phase heat exchange medium 7 is introduced into the space below the supporting partition plate 62 in the tank body 3, and the liquid-phase heat exchange medium 7 can heat air in the inner cavity of the tank body 3 so that the temperature of the air is close to that of the liquid-phase heat exchange medium 7.

As an embodiment, the overflow supporting mechanism includes at least 2 hollow supporting rods 13 arranged in the inner cavity of the tank body 3 at intervals along the length direction of the tank body 3, and a hollow cavity penetrating through the rod body is arranged inside the hollow supporting rods 13 along the length direction of the rod body, and the hollow cavity is communicated with the inner cavity of the tank body 3.

Referring to fig. 5 and 6, as an embodiment, the bottom of the hollow support rod 13 is communicated with the space below the support partition plate 62, the top is provided with an overflow notch 14 which is concave and open towards the rod body, and the overflow notch 14 is an overflow notch 14 with an arc-shaped edge 15.

In a working state, the liquid-phase heat exchange medium 7 in the groove body 3 for supporting the space below the partition plate 62 adopts a proper flow rate, and the hollow support rod 13 has a hollow cavity with a narrow cross section, so that the liquid-phase heat exchange medium 7 can reach the top overflow notch 14 through the hollow cavity and form a stable liquid level higher than the lowest point of the arc-shaped edge 15 of the overflow notch 14, and thus, when a certain section of the PGA melt blank 2 passes through the hollow support rod 13, the liquid level formed at the top overflow notch 14 of the hollow support rod 13 can generate a floating support effect on the section of the PGA melt blank 2. While the overflow notch 14 is preferably designed with an arc-shaped edge 15, so that the edge above the liquid surface can limit the section of the PGA melt blank 2 that is in contact with the liquid surface, preventing the PGA melt blank 2 from deviating from the normal travel path.

Referring to fig. 7 and 8, as another embodiment, the bottom of the hollow support rod 13 is connected to the space below the support partition 62, the top of the hollow support rod is provided with a support head 17 protruding outward relative to the rod body of the hollow support rod 13 and connected to the hollow support rod 13, the support head 17 is provided inside with a buffer chamber 18, the top and bottom surfaces of the support head 17 are respectively provided with an overflow hole 16 connected to the buffer chamber 18, and the buffer chamber 18 is connected to the hollow cavity of the hollow support rod 13 through the overflow hole 16 formed on the bottom surface. The upper edge of the cross section of the support head 17 toward the extrusion die 1 is an arc-shaped edge 15.

In the working state, the liquid phase heat exchange medium 7 in the space below the supporting partition plate 62 in the tank 3 adopts a proper flow rate, and the hollow supporting rod 13 has a hollow cavity with a narrow cross section, so that the liquid phase heat exchange medium 7 can reach the buffer cavity 18 of the top supporting head 17 through the hollow cavity and overflow from the overflow hole 16 on the top surface of the supporting head 17, and a stable liquid level higher than the lowest point of the upper edge of the cross section of the extruding die head 1 of the supporting head 17 is formed on the top surface of the supporting head 17, so that when a certain section of the PGA melt blank 2 passes through the hollow supporting rod 13, the liquid level formed on the top surface of the supporting head 17 can generate a floating supporting effect on the section of the PGA melt blank 2. While the upper edge of the cross-section of the support head 17 is preferably designed as an arc-shaped edge 15, with the aim that the edge above the liquid surface acts as a stop for the section of the PGA melt blank 2 that is in contact with the liquid surface, preventing the PGA melt blank 2 from deviating from the normal travel trajectory.

In addition, in order to further enhance the heat preservation effect on the melt blank 2 in the working state, infrared heaters can be arranged on the inner walls of the groove bodies 3 positioned on the two sides of the top of the hollow support rod 13.

In the operating state, the infrared heater can radiatively heat the section of the melt blank 2 passing through the top of the hollow support rod 13. As an embodiment, a medium inlet is arranged at one end of the groove body bottom plate 61 far away from the extrusion die head 1, and a medium outlet is arranged on the side wall of the groove body 3 close to the extrusion die head

The lateral wall of the groove body 3 corresponding to the lower space of the supporting clapboard 62 and close to the extrusion die is provided with a medium outlet, the external circulating mechanism comprises a circulating pipeline 9 for connecting the medium inlet and the medium outlet, a liquid-phase heat exchange medium storage tank 10 arranged on the circulating pipeline 9, a heat exchanger 12 and a circulating pump 11, and the heat exchanger 12 is used for heating the liquid-phase heat exchange medium 7 to a set temperature.

Here, in addition to the heating method using the heat exchanger, a heating method such as providing a heating element (e.g., an electric heating rod) in the liquid-phase heat exchange medium storage tank 10 or providing a heating element (e.g., an electric heating rod, an electric heating coil, etc.) on the tank bottom plate 61 may be used to heat the liquid-phase heat exchange medium 7 to a suitable temperature.

As an embodiment, the liquid phase heat exchange medium 7 may be selected from tap water, deionized water, or purified water, etc.

As an embodiment, a reversible tank body cover 8 is arranged on the top of the tank body 3, and in the working state, the tank body 3 can be covered to seal the tank body 3.

The system also comprises a traction mechanism d, a drying mechanism and a cutting mechanism e which are sequentially arranged at the downstream of the cooling and shaping device b, wherein the traction mechanism can adopt a conventional belt conveyer which is arranged in an up-and-down symmetrical manner, the drying mechanism can adopt a conventional blowing dryer, and the cutting mechanism can adopt a conventional rotary knife cutting machine.

Taking the preparation of PGA-based straws as an example, the working principle of the system is as follows:

under the normal production state, the external circulation mechanism in the heat-preservation stretching device c leads a liquid-phase heat exchange medium 7 (for example, tap water with the temperature of about 60-100 ℃) with a certain flow speed to the hollow support rod 13 arranged in the groove body 3, so that the overflow notch 14 at the top of the hollow support rod 13 or the top surface of the support head 17 can keep a liquid level with a certain height, the liquid-phase heat exchange medium 7 entering the groove body 3 can heat air in the inner cavity of the groove body 3, the temperature of the air is close to that of the liquid-phase heat exchange medium 7, the PGA melt blank 2 extruded by the extrusion die head 1 is fed forward to the heat-preservation stretching device, the PGA melt blank 2 enters the groove body 3, and the PGA melt blank 2 can support and limit the hollow support rod 13 (the flowing liquid at the overflow notch 14 at the top of the hollow support rod 13 or the top surface of the support head 17 can support the PGA melt blank 2 in contact with the hollow support rod 13, Limit function) continuously and stably forwards, in the process, the PGA melt blank 2 positioned between two adjacent hollow support rods 13 can be cooled more slowly in the heated air, the PGA melt blank 2 can be fully and longitudinally stretched under the traction action, the melt blank 2 can generate longitudinal orientation crystallization to a greater extent, the PGA melt blank 2 guided out by the heat-preservation stretching device c is continuously and forwards fed to the cooling and shaping device b, the PGA melt blank 2 enters the tank body 3 containing the liquid-phase heat exchange medium 7 (such as tap water) with the temperature of about 5-30 ℃, the PGA melt blank 2 is immersed in the liquid-phase heat exchange medium 7, the flow direction of the liquid-phase heat exchange medium 7 in the tank body 3 is opposite to the feeding direction of the PGA melt blank 2, the PGA melt blank 2 is rapidly cooled and shaped in the liquid-phase heat exchange medium 7, and under the limit guide function of the guide wheel 4 in the limit guide mechanism, and continuously feeding forwards, guiding out by a cooling and shaping device b, drying and cutting to obtain a finished product.

In the process, the liquid-phase heat exchange medium 7 in the groove bodies 3 in the heat-preservation stretching device c and the cooling and shaping device b can select a smaller flow speed, so as to ensure that the PGA melt blank 2 does not disturb to normally advance forwards.

Example 3

Referring to fig. 9, a molding system includes a heat-insulating stretching device c, a heat-insulating crystallizing device a, and a cooling-setting device b, which are sequentially disposed downstream of an extrusion die 1 (see example 1 for structural features of the cooling-setting device b and the heat-insulating crystallizing device a, and see example 2 for structural features of the heat-insulating stretching device c).

The system also comprises a traction mechanism d, a drying mechanism and a cutting mechanism e which are sequentially arranged at the downstream of the cooling and shaping device b, wherein the traction mechanism d can adopt a conventional belt conveyer which is arranged in an up-and-down symmetrical manner, the drying mechanism can adopt a conventional blowing dryer, and the cutting mechanism e can adopt a conventional rotary knife cutting machine.

Taking the preparation of PGA-based straws as an example, the working principle of the system is as follows:

under the normal production state, the external circulation mechanism in the heat-preservation stretching device c leads a liquid-phase heat exchange medium 7 (for example, water with the temperature of about 60-100 ℃) with a certain flow speed to the hollow support rod 13 arranged in the groove body 3, so that the overflow notch 14 at the top of the hollow support rod 13 or the top surface of the support head 17 can keep a liquid level with a certain height, the liquid-phase heat exchange medium 7 entering the groove body 3 can heat air in the inner cavity of the groove body 3, the temperature of the air is close to that of the liquid-phase heat exchange medium 7, the PGA melt blank 2 extruded by the extrusion die head 1 is fed forward to the heat-preservation stretching device, the PGA melt blank 2 enters the groove body 3, and is fed forward continuously and stably through the supporting and limiting functions of the hollow support rod 13 (the flowing liquid at the overflow notch 14 at the top of the hollow support rod 13 or the top surface of the support head 17 can support and limit the PGA melt blank 2 in contact therewith), in the process, the PGA melt blank 2 positioned between two adjacent hollow support rods 13 can be cooled more slowly in the heated air, the PGA melt blank 2 can be fully longitudinally stretched under the traction action, the melt blank 2 can generate longitudinal oriented crystallization to a greater extent, the PGA melt blank 2 guided out by the heat-preservation stretching device c is continuously fed forward to the heat-preservation crystallizing device a, the PGA melt blank 2 enters the tank body 3 containing the liquid-phase heat exchange medium 7 (such as tap water) with the temperature of about 60-100 ℃, the PGA melt blank 2 is immersed in the liquid-phase heat exchange medium 7, the flow direction of the liquid-phase heat exchange medium 7 in the tank body 3 is opposite to the feeding direction of the PGA melt blank 2, the PGA melt blank 2 is relatively slowly cooled in the liquid-phase heat exchange medium 7 with the higher temperature, and in the process, the melt blank 2 can generate crystallization to a certain extent, the PGA melt blank 2 is continuously fed forward under the limiting and guiding action of a guide wheel 4 in a limiting guide mechanism, is guided out by a heat-insulating crystallization device a and is fed forward to a cooling and shaping device b, the PGA melt blank 2 enters a tank body 3 containing a liquid-phase heat exchange medium 7 (such as tap water) with the temperature of about 5-30 ℃, the PGA melt blank 2 is immersed in the liquid-phase heat exchange medium 7, the flow direction of the liquid-phase heat exchange medium 7 in the tank body 3 is opposite to the feeding direction of the PGA melt blank 2, the PGA melt blank 2 is rapidly cooled and shaped in the liquid-phase heat exchange medium 7, is continuously fed forward under the limiting guide action of the guide wheel 4 in the limiting guide mechanism, is guided out by a cooling and shaping device b, and is dried and cut to obtain a finished product.

In the process, the liquid-phase heat exchange medium 7 in the groove bodies 3 in the heat-preservation stretching device c, the heat-preservation crystallizing device a and the cooling and shaping device b can select a smaller flow speed, so as to ensure that the PGA melt blank 2 does not disturb to normally advance forwards.

Application example

In terms of application, the system of examples 1-3 above can be used to manufacture straw articles, and the PGA straws are described in detail below.

When the system of example 1 is used for manufacturing the PGA drinking straw product, the temperature of the liquid-phase heat exchange medium 7 in the tank 3 of the thermal insulation crystallization device a is set to about 60-100 ℃, the temperature of the liquid-phase heat exchange medium 7 in the tank 3 of the cooling and shaping device b is set to about 5-30 ℃, the rate of forward movement of the PGA melt blank 2 under the traction of the traction mechanism d is about 0.5-3m/s, the time of the PGA melt blank 2 passing through the thermal insulation crystallization device a is about 5-10s, and the time of the PGA melt blank 2 passing through the cooling and shaping device b is about 1-2s (it should be noted that the time of the PGA melt blank 2 passing through the thermal insulation crystallization device a refers to the time of the PGA melt blank 2 from a point on the thermal insulation crystallization device a to a point on the PGA melt blank 2 leaving the thermal insulation crystallization device a, and similarly, the time of the PGA melt blank 2 passing through the cooling and shaping device b).

When the system of example 2 is used for manufacturing the PGA drinking straw product, the temperature of the liquid-phase heat exchange medium 7 in the tank 3 of the holding and drawing device c is set to about 60-100 ℃, the temperature of the liquid-phase heat exchange medium 7 in the tank 3 of the cooling and shaping device b is set to about 5-30 ℃, the rate of forward movement of the PGA melt blank 2 under the traction of the traction mechanism d is about 0.5-3m/s, the time of the PGA melt blank 2 passing through the holding and drawing device c is about 3-6s, and the time of the PGA melt blank 2 passing through the cooling and shaping device b is about 1-2s (it should be noted that the time of the PGA melt blank 2 passing through the holding and drawing device c refers to the time of the PGA melt blank 2 from a certain point on the PGA melt blank 2 entering the holding and drawing device c to leaving the holding and drawing device c, and similarly, the time of the PGA melt blank 2 passing through the cooling and shaping device b).

When the system of example 3 is used for manufacturing the PGA drinking straw product, the temperature of the liquid-phase heat exchange medium 7 in the tank 3 of the thermal insulation drawing device c may be set to about 60-100 ℃, the temperature of the liquid-phase heat exchange medium 7 in the tank 3 of the thermal insulation crystallizing device a may be set to about 60-100 ℃, the temperature of the liquid-phase heat exchange medium 7 in the tank 3 of the cooling and shaping device b may be set to about 5-30 ℃, the rate of forward movement of the PGA melt blank 2 under the traction of the traction mechanism d is about 0.5-3m/s, the time of the PGA melt blank 2 passing through the thermal insulation drawing device c is about 1.5-3s, the time of the PGA melt blank passing through the thermal insulation crystallizing device a is about 3-6s, and the time of the PGA melt blank 2 passing through the cooling and shaping device b is about 1-2s (it should be noted that the time of the PGA melt blank 2 passing through the thermal insulation drawing device c means that a certain point on the PGA melt blank 2 is from entering the thermal insulation drawing device c to leaving the thermal insulation drawing device c The same applies to the time for the PGA melt blank 2 to pass through the thermal insulation crystallization device a and the cooling and shaping device b).

The system can be used for processing and preparing straw products, and can also be used for processing and preparing other similar profile products such as pipes, rods or wires.

Specific application examples 1-6 for processing and preparing PGA straw products using the above system are provided in Table 1 below, wherein application examples 1-2 correspond to the system of example 1, application examples 3-4 correspond to the system of example 2, and application examples 5-6 correspond to the system of example 3.

TABLE 1 relevant Process parameters for the preparation of PGA straw articles

Note: the liquid-phase heat exchange medium and the liquid-phase heat exchange medium used in the above application examples are tap water.

In the above application examples 1 to 6, the molten material discharged from the cooling and shaping apparatus was dried and cut to obtain a straw product (about 21.5cm in length, about 7mm in outer diameter and about 0.15mm in wall thickness).

Comparative example:

the comparative example is based on the existing conventional processing equipment (i.e. the downstream of the extrusion die head is sequentially provided with a conventional cooling water tank, an air cooling mechanism, a traction mechanism, a drying mechanism and a cutting mechanism) to prepare the PGA straw product, namely, a PGA pipe blank extruded by the extrusion die head is led into the water tank with the temperature of about 25 ℃ at the speed of 2m/s, the time for the PGA pipe blank to pass through the water tank is about 2s, and the PGA pipe blank is cut after being dried by blowing to prepare the straw product (the length is about 21.5cm, the outer diameter is about 7mm and the wall thickness is about 0.15 mm).

It is to be noted here that the application examples 1 to 6 and the comparative example are different in the downstream equipment of the extrusion die and are otherwise identical.

The straws produced in the above application examples 1 to 6 and comparative examples were evaluated for their respective properties by the following methods:

relative heat resistance：

Taking a cup of hot water with the temperature of about 80 ℃ (small gravels are deposited on the water bottom, the volume of the small gravels is about 1/3 of the volume of the water), extending a suction pipe to be tested into the water bottom, then stirring, grading according to the difficulty degree of stirring, wherein the stirring is easier, which shows that the heat resistance of the suction pipe is better, the suction pipe can still keep better rigidity at high temperature, and the higher the grade is, the full grade is 10;

thickness uniformity：

Measuring the thickness of the cross section of the suction pipe by using a pipe thickness gauge with the precision of 0.01mm, selecting 4 points for each cross section, randomly selecting 10 suction pipes for testing, calculating the variance according to the measured 40 wall thickness values, wherein the smaller the variance is, the better the uniformity of the wall thickness of the suction pipe is, the higher the score is, and the full score is 10 minutes;

puncture performance：

Selecting PE films with the thicknesses of about 0.1mm, 0.15mm and 0.2mm respectively, puncturing the PE films by using the tips of the straws to be tested, scoring according to the difficulty degree of puncturing, and more easily puncturing the PE films, wherein the better the puncturing property of the straws is, the higher the score is, and the full score is 10;

rebound resilience：

Lightly pressing the to-be-tested suction pipe by fingers to enable the to-be-tested suction pipe to deform to a certain degree (note: the deformation degrees of all the suction pipes are basically the same), then immediately loosening the fingers, observing the recovery speed, recovery degree and stress whitening of the pressed part of the suction pipe, wherein the better the comprehensive effect is, the better the rebound resilience of the suction pipe is, the higher the score is, and the full score is 10 minutes;

under load/isostatic deformation：

The method comprises the following steps of flatly placing a suction pipe to be tested on a testing platform, vertically applying the suction pipe with the same pressure (different pressure options are provided, and the pressure resistance of the whole suction pipe to be tested is determined) on the suction pipe through pressing a metal block, observing the deformation degree of the cross section of the suction pipe, wherein the smaller the deformation degree is, the better the rigidity of the suction pipe is, the higher the score is, and the full score is 10 minutes;

bending resistance：

Shearing a suction pipe to be tested into a fixed length, vertically fixing the suction pipe on a clamp, applying a horizontal force to the suction pipe by pushing and pressing a metal block at a position 10cm above a clamp opening, gradually increasing the horizontal force until the suction pipe cannot bear and is bent, recording the stress change and the corresponding pushing and pressing head displacement in the test process, and indicating that the larger the corresponding horizontal thrust when the suction pipe is broken (the sudden depression point of the pushing and pressing force), the larger the anti-breaking thrust of the suction pipe is; the larger the force applied to the same displacement of the pressing head, the higher the bending strength of the pipette, the better the bending resistance, and the higher the score, the full score was 10.

The results of test evaluation of the straws manufactured using examples 1 to 6 and comparative example are shown in table 1 below:

TABLE 1 results of the evaluation of the correlation Properties

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.