Vertical polypropylene infusion bag hanging ring welding method

Abstract

The invention relates to a welding method for a lifting ring of a vertical polypropylene infusion bag. The method comprises the following steps: 1) arranging the lifting ring at a sprue of the polypropylene infusion bag; (2) non-contact heating is conducted on the sprue part, and the sprue is softened; (3) cooling and shaping the pouring gate by using a cold riveting device; and 4) separating the cold riveting device from the sprue to finish welding of the lifting ring. The invention discloses a welding method for a lifting ring of a vertical polypropylene infusion bag, which is characterized in that the lifting ring is fixed by performing non-contact heating and cold riveting on a sprue part, used for fixedly mounting the lifting ring, of the polypropylene infusion bag, so that the production efficiency is improved, and unattractive molding of a sprue riveting part caused by wire drawing is effectively avoided; the energy consumption required by production is large, and generated high-temperature decomposed products pollute the environment.

Description

Technical Field

[0001] The invention relates to a welding method for a polypropylene infusion bag hanging ring, in particular to a welding method for a vertical polypropylene infusion bag hanging ring. Background Art

[0002] Vertical polypropylene infusion bags are commonly used infusion drug packaging bags and are widely used in the packaging of various infusion drugs. Figure 1 As shown, the polypropylene infusion bag blank mainly includes a bag blank body 3, a gate 2 and a hanging ring 4. The production method of the polypropylene infusion bag is to transport the polypropylene infusion bag blank produced by the injection molding machine to the bottle blowing accompanying clamp (the tail of the bag blank faces upward) through the bag blank conveying mechanism, and automatically install the hanging ring on the gate 2 at the tail of the bag blank body 3 through the automatic installation hanging ring mechanism. Figure 2a , 2b As shown, in the prior art, the method for installing the lifting ring of a polypropylene infusion bag is as follows: first, a rotary welding lifting ring mechanism (not shown) is used to install the lifting ring 4 on the tail of the bag blank body 3, and the rotary welding lifting ring mechanism is composed of a plurality of heating tubes and a pressing plate 1; after the heating tube heats the pressing plate 1 to a set temperature, the pressing plate 1 is pressed down to contact the gate 2 at the tail of the bag blank body 3, and the gate 2 is heated and pressed down to form. After forming, the pressing plate 1 rises to the initial position, and the welding forming of the lifting ring of the upright polypropylene infusion bag blank is completed.

[0003] The disadvantages of welding the vertical polypropylene infusion bag welding ring in the above-mentioned way are: after the pressing plate 1 heats and presses the gate 2 to form, a small amount of drawing and high-temperature decomposition products will be generated during the upward reset process. The drawing will cause the surface of the infusion bag to be rough and the molding part to be unsightly; although the high-temperature decomposition products will be discharged from the production workshop through the exhaust system, there is still a risk of contaminating the clean area. The exhaust system will also bring out a lot of heat, which will increase energy consumption in the production process. The emission of high-temperature decomposition products will also cause pollution to the surrounding environment. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a method for welding a vertical polypropylene infusion bag ring; the ring is welded by adopting a non-contact heating and cold riveting process for the gate, which effectively avoids the problems of wire drawing, high temperature decomposition products, environmental pollution, etc. in the prior art during the ring welding process.

[0005] To achieve the above object, the technical solution of the present invention is as follows: A method for welding a hanging ring of an upright polypropylene infusion bag, wherein a gate for fixing the hanging ring is provided on the polypropylene infusion bag, comprising the following steps: 1) Setting the hanging ring at the gate of the set welding position of the polypropylene infusion bag blank; 2) non-contact heating of the gate portion to soften the gate; 3) Using a cold riveting device to cool and shape the gate; 4) The cold riveting device is separated from the gate to complete the welding of the lifting ring.

[0006] Furthermore, the heating device used for non-contact heating of the gate in step 2) is a directional heating device.

[0007] Furthermore, the distance between the end of the directional heating device in step 2) and the top of the gate is 2.2-2.4 mm.

[0008] Furthermore, the heating temperature in step 2) is 130-140°C.

[0009] Furthermore, the cold riveting device in step 3) is a cold riveting plate, and a working end thereof in contact with the gate has a recess.

[0010] Furthermore, the cooling temperature in step 3) is 60-80°C.

[0011] Furthermore, the cooling temperature in step 3) is 70-80°C.

[0012] Furthermore, the cooling time in step 3) is 1-5 seconds.

[0013] Furthermore, the cooling time in step 3) is 2-3 seconds.

[0014] The present invention discloses a method for welding a vertical polypropylene infusion bag ring. The method performs non-contact directional heating on the gate part of the polypropylene infusion bag for fixing the ring and fixes the ring by cold riveting. The use of non-contact directional heating can avoid the uneven heating of the bottom of the polypropylene infusion bag blank caused by non-directional heating, and even the deformation of the ring due to heating, resulting in a low qualified rate of bag making; and can effectively reduce the large amount of smoke and dust generated by non-directional heating, which pollutes the environment. After directional heating, cold riveting is performed directly on the fixture without transfer, and the cold riveting time is long, which can avoid the shortcomings of the prior art such as the unsightly molding of the gate riveted part caused by wire drawing caused by the cooling step, the large energy consumption required for production, the pollution of the environment caused by the generation of high-temperature decomposition products, and the low qualified rate of finished products. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Polypropylene infusion bag blank structure diagram; Figure 2a A schematic diagram of the heating steps in the welding method of the hanging ring of a polypropylene infusion bag blank in the prior art; Figure 2bSchematic diagram of the forming steps in the welding method of the hanging ring of the polypropylene infusion bag blank in the prior art; Figure 3a It is a schematic diagram of the heating step in the welding method of the polypropylene infusion bag blank hanging ring of the present invention; Figure 3b This is a schematic diagram of the state of the polypropylene infusion bag blank after the gate is heated and softened in the present invention; Figure 4a It is a schematic diagram of the cooling step in the welding method of the polypropylene infusion bag blank hanging ring of the present invention; Figure 4b It is a schematic diagram of the gate molding of the polypropylene infusion bag blank in the present invention. DETAILED DESCRIPTION

[0016] like Figure 1 As shown, the polypropylene infusion bag blank involved in the present invention comprises: a bag blank body 3, a gate 2 and a hanging ring 4 arranged on the gate 2. Usually, the hanging ring 4 is arranged at the tail end of the bag blank body 3, and is used to hang the polypropylene infusion bag on the infusion stand during infusion.

[0017] like Figure 3a , 3b As shown, the device for heating the gate 2 in the present invention is a non-contact heating device, preferably a directional heating device 5. In this field, a directional heating lamp is usually used, but other directional heating devices can also be selected according to actual conditions.

[0018] like Figure 4a , 4b As shown, a cold riveting forming device is used to cool and shape the softened gate 2, and a cold riveting plate 6 is usually used. The working end of the cold riveting forming device in contact with the gate 2 has a depression, which is used to shape the top of the gate. The shape of the depression can be set as needed, and is usually Figure 4a , 4b The inwardly concave arc shown in the figure has a maximum concave depth of 1-3 mm, preferably 1 mm.

[0019] like Figure 3a , 3bAs shown in , 4a and 4b, the welding method of the hanging ring of the polypropylene infusion bag blank in the present invention mainly includes: setting the hanging ring at the gate of the polypropylene infusion bag; the position is the predetermined installation position of the hanging ring. Subsequently, a non-contact directional heating device 5 is used to non-contact heat the gate 2 part and soften the gate. Preferably, the directional heating device 5 is arranged above the gate 2, with a distance of 2.2-2.4mm from the gate 2, and the heating temperature is 130-150°C, preferably 130-140°C. Next, the cold riveting plate 6 is used to cool and shape the gate 2, specifically: the cold riveting plate 6 is used to press down the gate 2, the gate 2 is cooled and the shaping of the gate 2 is completed at the same time. The cooling temperature of the cold riveting plate 6 is 70-80 degrees; the cooling time is 1-4 seconds, preferably 2 seconds. Finally, the cold riveting plate is separated from the gate to complete the welding of the hanging ring. It should be noted that: after the gate 2 is heated in a directional manner, the method performs cold riveting directly on the fixture without transfer. The heating distance of non-contact heating is related to the heating temperature. As the distance increases, the power output of the required directional heating lamp is higher. If the distance is too large, when the maximum output power of the directional heating lamp is exceeded, the heat of the heating gate will be insufficient and the gate cannot be completely softened. When the heating lamp is too close to the gate, the gate may be ignited or smoke may be generated, causing pollution to the production environment.

Claims

1. A method for welding a hanging ring of an upright polypropylene infusion bag, wherein the polypropylene infusion bag is provided with a gate for fixing the hanging ring, comprising the following steps: 1) Setting the hanging ring at the gate of the set welding position of the polypropylene infusion bag blank; 2) non-contact heating of the gate portion to soften the gate; 3) Using a cold riveting device to cool and shape the gate; 4) The cold riveting device is separated from the gate to complete the welding of the lifting ring.

2. The method for welding the vertical polypropylene infusion bag ring according to claim 1, characterized in that: The heating device used for non-contact heating of the gate in the step 2) is a directional heating device.

3. The method for welding the vertical polypropylene infusion bag ring according to claim 2, characterized in that: The distance between the end of the directional heating device in step 2) and the top of the gate is 2.2-2.4 mm.

4. The method for welding the vertical polypropylene infusion bag ring according to claim 1, characterized in that: The heating temperature in step 2) is 130-140°C.

5. The method for welding the vertical polypropylene infusion bag ring according to claim 4, characterized in that: The cold riveting device in step 3) is a cold riveting plate, and a working end thereof in contact with the gate has a recess.

6. The method for welding the vertical polypropylene infusion bag ring according to claim 1, characterized in that: The cooling temperature in step 3) is 60-80°C.

7. The method for welding the vertical polypropylene infusion bag ring according to claim 1, characterized in that: The cooling temperature in step 3) is 70-80°C.

8. The method for welding the vertical polypropylene infusion bag ring according to claim 1, characterized in that: The cooling time in step 3) is 1-5 seconds.

9. The method for welding the vertical polypropylene infusion bag ring according to claim 1, characterized in that: The cooling time in step 3) is 2-3 seconds.

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