Anti pollution improvement of the mouth of the hot

Anti pollution improvement of PET beverage bottle mouth

many consumers have experienced such a situation: after opening the PET bottle of beverage, they found that the bottle mouth had black mildew, which was really disgusting. In the study of how to improve bottle mouth pollution, this paper introduces the improvement scheme of obtaining the national new utility patent

the main material of the existing plastic beverage bottles with screw threads and repeatable seals is pet, the bottle cap is mainly HDPE, and the sealing position is on the top of the bottle mouth. According to the different pressure in the bottle, the sealing forms of gasket, sealing ring, sealing inner plug or the combination of sealing ring and sealing inner plug are adopted respectively, and the difference of these sealing forms only plays a role in improving the sealing performance. The beverage bottle shown in Figure 1 adopts the sealing form of combining the sealing ring with the sealing inner plug

since the sealing position is only at the bottle mouth, the screw thread part is not sealed. During the process from production to consumer drinking, many factors will pollute the screw thread part of the bottle mouth. For example, during the filling process of nutritious beverages, beverages splash onto the screw thread part of the bottle mouth. Under the action of bacteria and air, the screw thread of the bottle mouth appears mildew and accumulation of color spots; Or the poor environment during transportation and storage leads to the pollution of the original clean bottle mouth thread, such as the long-term storage of beverages in ice water when they are sold

many consumers will find dirt at the screw thread of the bottle mouth after opening the bottle cap. Because the bottle cap has been opened, the effect of complaint is limited, so they have to admit bad luck. From the perspective of drinking habits, most consumers don't use straw when drinking plastic bottled drinks. They use the mouth to directly contain the mouth of the bottle, and the pollutants at the thread will enter the body with it. This phenomenon is particularly prominent in children

in fact, many beverage manufacturers are facing this problem and are also taking various methods to solve it, such as controlling the filling volume, reducing the vibration from filling to capping transmission, cleaning the bottle mouth before capping, etc., but this problem still occurs from time to time, and the current methods can not fundamentally solve it. For example, the full mouth liquid level and overflow required for filling prepared by blowing at high temperature are a contradiction. Sometimes, this kind of defective products even exceed 1%. Manufacturers often recycle products internally because of this problem. In addition, it is difficult to control the pollution in the process of transportation and sales. Finally, many products flow to consumers, causing complaints and seriously affecting the reputation of products

from the above defect cause analysis, the main problem is that the screw thread part of the bottle mouth is not sealed. From the food packaging on the market, there are already some designs to protect the parts that consumers can directly contact, such as the rubber cover on Babao porridge, but these packaging are added, the sealing effect is general, and the cost increases a lot. There is no such protective packaging in plastic beverage bottles. Is there a simple and inexpensive package? We propose a practical and feasible method

from the perspective of sealing principle, there are mainly two kinds of sealing of plastic beverage bottles mentioned above, one is the top sealing gasket in the bottle cap, which can be formed once or added after (two-piece cap), and the other is the sealing inner plug of the bottle mouth. The sealing gasket acts as a seal against the extrusion deformation of the sealing gasket by the top of the bottle mouth; The inner plug is sealed by the interference fit between its outer diameter and the inner diameter of the bottle mouth. Due to different principles, the sealed bottle cap can withstand large bottle pressure. At present, it is used in many kinds of plastic beverage bottle packaging. The inner cork cap is relatively used in beverage varieties with no or less bottle pressure. For example, at present, the sealing performance of most hot filled beverages is related to the matching of the outer diameter of the inner cork with the inner diameter of the bottle mouth and the inner cork material

from the perspective of production process, the inner corking process is simple, the cost is low, and the sealing change of re tightening is less, so it is widely used in non carbonated beverages. From its sealing principle, its sealing performance has nothing to do with the final tightening torque of the bottle cap. The final tightening torque required for the actual production of the bottle cap only prevents the accidental loosening of the bottle cap. Therefore, we can obtain the required bottle mouth thread seal by improving the inner plug seal as shown in Figure 2

the two sealing principles mentioned above are used in this structure. There is a sealing boss under the male thread of the bottle mouth of the beverage bottle, the inner wall of the bottle cap forms a contact surface that coincides with the sealing boss, and there is an air tight sealing ring at the contact surface, which can be integrated with the bottle cap for injection molding (compression molding) or as a movable sealing gasket. Before tightening the bottle cap, the inner plug is pressed into the bottle mouth to seal the drink. After tightening, the thread is compressed by the gas seal ring to realize the isolation between the drink and the outside world. In this structure, the structure and position of the anti-theft ring have not changed. Since the reliability of the two sealing principles has long been confirmed, the sealing reliability of this structure is also beyond doubt. The specific size design of bottle caps and bottles, especially the sealing parts, can be designed according to the existing bottle caps and bottles. The sealing performance of the new price rise structure will not be lower than that of the current structure

we simulated the actual production and storage conditions by making samples of the new structure bottle mouth (87 ℃ hot water to clean the cap and bottle thread, fill 87 ℃ 10% orange juice beverage, tighten the torque about 12lbs, the thread is contaminated with the beverage, store in the dusty air at room temperature and store in the water at room temperature for 3 months). We found no problems mentioned at the beginning of this article at the thread. At present, some inner plug bottle caps are designed with air tight sealing rings on the inner top, as shown in Figure 3. The position e between the inner plug and the air tight sealing ring is just like the thread position in the new structure we designed. We have never found mold and color spots in a large number of samples collected in different markets

from the application point of view, this kind of bottle and cap can also solve some problems we encounter when using the current bottle and cap. For example, the current hot filling products with internal stoppers will have smaller loosening torque than screwing torque after cooling, because the size of all parts of the bottle, including efficient production, will become smaller after cooling, resulting in smaller tensile prestress of the cap thread and cap top. During production, we have to increase the torque of the screw cap. For example, to achieve the loosening torque of 12lbs, the screw in torque must reach 28lbs or above. This situation requires high equipment requirements and is difficult to control. The bottleneck holder is very easy to produce wire scraping, which affects the appearance quality. The tightening and unscrewing force of the new structure depends on the compressive stress from the screw thread of the bottle cap to the sealing gas ring. The reduction of the size of the bottle after cooling will lead to the increase of the original compressive stress, that is, to achieve the required unscrewing torque, the tightening torque will be much less than the original, the requirements of the capping machine will be reduced accordingly, the wire scraping problem will be reduced, and the appearance quality will be more guaranteed

from the production process of bottle caps and bottles, the realization of this new structure is the same as that of current bottle caps and bottles. Only from the technical point of view, there is no difficulty in adopting this packaging structure. The production of bottle caps and bottles only needs to replace new molds, and the conversion of bottle washing, filling, capping and other equipment can be realized with a little change. As the weight of new bottle caps and bottles has increased, beverages can help protect the safety of our operators who are exposed to the risks of toxic chemicals and deflagration. This low profit industry will be more sensitive to the increased cost of digesting this part. However, the increase of this part of the cost is insignificant compared with the damage to the health of consumers and the image of manufacturers. Once this new packaging is introduced to the market, consumers will understand the defects of the current plastic beverage bottle packaging and gain widespread recognition. This new packaging will quickly replace the old packaging. Market demand is the eternal truth

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