Research on Structural Optimization Design of Plastic Packaging Containers

Among the numerous packaging containers, plastic containers are the most widely used type of packaging containers, and they are widely used in pharmaceutical packaging. The reason why plastic packaging containers are widely used is that they have a series of advantages such as light weight, durability, good barrier property, Easy molding, variable shape, and low cost, and have a very strong competitiveness in the packaging industry.

The ability to develop and manufacture competitive products is the key to business survival and development. The birth of competitive products starts with the optimal design of the product.

The first point of optimization design : It is necessary to deeply understand that plastic packaging containers should have the following functions.

1) The container must have the function of protecting the contents. The container can be protected against moisture, water, dust, and corrosion. Blocking of dust, water, and other liquid substances from outside; Preventing contamination and corrosion of packaging materials; Preventing penetration of UV rays, adapting to changes in ambient temperature, and protecting packages from sunlight and UV rays.

2) The container must have the function to withstand external forces, it can adapt to a variety of transport modes and warehouse storage, protect the contents will not be damaged.

3) The container enables the product to have a display function. The container can display the display function of the product through beautiful appearance, vivid colors, smooth surface and transparency. Attract customers and stimulate customers' desire to buy.

For example, bottles of different colors can clearly indicate the series, type, or model of the product. The transparent container can show the color and quality of the contents. The translucent container partially displays or conceals the contents. The opaque container can be canned. Various color items. The surface of the container is printed so that the printed information can be passed directly to the consumer.

The container should have easy-to-use functions. The opening of the container should be designed to be easy to open, and it can be opened and closed multiple times. It is convenient to dump the contents. Can not cause spatter injury. When designing a product, additional functions can be added to the sealer: eg, anti-counterfeit, anti-theft, anti-blocking, spray, etc.

The second point of optimization design is that at the beginning of product design, designers must conduct market research, specify customer requirements, learn the longevity of similar products in the industry, be familiar with the molding equipment and production technology level of the company, and establish the design products. Preliminary concept.

The third point of optimization design: According to various technical materials, my own design experience and imagination, material formula, molding process, unconventional. The courage to innovate and design product drawings, product renderings or models to form a preliminary design. Design considerations include: product stiffness and shape design, printed surface design, edge and wipe design, bottle design, and bottom design.

The container should have sufficient rigidity and aesthetic appearance. The most common shapes of plastic containers are round, square, oval and so on. From the use point of view, they have their own advantages and disadvantages. The circular container has a high stiffness, but its appearance is not beautiful. The shape of the square container is beautiful, but it is not easy to control the thickness of the container evenly during molding. Oval containers have higher rigidity, but the manufacturing cost of the mold is higher. Therefore, in order to ensure the rigidity of the container, in addition to selecting a material with high rigidity, the shape design of the container is also required to enhance the rigidity and load bearing strength of the container.

1) Change the surface shape of the container. For example, if the container is relatively thin in the Middle, increase the circumferential groove or rib on the surface of the container to improve the rigidity and bending resistance of the container. Longitudinal grooves or ribs eliminate the tendency of containers to deflect, sag, or deform under long-term loading.

2) In the design of extruded containers, if the material is high-density polyethylene or polypropylene, the cross-section of the container should be rectangular or elliptical. For the material is low-density polyethylene or other flexible plastic container, its cross-section is in a circle Shape is good. This facilitates the extrusion of the contents from the container.

3) In order to make the container wall thickness uniform, it should be noted that the container's shape must have symmetry. Minimize extreme stretch points and locations. All transitions use circular transitions.

4) The printed surface of the container is the most concentrated part of the consumer's attention. The printing surface should be flat and continuous; if the container contains handles, grooves, ribs, etc., the design should be careful not to cause inconvenience to the printing operation.

5) When the surface of the container is labelled, the surface of the label should be flat. A "sash" can be designed on the surface of the container to allow the label to be accurately positioned without movement.

6) At the time of blow molding, the place where the parison is inflated first is always the area that tends to be hardened first. Therefore, the wall thickness of this part is also larger. The edges and corners are the parts where the parison is inflated last, and the wall thickness is smaller. Therefore, the edges of the container and the rounded corners should be rounded.

7) Since most plastics have notch sensitivities, the container is susceptible to cracks and cracks at sharp corners, at the root of the mouth thread, at the neck, etc., so these locations should be rounded. For the transfer of a rectangular container, a large part of the load of the container needs to be supported. Therefore, the wall thickness at that part is locally increased, and it is also advantageous to improve the rigidity and load-bearing strength of the container. The plastic parts used with the container mouth are mainly caps and sealers. The design of the container mouth should focus on examination; how to make the mouth of the container fit the bottom of the container better with the cap and the sealer is the weak part of the mechanical performance of the container. Therefore, the bottom of the container is generally designed to be concave; at the corners of the container, and at the concave, large arc oversizing is performed. In order to facilitate the stacking of containers and increase the stacking stability of the containers, the bottom of the container should be designed with internal grooves.

The fourth point of optimizing the design is to extensively listen to everyone's comments on the preliminary design, and make repeated modifications after repeated modifications. Including the product after the trial change, the customer's final modification, until the final confirmation of the type. Plastics have a variety of molding methods, and they can all be used to make plastic containers of different shapes and purposes. Among them, blow molding is one of the most widely used and most productive methods. Extrusion blow molding is the earliest and most used process for producing plastic blow molded containers. Its processes include the extrusion of plastics, the preparation of parisons, the inflation and cooling of parisons, the opening of molds and the removal of products. Products that have been demolded, according to the design requirements, need to be processed and tested. Stretch blow molding, also known as biaxial orientation blow molding. It is to make thermoplastics by extrusion or injection process into parisons, the tempering process, so that the parison is in a high elastic state of polymer, the first axial mechanical stretching, and then pulled axially with compressed Air Stretching, a method of forming a biaxial container. Stretch-orientated containers have better physical and mechanical properties and economy than non-stretch oriented containers. Stretch-blow containers have a growing trend. Among the various biaxial stretch blow-molded containers, PET bottles are the most used; PP stretch blow-molded bottles are the fastest growing in the United States; hot-fillable, reusable PET bottles are in the beverage market. rise rapidly. Guangzhou Tech-Long Packaging Machinery Co., Ltd. recently developed the first fully-automatic rotary high-speed PET bottle blowing machine in China with a production speed of 8600 per hour. The new blow molding machine is fully automatic in the process from the top blank to the bottle, unqualified product detection and troubleshooting in the whole operation process. The technical level is leading domestically and fills the domestic blank injection blow molding. It is composed of injection and blow molding. A blow molding method. The injection molding process was used to make parisons that were used in the 1950s. It was used as an accessory process for injection molding. However, due to lack of plastic varieties, mold manufacturing technology, market, and other reasons, it failed to promote the application. Until the 1980s, the development of modern plastic molding technology only expanded in the field of plastic container manufacturing. In the future, with the miniaturization of households, the security of packaging materials, and the growth of supermarkets, the demand for Small bottles will inevitably continue to grow. At the same time, the plastics industry will further reduce the cost of molds, use long blow molding, use new plastic products and models, and the emergence of a new generation of blow molding machines, injection blow containers will have greater development. The rapid development of China's pharmaceutical packaging industry, its increasing demand for plastic packaging containers, blow molding equipment is also growing. As the injection blow molding equipment is in operation, the bottle mouth is first injected, the accuracy of the bottle mouth is maintained, and then the bottle body is blown. Therefore, the gas in the container can be prevented from evaporating and the outside air can penetrate into the bottle. This ensures a very close performance between the bottle mouth and the bottle cap. Although China's plastic injection molding hollow containers can now be produced in small quantities, the accuracy and performance of the equipment itself is not as good as foreign equipment.

At present, the production of this kind of equipment needs to increase the level of precision. The development direction of China's injection machine for a period of time in the future is:

1) Hydraulic control system with high sensitivity, high reproducibility and stability.

2) It has fine-tuned control performance, excellent and reliable operation, and easy-to-use electronic control system.

3) It has an excellent plasticizing device that can fully plasticize the plastic under uniform temperature and can measure correctly.

4) High-speed high-pressure injection of parisons, which minimizes the shrinkage of the container during blow molding.

5) Precision injection molds. Development of blow mold design and manufacturing technology.

With the rapid development of China's pharmaceutical industry, the pharmaceutical packaging industry has begun to move forward and become an important part of the development of China's pharmaceutical industry. At present, the overall technical level of China's pharmaceutical packaging industry is not high, lagging far behind the developed countries. In the developed countries, pharmaceutical packaging accounts for 30% of the drug value, but China is still less than 10%. In the next five years, it will still be a critical period for the rapid development of China's pharmaceutical industry, and it is tempting for huge business opportunities. Among the many factors of commodity competition in the international market, product quality, price, and packaging design are the three main factors. As a foreign marketing expert said: “In the path to the market, packaging design is the most important one, packaging plays a role in the overall image of the product as much as advertising.” So we must seize this opportunity for development. With courage to innovate and innovation, the product is novel, bizarre and full of modern awareness.