Essentials of optimal design of plastic bottles fo

2022-08-09
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Optimization design essentials of pharmaceutical plastic bottles

among many packaging plastic bottles, plastic bottles are the most widely used type of packaging containers, which are widely used in pharmaceutical packaging. The reason why plastic bottles are widely used is that they have a series of advantages, such as light weight, durability, good barrier, easy molding, variable shape, low cost and so on. They are very competitive in the packaging industry. With the rapid development of China's pharmaceutical industry, the pharmaceutical packaging industry has begun to step on the front stage 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, far behind developed countries. In developed countries, pharmaceutical packaging accounts for 30% of the value of drugs, while China is less than 10%. The next five years are still a critical period for the rapid development of China's pharmaceutical industry, which contains attractive and huge business opportunities. Among the many factors of commodity competition in the international market, commodity quality, price and packaging design are the three main factors. As a foreign marketing expert said: in the road to the market, packaging design is the most important one, and packaging plays no less important role in the overall image of goods than advertising. Therefore, we must seize this great opportunity for development, be brave in innovation and innovation, so that products are novel, strange and full of modern consciousness

whether they can develop and manufacture competitive products is the key to the survival and development of enterprises. The birth of competitive products begins with the optimal design of products

the first point of optimal design: we must deeply understand that plastic bottles should have the following functions

1) the plastic bottle must have the function of protecting the contents. The plastic bottle can be moisture-proof, waterproof, dustproof and corrosion-proof. Barrier effect on external dust, water and other liquid substances; Prevent the package from being polluted and corroded; Prevent ultraviolet penetration, adapt to environmental temperature changes, and protect the packaging from sunlight and ultraviolet damage

2) the plastic bottle must have the function of withstanding external forces. It can adapt to a variety of transportation methods and warehouse storage methods to protect the contents from damage

3) plastic bottles enable commodities to have the display function. Plastic bottles can show the display function of commodities through beautiful shapes, bright colors, smooth surfaces and transparency. Attract customers and stimulate their desire to buy

for example, bottles of different colors can clearly indicate the series, type or model of goods, and transparent plastic bottles can show the purity of the color and quality of the contents; Translucent plastic bottles partially display or hide content items; Opaque plastic bottles can contain items of various colors. The surface printing of plastic bottles can directly transmit printing information to consumers

the plastic bottle should have the function of convenient use. The bottle mouth of the plastic bottle should be designed to be convenient to open, and can be opened and closed for many times. It should be convenient to dump the contents. No splashing injury. When designing products, other functions can be added to the sealer, such as anti-counterfeiting, anti-theft, anti blocking, spray, etc

the second point of optimal design: at the beginning of product design, designers must conduct market research, clarify customer requirements, draw on the strengths of similar products in the same industry, be familiar with the molding equipment and production technology level of the enterprise, and establish the preliminary concept of the designed products

the third point of optimal design is to innovate according to various technical data, my design experience and imagination, material formula, molding process. Have the courage to innovate and design product drawings, product renderings or models to form a preliminary design. The design should focus on: product stiffness and shape design, printing surface design, edge and corner design, bottle mouth design, bottom design, etc

plastic bottles should have sufficient rigidity and beautiful appearance. The most common shapes of plastic bottles are round, square, oval, etc. From the perspective of use, they have their own advantages and disadvantages. The round plastic bottle has high rigidity, but its shape is not beautiful. The square plastic bottle has a beautiful appearance, but it is difficult to control the uniform wall thickness of the plastic bottle during molding. Oval plastic bottle has high rigidity, but the manufacturing cost of the mold is high. Therefore, in order to ensure the rigidity of plastic bottles, in addition to selecting materials with high rigidity, we should also enhance the rigidity and load-bearing strength of plastic bottles through the shape design of plastic bottles

1) changing the surface shape of the plastic bottle, such as the middle of the plastic bottle is relatively thinner, and increasing the circumferential grooves or ribs on the surface of the plastic bottle can improve the rigidity and bending resistance of the plastic bottle. Longitudinal grooves or stiffeners can eliminate the offset, sag or deformation of plastic bottles under long-term load

2) when designing extruded plastic bottles, if the material is high-density, 1. The instruments and equipment should be placed on the leveled road surface (preferably on the concrete floor). There should be no shaking polyethylene or polypropylene for correction. The cross section of the plastic bottle should be rectangular or oval. For low-density polyethylene or other flexible plastic bottles, the cross section should be circular. This facilitates the extrusion of contents from the plastic bottle

3) in order to make the wall thickness of the plastic bottle uniform, attention should be paid to the symmetry of the shape of the plastic bottle. Minimize extreme stretching points and locations. Arc transition is adopted at all transitions

4) the printing surface of plastic bottles is the most concentrated part of consumers' attention. The printing surface should be flat and continuous; If the plastic bottle contains handles, grooves, stiffeners and other structures, attention should be paid to not causing inconvenience to the printing operation during the design

5) when labeling is used on the surface of plastic bottles, the labeling surface should be flat. A frame can be designed on the surface of the plastic bottle, so that the label can be accurately positioned without moving

6) during blow molding, the first contact part of parison expansion always tends to harden first. Therefore, the wall thickness of this part is also larger. The edge and corner are the last contact part of parison inflation, and the wall thickness of this part is small. Therefore, the edges and corners of plastic bottles should be designed into rounded corners

7) due to the notch sensitivity of most plastics, plastic bottles are prone to cracks and cracks at sharp corners, the root of mouth threads, neck and other parts, so these parts should be designed as rounded corners. For the transfer part of the rectangular plastic bottle, it is necessary to support most of the load of the plastic bottle, so locally increasing the wall thickness of the part is also conducive to improving the stiffness and load-bearing strength of the plastic bottle. The plastic parts used with the plastic bottle mouth are mainly caps and sealers. The design of plastic bottle mouth should focus on examination; Considering how to make the plastic bottle mouth better match with the cap and sealer, the bottom of the plastic bottle is the weak part of the mechanical properties of the plastic bottle. Therefore, the bottom of the plastic bottle is generally designed to be concave; The corners and inner recesses of plastic bottles are subject to large arc transition. In order to facilitate the stacking of plastic bottles and increase the stacking stability of plastic bottles, inner grooves should be designed at the bottom of plastic bottles

the fourth point of optimal design is to widely listen to everyone's review opinions on the preliminary design, and after many modifications, repeated modifications. Including the modification of the product after the mold test, the final modification of the customer, until the final finalization and confirmation. There are many molding methods for plastics, all of which can be used to make plastic bottles with different shapes and uses. Among them, blow molding is the most widely used and most productive molding method. Extrusion blow molding is the earliest and most used process method for manufacturing plastic blow molding plastic bottles. Its technology includes plastic extrusion, parison preparation, parison expansion and cooling, mold opening and product removal. According to the design requirements, the demoulded products need to be processed and tested. Stretch blow molding is also called biaxial oriented blow molding. It is a molding method that thermoplastic is made into parison by extrusion or injection process. After temperature adjustment, the parison is in the high elastic state of polymer. Axial mechanical stretching is carried out first, and then compressed air is used for axial stretching to make biaxial plastic bottles. The stretch oriented plastic bottle has better physical and mechanical properties and economy than the non stretch oriented plastic bottle. Stretch blow molded plastic bottles have a growing trend. Among all kinds of bi-directional stretch blow molding plastic bottles, PET bottles are the most used; PP stretch blow molding bottle has the fastest development speed in the United States; Hot canned and reusable PET bottles are rising rapidly in the beverage market. Guangzhou dayilong 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/hour. In the whole operation process of this new type of bottle blowing machine, from blank loading to bottle discharge, unqualified product detection and troubleshooting, we should first confirm the experimental force of the tested materials and select different universal experimental machines as the full-automatic process. The technical level is leading in China and fills the gap in China. Injection blow molding is a blow molding method composed of injection and blow molding. The use of injection technology to make parisons was used in the 1950s, and it was used as an auxiliary process of injection molding. However, due to the lack of plastic varieties, mold vacuum exhaust device manufacturing technology, market and other reasons, it has not been popularized and applied. It was not until the 1980s that the development of modern plastic molding technology expanded in the field of plastic bottle manufacturing. In the future, with the miniaturization of families, the safety of packaging materials and the growth of supermarkets, the demand for small plastic bottles is bound to continue to grow. At the same time, the plastic products industry will further reduce the mold cost, adopt long blow molding, select new plastic products and models, the emergence of a new generation of blow molding machines, injection blow molding plastic bottles will have greater development. With the rapid development of China's pharmaceutical packaging industry, the demand for plastic packaging plastic bottles is increasing, and blow molding equipment is also growing. During the operation of the injection blow molding equipment, the bottle mouth is first injected to ensure the accuracy of the bottle mouth, and then the bottle body is blow molded. Therefore, it can prevent the gas in the plastic bottle from volatilizing and the external gas from penetrating into the bottle. It ensures a good close performance between the bottle mouth and the bottle cap. Although the equipment of plastic injection molding hollow plastic bottles in China can be produced in a small amount, the accuracy and performance of the equipment itself are inferior to those of foreign equipment

at present, efforts should be made to improve the precision of the production of such equipment. In the future, the development direction of injection and blowing machines in China is: 1) hydraulic control system with high sensitivity, high reproducibility and stability

2) it has fine-tuning control performance, excellent and reliable operation, and easy-to-use electronic control system

3) it has an excellent plasticizing device, which can fully plasticize the plastic at a uniform temperature and can be measured correctly

4) it can carry out high-speed high-pressure injection molding, and minimize the shrinkage of plastic bottles during blow molding

5) precision injection mold. Develop the design and manufacturing technology of blow mold

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