It is done by a technique called the Blow molding technique. It is a technique in which the plastics are melted and are extruded into a hollow tube. The pressure is exerted to form them into the shape of the container using the pp bottle-making machines. It has been famous for years as it is a technique used worldwide to produce containers in the form of these plastic bottles made up of fantastic finishes at very affordable prices. This method is also famous because it provides the most efficient and the most cost-effective way of producing high volumes of containers for packaging. Why Use Blow Molding? Various factors describe why blow molding had been used so much. Some of these factors are: •Higher Rates Of Production These Blow molding machines have a faster cycle compared to other manufacturing processes. •Easy Molding Of Complex Parts It is a helpful process when it is about handling complex and challenging shapes; even if they are asymmetrical and irregular, it is famous for handling them well. •Cost-Effective Method This production method is comparatively cheaper in the long run than other production methods as it works more efficiently and effectively, playing a good role in the production process. Types Of Blow Molding Methods To Select From Although the general purpose of these blow molding machines is to create hollow objects, like bottles or packaging, by applying pressure that forces the material into a mold cavity, which gives the object a hollow shape. If one plans to use the method of blow molding, one must be familiar with the types of blow molding and what they are used for. The main and common types of blow molding processes are known as: Extrusion Blow Molding (EBM) In this process, the resin is heated and extruded to form parison, a vertical tube-like piece of plastic that allows compressed air to pass through. The two-part mold is used and closes at the parison at both ends. As soon as the mold is sealed, the blow pin is inserted into the neck of the bottle, and the air is blown into it. The pressure of the air causes the parison to take the shape of the mold. Including the threads in the neck portion of the mold. Mold is cooled, and the parison's bottom is cut, letting the mold open. The bottom of the parison is cut, and the bottle is placed over the conveyer belt. This process is used to manufacture •large-size, High-Density Polyethylene (HDPE) •Low-Density Polyethylene (LDPE) •Polypropylene (PP) bottles with large necks Compression Blow Molding (CBM) It is a special kind of extrusion molding in which the blow pin blows air into the parison, so the plastic takes the shape of the bottle; it also uses physical pressure to shape the neck area of the bottle. It is used in manufacturing bottles made with HDPE, LDPE, and PP resin and can quickly achieve critical neck dimensions. Injection Blow Molding (IBM) In this molding process, the heated resin is injected into the mold using a screw. This injected plastic is molded into the shape of mold then the air is used to blow the shape into the mold. The mold is allowed to cool down. The bottle is placed over the conveyor belt once ejected from the mold. They are used in the production of HDPE, LDPE, and PP bottles with a small to medium blowup ratio. Injection Stretch Blow Molding (ISBM) In this process, the resin is heated and is injected into the machine using a long screw. This injected plastic is then molded into the shape.
Blow molding refers to a molding procedure that the production industry employs to manufacture hollow objects composed of plastic. Selecting the appropriate plastic material for any blow molding process can be challenging. Strength, flexibility, density, cost, and more factors help decide which plastic material is suitable for blow molding. The blow molding capabilities expand to vast and small parts using multiple or single molds, including blow pin and air needle models. The exact blow molding techniques employed for a particular project depend on the design's desired physical attributes and complexity. Here is an outline of the drawbacks, benefits, and characteristics of plastic materials used in blow molding. High-density Polyethylene (HDPE) High-density Polyethylene is the first-ranked plastic in the world and the most frequently blow-molded plastic resin. This is because of its desirable physical qualities, high strength-to-density ratio, temperature resistance, and chemical resistance. High-density Polyethylene is employed in an extensive range of products, including consumer liquid bottles such as motor oil and shampoo, industrial drums, carrying cases, play structures, and coolers. It is molder-friendly, easily colored, chemically inert, and easily colored. The Food and Drug Administration has approved high-density Polyethylene, the safest plastic. A PP bottle-making machine helps consumer bottle manufacturers manufacture consumer liquid bottles with blow-molded high-density Polyethylene. Low-Density Polyethylene Versions of low-density Polyethylene encompass ethyl-vinyl-acetate and linear-low. Manufacturers employ low-density Polyethylene for softer items that require a high degree of flexibility or stress crack resistance. Usually, the higher the ethyl-vinyl-acetate content, the weaker the molded component is. Typical applications of low-density Polyethylene encompass boat fenders, traffic channelizers, and squeeze bottles. Low-density Polyethylene is also easily colored, translucent, chemically inert, and mold-friendly. Polypropylene Polypropylene is the second-ranked plastic in the world- it's a very famous injection molding material. Polypropylene is like high-density Polyethylene, but its slightly lower and stiffer density benefits. Manufacturers commonly use polypropylene in elevated temperate uses like medical components and dishwater tubes that need autoclave sterilization. It is molder-friendly, quickly colored, and translucent. Polyvinyl Chloride(PVC) Even though polyvinyl chloride is the third-ranked plastic of the world, Polyvinyl chloride has been intensely examined for utilizing lead and cadmium as stabilizers. It releases hydrochloric acids while processing and releases remaining vinyl chloride monomers following molding(most of these problems have been decreased). Polyvinyl chloride is translucent. It comes in soft and rigid forms- the soft material. Manufacturers usually use the soft version of polyvinyl chloride in blow molding. Typical use includes traffic cones, bellows, and delicate medical components. Acrylonitrile Butadiene Styrene (ABS) Acrylonitrile Butadiene Styrene is comparatively hard plastic. This ABS plastic is employed for injection molding football helmets. Blow molding standard Acrylonitrile Butadiene Styrene is usually colored for use and clear in small appliances and electronics housings. After drying, Acrylonitrile Butadiene Styrene molds well. Nevertheless, the chemical resistance of components composed of Acrylonitrile Butadiene Styrene is not like the chemical resistance of polypropylene. Therefore caution should be employed in using this plastic with ingredients exposed to chemicals. Polyamides/Nylon(PA) Nylon melts rapidly; therefore, manufacturers commonly utilize it in injection molding. The materials employed for extrusion blow molding are usually versions of nylon four to six, nylon six to six, nylon eleven, and nylon six. Nylon is an affordably priced translucent material that poses decent resistance to chemicals and gives a good performance in highly heated environments. Manufacturers use nylon to manufacture reservoirs and tubes in automobile engine compartments. Co-polyester And Polyester Manufacturers frequently employ polyester in making fiber. Unlike Polyethylene Terephthalate, manufacturers can do extrusion blow molding of modified polyesters such as co-polyester and Polyethylene Terephthalate glycol. Sometimes, co-polyester is employed to replace polycarbonate inside container products. It is like polycarbonate, but it is not that strict or precise, and it does not comprise bisphenol A, a substance that, according to some research, causes health problems. Polyurethane and Urethane Urethanes have performance qualities that are popular in coverings such as paint. Generally, urethane's elasticity is greater than polyurethane's, which needs to be formulated especially for becoming thermoplastic urethane. The thermoplastic standards can be injection or extrusion and cast blow molded. This is most frequently utilized as a single layer in multiple-layer blow molding. Thermoplastic Elastomers Manufacturers use thermoplastic elastomers to replace natural rubber inside molded components. This material is explicit and can be colored (usually black). Automobile manufacturers mainly utilize TPEs in grip surfaces, air intake ducts, bellows, and automotive suspension covers. After drying, it molds and usually reprocesses well.
Blow molding technology has become the most widely used method worldwide for its precision and efficiency in every product. The infinite number of benefits it has offered to almost every industry has led to its popularity globally. Today almost every product of either simple or complex shape is being produced using blow molding technology. With the rise in population, there has been a great rise in the demand for products, but the supply of products has never been able to meet it as better as it has with the use of blow molding technology. Therefore, the success of blow molding technology is evident from its worldwide application in all the different fields and industries. Benefits Of Blow Molding Technology •One benefit of blow molding technology that will always remain top of the chart is its precision. Never has another technology been able to provide precision in every product like blow molding technology. Thus, the precision of blow molding is exceptional and unmatchable. •Mass production of products is what industries have to do, but any other method or technology takes up a lot of time. Whereas blow molding technology does the same thing in a fraction of the time as traditional methods took and even did it better. •The cost of labor and all the other things was a lot in all the methods used before blow molding technology. However, blow molding is comparatively exceptionally low cost; neither does it require a lot of labor nor wastes any raw material. •It was a hell of a task to make products of complex shapes and designs before blow molding technology, but after the advent of it, it has become so easy to make any product of any shape. Blow Molding Technology – One Process, 3 Variants Three processes of blow molding technology are being used worldwide; all the methods are equally efficient and highly productive. The processes are almost the same; there are just a few steps that make one process different from the other. •Extrusion Blow Molding In extrusion blow molding, the raw material is melted and turned into a molten liquid first. It is then poured into a mold that is made according to the shape of the product that one desires to make. Once the parison is poured into the mold, the air is blown in its center to inflate it. Once the parison has been inflated into the shape of the mold, it is set aside to cool down with the mold. The final product is revealed when the parison has cooled down, solidified, and is ready to be removed from the mold. High-quality extrusion blow molding machines are being used to carry out the process efficiently. •Injection Blow Molding In injection blow molding, the only difference is that the molten liquid that is parison is not poured but injected into the mold with an injection-like machine. The raw material is also not inflated onto the same station but is taken to the other station, where a machine inflates it into its shape. •Stretch Blow Molding In stretch blow molding, the only difference is that the raw material isn’t inflated but instead stretched into the shape of the desired product.
Leshan machines’ approach towards innovation can be seen in the form of their highly innovative machinery equipped with the latest technology and provides the most satisfactory and the most sustainable solutions for plastic production. For instance, China bottle blow molding machines produce very light in weight and unique designs of bottles that are of brilliant quality. They add on an individual variation in bottle manufacturing and processing. They have also now introduced a range of latest machinery technology to improve the productivity in their industries and provide high-quality products to the customers. Design, Engineering, And Production With 100% Quality Leshan Machines had provided the solution of plastic bottle manufacturing very quickly. The way they have catered to this problem never catered this way before. Earlier, it was not only a time-consuming process but also required a lot of hard work and manual labor, which is not the case now. Now within a brief period and with the most advanced technological methods. Leshan Machine has built up considerable experience through its expertise in bottle design and the process of building technologies to enable the use of these bottles. They do not only create designs that take into account differences, marking themselves and their products as unique. They are known for introducing variations in processing characteristics of highly modernized machinery and other less obvious factors such as the increased level of their incredible expertise in manufacturing this machinery and running the process smoothly. Contents are checked thoroughly, and only the ones that arrive to be according to the international standards are accepted by brand owners and consumers if they perform as well as containers made from virgin material. That means the products and the raw material arriving at the converter have to be clean and consistent, and with processability during preform production and bottle blowing that is almost, if not precisely, the same as it was in the unprocessed form. A Brand Of Quality And Trust Leshan machines had been producing designs with the help of highly skilled experts involved in developing a large number of new methods of machinery every year. Their policy of following the rule of the three Rs – Reduce, Reuse, recycle – are unchanging principles in all of their projects, and it is the critical factor that helps them maintain their reputation. Leshan machinery has now developed a new approach that stands for an environmentally conscious approach to the design and produces environmentally friendly products. Recyclable Products Leshan machines, being the followers of the most efficient methods of environmental friendliness, strictly follows the Recycling guidelines established by the European Platform. The high standards set by this European Platform are the steps that ensure the quality of the product, keeping in mind the environmental friendliness. This European Platform is a voluntary industry that provides the initiatives and the design guidelines that are specially set for; recycling; it also evaluates production, packaging solutions, and technologies. It also facilitates understanding the effects of new technology-based machinery and its products for its innovations on recycling processes. To ensure the quality and standards, and to ensure that these guidelines have established several test procedures to assess the impact on recycling of new packaging and production technologies. Products that clear the tests and are up to the guidelines mentioned should not cause any problems during recycling and can easily be recycled. The Sustainability Factors Leshan machines produce solutions that are very advanced. They have been involved and devoted to this field for a very long time period. Hence their experience has helped them in making considerate and significant changes to the industry that have improved the standards of quality and living. Leshan Machines uses all the environmentally friendly components in the process of manufacturing these products. In every step, the factor of sustainability is considered as the priority; hence it is assumed to be followed in each and every step. The products that are produced as the end result are the products that ensure an environmentally friendly and sustainable environment. Using environmentally friendly components is just one Factor and tool that Leshan Machines uses in its process of design projects. They also have excellent performance, this could be indicated by high top-load strength, but these have to be weighed against factors that are not so positive, such as the fact that it is single-use. It requires the implementation of good logistics. Leshan Machines follow the XTREME renew processes that include ground-breaking technologies that enable their products to be converted into a fully integrated system according to the way they want. Their Renewable technologies help them eliminate an entire section of the environmental damages often seen in the past in various industries. Its outstanding features make it considerably a cost-effective option also offers extra benefits in terms of carbon footprint.
The blow molding process is a very high-tech manufacturing process that aids the manufacturing of hollow parts in a variety of materials. The process involves melting raw material and then pouring this molten liquid into the blow molding machine. The machine then inflates the liquid by blowing air into it to give it the shape of the mold. In the end, we get a final full-fledged product that requires no further processing mostly and is ready to be used for its purpose. However, it’s easier said than done; it requires immense expertise and practice to carry out this process smoothly. Although most of the work is done by the machines yet the role of the person carrying out the process is very crucial to the successful manufacturing of the hollow parts. Therefore, it will favor that person to be aware of all the problems that commonly occur in blow molding and their solutions. For making it more convenient, we have discussed some of the common problems in blow molding below. •Bottle Blow-Outs Bottle blow-outs are very common in blow molding; this problem usually occurs when the mold is contaminated. The presence of moisture also leads to bottle blow-outs in blow molding. If the mold is damaged or the mold closing is too fast, even then, bottle blow-outs happen. If there is bridging in the extruder feed section or the filling speed is too low, it causes bottle blow-outs. Sometimes if the pitch off is too hot or too sharp, even so, the bottle bows out. Solutions: To prevent bottle blow-outs from happening again, one will have to check for contamination and moisture in the regrind and resin before starting the process to clean it if it is there and then start the process. In case of damaged mold, one will have to repair the edges of the mold and pinch-offs to avoid the formation of holes in the product. To dodge bridging in the extruder feed section, one should increase the temperature of the rear barrel zone. Similarly, increase the filling pressure, reduce the mold closing speed and increase the width of the pinch-off, and you will not face any bottle out problem anymore. •Neck Finish Neck finish has also been a very commonly occurring problem in the blow molding processes. The bottles that have improper neck finish are not good to be used; instead, they are either discarded or melted again to go through the same process again. The reasons that are involved with this problem are having incorrect bottle weight, the alignment of the blow pin is not right or perhaps damaged, the shear steels and pinch-off lands are damaged or if the mold itself is not aligned. Solutions: Usually, underweight or overweight bottles lead to inappropriate shearing and issues with neck finish; therefore, the weight of the bottle should also be according to the standard. If the blow pin is not aligned then, one must align it centrally at the right elevation or replace it if it is damaged. In case of damaged shear steels, pinch-off lands, and misaligned molds, one will have to replace the shear steels, pinch-off lands, mold pins, and bushings. These are all the possible solutions that will care for the neck finish issues. •Bubbles Having bubbles in your bottles is a major defect, and it happens very commonly in blow molding. The possible reasons could be the presence of moisture in the resin, bridging in the extruder feed throat, very low filling pressure, and worn-out screws or barrel. All these complications cause bubble formations in the bottles. Solutions: To prevent bubbling in the bottles, one will have to check for the presence of moisture in the resin; it usually happens as a result of condensation in the feed throat; in that case, reduce the cooling in the feed throat to stop the condensation. The moisture could also if the resin handling system is not tight. However, if you see bridging in the extruder feed throat, then increase the temperature of the rear barrel zone. In case of low filling pressure, you just have to increase the filling pressure. Also, replace all the worn-out screws and barrels beforehand. Conclusion However, there are a number of other problems that occur in blow molding, like die lines, indented parting lines, webbed handles, etc., but among them all, we have discussed the most common of them all. Once you have understood these problems and the causes that lead to these problems, your performance will improve twofold. It is crucial to solving these problems at the right time; otherwise, they will do irrecoverable damage to your products and machines. Therefore, be careful and attentive to your blow molding machines all the time and check them regularly.
The hype about the blow molding machine is worth it; the precision that is achieved through the use of this machine in each and every part of any shape, be it complex or simple. The blow molding machine is used to carry out the blow molding of hollow parts. There are a total of three methods for manufacturing hollow parts by blow molding. All these methods take on the blow molding process differently. Therefore, all these methods use different blow molding machines to execute the specific blow molding processes correctly. Whatever machine is used with whichever process, as far as the single and double stage blow molding machine is concerned, it is used for injection stretch blow molding process. The three types of blow molding methods are: •Injection stretch blow molding •Injection blow molding •Extrusion blow molding What Is Injection Stretch Blow Molding? It is a blow molding process in which specifically PET bottles that are polyethylene terephthalate or, you can say, plastic bottles are manufactured. This process involves single- and double-stage blow molding using single and double-stage blow molding machines. Let’s discuss the two processes to understand their differences better and choose the right method that suits your needs. •Single Stage Injection Stretch Blow Molding Process In this process, everything is done in one go, all in one go. The raw material is melted and injected into the machine, where a preform is formed. This preform is then cooled and sent to a stretch blow molding station, which is reheated and blown into its final shape. All this is done in one go on the same machine. Therefore, this method is called the single-stage injection stretch blow molding process. There are some pros and cons of going with this method; let us be aware of them all so that you can choose accordingly. Pros: The pros of going with this method are that it is suitable for mass production of PET bottles in no time. It is very cost-effective as everything is being done by one machine only. It is a very compact, flexible, and convenient method for manufacturing PET bottles. The technical advantages of opting for this method are that the transferring is optimal, bottles are blemish-free, produces control over perform production, and thread starts to align. Cons: This method has inevitable setbacks, like its long cycles and changeover times. There are certain restrictions in methods like in the bottle design. The wall distribution in this method is often uneven. •Double Stage Injection Stretch Blow Molding Process This method is different from the single-stage method in this way that it does the same thing but in two stages with the use of two different machines. In its first stage, an injection blow molding machine is used in which the melted raw material is poured, and a preform is obtained. This is where the first stage ends and the second stage begins. Once the preform cools, it goes into that stretch blow molding machine, where it is reheated and stretched to its final shape. Although this process is almost the same as the single-stage process, it has some advantages that the single-stage method cannot provide. Pros: The first most wanted advantage is a faster cycle and changeover times; this process is twofold faster than the single-stage method. Hence, it helps to mass-produce plastic parts in much less time than the single-stage method. There are no restrictions when it comes to designing your bottle; you can design it in any way by using this method, unlike the single-stage method. The wall distribution that is achieved in this process is always even. One can even sell the perform without having to process them any further. Cons: It requires a lot of floor space to carry out this process, which is a disadvantage often when one doesn’t have enough space. The bottles that come out of the machine might have scratches on them. Its capital is very high to maintain, and there are chances of potential damage to the preform in this method. Final Word This is what the single and double-stage methods of blow molding are; when choosing one of the two methods, you need to make a wise decision. Both the methods have their own advantages and disadvantages. It is evident that where one fails, the other succeeds. Therefore, consider all these aspects and choose one method best suits your task. Only then will you be able to achieve what you have in your mind exactly as it is with proper wall distribution, threads, and more.