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 types of blow molding machines to execute the specific blow molding processes rightly. 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 is the process that involves the single-stage and two-stage blow molding process with the use of 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, where it 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 good 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 in this, the transferring is optimal, bottles are blemish-free, produces control over preform production, and thread starts to align it. Cons: This method always has certain setbacks, like it has very 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 however 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 do mass production of plastic parts in much lesser time compared to 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 does one fails and the other succeeds. Therefore, consider all these aspects and then land on one method that best suits your task. Only then will you be able to achieve what you have in your mind exactly as it is in with proper wall distribution, threads, and more of the same.
Injection molding has stormed the world with the most incredible precision products. The improvement that injection molding has made in the manufacturing of thermoplastic products is second to none. Therefore, all the industries have not switched towards adopting this method, but they have to be clear about one thing that is mastering this process is the only way to get going with it. If you are not a master at this magnificent innovative injection molding process, you are only going to waste your material. The process itself becomes very easy once you get hold of all the things. Having said that, first, let’s get you familiar with the process of injection molding before jumping onto the tips that will help you in it. What Is The Procedure For Injection Molding? You can say that it is a one-step process because it really is; the entire product is manufactured in just one step. From putting your raw material inside the mold to getting a perfectly shaped final product, all that happens in one go. The pre-process things are what make the most of your time and effort. All of the things that go behind running this process smoothly without any onset complications. The entire process can be divided into three steps. •Designing The Product: This is the initial step of injection molding and also the core step. If the design of your product is faulty, then your entire process will become faulty. You need to design your product by keeping in mind all the dos and don’ts of the injection molding process. However, injection molding has no restriction but still needs to meet certain criteria. You will have to pay close attention to the aesthetics, manufacturability, functionality, precision while designing your product. Only a product design that meets all these criteria will help yield an effective product. •Designing The Mold: After designing the product, comes the second crucial step of this process that is designing the mold for the product. The materials commonly used for making the mold are hardened steel, pre-hardened steel, and aluminum. Among these three, hardened steel is the ideal mold-making material as it lasts longer than the other two. The only drawback is that it is a lot expensive than the other two. in that case, people switch to pre-hardened steel, which is also quite durable but doesn’t last as long as hardened steel. Making the mold correctly is equally important because even if the design of your product is to the point, but mold has faults, then your product will be ruined. •Manufacturing The Product: This is the final step in which it all happens in one go. Your melt thermoplastic and pour this parison into the mold. The machine starts inflating the parison by blowing air into the mold at the center of the parison. Once the parison is inflated enough to achieve its desired shape, it is set aside to cool down with the mold. Upon cooling, it solidifies, and that’s when you remove the final product from its mold. The final product requires no extra machining and has the perfect finish. Tips To Employ In Injection Molding •Selection Of Material: We can not emphasize the importance of selecting the right material for injection molding. Choosing the right material makes a huge difference, more than you think it does. Selecting the right material will let you achieve a fine finish final product. It will also save the money that goes into the extra machining of the final product. Since the right material will help you make the perfect product, nothing will go to waste. •Add Texture Into Your Product: Adding texture to your product adds more appeal; therefore, using this tip will benefit you a lot. You can add texture to your products in two ways. You can either add texture into the mold of your product so that the final product can have it. The other way is to wait for the process to complete and add texture to the final product. •Take Help From An Engineer: To save yourself from spending time mastering the injection molding process, you can also collaborate with an engineer as they are trained professionals in the process of injection molding. An engineer will carry out the entire process for you and make sure that the product in the making comes out exactly like the mapped one. •Pay Close Attention To Wall Thickness: The wall thickness of any product matters a lot; if the wall of a product ends up being too thin, then it would be a fragile product. You can reduce the thickness of the wall to save on some money, but it shouldn’t be reduced to the ideal wall thickness; otherwise, the product will be a waste. Therefore, get to know about wall thickness more to handle this department perfectly.
The blow molding manufacturing of plastic bottles is a widely preferred process for the mass production of plastic bottles. The process itself is highly reliable and there are almost zero chances of any potential hazard in the way of the blow molding process. The products that are obtained through the blow molding process are highly durable and perfectly compatible with the world. However, where blow molding has simplified plastic bottle manufacturing for us there are still possibilities of technical problems which is why certain check and balance has to conduct. To ensure that the product is 100% according to the customer’s demand. One major problem that arises with plastic bottles is the leakage issue. Often when bulks and bulks of bottles are being manufactured there isn’t much time to check each and every bottle to ensure that there is no leakage. However, it is very much necessary to check for leakage in every single bottle. Otherwise, if your customer will fill up a leaking bottle and pile it up with other bottles, the damage that it would cause would be enough to lose him as your customer. You don’t want that, nobody does, therefore what you need to do is to test your bottles for any leak. How Are Leaks Formed in Bottles in Blow Molding Manufacturing? •While testing bottles for leakage, these are the defects that you have to look for: •Bottom blowouts are formed at the base of the bottle due to gross plastic leak; this type of plastic bottle will surely have a leak in it. •When you do not use enough parison for manufacturing your plastic bottle it results in short shots which look like the neck or threads of your bottle are not fully formed, this type of bottle won’t be sealed properly with a cap thereby it will surely leak. •Sometimes some problems come up in the blow molding process due to which the neck of the plastic bottles are not normal but stretched necks. •If your mold has been accumulated by impurities or oil from the hydraulic system, anything that has contaminated your mold will contaminate your plastic bottle and will form a leak in it. •Due to some problems in the blow molding process, you might get nicks and cocked necks in your plastic bottles and these will result in sealing issues. •Some other problems in plastic bottles can be gate leaks, gate cracks, and misformed bottles which will result in leakage. How Can You Test Bottles for Leakage in Blow Molding Manufacturing? The leak testing is done to make sure that none of the product has any defect in it, you can avoid leaks forming your bottles by making sure that nothing goes wrong in the process of blow molding and everything is according to the requirements. The other way is to test for leaks and discard the leaking bottles to be melted again and reused in making bottles. Some ways by which you can leak test bottles are: •When the final product is obtained, check its quality. This will tell you if the bottle is impenetrable or not and can hold pressure or not. A quality plastic bottle doesn’t allow penetration and holds any type of pressure either of the product inside it or of the transportation, it will handle it. •Check for any of the visible defects like cocked necks, gate cracks, misformed bottles, etc. if you find any such bottle which has even the slightest defect discard it. •Have a full inspection process of the plastic bottles. •Keep monitoring the entire blow-molding process constantly so that if any drawbacks occur in the middle of the manufacturing, you can correct them immediately before the full production is done. •After the production is done do the pressure test on each bottle by filling air into the bottle and sealing it. If the pressure of the sealed bottle drops then it has a leak. •The other way of leak testing bottles is by doing a vacuum decay test. If the sidewall of the bottle collapses when it is tested under a fixed amount of vacuum then there is a leak in the bottle. Final Word The role of leak testing bottles in blow molding manufacturing is much needed. This fast mass production of bottles can not only be monitored for leaks but properly tested for any potential leakage. The testing not only helps in shipping quality products to the customers but also helps in avoiding future problems that might occur in the process. All these plastic bottles are used for storing different liquids of different consistency therefore even if a micro-hole that is not visible to the naked eye is present in the bottle it will leak and no one wants that.
The use of a blow molding machine is a process of fabricating items from plastic. The uniqueness of this process is that it is specifically related to the manufacturing of hollow plastic items like jars, bottles, containers, etc. The process goes like this that first, a thermoplastic is melted and turned into liquid completely. This melted plastic called parison is then poured into a mold, where it is then inflated by blowing air into the mold. The inflated plastic is then left to dry with the mold for some time. Perhaps at the end, a hollow plastic item is obtained. This is the entire blow-molding process, but there are a variety of different machines that are used to perform this process. Each machine does the same thing, but differently; this is what creates a slight difference between the obtained products of each machine. With this being said, let's have a look at each machine to understand the difference in their working and functionality. By comparing and contrasting each machine, we will get to know the advantages that each machine produces, and this will aid you in choosing the right machine according to your need. Inverted Head Injection Blow Molding Machine The structure of an inverted head injection blow molding machine is like this that the hydraulics of this are present under the mold sitting at the base of the machine. The presence of hydraulics below the mold is a beneficial thing for getting a high-quality product in the correct desired shape. If the hydraulics are present above the mold like in some machines, then the hydraulic oil keeps leaking into the mold and contaminates the mold or the product. This is why the hydraulic oil, even if it leaks, is far away from getting into the mold or fouling the product. The other advantage of this machine is that since it has a pull-down tie bar system, it is best suited to use for large volumes of material. It can take up to 45 to 205 tons of material. This machine applies pressure directly to the center of the mold, which helps in preventing flexing that can cause the frame to crack; this is another plus point of this machine that you can count on. Hence the ultimate design of this machine is the best and has made this machine the most widely used injection blow molding machine. Inverted Head Hybrid Injection Blow Molding Machine The structure of this machine is similar to that of an inverted head injection blow molding machine. The difference comes here that the hybrid screw of this machine is 100% electric. This difference gives the inverted head hybrid injection blow molding machine the ability to save up to 30% of the energy as compared to the standard inverted head machine. The other benefit of using the inverted head hybrid machine is that its cycle times are faster than the standard inverted head machine. The cycle times of the inverted head hybrid machine are up to 15% faster than the standard inverted head machine. Some additional benefits of this machine that can also be counted are that this machine produces no noise and causes very low pollution. Inverted Head Full Electric Plastic Molding Machine The structure of this is again the same as that of the standard inverted head machine. Like an inverted head hybrid machine, this machine also saves 30% energy and has faster cycles times up to 15%. It also has a full-type hydraulic system. The benefit of this machine is that since it is driven by AC servo motors and controllers for being fully electric, the product that is obtained through this machine is highly stable in its shape and quality. Non-inverted Head Injection Blow Molding Machine This machine is slightly different in its structure from the inverted head blow molding machine series. However, the technique that this machine uses helps it to get the same high-quality products as that of all the inverted head machines. The benefit of this machine is that it is very reasonable as compared to all the inverted head machines. Therefore, if you can get the same quality product from a cheaper machine, then why won't you. This is why this machine is used widely. Final Word The injection blow molding technique has become the mainstream process for making hollow plastic items and has left all the traditional practices behind. This technique gives the ability to make complex designs that were not possible in the past. The strength and efficiency that are obtained by the products through this technique are beyond comparison. The use of machines makes the entire blow-molding process very cost-effective as there is no need for labor in this procedure. The entire process is carried out with the help of a machine. Therefore, fast production of complex plastic items at low cost. This technique is also very environmentally friendly as it produces reduced waste as compared to other techniques.
Plastic molding is a procedure in which liquid plastic is poured into a specific container or a mold to convert it into the desired shape. The use of plastic molding procedures is diverse, and today, they are used in a number of industrial applications. There are various types of plastic molding procedures that can be adapted depending on the required molding setup. There are various types of PP blow molding machines that are widely used for the manufacturing of different plastic products that are available in the market. The other methods of plastic blow molding might include options like extrusion molding, compression molding, and rotational molding. It is a fact that each type of plastic molding has its own benefits in different industries, but one process that has been a popular choice for many industrial applications is nylon plastic injection molding. It has become a go-to option for different industries due to the number of advantages that it provides in ideal substances. Here we are going to take a deep dive into the different benefits of nylon plastic injection molding. What Is Nylon Plastic? Nylon plastic is an artificial thermoplastic polymer that is utilized in the process of injection molding. The artificial thermoplastic polymer was first produced by American chemist Wallace Carothers in the year 1935, and it has been a popular material for the injection molding procedure. Nylon plastic is known to be immensely durable and flexible, making it one of the best options for the molding procedure. Nylon plastic is also known as polyamide. Reasons to choose nylon plastic injection molding. Low Friction The nylon plastic doesn’t heat up easily due to the excellent chemical composition that this material possesses. It is largely used in applications that require a higher amount of application. The lower coefficient of friction in this material makes it highly useful in different injection molding procedures. Due to the versatility that this material has, it can be used in applications such as slides, gears, bushings, and plastic bearings. The low friction element makes it highly compatible with different machines and eases the process of manufacturing in different scenarios. High Melting Temperature Thanks to the chemical composition of this compound, it has a higher melting point. It is a factor that makes it an ideal choice for applications that involve a considerable amount of heating methods. Tensile Strength When it comes to combining other compounds with nylon plastics aids in adding more tensile strength to the material, an example of this can be found in the filling of nylon with glass fibers which makes the resultant plastic less flexible and more brittle. Simpler Combination The flexibility of the nylon plastic makes it easy to combine with other compounds and materials. It is an attribute that makes it a suitable choice for the injection molding procedure with plastic as it involves a number of materials and compounds. When it comes to the manufacturing of different plastic parts, the use of nylon plastic makes it easier to manipulate the manufacturing procedures allowing the operators to take full advantage of the flexibility that the polyamide offers due to its diverse properties. Resistance Plastic nylon has the ability to be resistant to different chemicals, which makes it highly durable and reliable for many applications. Abrasion Plastic nylon is extremely strong and resistant to abrasions and moisture absorption factors. The attribute aids in making the material usable in the case of different complex injection molding procedures. Useful In Manufacturing When it comes to the injection molding procedure, then nylon plastic can be extremely useful in manufacturing different plastic products. The products that are mainly made by using the injection molding process might include plastic bearings, bushings, gears, and other important tools that are found in different engines and machining setups. The plastic compound is also useful when it comes to manufacturing different plastic parts, including the parts that are used in the manufacturing of different automobile parts. When it comes to the manufacturing of identical parts on a large scale, the use of injection molding becomes necessary and different manufacturers opt for the methods that seem feasible in various industrial circumstances. Nylon Plastic In A Nutshell The use of nylon plastic in the injection molding process has its own benefits, and that is solely why more manufacturers are shifting their focus on this plastic compound. It comes at a time when the use of metallic alternatives is becoming obsolete, and manufacturers are looking for far cheaper ways of conduction injection molding procedures. The attributes such as lower friction, higher melting point, higher tensile strength are the key reasons why the use of nylon plastic has become more popular than other methods that are used in the injection molding process.