Monthly Archives: July 2019

Blown Film Extrusion Introduction

Blown Film Extrusion Introduction
Blown film extrusion is a technology that is the most common method to make plastic films, especially for the packaging industry. The process involves extruding a tube of molten polymer through a die and inflating to several times its initial diameter to form a thin film bubble. This bubble is then collapsed and used as a lay-flat film or can be made into bags. Usually polyethylene is used with this process, and other materials can be used as blends with these polymers. A diagram of a polyethylene chain is shown in Figure 1 to the right.
Background Theory on Polymers

In the cooling step of blown film extrusion, the amorphous, transparent melt crystallizes to form a translucent, hazy, or opaque film. The point where opacity begins in the bubble is known as the frost line. 
Fig 1: Model of polytheylene chain frompolyethylene Wikipedia article.The frost line height is controlled by several parameters: the air flow, film speed, and temperature difference between the film and the surroundings. Properties of the film, such as tensile strength, flexural strength, toughness, and optical properties, drastically change depending on the orientation of the molecules. As the transverse or hoop direction properties increase, the machine or longitudinal direction properties decrease. For instance, if all the molecules were aligned in the machine direction, it would be easy to tear the film in that direction, and very difficult in the transverse direction.

The Film Blowing machine Process

Fig 2: Schematic of set-up from User:J.Chiang.

Typically, blown film extrusion is carried out vertically upwards, however horizontal and downward extrusion processes are now becoming more common. Figure 2 shows a schematic of the set-up for blown film extrusion. This procedure consists of four main steps: The polymer material starts in a pellet form, which are successively compacted and melted to form a continuous, viscous liquid. This molten plastic is then forced, or extruded, through an annular die. Air is injected through a hole in the center of the die, and the pressure causes the extruded melt to expand into a bubble. The air entering the bubble replaces air leaving it, so that even and constant pressure is maintained to ensure uniform thickness of the film. The bubble is pulled continually upwards from the die and a cooling ring blows air onto the film. The film can also be cooled from the inside using internal bubble cooling. This reduces the temperature inside the bubble, while maintaining the bubble diameter. After solidification at the frost line, the film moves into a set of nip rollers which collapse the bubble and flatten it into two flat film layers. The puller rolls pull the film onto windup rollers. The film passes through idler rolls during this process to ensure that there is uniform tension in the film. Between the nip rollers and the windup rollers, the film may pass through a treatment centre, depending on the application. During this stage, the film may be slit to form one or two films, or surface treated. Advantages Blown film generally has a better balance of mechanical properties than cast or extruded films because it is drawn in both the transverse and machine directions. Mechanical properties of the thin film include tensile and flexural strength, and toughness. The nearly uniform properties in both directions allow for maximum toughness in the film.
Blown film extrusion can be used to make one large film, two smaller ones, or tubes that can be made into bags. Also, one die can make many different widths and sizes without significant trimming. This high level of flexibility in the process leads to less scrap material and higher productivity. Blown films also require lower melting temperatures than cast extrusion. Measured at the die opening, the temperature of cast film is about 220 C, where as the temperature of blown film is about 135 C. Furthermore, the cost of the equipment is approximately 50% of a cast line.

Blown Film Extrusion Disadvantages Blown film has a less effective cooling process than flat film. Flat film cooling is done by means of chill rolls or water, which have significantly higher specific heat capacities than the air that is used in the blown film cooling process. The higher specific heat capacity allows the substance to absorb more heat with less change in the substance temperature. Compared to cast film, blown film has a more complicated and less accurate method to control film thickness; cast film has a thickness variation of 1 to 2% versus the 3 to 4% for blown film. The resins used for casting typically have a lower melt flow index, which is the amount of polymer that can be forced through a standard die in 10 minutes according to a standard procedure. The melt flow index for cast film is about 5.0 g/10 min where as for blown film it is about 1.0 g/10 min. Consequently, the production rates for cast film are higher: cast film lines can reach production rates of up to 300m/min where as blown film lines are usually less than half this value. And finally, cast film has better optical properties, including transparency, haze, and gloss.

Common Problems Air entrapment between film layers and rollers – this may cause film scratching or wrinkling, or processing problems when winding up the film due to reduced friction. Possible solutions to this is using a vacuum to remove entrapped air or by using winding rolls with a diamond shaped groove in the rubber cover to increase surface area and decrease amount of entrapped air in the film. Large output fluctuations from the die – this causes thickness variations, and can be prevented by keeping the extruder clean and by using more consistently shaped pellets in the extruder. Melt fractures – these appear as roughness or wavy lines on the film surface, and can be eliminated by lowering the viscosity of the polymer melt. This can be done by increasing the melting temperature or by adding an internal lubricant to the material composition. Thickness variations in the film – this can be avoided by centering the die in the extrusion line before every run, adjusting the air speed of the cooling system, or by using heated die lips. Die lines on the surface of the film – this defect reduces the aesthetic appeal of the film, reduces optical properties, and weakens mechanical properties such as tear strength. This can usually be avoided by routinely cleaning the inner surfaces of the die and by refinishing scratched or roughened flow surfaces. Gels – these defects are small, hard globules encapsulated in the film or stuck on the film surface and reduce the aesthetic appeal of the film and cause stress concentration points which may result in premature failure. These are caused by overheating to the point of polymer degradation in the die, and can therefore be avoided by cleaning the inner surfaces of the die on a regular basis. Optimization of the Process Coextrusion One way to improve the line efficiency of blown film extrusion is to implement coextrusion. This is the process of extruding two or more materials simultaneously through a single die. The orifices in the die are arranged such that the layers merge together before cooling. This process saves time because it extrudes two or more layers at the same time, and it provides a method with fewer steps to produce multilayer films. The production rate for a coextruded multilayer film of three layers is about 65m/min, and the production rate for a single layer of blown film is about 130m/min. Thus, in order to produce 10 000m of a three layer multilayer film, it would take almost 4 hours using a single layer blown film process, and only 2 and a half hours using the coextrusion process. Furthermore, the film produced from the single layer process would require an extra step to glue the layers together using some sort of adhesive. Coextrusion is the least expensive means of producing layered films and the coextrusion system is capable of quick changeovers to minimize production line down time.

Minimizing the Melt Temperature
The efficiency of blown film extrusion can be improved by minimizing the temperature of the polymer melt. Reduction of the melt temperature causes the melt to require less heating in the extruder. Normal extrusion conditions have a melting temperature at about 190 C despite the fact that the temperature of the melt only needs to be about 135 C. However, it is not always practical to decrease the melting temperature by that much. By decreasing the melt temperature 2 to 20 C, the motor load can be decreased by about 1 to 10%. Furthermore, reduction of the melt temperature causes less need for cooling, so there is a reduced use of the cooling system. Moreover, removing heat from the bubble is usually the rate-limiting factor in this extrusion process, so by having less heat in the polymer to remove, the rate of the process can be increased, thus yielding higher productivity. A way to maintain the melt temperature at a minimum is to choose an extruder that is matched to the specific processing conditions, such as the material of the melt, pressure, and throughput.

Heated Extrusion Die Lips
Typically, solutions to melt fractures involve decreasing the output or increasing the melt temperature to decrease the shear stress in the extruder. Both of these methods are not ideal because they both reduce the efficiency of the blown film line. Heated extrusion die lips can solve this problem. This targeted heating method allows for film extruders to be run at higher production rates with narrower die gaps while eliminating melt fractures. Direct heat is applied to the surface of the polymer melt as it exits the die so that viscosity is reduced. Therefore, melt fractures, which are caused when trying to extrude too much of the polymer at one time, will no longer act as a limiting factor to increasing the production rate. Furthermore, heated die lips use less energy than increasing the melting temperature because only the surface of the melt is heated and not the bulk of the liquid. Another benefit of using heated die lips is that thickness variations can be controlled by adding heat to certain areas along the die circumference to make the film at that position thinner. This would ensure that no excess material is used.
Determine how much energy each of these processes can save per given volume of material. 

Above article from www.appropedia.org

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How Extra Curricula Activities Beneficial for your Kid?

Today, with video games and modern technology it is becoming hard to motivate kids to get outside and get involved in extracurricular activities, the moment the kids get out of school they are glued to their video games and IPad and research shows too much exposure to the screen is harmful at a young age.

Once you motivate your kids to be exercising, there is a high chance they will not be obese and they will have new friends, in addition they gain self-esteem and even get better grades.

The most important thing is for you to find what your child loves and then match if they love fantasy films take them to the theater for acting and if they are active you can enroll the to a soccer school.

Do your research well and enroll your children to a school that goes in line with what they love, if they love acting look for a school that has acting lessons so that they grow following that routine.

If you do your research well you will have a chance to come across schools that offer drama lessons and a whole wide range of activities that are interesting to your child and this will help them in the future.

Motivate you kids to select the things that they feel they love and can connect with them easily, this way you are sure that even if you take them to school they are where they are supposed to be and they are working on making their dreams come true, if the love singing take them to a music school and the good news is that you can try trial and error and see if at all they love it 100%.

Once your children are at home ask them what they have learned, you can even ask them to demonstrate to you what they are learning like if it is acting and this will give you a clear picture they are doing what they love.

Ensure that your kids time is well balanced and this means they are well motivated because some kids may have a hard time balancing school and extracurricular activities and also ensure they are not stuffed with activities more than they can handle.

The kid might not feel the connection after some time being in a certain activity, do not allow your child to be a quitter, rather encourage and motivate them to push on harder and if they dislike it completely allow them to change their mind and give them another chance to explore other activities.

Always have a positive mind so that you are able to motivate and encourage your child in the path they have chosen this gives them hope to continue doing better.

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A Beginners Guide To Businesses

Merits of Hiring a Professional Plumber

You can always protect your home from accidents related to water and plumbing by hiring a professional plumber. You will avoid dealing with a lot of stress when you hire a professional plumber. One of the merits of hiring a professional plumber is that you will enjoy customer support. You can benefit a lot from getting continued support especially in the future. You will always be given direct contact when you hire a licensed plumber. In this case, you will be ensuring that everything will be done in an effective way. It will also ensure that things will be done with a reduced amount of damage.

Another merit of hiring a professional plumber is that he is professionally trained. Training has to be done to professional plumbers before they can start working. In this case, they get a chance to be updated on the latest plumbing methods when they undergo this training. They will use these methods when doing installations and repairs. This helps them in ensuring that they don’t keep making any errors. Not knowing the best methods to use will make you encounter a lot of mistakes.

Another reason, why it will be essential to hire a professional plumber, is that you will have a professional protect your property. You may repair a plumbing issue but then, it may recur again. If your bathroom is leaking and you are not around, it can cause extensive damage. You may then need to spend a lot of money having all these issues fixed. You can ensure that such errors will not happen by hiring a professional plumber. Even when you are not around you will still get a chance to protect your property. This will ensure that you will be able to save a lot of money from costly repairs.

Another reason why hiring a professional plumber is that he will help you avoid havoc. When you hire a plumber, he will be coming to your home for regular checkups. He will also be doing regular repairs to your plumbing system. A professional plumber can detect problems early enough and fix them. When plumbing issues are fixed early enough, they don’t cause disasters. You can be saved from unexpected plumbing issues when you hire a professional plumber and this is always an added advantage. A plumbing emergency can cause extensive water damage, and this can be a significant problem in your home. A professional will come to your rescue when you are having an emergency plumbing issue within a short period. In conclusion, hiring a professional plumber is the best way of ensuring that you will be able to protect your home.

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Why No One Talks About Dogs Anymore

How to Go About Looking for the Most Accommodating Pet Grooming Service Application

There are many ways that you can go about taking care of your pet. Making sure that you always accompany your pet for grooming services can be challenging. It is known that having the grooming done requires of the owner to practice a lot to have it well done. A pet grooming service application ensures that you have it handled most effectively. It is always relevant for the pet owner to choose the most accommodating app to be promised of the best pet grooming service. Click here for more information on how to go about looking for the best pet grooming service app.

It is of great relevance for one to be conversant on the details that the application offers. It is always significant for the app user to be guaranteed of the assistance portrayed through its activities. The applications should be accommodating in such a manner that it covers all the necessary aspects of the pet that you have at home. The structure of the pet grooming service should meet all the relevant requirements to fit for mobile or any other gadget use. The details provided through the app should be accommodating to the particular pet grooming service that you need. The pet grooming service application should have all the features that makeup to its functioning.

All the activities regarding the pet grooming service should be provided to the pet owner in the most satisfying manner. You need to rely on an app that will have all the grooming details well highlighted up. For the pet owner, it is always necessary for one to know if the app will suit what you require to have at best. The application should support several variations to makes sure that you have your pet best groomed. It is always important for one to make use of a pet grooming service app that has inbuilt features with the finest technical assistance.

The application needs to be running for a trusted duration. With this you understand on the much relevance that the app has to offer. It is always important for one to choose an app that has the best details to provide to the pet owner when it comes to grooming. This is to ensure that you are guaranteed on the results to have when it comes to taking care of your pet. For the best manner of understanding the pet grooming service, the app should be best accommodating when it comes to connectivity. With so doing one is promised of the best pet grooming service through the application.

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The Essentials of Mobile – Breaking Down the Basics

The Essentials of Roofing – Breaking Down the Basics

Merits of Tile Roofing

Our houses are the best places that we have. In our homes, we have the ability to do anything that we want as no one will distract us. It is through our homes that we can be able to do all that we want in a safe and private environment. In our homes, we are able to safely keep our documents and other certificates that are important to us. This is why we must ensure that we have the best house. It is vital for the house to be able to have materials that are of the best quality. The roof of the house is a great consideration for you to have the best house. The best roofing material will ensure that you are able to get the best conditions in the house.

Tile roofing have become more common as more people have appreciated the benefits that they have. The tiles are able to enhance the beauty factor. Through the tile roofing, we are able to get these conditions and benefits. This is because beauty attracts the eyes of all people. It is with this reason that we have to consider the most beautiful things as we purchase things. It is through this way that we are able to enhance the beauty aspect of the house. Through this, the value of the house will have improved.

As the quality of the house improves, it is also the same way that the value will also improve. This is the reason as to why they have been embraced by the people that are involved in the real estate sector. When people are able to roof their houses, using the tiles, they are able to raise the value of the house, therefore enjoy selling it at a higher price. Prospective clients will also be able to buy the house as it will have a beautiful look that they are looking for. The tiles are also able to offer some security to the house.

This is because it is able to discourage fire. This is what people love about the tiles. It implies that in an event of fire outbreak, there will not be much damage as the tiles are able to discourage the fire. This is because the tiles will prevent easy movement of fire in the house. This is the best way that we will be able to save our property from much destruction. This is also the best way that we can be able to see to it that we have away with pests. The tiles make it impossible for the pests to make holes in the roof. This is why it is the most recommended way of preventing pests.

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The Trending Jewelry Styles and Designs That Everyone Needs to Try Out In 2019
Trends keep changing constantly which explains why the competition to stay at the very top keep becoming more and more fierce with each passing day not only for the people to keep up but also the popular jewelry trends as well which are also in the race for the leading spot. The process of researching to familiarize with the latest jewelry brands in the market is challenging and overwhelming for the jewelry lovers and yet inevitable all thanks to their hunger to remain at the top of the industry at all the time. Reading through this post enlightens people of what jewelry designs and styles they should try out in 2019 and keep up with fashion instead of going to research before coming back to the market to make their purchase of the same.

Top on the list is the Big and Bold Chain-Link Necklaces that seem to be getting so much attention this year regardless on having been in the market for some time now with no such huge statement. They are not only chunky but also come in silver and gold and suitable not only for people that love symmetrical jewelry but also the uneven ones as well. The latest jewelry trend of the chains this year, in fact, focuses on the unevenly-sized ones that hold the overly sized pendants with the latter being nothing but very simple. There also very creative designs of the chains that more and more people are going for which create a very innovative fashion statement as well.

There is always that once in a while when one wakes up feeling like all they need is a simple look which makes the simple rings the best solution at the time. The rings are thin and golden and they make a fashion statement without pushing one to put in so much effort all thanks to their simplicity and elegance that allows them to go great with anything that comes along. The best things about the simple rings is that one can choose what they like most whether it is wearing the stackable option on a single finger or on several as well depending on what they would be feeling at the time or whatever look they love. There are many other jewelry trends that people should look out for and try out in 2019 in addition to the above and they include wearing a solo earring, the seashell and leaf inspired pieces as well as the oversized ones, versatile pearls, the pieces with ulterior motives, the diamonds that are always trending as well as dripping crystals.

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What Almost No One Knows About Cleaning

Tips to be Considered When Looking for Cleaning Services

One may find it difficult to clean their house at times as a result if being held up or tiredness. Hiring a good cleaning company is one vital task that should not be lightly taken. Hiring cleaning services today are an excellent way one can keep their home neat and clean. If you are seeking to have an easy and productive cleaning experience, it is essential that one hires the right cleaning company. The availability of many cleaning companies today makes it difficult for one to select the best one. It is important that one examines the best cleaning services that are present in their area before hiring one. In this article, the features to be considered when looking for a cleaning company are presented.

The first factor to consider when looking for a cleaning service is their fee charges, The rates charged by cleaning services will differ depending on factors such as costs of labor. The cleaning service you are to hire should first explain to you the factors they consider when pricing their clients. When looking for a cleaning service, you should ensure you go for one whose fees you can easily afford. You should ensure you select an affordable cleaning service without compromising their quality and professionalism. By using the internet, one can search for affordable cleaning companies in their area which deliver exceptional services.

Before hiring a cleaning company, you should ensure you check on their level of experience. You can deduce the experience level of cleaning companies by checking the number of years they have worked for in their field of profession. Experienced services such as cleaning services toronto east have many working years of experience as compared to less experienced services. You will be guaranteed excellent services if you choose an experienced service such as cleaning services toronto east for they have an easy time understanding their client’s demands.

Before choosing a cleaning company, you should ensure you check on their status in the industry. You can determine the reputation of cleaning services by checking their online reviews on their websites and social media platforms. A prominent cleaning company is one that has many positive online reports from clients as compared to less reputable companies. You will be guaranteed excellent services if you choose a reputable cleaning company for they will, want to uphold their high reputation to attract potential client’s.

The credibility of cleaning companies should be considered before choosing one. You should ensure you select a cleaning company that you trust with its services. Checking the credibility of cleaning companies have been made easier today thanks to the internet. The cleaning company you are to hire should be one that has a legitimate business license and work certificates which certifies their services.

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Fitness and Nutrition: Practices You Might Want to Stop Doing

There many misconception that is all about the proper care in fitness and nutrition programs. One should be aware that some of these practices instead of helping you with your health condition it may worsen.

In some cases, there are people who would switch from one diet plan to the other one without even giving a though of the risk they will be facing. Particularly these kind of people who turn their backs on their current diet plan once they would hear the latest diet plan that can lose one’s weight in a much faster way. Apparently, there are so many ways for an individual to achieve his or her desired body, and with that here are some practices you should be refraining from doing in order to avoid any health complication, check out this post.

Eating power bars instead of a healthy meals would seem one of the common mistake of people who though it would improve their fitness and nutrition. Well it is a fact that power bars would really help improve our metabolism but making it as a substitute to the exact and proper meals then it would deem unhealthy. If you try look at it power bars are made to supplement our balance meals in our fitness and nutrition program we choose, and take note they are not made to replace it, check out this post.

Also one of the common misconception of other people who are doing their fitness and nutrition program is the avoidance of carbohydrates in their meals. Well it is true that carbohydrates would make you fat but they are also helpful in promoting fitness and nutrition because carbohydrates is a good source of energy.

There are also other people who thought that reducing their consumption of water would make a person lose weight much faster. Sad to say this is quite incorrect. In order to promote fitness and nutrition one must meet the 8 glasses of water every day, check out this post. Some experts say that if you would lose even a single percent of fluid your body will be affected negatively in a way. Especially when you are exercising, it is advised to drink surpass the 8 glasses of water in order to replenish the fluids you have lost, check out this post.

Lastly, there are some people think that through starvation it would help them stop gaining weight and even would help loss some. However, if you would just eat the right food on a regular basis you will not gain any weight but if you would overeat on foods that aren’t good for you then expect yourself to gain some weight. Always remember that starving yourself is not a better way for your to attain a better health, check out this post.

So overall these are the things you might to keep in mind if you want to attain that fit body in the future.

The Key Elements of Great Tech

What You Can Do With 3D Printing

It has been a long way since people started creating objects and designs from the simple printing press. Human advancement in technology in just half a century has resulted in much innovation including the creation of 3D printers. 3D printing technology has now furthered ways in making solid physical designs using an assortment of materials. Process using 3D printing allows the printing of solid tangible objects designed from electronic information. This printing allows one to create any object through a layered printing process. Materials such as plastic, metal and even cement can be used to create physical prints.

The process of making prints is actually very easy in principle. The foremost in creating 3D prints is to start first with creating designs through 3D editing softwares. Once the design has already been made in the computer, the next step is getting the materials to be used for printing and the right printing options for the 3D object which is as simple as putting the right kind of paper in a normal printer and setting up the right options. Often, it takes a bit of time for the 3D printing process to finish. The 3D printer itself will map out the whole design up to the final layer.

You can create your own custom plastic phone cover or even build a concrete house using 3D printing technology. Many industries now use 3D printing due to the many benefits it brings especially to designing and creating prototypes of their products. 3D printers are useful for making even the final finished product. In recent years, it is no longer hard to acquire 3D printing technology and it is becoming affordable to a lot of people as time goes on. Lots of companies manufacture 3D printers nowadays.

Commercial uses of printers are for creating custom designs and objects. This has especially great applications in terms of medical uses. As an example, 3D printing can help make an accurate 3D prosthetic to any patient with unique anatomical structures. Architecture design firms gain a lot from 3D printing as it allows them to make accurate scale models of building designs. The technology of 3D printing can be very useful for copying near perfect components for customization of old vehicles, especially ones that have rolled-out for over decades.

One can even buy their own personal 3D printer particularly for people who have a knack for creativity. 3D printing will give creators the edge in designing and creating actual physical objects. Hobbyists often have a lot of fun using this technology as it gives them the freedom to make wonderful creations.

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Important Benefits Of Hiring Professional Project Management Services

If you have a project, one thing that you need to ensure that it is managed in the best way. It essential to consider the best management regardless of the size of the project you have. There are experts that you can employ for the project management services or do it on yourself. When you decide to do the project management alone, then it may not yield a good result because you do not have the required skills. For this reason, take note employing the services of an expert when you need a guarantee of an excellent job. Choosing a suitable expert to provide you with the project management services is hard because of their huge number in the market. For this reason, when you choose the best one, then you will have some advantages to enjoy. Here are the advantages you will incur if you take note of enrolling proficient project management.

Competent project management services have profound knowledge for the job which is the number one merit you will incur. Professionals have been handling several projects which is why they have the right experience for the job. For this reason, they know the right steps to make when they are doing your project management services. You will thus have a surety of quality services when you consider professional project management services. When you attempt to do the project management services alone, then you will face some challenges if you lack the required experience.

The second reason to hire competent project management services that they day away with mistakes. If you consider the nature of project management services, then you will find that you can make several mistakes. For this reason, if you employ the services of an expert, then he or she knows the right strategy to handle the project. You can make some mistakes if you attempt to do the project management services if you do not know what to do. You can make expensive mistakes that prevent the whole project from happening. You can prevent these mistakes from happening if you consider the services of an expert.

Saving time and money is the third merit that you will enjoy from employing competent project management services. If you attempt to do the project management services, then you will take a lot of time since you lack the required skills. Therefore, you need an expert that will help you finish the project within the scheduled time. If you consider the services of an expert, then you will use a less amount to complete the job. When you consider the article herein, you will know the benefits of hiring professional project management services.

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