01.
Introduction
Are you looking to buy some new machinery to expand your operation?
Not sure which equipment will be most beneficial for your upcoming projects?
This article aims to cover two of the most popular processes used in a production facility. You can create a wide array of products for the end-user between these.
If you’re setting up a new factory but not sure where to start with the equipment and machinery you’ll need, this article is a great starting point, or even if you are a more seasoned factory owner or manager but wanted to know what other options may be available to you and gain a better understanding of the industry.
02.
Why Might You Need Either Process?
Suppose you’re in the business of manufacturing. In that case, your clients will be most satisfied when you’re able to consistently produce high-quality items in an efficient manner and for a competitive price.
They also really value your services if there is an ability to have variants of the initial product line, such as different colours where applicable, smaller or larger versions, or perhaps even a slightly different shape.
Minor adjustments such as this can make the difference, especially when they’re trying to create a product that stands out in the store or have decided to enter a very competitive market space.
Products that are instantly recognisable to the consumer can result in more robust positioning and brand loyalty, providing the goods are of a high standard and live up to expectations.
For your factory to be successful, the efficiency of the operation and output production levels will have a massive impact, so getting the correct machinery installed and maximising floor space and the workforce available is essential.
Reliance on computers and automated machinery can mitigate the human error component, allowing for higher volumes of goods to be processed.
Blow molding and injection molding have their place within production; however, it’s imperative to know which is the most applicable for the good you wish to produce.
03.
Which Materials May Be Used?
Typically these production methods are aimed at manufacturing goods from plastics.
There will be further diversification within plastic products based on the particular polymers you want to use.
Naturally, or more so synthetically, in this case, each category of plastics will have its mechanical properties and characteristics.
Processes and machinery are usually precise to one group of plastics or blend of, so getting the right decision early on and planning for future line items can save you money and waste time overall.
Not only that, if the wrong material is chosen, it can lead to components failing or degrading faster than anticipated, which can be a potentially tricky issue or become very costly to rectify.
Thermosoftening plastics are used for blow molding; they become soft, malleable and can be shaped once warmed. This type of plastic can also be referred to as thermoplastics.
Whereas for injection molding, you can also use thermosets, along with composites and elastomers.
Thermosetting plastics do not soften when heated unless they are heated so much they become molten.
04.
What Is Blow Molding Used For?
Blow molding is a process commonly used in the production of plastic bottles, cans, or containers.
Bottling for the beverage industry is heavily reliant on this method; if this is the desired product you want to produce, for either soft drinks, water or carbonated beverages, then chances are this is what you’ll settle on.
It creates hollow products with great accuracy and in high volumes, including transparent and opaque bottles that are strong and lightweight.
The applications can vary massively from beverage bottles to those used to store chemicals, containers for food items or medications through to watering cans; as long as it ends up as a hollow product, then blow molding is suitable.
With such variety in goods that can be produced, it’s no wonder that blow molding has grown in popularity year on year to coincide with worldwide demands for plastic goods.
The critical stages of the blow molding process are as follows but can vary slightly, depending on the exact machines available, material being used and desired product but are outlined below:
- Create preform or parison; the preforms can also be purchased from other suppliers and stockpiled until ready to use.
- Load the preform or parison into the machinery, ready to be blown.
- Heat the plastic until workable, or transfer to be blown whilst still warm.
- Use hot pressurised air to blow the plastic into the desired shape after clamped on one end. This can be likened to inflating a balloon.
- Stretching the shape to final dimensions, if using the injection stretch blow molding technique, there will be additional processing to achieve the desired output.
- Cooling the finished items so they’re ready to eject and won’t become damaged.
- Release the freshly molded plastic item ready for the next step in the production line, filling the bottles with liquids and labelling.
What Materials Are Used For Blow Molding?
The primary materials that are used for blow molding are:
- Glass
- Plastic
Since the use of plastics is ever-increasingly more popular, this article focuses on that.
Within the world of plastics and polymers, we can further establish the specific plastics that are used for blow molding as follows:
- Acrylonitrile Butadiene Styrene (ABS)
- Polyethylene Tetraphalate (PET)
- Poly Vinyl Chloride (PVC)
- Polypropylene (PP)
- Polystyrene (PS)
- Polyurethane (PU)
- High-Density Poly Ethylene (HDPE)
- Low-Density Poly Ethylene (LDPE)
- Kostrate
- K -Resin Styrene-Butadiene Copolymer (K-Resin SBC)
- Santoprene
What Are The Benefits of Blow Molding?
- Intricate or detailed shapes are formed from one piece, and you don’t have to worry about trying to join several pieces together.
- A cost-effective solution, less expensive to purchase the molds and tooling equipment
- High volume output can be achieved.
- Containers or bottles produced can be thin-walled and precise, with low tolerances.
- This method is suitable for beverage bottles.
Are There Disadvantages of Blow Molding?
Like any process, this manufacturing technique does come with its own set of potential issues you may want to consider whilst performing the critical analysis.
The common flaws or defects that can occur during production are:
Warping of the bottle, splitting of the walls, air bubbles or defects in the material and inconsistent wall thickness.
These generally can come down to the quality of materials used, temperatures or lack thereof during the molding and shaping process or imperfect preform/ parisons being used.
To rectify such issues, it is essential to have a suitably trained and skilled operator who knows how to quality check and adjust equipment accordingly. Sometimes it is as simple as changing the temperatures or pressure of the air.
Other times more regular cleaning, especially of the mold, may rectify problems that you experience.
In any instance, having well maintained, clean and correctly aligned equipment will give a better chance to produce products your clients will love.
05.
What Is Injection Molding Used For?
This equally popular manufacturing method is used widely in producing bottle caps, gears, and small complex components.
Essentially, if you are looking to create solid, flat, detailed or have complex shapes, injection molding will probably be the most suitable method.
As the material is injected into the mold whilst in a melted state, it can penetrate trickier designs that may not be achievable in blow molding.
There are six key stages to the injection molding process outlined below; these are commonly contained within one piece of machinery, which helps keep your operation compact.
- Clamping of the mold, so it’s ready to be injected.
- Injection of heated materials using a screw drive which creates pressure and forces the molten plastic into the mold
- Dwelling allows the materials to permeate and set in the desired shape fully.
- Cooling allows the freshly molded body to harden enough so not damaged when released.
- Mold opening gives a chance for an item to be removed.
- Removal of products that may require further tooling.
For a helpful visual reference that can assist in the understanding of the steps involved with this manufacturing technique, click [here]
What Materials Are Used For Injection Molding?
It is most common to use a polymer-based material for your injection molding components; several factors come down. The materials knowledge isn’t covered here, but it is essential to be aware of the main types.
If you need further clarification on which materials are suitable for your project, speak with the materials or manufacturing specialist who can best advise.
The specific plastics that are used as:
- Acetal
- Acrylic (PMMA)
- Fortron Polyphenylene Sulfide (PPS)
- Nylon 6/6
- Nylon Polyamide (PA)
- Poly Carbonate (PC)
- Polyester
- Polybutylene Terephthalate (PBT)
- Polycarbonate (PC)
- Polyetheretherketone (PEEK)
- Polyoxymethylene (Delrin)
- Poly Vinyl Chloride (PVC)
- Thermoplastic Elastomer (TPE)
- Thermoplastic Polyurethane (TPU)
- Ultem
- Urethane
There have been recent advances in glass injection molding, which has reduced the temperatures significantly and is now a viable option as the molds are more cost-effective. To find out more about this emerging technology, check this website.
Once this is more thoroughly tested and accepted as a serious contender, we can see the polymers being replaced for particular items.
Benefits of Injection Molding?
The key advantages for using this manufacturing technique are:
- Ability to change colours of the item or material used yet to cast the same thing and use the same equipment.
- Can continually produce high volumes of product with a reasonable degree of accuracy, so it is an excellent choice for long runs of an item where consistency is required.
- The cost for ongoing production is relatively low once the initial outlay of the mold and machinery have been covered.
- Low waste and any that is created can be recycled and melted into another batch via re-grind.
What Are The Disadvantages of Injection Molding?
Although it is a very desirable manufacturing process for plastic items, there are a couple of points to consider, which are:
There is a relatively high initial cost for the tooling and mold, so if you only have a short run, it may not be very cost-effective.
As part of the setup, you’ll need to create prototypes and ensure that the preparation has been done correctly to achieve a good product that can scale; this experimental phase can be costly and take time.
For some, this tooling cost isn’t viable.
Also, imagine that after several molds, you need to change the design; this can lead to a new one being cut, adding to the time and expense.
Long lead times are also not that exciting, from the stage of an initial idea to delivery of suitable prototypes or first runs may be several months or even years.
If the market has shifted during this type, new advances make your product less desirable or obsolete, then all of this work could be for nothing.
Another scenario is a competitor has made it to market sooner.
It is much quicker to get your manufacturing operation up and running with blow moulding.
The overall size of the single pieces being injection molded can be considered a slight disadvantage. It will require multiple machines than the joining process, which adds more steps or costs in, alternatively much larger equipment with a high price tag.
Lastly, there are limitations on the thickness of walls being molded, too thin, and the material may struggle to fill the mold, too thick uniformly. You’re setting yourself up for a range of defects, a slower cycle rate and higher material costs.
The scope of this article isn’t to explore each of the materials and their suitable applications in detail. Should you be interested in finding out more about these materials, we recommend checking out the following websites; here or here.
Cost is always going to be a factor, and with injection molding being the more costly operation to set up and run, some people would lean towards the blow molding to produce their items if it’s feasible.
06.
Conclusion
With all things considered, you should now have a much clearer understanding of what’s involved, materials commonly used, and any potential advantages of using either blow molding or injection molding for your manufacturing operations.
Both techniques are beneficial and have their relevant positions within the production line.
When looking to make an informed decision on what equipment and machinery will be the best solution for your company needs, it is essential to weigh up all possibilities, costs involved and any potential limitations or drawbacks.
If you have any specific questions about the processes outlined or would like to discuss your needs in more detail, feel free to contact us directly via the website https://ibottling.com or email to johnlauvip@gmail.com