An Insight Into The World of Blow Molding

An Insight Into The World of Blow Molding

Blow molding refers to manufacturing techniques employed by experts to produce hollow plastic products, like bottle lids, plastic jars, toys, and other plastic containers suitable for multiple purposes.

The process usually begins with melting plastics through heating until it is liquified and forms a parison. 

The outcome of this process involves compressed air being used to stretch the parison across the walls of the mold cavity by blowing air onto it, as the results are used to design toys, accessories, automobile parts, watering cans, and many engineering components.

Importance of Blow Molding

When your annual production volume reaches about two thousand units or more, blow molding is the fastest, most reliable, and most economical plastic molding process for you.

With the milestone in technological development, conventional blow molding technology possesses the qualities of conventional glassblowing.

Little wonder why experts implore the usage of these blow molding technologies especially when there are high-production demands.

Based on wide usage and acceptance, the windfalls of using the blow molding techniques are:

Blow Molding Reduces Scrap Rates

Blow Molding technology creates a low scrap rate relative to regular manufacturing processes. For instance, while CNC milling removes a large portion of the plastic block, injection molding has reduced scrap rates to the barest minimum, preventing wastage as well.

Although additive manufacturing techniques like 3D printing offer even lower scrap rates, this could be a drawback.

Blow Molding Leverages Repetition & Consistency

Blow Molding Leverages Repetition & Consistency

Blow Molding is quite easy to replicate. For example, you can easily duplicate objects formed by Injection molding.

To ensure consistency, quality, and durability of your plastic production, now molding technology helps replicate your designs and intricate shapes easily and at a fast rate.


Blow molding techniques aren’t straight-jacketed in producing finished goods. It implores different techniques to achieve its result, hence It’s a suitable choice for you. For starters, when using extrusion methods, the air is blown through a long tube to create products like light bulbs.

On the other hand, injection blow molding achieves its result by inserting melted polymers into the blow mold.

With technological advancement resulting in design alterations or modifications, blow molding technology has currently reached its landmark in enhancing manufacturing processes.


When producing on a larger scale, you’ll require equipment that can give you good results and speed up the production process.

The ability of this molding technology to duplicate designs saves time and money. Additionally, a drastic increase has been seen in the technology’s usage within a couple of years as suppliers and other experts can deliver large quantities of their products within short notice.


One key feature of the extrusion method which makes it a viable option amongst engineers is its lower equipment costs. In addition, it requires less pressure to mold external threads or large fractions.

More so,  since labor is an important factor in production, blow mold technologies help to maximize manpower and reduce labor costs.


One major reason consumers patronize a particular brand’s product is its ability to satisfy their wants by giving them quality. It is a bonus if these products are affordable as well.

Quality goods cannot be unmatched and blow molding technologies aids rapid production enabling the business to meet the demand target. We must say that this technology is a life hack to the successful production of plastic goods.

The outreach of this technology is massive as experts are at liberty to experiment with different design software applications leading to more creative patterns of products toys, car seat supports, gasoline tanks, etc.

What Is The Downside Of Blow Molding?

What Is The Downside Of Blow Molding

Swift production, cost-effectiveness, quality, and durability are some of the remarkable benefits of using blow molding technology. However, companies that create and develop the machines know that shortcomings, such as small errors in injection molding, can have big financial and logistical repercussions. This is mainly because of the enormous manufacturing scale that is often required.

Despite the limited error margin, the consequences are significant. The shortcomings are;

Errors Made With Blow Molding Designs Have Big Costs

Tooling, product testing, and design modification and expenses amassed are usually on the high side. If you are planning to produce parts in large quantities, you need to make sure the design is perfect from the start, and that is more difficult than you may imagine.

Making the designs accurate entails

  1. Using a conventional machine la ike a 3D printer to help replicate the prototype according to specification.
  2. Creating 300–1,000 prototypes by designing a blow mold tool for the first production cycle.
  3. Before mass production, the blow-molded prototypes must be fine-tuned in every aspect.

Tooling Costs for Blow Molding Are On The High Side

Tooling is one phase of the whole blow molding process and is quite expensive. To produce a blow-molded component, you must first create and prototype with a 3D printer or CNC machine.

Subsequently, you will have to create and prototype a mold tool and duplicate the components in large quantities. Finally, after extensive testing, you get your acquired result.

Tooling modifications for production cost time and money. This usually leads to unnecessary expenses as making a prototype has not been perfected.

Poor Lead Times Management

Although this technique uses numerous manufacturing methods, this could also be a detriment as there is simply no way to eliminate correspondence.

How does Blow Molding work?

Today, automation of the blow molding process increases the production process and reduces labor costs.  Blow molding procedures usually first entail melting a plastic tube before inserting it into a molded hollow. 

However, with each different type of blow molding method, one can outline the method suitable for each plastic product. Using a general overview, the procedure of blow molding consists of the following steps:

  • Step 1: Depending on the machine, an extruder hopper, vacuum pump, or a screw may be used to feed plastic pellets into it.
  • Step 2: When the plastic pellets pass through the extrusion machine, it starts to melt through the process of continual kneading and heating. Furthermore, after undergoing the heating process twice, a parison, shaped like a tube is formed.
  • Step 3: When using extrusion blow molding, the end of the preform is sealed or clamped, excluding one hole, usually the opening of the container where compressed air will be filled.
  • Step 4: By this point, the preform has taken its form, and compressed air will be introduced into it. This process enhances the preform until it is molded following the shape of the die. When the plastic has cooled off, the machine opens the mold and it is sent offending it trimming and further detailing

Types of Blow Molding

In blow molding, there are different types of techniques utilized by professionals depending on the raw material to be used, designs to be made, and so on.

We shall be discussing the three common types of blow molding techniques. The onus of choosing the best technique is on our dear readers.

Extrusion Blow Molding (EBM)

Extrusion Blow Molding (EBM)

When looking for the most secure way to create intricate product shapes, the extrusion method is preferable. This technique starts with heating the plastic until it has melted completely and then it is extruded into a hollow tube known as a parison.

To accomplish your required form, air must continuously be blown into the warm plastic until the parison is closed. Once cooling is completed, the mold is removed totally.

Also, it is a common blow molding technique utilized in the manufacturing sector since it allows for the mass production of a large quantity of identical size and shaped products.

Injection Blow Molding (IBM)

Injection Blow Molding (IBM)

Unlike the extrusion method, the injection method introduces polymer into a core pin. As the blow molding machine swivels, the polymer is inflated into the required shape and size.

Subsequently, it is quickly cooled and evacuated.  When compared to both the extrusion and injection stretch-blowing methods, this method is less favorable.

Injection Stretch Blow Molding (ISBM)

Injection Stretch Blow Molding (ISBM)

Although sometimes mistaken as the injection method, the injection stretch blow molding is a substitution for it as it requires less material.

When using this method, plastic is shaped into a solid preform.  Thereafter, it is poured into the stretch blow mold machine to undergo the heating process. Once the object is heated, it is forced with air into a plastic container. 

Plastic products like bottles for soft drinks and hot sauce undergo this process.

What Raw Materials Used in Blow Molding

Raw materials are essential in the production process as without them, we cannot achieve our desired results. While there are several materials used in blow molding thermoplastics singles out itself as it does not deteriorate easily under high temperatures.

The consumer products, construction, and transportation industries are all currently seeing growth in blow molding and plastics like polycarbonate and polyamides. Are put to effective use in such industries.

Other raw materials used in blow molding processes are:

Acrylonitrile Butadiene Styrene (ABS)

ABS is the ideal choice for you if you are searching for materials suitable for housings, containers, and other household items. However, ABS does not have the same exceptional chemical resistance as other widely used blow molding plastics.

Polypropylene (PP)

Another common and adaptable molding material that parallels High-Density Polyethylene (HDPE) in many respects is PP. The primary distinction is that PP is more rigid, less dense, and temperature resistant.

Polystyrene (PS)

Although PS is occasionally better known as the main ingredient in Styrofoam, it is also a stiff plastic that can be used for food containers, cases, and laboratory equipment in its solid state. PS is notably brittle despite being relatively cost-effective, so it is probably a bad option when durability is an issue.

Polyurethane (PU)

The diverse spectrum of items utilized in industrial settings or marine situations benefits from PU’s ease of molding. Because it is rigid and comes in temperature-resistant variations, it is a preferred option for challenging working settings.


Santoprene is a thermoplastic that resembles rubber in some ways. Santoprene is a versatile and long-lasting material option for use in electronics, medical equipment, and home appliances.

High-Density Polyethylene (HDPE)

The excellent physical characteristics of HDPE, such as its high strength-to-density ratio, resistance to chemicals and temperatures, and temperature resistance, make it one of the most widely used blow molding materials.

For both industrial and consumer goods, including a variety of bottles and containers, HDPE is easily molded and acceptable.

Low-Density Polyethylene (LDPE)

Since it is softer and more flexible than HDPE, LDPE is a great material for flexible packagings like squeeze bottles and plastic bags. LDPE and HDPE do share some characteristics, such as being moldable and chemically inert.

What Industries Can You Use Blow Molding?

What Industries Can You Use Blow Molding

The bedrock of transforming these raw materials into intricate products starts in these industries. However, to meet the demand of society, certain industries find cost-effective means to produce quality products while rendering top-notch services.

In a bid to find the lowest cost and most reliable materials suitable for consumers, industries that rely heavily on blow molding techniques are as follows:

Food and Beverage

The food and beverage industry uses injection molding methods to make plastic product packaging. It is plausible to say that plastic injection molding is an ideal choice that ensures that sanitary standards and statutory regulations are adhered to, on the other hand, the above situation has contended.

When using blowing molding techniques, the brands in this industry food create unique plastic products ranging from bottle lids and plastic jars to Tupperware, etc.

Medical and Pharmaceuticals

Blow molding is essential for manufacturing medical and pharmaceutical products because many of them need to be non-porous and perfectly shaped.

To make discounts and profits, the medical and pharmaceutical industry purchases medical-grade products that are suitable for all health purposes.

For instance, pill bottles, disposable trays, and x-ray equipment are medical products made using blow molding techniques.

Automotive Components

When it comes to getting new automobile parts, you should consider quality, cost, and availability. With blow molding technologies,  mass production of auto parts and design modification have been made simple and affordable. Liquid reservoirs, electrical covers, consoles, seatings, paneling, fenders, and automotive ductwork are blow-molded automotive parts.


The agricultural industry is one of the largest sectors which uses blow molding technologies. At some point, metal-made parts were proscribed as the future since they had long-term usage but, the cost of maintaining them was quite high.

However, reinforced plastic choices like UV resistance, and humidity resistance, among others are the go-to choices.

Electrical Appliances

When purchasing a new appliance or leasing one, check for corrosion-resistant plastic housings to make the appliance long-lasting as well as boost performance. Most electrical appliances like, like television, and radios, contain parts made using blow molding.

Household Products

We might say that convenience isn’t cheap, but when it becomes affordable, one must grasp the package with both hands. These concepts apply to household appliances made from blow molding.

Also since there are nationwide and international shipping options, the availability of these affordable products for your home is just one click away.

Is Blow Molding the Right Option for My Project?

By increasing a dense plastic tube, or parison, until it fills a mold and takes the appropriate shape, hollow plastic pieces are created by a blow molding technique known as blow molding.

When making your survey about making a product using blow molding techniques, consider these factors;

Start with Financial Considerations

It would be best if you first considered calculating the volume of components produced at which blow molding becomes the most durable and cost-effective manufacturing technique.

The following step is figuring out how many parts are required to be manufactured to anticipate recouping your investments.

In essence,  examine the costs of design,  production, testing, assembly,  and distribution, the required price level for sales, and, most importantly, includes a small safety margin.

Lastly, remember to factor in entry expenses. Investment is needed upfront to get a product ready for blow molding. Also, ensure that you are clear on this vital aspect right away.

Consider Design

When taking on component designs, you want to design the component with blow molding in mind from the very beginning. It will be beneficial in the long run to simplify geometry and reduce the number of components early on.

Also, when creating the mold tool’s design, the top focus is to avert defects during the manufacturing process. Examining gate locations and handling simulations using mold flow applications like Solidworks Plastics is important.

Getting Production Right for Blow Molding

Cycle time is an essential factor to consider. Cut down on cycle time as much as you can. Also, it will be beneficial to use hot runner machines and carefully designed tooling.

Small adjustments can have a tremendous impact, and when you’re producing millions of components, shaving a few minutes off your cycle time can result in significant savings

Blow Molding vs. Injection Molding: What’s the Difference?

When examining molding operations, the phrase “blow molding” and “injection molding” are often used interchangeably, but even if they share similarities, they aren’t identical.

Taking a cursory at both molding techniques, each requires forcing a liquid plastic substance into a mold cavity.

However, while blow molding creates a liquid-filled opening with output used in making hollow containers like jugs and bottles, injection molding generates a concrete course used in making solid plastic items.

Kemal: The Best Choice for Blow Molding Services

When the creativity of the minds matches the outcome of the products made, customer loyalty increases. Today, the significant usage of blow molding technology has increased production demands and supply of plastic products from major industries.

At Kemal, we are passionate about giving our customers quality products that will provide them with convenience and total satisfaction. With our team of qualified experts, we can work with your dream board, following every detail to make it a reality.

Are you facing difficulties in getting selecting the best blow molding service? Look no further! Kemal will answer all your questions, making your molding journey seamless.

Put your parts into production today

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