Plastic goods often outperform and cost less than other materials such as wood, paper, glass, and metals. So, it’s no wonder that analysts expect plastic manufacturing revenue to grow to $609 billion in 2024.
There are two main types of molding options manufacturers generally use. One is injection molding and the other is blow molding, and they have several key differences and benefits.
Read on to learn which method is right for your business when it comes to blow molding vs injection molding.
How Blow Molding Works
Blow molding uses an extrusion process that pushes molten plastic into a mold cavity. Then, it inflates the plastic in the cavity with compressed air to form a shape.
The formed part must cool down before leaving the mold. Molding parts this way creates hollow products with linear shapes, 2-D forms, and a continuous length. Examples include water bottles, automotive air ducts, and plastic drums.
How Injection Molding Works
Injection molding uses special electric or hydraulic machines to melt, inject, and set plastic into custom molds. This way of molding manufactured parts has a high output but requires careful control by experts.
It’s a quick overall process that ranges from 2 seconds to minutes to make a part. Each cycle contains 4 stages which are clamping the mold together, the injection, cooling, and the ejection.
It can create 3-D shapes and usually produces solid parts and finished products. Examples include discs, plates, bottle caps, and furniture.
Blow Molding Advantages and Drawbacks
Because blow molding produces hollow parts, it limits material usage and cuts down costs. It has excellent versatility when it comes to intricate designs and parts. Blow molding can also produce a high-volume output at a rapid pace.
However, blow molding has a few drawbacks such as limited wall thickness and less precision. Blow-molded parts usually lack strength and require trimming. It’s also limited to creating hollow parts.
Injection Molding Advantages and Drawbacks
Injection molding uses automation and robots which helps cut down labor costs. It also limits the risk of rework and human error to save time and money.
There are many plastics to choose from for injection molding which adds to its flexibility. It can create bigger parts with ease and also create smaller parts with complicated geometries.
Compared to blow molding, it creates a much lower output volume and has longer lead times. The machinery for injection molding also costs much more upfront. Injection molding can’t produce hollow parts like blow molding can.
Blow Molding vs Injection Molding
When it comes to blow molding vs Injection molding, the choice comes down to the part you want to make. It also depends on how much stock you need and your lead times. Solid parts require injection molding and hollow parts require blow molding.
At Nova Stevensville, we strive to create plastic parts using our top-quality injection molding processes. We use adaptable and long-lasting materials to fulfill the needs of many diverse industries.
You can request a quote from us for projects of any size or complexity. From engineering design to product delivery, we’re here to help.
