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Packaging crash course: Stretch Blow Molding for PET bottles and jars

  • O.Berk
Primary Packaging, Bottles, Bottles - Preform, Bottles - Plastic, Bottles - Plastic PET, Jars, Pots, Custom Primary Packaging, Custom Injection Stretch Blow Molding (ISBM) Single Stage, Custom Injection Stretch Blow Molding (ISBM) Two Stage, High PCR Content Packaging, Machinery, Plastic, Plastic - PE, Plastic - PET, Eco Sensitive, Eco Plastic, Plastic - PCR, Tooling, Mold Making, Recycling

Polyethylene terephalate (PET) bottles and jars are created through the manufacturing process called Stretch Blow Molding (SBM). PET plastic is a packaging material that is widely recognized for its safety, product quality and environmental friendliness.

The Process
There are two SBM manufacturing techniques: the Single Stage Process and a Two-Stage Process. Both processes are divided into three similar and distinct steps. In the Single Stage Process, preforms are created and blown into bottles by a single machine in one continuous procedure. This process is a good choice when an application calls for special shapes like wide mouth bottles and jars. In the Two-Stage Process, the operation is split between two machines that operate independently. This division of manufacturing allows for more efficient management of throughput and is well suited to larger production runs.



One Or Two - Which Is The Right One?

While Single Stage and Two-Stage SBM have many similarities and share many of the same characteristics, there are differences. The specific circumstances and requirements of your product will help determine which of the two processes is the best choice. The best manufacturing process can also be determined by comparing and contrasting several key factors:

Speed:
Cycle times for the Single Stage Process can take as long as 43 seconds. In the Two-Stage Process this time may be reduced by as much as 22%.

Color:
While standard SBM preforms are clear, both Single Stage and Two-Stage Process preforms may be customized to match just about any color.

Quantity:
The Single Stage process requires a minimum order of 10,000, while the minimum order quantity for the Two-Stage Process is 50,000.

Recycling:
The PCR potential for containers produced by the Single Stage Process ranges from 25% to 100%. The Two-Stage Process offers a maximum PCR potential of 30%.

Neck Bead:
Bottles formed by the Single Stage Process can be produced without a neck bead. In the Two-Stage Process, a neck bead is required to carry and align the bottles into the RHB machine.

Extensive Comparison Of Single Stage And Two-Stage SBM

  SINGLE - STAGE ISBM
2 - STAGE RHB
Process
3 Stages Within One Machine 3 Stages Across Two Machines
Speed
Cycle Times Range From ~ 12 Seconds To 43 Seconds 2-Stage Times Range From ~14 Seconds To 34 Seconds
Colors
Great Ability To Color Match  
Minimums
10,000 Pieces Minimum 50,000 Pieces Minimum
Tooling Cost
(with existing preforms)
$2,500 for unit cavity: $15,000 For Full Production Tool $7,000 for unit cavity: $15,000 For Full Production Tool
PCR Potential
25% And 100% PCR 30% PCR
Orientation Potential
Threads On Necks Are Always Oriented Necks Cannot Be Oriented Unless There Is A Notch Put Into The Preform Transfer Bead
Scuff Mark Concern
Not A Worry Potential Scuff Marks From Handling Preforms Into RHB Machine
Neck Bead
No Concern, Bottles Can Be Produced With No 'Neck Bead" A Neck Bead Is Required To Carry The Bottles Into The RHB Machine


Interested In Learning More About PET Plastic Bottles And Jars?
If there are specific questions about PET plastic bottles and jars manufacturing process, contact O.Berk today.

Browse O.Berk's PET plastic bottles catalog here.

See also

Simple yet sophisticated: O.Berk's new glass Stout Bottles

The new glass Stout Bottles from O'Berk provide a superior package for food and beverages offering a simple yet sophisticated product. Now available in production stock and ready to ship in pallet quantities within 1-3 weeks, the Stout Bottle, available in 12oz and 16oz glass capacities, is truly unique. With a 38-405 neck finish, the Stout Bottle has a wide mouth, perfect for thick pourable applications, sauces, syrups, dressings and a variety of food and beverages.

O.Berk's perfect complements: PET clarity and tamper evident closures for beverages

New to the beverage market from O.Berk are cylinder round wide mouth beverage bottles. Available in pallet quantities with lead times as short as 1–2 weeks, these bottles are made of PET plastic that is BPA free as well as food-grade safe. The cylinders have a smooth, curved shoulder for maximum shelf appeal, and built-in tamper evident bead that accepts a wide variety of stock 38-385 tear away band tamper evident closures.

O.Berk's "Which plastic?" cheat sheet

When it comes to product packaging in plastic bottles, jars and jugs, resin characteristics and compatibility with your specific product are critical. O.Berk has compiled some general guidelines to help. Packaging your product in a plastic container goes beyond color, shape, and marketability – as different plastic resins have their own distinct characteristics that can dramatically impact a successful package. It's a critical choice that will either protect, or affect a product.

  • Company News
  • English
  • Modified 26 Aug 2015
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