by engineering one of the world’s lightest PET bottles for still
beverages to date. Under the working title of Factor 101, in close
cooperation with Canadian-based injection molding technology
equipment and services provider Husky Technologies, a container has
been produced that uses just 5.89 grams of material to hold 591
milliliters of product. This is equivalent to the 20-ounce size common in
the United States.
At drinktec 2017 KHS presented its Factor 100 concept as a feasibility study
that featured a PET bottle weighing approximately five grams with a capacity
of 500 milliliters. A number of optimizations have now been made to the
further development, as KHS packaging designer Fabian Osterhold in
Hamburg explains. “With such extreme lightweighting, what’s known as the
top load is especially important. This value tells us how sturdy the bottle is
from a vertical perspective. It determines whether the container can be
stacked or not and survive transportation undamaged.”.
Extremely robust lightweight
To increase stability, the shoulder design of Factor 101 has been modified
and the bottle body reinforced with functional webbing. Moreover, Osterhold
and his colleagues have developed a base with a pop-in effect. Here, the
base pops inwards to a certain degree when a top load is applied, increasing
the internal pressure and therefore the stability of the bottle.
Two hundred newtons is a common top load threshold in the industry; at 220
newtons, the Factor 101 exceeds this. In order to achieve this high value for
a PET bottle used for still beverages, adapting just the container shape
wasn’t enough. “The preform design also needed to be developed further,”
emphasizes Osterhold. This is why KHS joined forces with the specialists at
Husky. The company has a wealth of expertise as the world’s leading
equipment supplier of PET preform injection molding systems and services
and has been in cooperation with KHS for many years.
Challenging coordination
Technically speaking, the stretching factors from blank to bottle and the
resulting preform dimensions were especially important here. The relation of
length to wall thickness is particularly relevant to injection molding. In this
context, KHS addressed the specifications and feasibilities of the stretch blow
molder and bottle design, while Husky made the necessary modifications to
the preform. “The focus here was on the exact profiling of the preform made
possible by KHS technology,” Osterhold ascertains. “Focus lamps in the
heater on our InnoPET Blomax Series V, for example, make for extremely
precise temperature profiling directly under the bottle neck ring. This ensures
that no material stays unstretched. In turn, this considerably reduces the
amount of plastic used.
30% less material
Compared to the standard lightweight PET container holding 500 milliliters of
still water that usually weighs seven grams on the US market, the joint
KHS/Husky product requires 30% less material. It can also be manufactured
entirely from rPET.
However, bottle geometry is just one factor. “Line compatibility in the high-
capacity range of up to 90,000 bottles per hour was a key challenge,” says
Osterhold. “The main issues here were conveying, labeling and the
secondary packaging. In the shrink tunnel, for instance, special attention had
to be paid to the bottle shoulder – and the bottle of course shouldn’t fall over
during conveying.”
High-speed development
“Not only the weight but also the time in which the project was implemented
are possibly record-breaking,” Osterhold states. Thanks to the great
teamwork between Husky and the many KHS departments involved in the
development process, the project was successfully concluded in just four
months.
Great interest on the market
Factor 101 was first presented live by Husky at the NPE 2024 plastics trade
show in Orlando, Florida, in May of last year. The extreme lightweight was
met with great interest in the industry. “The bottle in this form is of particular
relevance to contract fillers who operate under great cost pressure,” believes
Osterhold. The prime target markets are the United States, the Middle East
and South America. The first projects are already in preparation.
In conversation with Frank Haesendonckx, head of Stretch Blow
Molding Technology at KHS, and Michael Müller, Director of
Aftermarket PET Tooling for Husky Technologies
Haesendonckx: Factor 101 is an excellent example of how we’re combining
Husky’s engineering expertise in preform manufacturing with our proficiency
in bottle design and production. Our joint aim is to produce a high-quality,
high-performing, lighter weight result than either of us could do working on
our own. Or, as I like to put it: for us, one plus one is greater than two.
Müller: We see great benefit in combining our technical expertise and
envisage leveraging this for future projects. Here, Factor 101 acts as a
starting point for discussion of a lightweight program and optimization of
current packaging systems and solutions.
Haesendonckx: We aim to combine more cost-efficient preform and bottle
manufacture with improved performance – also above and beyond Factor
101.
Müller: We’re joined by a common spirit and goal – namely working towards
developing sustainable packaging.
For more information go to:
https://www.khs.com/en/company/media
