> Mechanical engineering & imaging in a perfect union
APPLICATION STORY
> PHARMACY
> Safe clean room filling
By joining their expertise, Harro Höfliger, a mechanical engineering company, and the machine vision experts at STEMMER IMAGING have
implemented a high-performance filling system for functional pharmaceutical tubes.
The design and construction of clean room systems for pharmaceutical industry is particularly challenging. The production of
pharmaceuticals and medical solutions as well must meet the
highest requirements in terms of processing and quality. The internationally successful company, Harro Höfliger Verpackungsmaschinen GmbH, located in the Swabian Town Allmersbach im
Tal, has been specialising in these demanding industrial sectors,
developing integrated system solutions and customised machines
for pharmaceutical, chemical and food industry for more than a
quarter century.
One of the company's strongest points is the design of clean room
machines for the manufacture of pharmaceutical and medical
products. "These systems must be capable to meet above-average
standards", explains Manfred Hild, Control Engineering Department Manager at Harro Höfliger. According to him, this results from
the aggressive cleaning agents frequently used in clean rooms, significantly reducing the range of suitable materials that can be used.
"Such systems", adds the Division Manager, "need to be easily cleanable and must not be susceptible to failure as the individual system
components may be difficult to access. The integrated systems for
measurement, illumination and detection usually need to be encapsulated, thus involving tedious and complicated work to replace
them in case of fault or for maintenance."
Pre-orientated tubes are conveyed to the alignment station in an arbitrary rotation position and then turned according to the print mark.
imaging is our passion
> Mechanical engineering & imaging in a perfect union
> The task
In a recent project, which again was subject to such difficult conditions, the Swabian company has supplied to their customer a solution with two identical filling machines for "tubes for oral live-virus
vaccines", designed for filling liquids and paste-like materials into
plastic tubes. The user can then easily squeeze out, like toothpaste,
the contents of these tubes and use them. "During implementation
of these two machines not all optical material properties had been
known", describes Manfred Hild one of the difficulties experienced
by his team.
Even more challenging, however, was to select the best machine
vision components for the alignment station of the machine. Before reaching the alignment station, the tubes are transported in a
non-oriented position. Once the tubes have been separated, they
are aligned in an upright position with the tube cap downward. A
special gripper seizes ten tubes simultaneously in each step and
transfers them to the alignment and rotation station.
Before the substances can be filled into the tubes, they need to be
aligned and moved into a defined rotation position. This intermediate step has two reasons: one is to ensure that the tubes will not
break along the longitudinal joint during sealing and become leaky.
The other reason is that the pharmaceutical manufacturer wants
to ensure that the prints on the tubes always have the same location after sealing, thus being perfectly readable.
Before filling the tubes, they are moved into a defined rotation position with an
accuracy of less than 2 degrees.
” facts
Industrial sector:
Pharmacy
Task:
Accurate alignment of tubes before filling with
pharmaceutical substances
Details of the image processing components used
Each of the two functional tube filling systems uses five DALSA Genie-HM1024
cameras from Teledyne DALSA, each of them combined with a Fujinon HF35HA
lens and two blue CCS LDL2-146x30 bar lights. Data transmission to the two
Quad-Core computers with Cognex VisionPro software is performed using
GigE cables. The lights, lenses, cameras and cables have all been purchased
from STEMMER IMAGING after internal tests at Harro Höfliger's.
” harro höfliger: a mechanical engineering company above the standard
Harro Höfliger (www.hoefliger.com), with its headquarters at Allmersbach im Tal, started to focus on the design of machines with sophisticated requirements
already many years ago. The company employs more than 600 people across the world and considers itself above standard mechanical engineering companies as
it mainly develops customised machines for clients operating on an international level with core activities in the medical and pharmaceutical industries. In many
other industrial sectors, Harro Höfliger has an excellent reputation as a key supplier of production systems and system solutions, for example in the fields of aseptic technology, blister and tablet technology, syringe/injection technology and capsule and powder filling machines and in other fields.
Aiming to make life easier to its customers, the company is part of a network of globally acting mechanical engineering suppliers to the pharmaceutical industry.
"The complementary competencies of these companies make the customers of the association benefit from quick and uncomplicated solutions", explains Manfred
Hild. "This network of companies provides the advantage of using synergies, because sharing technologies means halving the cost of development. Thus the associated companies are not only in a position to cover a huge area, but also to provide services at favourable prices, guaranteeing, for example, a 24 hours service."
w w w. st e m m e r- i mag i n g .c o m
> Mechanical engineering & imaging in a perfect union
> Implementation facing obstacles
To accomplish the task, ten tubes each are grasped by the gripper
mentioned above and deposited in special holders where they are
then positioned by turning them around their longitudinal axes in
400 ms. During this process, five DALSA Genie CMOS cameras from
the Canadian manufacturer Teledyne DALSA check two tubes each
for correct position of the print marks needed for proper orientation
of the tubes. The image signals transmitted via Gigabit Ethernet
interface are evaluated on two PCs using the powerful VisionPro
software by Cognex. The results of this evaluation are then communicated to the rotation stations. The image processing system
thus ensures that the positions of the ten tubes remain within the
necessary precision limit of less than 2 degrees.
The Genie cameras used were able to provide the necessary frame
rate of about 110 images per second with a defined field of view
resolution of 1024 x 768 pixels. "As only part of the image was
needed for tube alignment, we were able to operate the cameras in
partial scan mode which made it possible to increase the frame
rate even more", reports Manfred Hild. In this way, the system
manages more than 220 tubes per minute, thus providing the
performance needed for cost-effective production.
Blue light: Tests revealed that LED light sources in the blue wavelength spectrum
are the best solution to obtain an optimal contrast between the tube and the
print mark and between the tube edge and the background.
Once the suitable cameras had been selected, further issues still
had to be addressed. Taking into account that the system has been
designed for clean room applications, the entire hardware for image
processing inside the machine had to be installed in a housing specially developed by Harro Höfliger. This housing has been designed
in accordance with GMP regulations (Good Manufacturing Practice)
and has a special surface coating for easy cleaning.
As the cameras, lenses and lights had to be installed under glass
owing to the cleaning requirements, the installation angle of the
cameras had to be selected in such a way as to prevent light reflections on the camera. Another difficulty was the limited space for
the cameras inside the housing. "To solve this problem, we have
chosen 90° angled heads for the Genie cameras, as recommended
by our vision partner STEMMER IMAGING", explains Hild.
We also had to take into account that it was not possible to completely shield the system from extraneous light and that pivoting
tools of the machine protruded into the camera's field of vision.
"These brilliant chrome parts create various disturbing reflections
while moving. But we have managed to solve this problem by
combining edge detection and histogram vision software tools",
describes Manfred Hild the approach taken in this matter.
imaging is our passion
Another difficulty was to detect the white semi-transparent tube
edges and the print marks on the tubes against the silver steel
background or the glass panes in the machine. According to
Mr.Hild, STEMMER IMAGING provided a solution for this problem as
well: "Tests performed during the design phase made it clear that
LED light sources with wavelengths in the blue spectrum provided
the best contrast between the tube and the print mark and between
the tube edge and the background."
> Mechanical engineering & imaging in a perfect union
> Image processing as the key element
According to him, this is a reason why Harro Höfliger, in contrast to
other players of the branch, employs its own machine vision specialists. "We consider this technology a central topic of our work.
Having the necessary expertise ourselves enables us to provide a
more comprehensive and faster service to our customers", explains
Mr. Hild, who feels confident that this strategy is much more efficient considering the large number of machines produced by his
company every year.
In spite of, or maybe just because of, the machine vision expertise
available in their own company, the team around Manfred Hild rely
on a strong supplier for the image processing components required.
Hild feels certain that he has already found the right partner:
"STEMMER IMAGING has been Harro Höfliger's supplier of machine
vision products for many years already. I particularly appreciate the
company's consultancy services when it comes to select the best
components for the respective application. This has often saved us
precious time", stresses Hild.
Hella Gillig is the sales contact at STEMMER IMAGING for many of
the projects already carried out. In cooperation with colleagues
specialised in certain fields, she determines the suitable components and has the necessary tests performed in the company's laboratory. "In this way, we can always use our wide range of available
resources, with the option of drawing on the latest developments
from our suppliers", says Gillig and adds that hardly a customer
could afford to have his own image processing laboratory with
comparable comprehensive and up-to-date equipment. Manfred
Hild also values this offer: "I can take my customers to STEMMER
IMAGING to check out some ideas in an early stage of the project.
This is really a great service!"
WWW.STEMMER-IMAG I NG.COM
•
With the cover removed, the five DALSA Genie cameras with angled head, their
lenses and the two LED luminous panels can be clearly seen.
He mentions another reason for their cooperation with the technology suppliers from Puchheim: "Purchasing image processing
components from one source and relying on globally available
products is part of Harro Höfliger's strategy. The systems we produce for our customers are used all over the world. Being able to
provide fast replacement of components even internationally is
therefore very important to us."
Since both Harro Höfliger and STEMMER IMAGING use standard
components as far as possible, the new owner of the functional
tube filling machine can be assured that maintenance of the system will not cause any problems.
I MAG I N G I S O U R PAS S I O N
GERMANY
UN ITED KI NGDOM
FRANCE
SWITZERLAN D
Phone: +49 89 80902-0
[email protected]
Phone: +44 1252 780000
[email protected]
Phone: +33 1 45069560
[email protected]
Phone: +41 55 415 90 90
[email protected]
APP-PHARM1-08/2011 ∙ Subject to technical change without notice. No liability is accepted for errors which may be contained in this document.
For Manfred Hild, the alignment station developed together with
STEMMER IMAGING is the key part of the machine: "Our customer
attached great importance to the correct rotation position of the
tubes before filling and to an increase in productivity. To meet these
requirements we absolutely needed a suitable image processing
system." He summarized his words in a general statement: "The
pharmaceutical industry insists on total control of their products,
covering all fields, from plasters to capsules. For this reason, there is
practically no machine without a complex image processing system in this industrial sector."