Specification :
It is our pleasure to service your sealing needs
Quality makes the difference
Superior manufacturing concept
A global partner to share your vision
High performance sealing materials
Classification of sealing materials
- Elastomers
- Thermoplastics
Material availability restrictions
Standard range of food compliant materials
Injection moulding, test facilities and general terms
Material data
Piston seals
Rod seals
Wipers
Rotary seals
Guide rings
Back-up rings
Static seals
Piston seal housing details and recommendations
Rod seal housing details and recommendations
Wiper housing details and recommendations
Rotary seal housing details and recommendations
O-ring housing details and recommendations
Guide ring housing details and recommendations
Introduction
Material Specs - Overview
Product Range SEALS
Housing Details
Due to our production process we are able to produce any special seal profile in any diameter ( up to 4.000 mm) .Therefore - in combination with our
R& D department - we can offer tailormade sealing solutions to our customers. Furthermore we produce a wide range of gasket types, engineering
plastic parts ( EPP) and advanced engineering plastics products ( AEPP) .
Do not hesitate to contact our technical department for further informations.
of contents
onte
Back-up ring
Rod seal
Wiper
Whenever it comes to sealing technology,
we are your most versatile partner.
High performance sealing materials
A global partner
to share your vision
It is our pleasure to
service your sealing needs
Quality makes the difference
Superior manufacturing concept
At DMH, we offer you:
• Sealing solutions tailored to your specifications
• Partnership from the design phase to serial production
• Just-in-time manufacturing of seals and components up to 4.000 mm diameter
• Production of gaskets in miscellaneous materials by water-jet-cutting technology
• Production of Advanced Engineering Plastics Products ( AEPP)
Quality is at the core of everything we do. Production breakdowns due to sealing problems
can cause huge losses. Therefore, we make every effort to deliver high quality
sealing products that meet our customers‘ needs.At DMH, we are constantly striving
to enforce and improve our quality standards, since customers demand the highest
quality sealing solutions to compete in their highly competitive markets and thereby
gain a competitive edge on their competitors.
At DMH we know that only state-of-the-art technology can provide us with an
edge on our competitors. A rapidly changing environment demands new production
concepts that surpass our customers‘ requirements, such as:
• Delivery on demand with short cycle times
• No mould or tooling limitations
• No stock requirements for our customers
• Seal engineering to customer specification
To face this challenge, we developed the Seal-Jet System to manufacture seals with
cutting edge CNC turning technology to satisfy the very specific needs of every customer,
in every industry.
Wherever sealing is an issue, that‘ s where we do our business. At DMH, we offer
innovative sealing solutions that make us the first call when it comes to sealing technology.
We provide a comprehensive technical service and are committed to supply a
complete sealing solution best suited to our customers‘ needs.
Our world wide network of subsidiaries and partners allows us to meet these needs
any time, anywhere, around the globe.
At DMH, we know that only high performance materials can meet the demands
of the marketplace today and tomorrow. For this reason, we have invested in a stateof-
the-art R& D center at our Austrian group headquarters to constantly improve our
materials and seal design, thus maintaining our sealing industry leadership. The
DMH family of polyurethanes for instance, is renowned throughout the world.
This in-house expertise in the field of high performance sealing materials, combined
with close co-operations with universities, has given us a competitive edge on our
competitors.We offer our customers not only a wide range of class leading standard
materials, but we can also develop specialist compounds to meet specific needs when
required.
In sealing technology, mainly representatives of two groups of macromolecular
( polymeric) substances are used, i.e. substances of the groups of elastomers and
thermoplastics.
Macromolecular substances are organic compounds whose molecules exist of
several thousands, often even millions, of atoms which are known as macro, giant,
string or chain molecules. They can be created either by modification of highly
molecular natural materials ( e.g. natural rubber) or by depositing low-molecular
elements ( so called monomers) through various chemical reactions ( synthetic
materials, plastics) .
POLYURETHANE, RUBBER, ...
Elastomers are materials that can be highly expanded by exerting relatively little
power. Because of their structure, elastomers have a high elasticity and resilience,
which means the remaining deformation is very small. There are two main groups
of elastomers, the chemically cross-linked materials ( rubber materials) and thermoplastic
elastomers.
The thermoplastic elastomers ( e.g.TPU, TPE, ...) demonstrate the characteristic properties
of elastomers over a wide temperature range. They are physically but not
chemically cross-linked, therefore they can be melted at higher temperature and
can be processed with traditional thermoplastic processing techniques.
Thermoplastic elastomers are soluble, generally, they swell less in comparison to
their chemically cross-linked equivalents.
The rubber materials or elastomers ( e.g. NBR, FPM, EPDM, ...) are polymers, which
are formed by cross-linked macromolecules with various vulcanization additives.
Due to their chemical cross-linking they do not melt and they begin to decompose
at high temperatures. In addition the cross-link ensures that rubber materials do
not dissolve and, depending on the medium, do suffer more or less intensive swell
or shrinkage.
POM, PTFE, PAEK, ...
Thermoplastics can be melted. They are polymer materials, which are essentially
harder and rigid at their application temperature compared to elastomers.
Depending on the chemical structure, the properties vary from hard, to stiff, to
ductile and flexible. Due to the morphological structure, extensive stretching is
non-reversible and moulded parts remain in the deformed state. Thermoplastics
are therefore called plastomers.
Plastomers are mainly used as construction parts and sometimes as spring-energized
sealing parts as well.
• Thermoplastic elastomers up to ø 4.000 mm
• Rubber materials or elastomers up to ø 1.500 mm
• Plastomers & PTFE materials up to ø 2.000 mm
Elastomers
Thermoplastics
Material availability restrictions
Classification of sealing materials
m Standard range of food compliant materials
food compliand
DMH products are well known and are specified by many of the leading
companies in many different industries worldwide and are renowned for their longevity
and ability to outperform traditional seals. These factors are becoming
more and more appreciated in the food and beverage industry, where the trend is
for increased productivity, less downtime and better hygiene.
Supplying a wide range of applications in the food and beverage industry, including
many in the bottling, canning and food machinery sector, our global experience
is at our customers’ command. Wherever seals and seal components are
required DMH can provide Quality Sealing Solutions on time.
H-PU ( red)
H-PU ( blue)
H-PU-95A-NC ( white/ natural)
NBR-H-85A-B-FG ( black)
FKM-85A-W-FG ( white)
EPDM 3-85A-W-FG ( white)
EPDM 3-85A-B-FG ( black)
MVQ ( reddish brown)
PTFE 1 ( white)
ECOPE ( white/ natural)
PAEK ( cream)
others upon request
Suction cups, Can flange seals, Guide bushes, Valve stem packings, Bottle top seals,
Rollers, Pump packings, O-rings, Centre column seals, Filling head seals, Pneumatic
U-cups, Depositor seals, Distributor seals, Pigging seals, Ball valve seats, Seal kits
etc...
Material science is an DMH strength. For instance, our world class polyurethane
H-PU is not only FDA, NSF & KTW compliant, but is also resistant to hot
water, caustic solutions and just about anything else found in the food and beverage
industry. This material outperforms conventional materials in most applications,
particularly depositor seals and filling head seals.
Food industry
Food and pharmaceutical
compliant materials
Typical applications
Material science
7
Injection moulding, test facilities and general terms mater
nncjeection mou In the late 90´ s DMH started to work also with injection-moulding of seals in
a conventional manner and therefore we are a well qualifyed partner, able to supply
sealing solutions from a single piece up to thousands and more.
The in-house research centre and excellent human resources in material science
enables DMH to offer individual material development for specific customer
needs or special projects.
Years of experience in dynamic and static sealing solutions in connection with the
use of modern finite element analysis programs ( FEA) for non-linear material
behaviour became an important tool to optimize seal profiles, r esulting in excellent
sealing characteristics for all pressure ranges and reliable performance.
The state-of-the-art test rigs at DMHR& D centre support practical experience
for both, linear and rotary movement of seals.
Polyurethane materials:
Please note, tha t seals with a diameter of more than 600 mm are made of G-PU
( as a substitute for PU or H-PU) .
Rubber materials:
The whole elastomer material range ( NBR, FKM, EPDM, H-NBR , ECOFLAS, MVQ) can be
offered now with outer diameters up to 1550 mm.
The stated operating parameters represent general conditions. It is recommended
NOT to use all maximum values simultaneously.The specified pressure limits apply
for use in mineral oil with a maximum temperature of 60° C and a maximum metal
extrusion gap of 0, 25 mm.The speed limits apply for adequate lubrication and running
surface finishes as recommended.
Due to the many variable conditions to achieve sealing solutions DMH also
recommends that material / media compatibility and sealing function be tested
for targeted performance under actual field conditions.
Depending on application details, higher pressures and speed limits can be attained
in most cases. If any of the indicated limits do not meet specific requirements
please contact the nearest DMH Branch or Subsidiary.
This brochure is for information purposes only and cannot substitute individual
consultation. The information is based on many years of experience, on FEA-calculations
and test results. As far as we can assess this information is the most updated
and according to the highest technical standard currently available. However,
DMH cannot guarantee and/ or take any responsibility, obliga tion or liability
whatsoever in connection with this information. In particular, DMH is not liable
for damages or losses that occur in connection with the use or implementation
of this information.Warranties for special features, cer tain aim and utility are subject
to a separate agreement.
Injection moulding
Material development
Test- & simulation facilities
Notes for large diameter seals
General terms and conditions