PRIMIX is a manufacturer of static mixers and heat exchangers for the production and processing of polymers and fibres. With over 30 years of experience, we provide solutions through static mixers and heat exchangers for:
Homogenisation of molten material
Removing vaporous components
Cooling of molten fibre / polymer
Mixing additive – Admixing
Plastic / Polymer by means of injection moulding
Blending titanium into liquid polymer
Mixing several different sorts of polymer
Polymerization in a plug flow reactor
Static mixers and heat exchangers for polymers and fibers
The PRIMIX static mixers and heat exchangers can be used in production systems for the processing of the following types of polymers:
ABS (Acrylonitrile Butadiene-Styrene)
Polyethylene - PE
PTA (Purified Terephthalic Acid)
Polypropylene - PP
PET - Polyethylene terephthalate
EPS and PLA
Optimal homogenisation of the melt
A perfectly homogenised melt is one of the most important requirements for obtaining a high-quality polymer or fibre product. Irregularities, such as streamlines, colour streaks, non-uniform wall thickness, and flow variations lead to increased product failure and thus to higher production costs. This is often due to the homogenising of a bad melt.
Heat exchangers for polymer chemistry
Within this field of application where high viscosity, pressures and temperatures play a role, a number of aspects are of interest which can adversely affect heat transfer within a heat exchanger. These are:
- Thick tube walls, for the necessary strength as a result of the high process pressures
- Low thermal conductivity of the polymer
- Laminar flow as a result of the high viscosity
- Small acceptable logarithmic temperature differences due to the strongly temperature dependent viscosity.
PRIMIX technology for static mixer heat exchanger
During the development of the static mixer heat exchanger PRIMIX paid a great deal of attention to the technology to be applied for the connection of the mixing element and the process tube. The solder connection between element and tube is not an amorphous layer, but because of the soldering method it takes on the austenitic structure of the parent material, which creates one entity. The resistance to heat transfer of the compound is equal to the material of the tube and element, while the mechanical strength comes to approximately 70% of the parent material. This connection technology results in the element surface also behaving as a heat-exchanging surface. This allows the heat exchanger to be of a more compact construction with an unchanged output. The Nusselt number of a heat exchanger with non-soldered elements is approximately three-times higher. Soldered elements are up to 10 times better.
Small residence time spreading in the PRIMIX heat exchanger for polymers
In addition to good heat transfer a low residence time spread is also very important. This is because the polymer continues responding during cooling. Polymer that stays in the heat exchanger for too long can have a negative impact on the quality of the end product. As a solution PRIMIX has adopted the application of a unique manifold, which provides a perfect distribution of the polymer across the process tubes, with complete elimination of dead zones.
The walls on the product side are finished to a roughness of 0.5 microns. Cooling is achieved by letting thermal oils flow through the process tubes in counter-current. Baffles ensure that there is good contact between the cooling oil and the process tubes. The above described design has resulted in a heat exchanger, that - thanks to its relatively small size - can be economically deployed for high viscous process media and shows an almost ideal plug -flow.
In the meantime the PRIMIX design for polymer chemistry is standard
The design is now used as standard in the polymer chemistry. The design and construction take place under all of the required design codes, including testing and inspection. Known codes are ASME VIII, AD2000, EN 13445, etc.)