Pond tarp as an example of PIB compounding
Application

Polyisobutylene (PIB) for technical applications

The special features of PIB include outstanding insulation properties and a good resistance to chemicals

The plastic polyisobutylene (PIB) belongs to the olefin polymer family. It has been manufactured industrially since the 1930s and is produced within a wide viscosity range from oil-like to raw rubber-like masses. Its mechanical properties here depend heavily on its average molar mass.

Its excellent electrical insulation property and electrical values, very good resistance against acids, alkalies and saline solutions as well as very low steam and gas permeability are its special features.

Typical areas of application

Yellowish PIB pellets, produced in a compounding plant
Scene with polyisobutylene products in technical PIB plastic applications
Dark grey cube-shaped PIB granulate, manufactured in a BUSS compounding plant
White gum base pellets from a PIB gum base compounding plant

Corresponding applications can be derived from this property profile, in which PIB (polyisobutylene) is used as a determining formulation component: Thus, its corrosion resistance is used in container linings or pipe lagging.

For sealing functions as tracks or joints the usability is valued in a wide temperature field to very low temperatures (to -50°C).

The adjustable stickiness is used both for films/foils and also hot glue applications. For packaging, in particular also for use for food due to its gas impermeability.

Further insights into our options for the plastics industry

Benefits

BUSS compounding systems offer the following specific benefits

Latest generation multi-flight BUSS compounders achieve a better mixing effect with a low overall specific energy input. This is because there is a high number of mixing cycles, optimally attuned to the respective process zone. The energy required for melting is almost exclusively introduced mechanically (dissipated) as shear energy in the compounding system.

The BUSS Co-Kneader allows precise temperature control due to controlled energy input and uniform, moderate shear rates as well as their temperature monitoring by thermocouples, which are mounted in drilled kneading pins surrounded by polymer at relevant positions along the process section.

The BUSS Co-Kneader guarantees intense distributive mixing, as the superimposition of rotation and axial movement of the mixing and kneading screw causes flow separations and a large number of shearing surfaces, thereby generating cross-channel mixing.

Screw elements, liners and kneading pins are components which are easy to replace and are easily accessible by opening the hinged process section of the BUSS Co-Kneader. All these elements can be replaced without removal of the casing or the screw shaft.

Injection pins, which can be mounted in the BUSS Co-Kneader at any position along the process section, allow liquid components to be injected directly into the molten polymer at the optimum location for the process. The mixing process begins immediately, without smearing on the barrel wall and enables mixing over the shortest possible process length.

Compounding requirements

PIB compounding

The wide range of possible applications and excellent combinability with other plastics result in challenging compounding tasks. Thus, the stickiness or also the cold flow property of the PIB (polyisobutylene) can already present a challenge when dosing and feeding to the compounding system. With sophisticated processes these high demands are taken up and implemented.

When compared with alternative systems, the BUSS Co-Kneader can take advantage of its specific strengths very well: the moderate and adjustable shear rates dissipate the met energy highly efficiently and a wide viscosity field is mastered problem-free. In the mixing zones, the enormous number of mixing cycles means that even the highest contents of aggregates such as carbon black or graphite can be controlled very well.

With the BUSS Co-Kneader's two-stage system, compounding and the pressure build-up step are strictly decoupled. This enables the optimisation of the process steps independent of each other.

For PIB compounds, the appropriate pressure build-up device is selected depending on the application. Gear pumps, for example, can be used for direct film/foil processing or a flange-mounted extruder for pelletizing highly viscous and/or filled formulations.

The hinged BUSS Co-Kneader housing enables fast access and high system availability. The modular and therefore adjustable structure of the entire line and the widely supported BUSS process expertise make the BUSS Co-Kneader an excellent choice for compounding technical PIB in all of its diverse applications.

Typical plant layout

Typical plant layout for a PIB compounding machine

COMPEO compounder for PIB manufacturing

Take a look at our typical plant layout for the production of polyisobutylene compounds in our COMPEO showroom.

Get to know our COMPEO compounder series

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COMPEO series

We present: COMPEO, the state-of-the-art compounder that offers more versatility in its application, higher flexibility in process engineering, and increased added value in compound manufacturing.

Gum base

In addition to the technical applications which are described on the corresponding pages, PIB is often used as an elastomer formulation component in the basic mass for chewing gum, the so-called gum base.

Plant and System Solutions

Custom compounding systems from BUSS: tailor-made concepts, integration of all components, precise assembly, and smooth commissioning. Comprehensive expertise results in sustainable compounding solutions for a wide range of material applications.