SABIC®LDPE, SABIC®LLDPE and SABIC®HDPE, stable foundations for masterbatches
Masterbatches
Spices are never far away from the thoughts of famous chefs preparing haut cuisine recipes. They give both a strong basic taste and the final touch to a dish. When salt and pepper will do to satisfy the average eater, sometimes delicate spices are needed to impress the gourmet.
Similarly as spices in the cooking business, polymer converters use additives. Technicians in polymer processing give their products essential properties by adding these additives as masterbatches into basic polymers. As adding average masterbatches is sufficient for low-end applications, selecting the right mélange for the high-end technical performance is essential.
Different from spices however, masterbatches are not grown by nature, but are produced by masterbatch manufacturers. Masterbatches provide end products with a wide range of colours including black and white. For technical purposes a large number of additive masterbatches are produced.
Foundation
The foundation of the masterbatch is called the carrier, the virgin polymer into which all ingredients are mixed. This mixing process is executed at temperatures in excess of the melting point of the carrier polymer. By using high shear forces (during kneading) pigments and additives are dispersed in a proper way.
SABIC® LDPE has a long history in this application and has been proved to be a very reliable foundation in the production process of many masterbatch producers in Europe and other parts of the world.
SABIC Europe produces SABIC® LDPE both by the tubular CTR® and autoclave reactor process.
Stamylan’s excellent performance in the masterbatch segment is based upon a few of its main characteristics
- Low gel level, due to very constant production conditions in the reactor systems and a special designed homogenisation process.
- In the polymerisation processes, no catalysts are used. All SABIC® LDPE grades do not contain anti-oxidants or thermal stabilizers due to their intrinsic stability and absence of catalyst-residues. This results in a material eminently suitable for all heavy kneading processes.
The SABIC® LDPE assortment for masterbatches comprises:
- Standard grades, for film extrusion, blow moulding and injection moulding applications
- Special grades, for extrusion coating applications
Standard grades: SABIC® LDPE from SABIC’s proprietary CTR® reactors
The grades produced in the CTR® reactor systems are characterized by following qualities: The polymerisation process is operated under very stable and constant conditions resulting in grades that are very homogeneous with a consistent high quality. They further show a low gel level and an excellent intrinsic stability.
The final viscosity of the masterbatch, for example containing 70% TiO2, can be varied by choosing a SABIC® LDPE grade of differing MFR. This is illustrated in the viscosity/MFR graph, which shows viscosity at 190° C, at shear rates, which occur under extrusion conditions.
A broad range of different MFR’s is available for different applications.
Viscosity vs. MFR at 70% TiO2 loading
SABIC® LDPE "tubular" product range for masterbatches
Special grades: SABIC® LDPE from Autoclave reactors LD
The grades produced by the high-pressure autoclave process are characterized by their high purity. Compared with the “tubular” grades they show a more broad molecular weight distribution.
Because of this wider molecular weight distribution, autoclave grades are special suited for high-speed extrusion coating applications. Masterbatches for this application are preferable produced with autoclave grades.
The final viscosity of the masterbatch, for example containing 70% TiO2, can also be varied by choosing a grade of differing MFR. This is again illustrated in the viscosity/MFR graph, which shows viscosity at 190° C, at shear rates, which occur under extruding conditions. SABIC® LDPE autoclave grades are shown below.
Viscosity vs. MFR at 70% TiO2 loading
SABIC® LDPE "autoclave" product range for masterbatches
New: SABIC® LLDPE and SABIC® HDPE for masterbatch applications
From the new SABIC Europe gasphase process two grades are specially suited for masterbatch and compounding applications:
- SABIC® LLDPE 318B a basic LLDPE grade, for general use in LLDPE film applications, general extrusion and compounds.
- SABIC® HDPE 0863F is a special homopolymer HDPE grade with a very low gel level and a good intrinsic stability. This makes the grade especially suited for extrusion coating when stiffness is needed. Also the product finds its way to other HDPE applications, when stiffness, combined with good flow properties are required.
SABIC® LLDPE "gasphase" product range for masterbatches
Any Questions? TCC.TM-PE@sabic-europe.com
