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Use of inorganic fillers to reduce flammability in polymers
June 1991
Additivesfor Polvmers
TECHNICAL NOTES Plasticizer retention in PVC
Fo~~a~o~ developed in Czechoslavakia reduce plasticizer migration from PVC by two methods 1) co~l~~zation in the presence of polymeric plasticizers with special crosslinking agents which results in a lightly crosslinked network, and 2) copolymerizing a proprietary monomer with the PVC which flexibilizes the material. End use applications include building materials and medical tubing. P&x&. Tech., 1991,37,(Feb.), 14
Migration from packaging
PIRA International of Leatherhead, Surrey (UK) is launching Phase IV of its research programme Migration from Packaging into Foods with the aim of developing test methods to be established as European stsndards, and to provide migration and other data on substances which will allow their continued use in food packaging. Since 1985 the PIRA Migration Research Programme has provided industry with research in the field of migration, relating to the EC. Legislation on food packaging covering additives for plastics for food packaging use is expected later this year.
Use of inorganic fillers to reduce flammability in polymers
This paper examines the usefulness of the oxygen index test for screeningfire r&ardant fillers. This test is shown to be very sensitive to the ash residue formed and hence can be misleading. In particular it appears to overestimate the beneficial effects of some fillers and the deleterious effects of some coatings. The potential for calcium hybxide as a fm retardant is also examined. It exhibits little activity, apparently because it reacts exothermically to the carbonate rather than endothermically to the oxide. Pltzst. R&b. & Composites Proc. & Appii,
Improving the processing and mechanical properties of WC
1992, lb;29-21
The use of increased quantities of filler in rigid PVC is desirable to reduce raw material costs. Despite the increase in specific gravity which occurs with increasing filler concentration, cost per unit volume decreases as the fIIler concentration is increased f+om 10 - 100 parts per hundred of resin (phr). With increased filler loadings increases in stabilizer, lubricant and processing aids are required to maintain an acceptable rate of extrusion. Coating the filler results in a reduction of fusion time and a decrease in the level of additions required. Snowcal Coated 758150 has been developed by Blue Circle Industrial Minerals for use in UPVC, and its use is described in Information Sheet No. 3 available from: Blue Circle Industrial Minerals, Melton, North F&by, Bull HU14 3HW (UK). Tel: +&4%&633351.
Q1991 Elsevier Science Publishers Ltd.
Additivesfor Polvmers
TECHNICAL NOTES Plasticizer retention in PVC
Fo~~a~o~ developed in Czechoslavakia reduce plasticizer migration from PVC by two methods 1) co~l~~zation in the presence of polymeric plasticizers with special crosslinking agents which results in a lightly crosslinked network, and 2) copolymerizing a proprietary monomer with the PVC which flexibilizes the material. End use applications include building materials and medical tubing. P&x&. Tech., 1991,37,(Feb.), 14
Migration from packaging
PIRA International of Leatherhead, Surrey (UK) is launching Phase IV of its research programme Migration from Packaging into Foods with the aim of developing test methods to be established as European stsndards, and to provide migration and other data on substances which will allow their continued use in food packaging. Since 1985 the PIRA Migration Research Programme has provided industry with research in the field of migration, relating to the EC. Legislation on food packaging covering additives for plastics for food packaging use is expected later this year.
Use of inorganic fillers to reduce flammability in polymers
This paper examines the usefulness of the oxygen index test for screeningfire r&ardant fillers. This test is shown to be very sensitive to the ash residue formed and hence can be misleading. In particular it appears to overestimate the beneficial effects of some fillers and the deleterious effects of some coatings. The potential for calcium hybxide as a fm retardant is also examined. It exhibits little activity, apparently because it reacts exothermically to the carbonate rather than endothermically to the oxide. Pltzst. R&b. & Composites Proc. & Appii,
Improving the processing and mechanical properties of WC
1992, lb;29-21
The use of increased quantities of filler in rigid PVC is desirable to reduce raw material costs. Despite the increase in specific gravity which occurs with increasing filler concentration, cost per unit volume decreases as the fIIler concentration is increased f+om 10 - 100 parts per hundred of resin (phr). With increased filler loadings increases in stabilizer, lubricant and processing aids are required to maintain an acceptable rate of extrusion. Coating the filler results in a reduction of fusion time and a decrease in the level of additions required. Snowcal Coated 758150 has been developed by Blue Circle Industrial Minerals for use in UPVC, and its use is described in Information Sheet No. 3 available from: Blue Circle Industrial Minerals, Melton, North F&by, Bull HU14 3HW (UK). Tel: +&4%&633351.
Q1991 Elsevier Science Publishers Ltd.