TRANSFORMING PROCESSES
»Solplast« compounds can be processed through the typical thermoplastic technologies like polyolefines, such as injection-moulding, extrusion, blow-moulding and thermoforming.
»Solplast« compounds do not require drying before processing, apart from some special grades.
Finished product hardness strongly depends on the used processing technologies and the construction of tools.
Finished products hardness is basicaly lower by extrudirated products then injectionmoulded ones when the same raw material is used.
INJECTION MOULDED
Srew construction:
Polyolefins screws having L/D ratio >= 20 and compression ratio ranging from 2.0 to 3.5:1 are the most suitable. Most injection-moulding machines are equipped with universal screws that have a compression ratio between 2:1 and 3:1. Special screws with short sections and higher compression ratio (3:1 to 4:1) mast be good at low screw speeds.
Nozzles:
Most nozzle types can be used. Solplast compounds based on SEBS block
copolymers may remain stationized in heated place much longer then compounds based on SBS block copolymers. For the materail does not degrade at normal processing temperature and does not give rise to gas and high gas pressures inside nozzle neither inside screw.
Plasticizing speed:
High
Injection speed:
- SOLPLAST TC : low to medium high
- SOLPLAST TH , TV : medium high to high
Injection pressure:
Medium high
Influxes into mould:
Recommended are extremely short canales in a rolle shape with slightly reducing diameter rolles until injection point into mould.
Injection point:
Normally having circular shape and diameter >= 0,7 mm.
Air-venting the mould:
Mould should have a proper air-venting.
- PROCESSING TEMPERATURE;
- SHRINKING
PROCESSING TEMPERATURE
- SOLPLAST TC : between 150 and 200 °C
- SOLPLAST TH,TV : between 160 and 220 °C
Recomended temperatures (SOLPLAST TH and TV series):
| Hardness | 1 Zone (°C ) | 2 Zone (°C ) | 3 Zone(°C ) | Nozzle(°C ) | Mould(°C ) |
| < 55 ShA | 160 | 170 | 175 | 180 | 20-40 |
| 55-85 ShA | 170 | 175 | 180 | 185 | 20-40 |
| > 85 ShA | 180 | 190 | 195 | 200 | 20-40 |
Recomended temperatures (SOLPLAST TC series):
| Hardness | 1 Zone (°C ) | 2 Zone(°C ) | 3 Zone(°C ) | Nozzle(°C ) | Mould(°C ) |
| 30-55 ShA | 140 | 150 | 160 | 160 | 20-40 |
| < 80 ShA | 160 | 170 | 180 | 180 | 20-40 |
| > 80 ShA | 170 | 180 | 185 | 195 | 20-40 |
Exact setting depands of technical properties from injection-moulding mashines and geometry of the final product.
SHRINKING
When a mould is being designed, considerations must be giving to the shrinking properties. For:
- SOLPLAST TC compaunds (SBS block copolymers / PS ) is shrinking between 0,4% and 1%
- but as for SOLPLAST TH ( SBS block copolymer /PP) is between 1% and 2,5%
- and for SOLPLAST TH,TV ( SEBS,SEEPS block copolymer /PP) is shrinking between 1% in 2,5%.
Shrinking depends on composition, hardness and a processing type of compaunds.
For SOLPLAST TH, TV series orientation data is givig in table below:
| Hardnes | Shrinkage |
| ShA 35 | 2,0%-3,0% |
| ShA 65-70 | 1,5% -2,5% |
| ShA 90 –ShD 40 | 1,0% -1,5% |
EXTRUSION AND BLOW-MOULDING
Solplast compounds can easily be extruded, provided the right process parameters are used.
Screw construction
Screws having L/D ratio >= 20 and compresion ratio 3 : 1 are most suitable. Screw must be able to provide sufficient mixing of the material, breaking plate with little holes for a better dispersivity and mixing of material is used befor the head.
Profile thickness:
Recommended thickness of walls is < 10 mm
Breaker plate:
Holes dimeter 60 Mesh.
Drying:
Usually not necessary.
- PROCESSING TEMPERATURES;
- SOLPLAST TC : between 150 and 200 °C
- SOLPLAST TH,TV : between 170 and 220 °C
Recomended temperature (SOLPLAST TC):
| Hardness | 1 Zone (°C ) | 2 Zone (°C ) | 3 Zone (°C ) | Head (°C ) | Mould (°C ) |
| 30-55 ShA | 140 | 150 | 160 | 160 | 150 |
| < 75 ShA | 150 | 160 | 170 | 180 | 170 |
| > 75 ShA | 160 | 170 | 180 | 190 | 180 |
Recomended temperature (SOLPLAST TH,TV):
| Hardness | 1 Zone (°C ) | 2 Zone (°C ) | 3 Zone (°C ) | Head (°C ) | Mould (°C ) |
| 30-55 ShA | 160 | 165 | 170 | 170 | 160 |
| < 75 ShA | 165 | 175 | 185 | 185 | 175 |
| > 75 ShA | 170 | 180 | 185 | 195 | 185 |
Exact setting depands on technical properties from exstruding mashine and
caracteristics from the exstrudirated product.