INSERT BLOCKS WITH SLIT VENT PERFORMANCE EVALUATION DATA AND INTRODUCTION EXAMPLES
■ Performance evaluation overview Molded a product (Fig. 1) with a shape that easily causes appearance defects using a prototype mold, and checked the appearance. In addition, the pressure inside the mold was measured and the performance was compared with other commercially available products (Table 1). Equipment used, etc. • Molding machine: GL150 (Sodick) • Pressure sensor: LSMS–100K–S06 (MinebeaMitsumi) • Resin: PP Sun Aroma VM970Y PA66 Toray CM3001M
[Fig. 1] Image of molded product
[Table 1] Gas Vent Components
3) Resin clogging durability
※ Resin: PA66
Pressure sensor (Final lling part)
Installation components Insert blocks with slit vent (SGWD24)
Shape/Size
Number of shots
2000th shot
10000th shot
30
30
20mm 10mm
25
25
Runner gate
Pressure waveform in one shot
Porous metal
20
20
15
15
20mm
10mm
Pin with slit
10
10
Insert blocks with slit vent Pin with slit Porous metal
5
5
Gas release parts
φ 6mm
■ Evaluation results
0
0
1.5
1.6
1.7
1.8
1.9
2
2.1
1.5
1.6
1.7
1.8
1.9
2
2.1
• Gas vent performance test
Time (sec)
Time (sec)
1) Appearance of final filling part under high injection speed conditions
※ Resin: PP Injection speed: 160 (mm/s)
Insert blocks with slit vent
No abnormality
No abnormality
Components No gas release measures Insert blocks with slit vent
Pin with slit
Porous metal
Pin with slit
No abnormality
No abnormality
Porous metal
Burning occurs
(Not implemented)
Burning occurs quickly in porous metal, and abnormalities do not occur in insert block with slit vent and pins with slit.
Appearance
■ Introduction example
1) Elimination of weld due to hole shape
Precondition • Molded products: A utomobile exterior parts
Molding condition • Maximum injection pressure: 160 (MPa) • Holding pressure: 80 (MPa) • Injection speed: 3.8 (mm/s) • Filling time: 2.9 (s) Introduction result Mass production of 109,000 shots completed without noticeable welds
State
Good item
Wide range burn
Burn
Microscopic short
(500 × 250 × 50, average wall thickness 3mm)
In the insert blocks with slit vent, no abnormal appearance occurs even if the injection speed is increased ⇒ Gas is efficiently released.
ASA + PC (MFR: 15cm 3 /10min)
• Resin:
• Mold temperature: 270 ℃ SGWD24 introduction details Due to the retention of hole shape, the resin flow is divided and welds occur frequently. Installed at 7 locations on the core side of frequent occurrence positions (blue in the left figure). Precondition • Molded products: A utomobile exterior parts (850 × 350 × 100, average wall thickness 2mm) • Resin: PP (MFR: 30g/10min) • Mold temperature: 220 ℃ SGWD24 introduction details Installed for improving resin clogging durability in preparation for no–maintenance molding at overseas bases. Installed at 2 locations (6 each) on the core side of the final filling part (blue in the left figure). Precondition • Molded products: A utomobile functional parts (150 × 80 × 40, average wall thickness 0.58mm) • Resin: PBT–GF15 • Mold temperature: 260 ℃ SGWD24 introduction details Since it is a thin–walled and glass–filled engineering plastic product, a large amount of gas is generated and shorts occur frequently. Installed at 5 locations on the core side of the occurrence position (blue in the left figure) to eliminate this.
2) Final filling part mold internal pressure under short conditions
※ Resin: PP Injection speed: 100 (mm/s)
2.5
2
2) No maintenance molding
Final filling part Pressure waveform in one shot
Introduction result 100,000 shots with no maintenance
1.5
Molding condition • Maximum injection pressure: 160 (MPa) • Holding pressure: 30 (MPa) • Injection speed: 40 (mm/s) • Filling time: 3.3 (s) (1500 hours: about 5 months) Achievement of continuous molding
1
Insert blocks with slit vent Pin with slit Porous metal
0.5
0
0.95
1
1.05
1.1
1.15
1.2
1.25
1.3
1.35
Time (sec)
Gas vent components Insert blocks with slit vent
Pin with slit
Porous metal
Pressure peak value
1.87
2.30
2.02
3) Eliminating shorts in thin–walled engineering plastic products
Introduction result Short resolution, 480,000 shots Ongoing mass production
Molded product appearance
Adjust the molding conditions so that the size of the short part is the same
Molding condition • Maximum injection pressure: 180 (MPa) • Holding pressure: 60 (MPa) • Injection speed: 20 (mm/s) • Filling time: 1.1 (s)
The peak value is the smallest in the insert blocks with slit vent ⇒
Gas is released more efficiently than
other commercially available products
441
442
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