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Cylinder Temperature

Contents Introduction Molding
Conditions		 Moldability Molded Product
Quality		 Mold
Design		 Safety Countermeasures
[ Standard conditions ] [ Pre-drying ] [ Cylinder temp. ] [ Mold Temp., Injection Speed and Molding Cycle ]
List of DURANEX® PBT grades This page's PDF (1.72MB)

2.3  Cylinder Temperature

Because the melting point of DURANEX® PBT is around 224°C,the appropriate resin temperature is from 250°C to 270°C. If the temperature exceeds 280°C, decomposition begins; therefore, a temperature around 270°C should be considered as the upper limit.

The effects of cylinder temperatures and residence time in the heated cylinder on mechanical properties of DURANEX 3300 are shown in section (a) Figs. 2-4 through 2-7, and DURANEX 3316 in section (b) Figs. 2-8 through 2-11. It is a matter of opinion what value should be regarded as the limit but in Table 2-1, the longest allowable residence times are estimated from such points as the melt index rises to 2 times of its initial value and color difference more than 2.5 of their original levels.

(a) Residence Time in Heated Cylinder vs. Various Properties
    of DURANEX® PBT 3300

Figure 2-4Figure 2-5

Figure 2-6Figure 2-7

(b) Residence Time in Heated Cylinder vs. Various Properties
    of DURANEX® PBT 3316

Figure 2-8Figure 2-9

Figure 2-10Figure 2-11

Table 2-1  Resin Temperature vs. Allowable Residence Time of DURANEX® PBT

Grade Resin temperature
250°C 270°C
DURANEX 3300 30 min 20 min
DURANEX 3316 30 min 10 min

 

[ Standard conditions ] [ Pre-drying ] [ Cylinder temp. ] [ Mold Temp., Injection Speed and Molding Cycle ]
Contents Introduction Molding
Conditions		 Moldability Molded Product
Quality		 Mold
Design		 Safety Countermeasures