tailieunhanh - Conductive Polymers and Plastics in Industrial Applications Part 14

Tham khảo tài liệu 'conductive polymers and plastics in industrial applications part 14', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 270 Conductive Polymers and Plastics Figure 2. Cellular phone test housing with 1-mm-thick walls. Table 1. Summary of results for drop impact testing Days Nylon 6 IM0 pass pass 14 Nylon6IM2 20 glass pass 27 Nylon 6IM2 15 glass pass pass 19 21 Nylon6IM1 15 glass pass pass 15 16 Nylon 6 IM2 33 glass pass fail 27 Nylon 6IM2 30 glass pass fail 26 Nylon 6 IM1 30 glass fail pass 14 15 PC ABS-1 HF fail fail 14 PC ABS-2 fail 27 telecommunications industry. These housings were dropped a total of 18 times from a height of meters onto a concrete surface at room temperature. The gram housings were weighted with a 160 gram internal steel plate secured on 6 bosses to simulate the influence of internal components on impact. Any crack in the housing was considered to be a failure. All housings were preconditioned for a minimum of 2 weeks at 50 relative humidity. Results of this testing are summarized in Table 1. The data generally show that The unfilled and 15 glass-filled nylon 6 materials consistently passed this test Nylon with 30 or higher glass-filler levels passed this test about half the time The two grades of PC ABS did not pass this test. Failures generally occurred at cracks along the weldline on the bottom of the part. These results are consistent with tests performed in our laboratory on commercial thin-wall housings. PROCESSING COMPARISON OF SIMULATION WITH EXPERIMENT Filling of the 1-mm-thick housing shown in Figure 2 was simulated for the nylon 6IM0 material and the PC ABS-1 HF material. This simulation was performed using the Multilaminate Filling Analysis from Moldflow of Australia Ltd. As shown in Figure 3 the predictions lines are in reasonable agreement with injection pressure data solid symbols obtained using a data acquisition system to measure pressure at the sprue. Thin-wall Housings 271 Figure 3. Comparison of simulation vs. data for injection Figure4. . pressure. SIMULATION OVER A RANGE OF OPERATING .