INJECTION MOLDING ENCYCLOPEDIA
Injection Molding Encyclopedia
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84 articles
PA6T Stringing: Should Melt Temp Exceed 330°C?
PA6T (Grivory HT1, PA6T/6I) has a tight window: melt 330–340°C, mold temp ≥140°C. Hard, glossy string breaks indicate semi-solidified material tearing. Outlines steps: inspect string shape, measure outlet temp, check gate shear, adjust cut-off position. Explains why SD Series is recommended for this material group.
PEEK Nozzle Clogging: Impact of 395°C Melt vs. 170°C Mold
PEEK 650G specs: nozzle 395°C, mold temp 170–200°C, yielding the largest differential (195–225°C) among five materials, causing rapid tip cooling. Distinguishes between freezing and degradation clogs. Provides three-step diagnosis: temperature measurement, heater band inspection, residence time calculation, plus actionable lists.
PEEK Drooling: Residual Flow After Stoppage
PEEK drooling often appears in initial shots after shutdown or mold changes. PEEK 650G specs: nozzle 395°C, mold temp 170–200°C; both sides remain hot, slowing outlet cooling and allowing residual material to flow out. Covers timing analysis, comparison with LCP, actual drying failure signs, and four-step shutdown procedure.
PEEK Stringing: Tough Strings – Melt Temp or Mold Temp Issue?
Thick, tough, elongated PEEK strings indicate high outlet melt temperature and retained melt strength, pointing to melt temp and residence time issues. PEEK 650G specs: nozzle 395°C, mold temp 170–200°C, melting point 343°C, leaving only 52°C margin. Provides sequence: measure temp, inspect gate, reduce residence time.
PA46 Stringing: Semi-Solid Layer Tear vs. LCP Behavior
PA46 stringing involves tearing of the semi-solid layer, distinct from LCP's whole-segment drag-out. Stanyl TS250F6D (30%GF) specs: melting point 295°C, melt must exceed 305°C, optimal 305–320°C. Outlines steps: inspect break surface, verify melt temp, preemptive cut-off. Explains why lowering mold temp is ineffective.
LCP Connector Nozzle Clogging: Gate Freezes First
LCP clogging occurs because the gate cools before the channel. E130i specs: melting point 335°C, mold temp 80–120°C; large nozzle-mold differential causes fastest outlet heat loss. Provides three-step diagnosis: measure temp, check heaters/thermocouples, verify gate dimensions. Identifies operations that accelerate clogging.
LCP Connector Drooling: Post-Stoppage Residual Flow
LCP drooling typically appears in initial shots after stoppage, mold change, or purge due to residual material flowing from the hot nozzle tip. LCP E130i specs: hot runner 335–345°C, mold temp 80–120°C. Clarifies timing judgment, distinction from stringing, sealing techniques during stoppage, and scenarios requiring valve pin inspection.
Gate Location: Why "Easy Feeding" Is Not Enough
Gate location is constrained by four factors: flow ratio (filling capability), weld line position (strength), flow direction (warpage), and end-of-fill position (venting). Multi-drop systems distribute gates based on equal flow lengths, with larger gates at remote ends. Hot runners allow sequential valve gate control, but the processing window for fast-freezing materials is narrow.
Hot Runner Gate Types: SD, TP, VG, and PVG Applications
SD (Open Gate): Low cost, seals via cold slug, visible mark. TP (Pin Point): Small mark, high pressure loss. VG (Valve Gate): Mechanical sealing, supports sequential control. PVG: Valve gate variant. PA4T/PA6T/PA9T/PA10T/PA46/PPS: Recommend SD only. LCP, PEEK: Compatible with SD/VG/PVG. PEI: Compatible with all four types.
What Does the Extra Cost of PEEK Buy in Board-to-Board Connectors?
PEEK (Victrex 650G): Melting point 343°C, nozzle 395°C, barrel 375/380–385/390°C, mold temp 170–200°C, drying 120–150°C × 3–5h, cylinder requires 400°C. PEEK value in board-to-board connectors lies in multiple reflow cycles and high mating durability. For single reflow cycles, PPS is more cost-effective.
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