Thin walls increase pressure loss.
Below 0.2 mm, the same flow length requires higher injection speed and pressure. For end-of-flow short shots, check runner resistance first, not clamping force.
Application
Telecom and Data Center
Wall thickness of 0.15–0.30 mm and pin pitch of 0.4–1.0 mm: end-of-fill and board-level coplanarity are the two critical limits for this component type.
Common Parts
High-speed backplane and board-to-board connectors, optical module housings, CPU and memory sockets
Common resins
LCP, PPS+GF, PA9T
Shot Weight and Wall Thickness
0.2–5 g per part
walls 0.15–0.30 mm
pin pitch 0.4–1.0 mm
Three constraints that determine the gate
Shot weight, wall thickness, and flow ratio determine the gate; appearance and cleanliness requirements determine the nozzle type.
LCP freezes quickly; cold slugs clog the gate first.
LCP flow depends on shear and temperature. A cold gate freezes at the tip; a cold slug entering the cavity causes short shots and black specks.
Coplanarity out of tolerance: Reject
Board-level coplanarity is determined by orientation and cooling; it cannot be corrected after ejection. Gate and runner balance must be resolved before steel cutting.
Common parts and matching exercises
Different gate practices are required for different components and requirements within the same industry. This table is organized by component, not by model.
Part | Common resins | Size and cavitation | Practice |
|---|---|---|---|
| Part High-speed backplane connectors | Common resins LCP | Size and cavitation 0.15–0.25 mm, multi-cavity, fine pitch | Practice SD with dynamic gate control; cavity-by-cavity zoning to prevent early-filling cavities from overheating |
| Part Board-to-board connectors | Common resins LCP, PPS+GF | Size and cavitation 0.20–0.30 mm | Practice SD as the base; TP where appearance is critical |
| Part Optical module enclosures | Common resins PPS+GF, PA9T | Size and cavitation 0.3–0.6 mm | Practice SD; Monitor weld-line position opposite the gate |
| Part CPU and memory slots | Common resins LCP, PA9T | Size and cavitation 0.2–0.4 mm | Practice Multi-cavity SD with zone sequencing; control weld lines in dense pin arrays |
Molding Challenges and Our Solutions
Each item first explains the mechanism, then our scope of work. Mold temperature, clamping, and drying are out of scope.
End-of-flow short shots
Thin walls with long flow paths cause excessive pressure loss, preventing the melt from reaching the end within a fillable viscosity range.
PRACTICE
Calculate pressure loss and required injection speed based on the flow ratio; set gate position using flow analysis; add cavity zoning if needed. Do not rely solely on increasing melt temperature.
Cold slug clogging
LCP freezes quickly; the tip freezes first at stop or low temperatures.
PRACTICE
The straight-through passage has no reduced section. Synchronize switch gate heating with the molding cycle, purge as resin requires, and ensure no residue remains at the tip.
Warpage and coplanarity
Fibre orientation and uneven cooling combine, especially in thin walls.
PRACTICE
Set gate and runner balance using flow analysis; verify mold-temperature zoning and packing profile separately. Hot runner controls gate temperature only, not mold temperature.
Selection and responsibility boundaries
Scope of services and exclusions are outlined before the proposal and quotation.
SERIES
Open SD and TP, and valve-gate VG and PVG; all are suitable for telecom and data center applications. The specific model is determined by gate position, appearance requirements, and cavitation conditions.
What We Don't Promise
Mold temperature, melt temperature, clamping force, and drying are part of the mold and molding process. A hot runner cannot replace them.
The no-clogging guarantee applies only to straight-through nozzles. Pin-point and valve-gate types have small sections and mating surfaces, so we cannot guarantee they will be clog-free.
We explain any out-of-range calculations at the proposal stage.
Related technical articles
Articles on materials and applications in this industry, sorted by newest first.
Multi-Cavity Flow Imbalance: Simultaneous Fill
In an 8-cavity mold, outer cavities exhibit short shots while center cavities flash. Adjusting injection speed only shifts the problem location, indicating inherent flow imbalance.
Silver Streaks and Water Marks: Gas Source and Flow Path
Silver-white streaks running along the flow direction near the gate, resembling water marks and more visible under light, caused by gas entrainment.
Customer case studies
Practice and results only; customer names are not disclosed.
Customer case studies for this industry are being prepared.
Drawings first, then the proposal
Send the mold 2D layout, part 3D data, resin grade, wall thickness (including the thinnest section), number of cavities, shot weight, current process parameters, and defect photos.