External stress during casting Insufficient molten supply during casting causes thermal cracks External stress after casting Cooling stress at thin-wall tie bars after casting

There are corrosion pits on the mold surface Impacted by cavitation inside the liquid Corrosion due to high-speed impact with liquid

There are cracks and damage on the mold surface Due to alternating hot and cold stress shock

Poor heat dissipation at the corners eventually solidifies Sudden changes in wall thickness in thick areas

Melt turbulence Differences in release agent adhesion status

Mold cavitation and melt erosion at corners cause defects to be reproduced Release agent residue and scale on all surfaces

Air is trapped under the die-cast skin Expansion occurs during mold opening and demoulding

Scratched during core pulling or ejection

The molten liquid that enters first is chilled and solidified first.

The mold is overheated and the internal metal solidifies slowly before extrusion. The internal melt solidifies after extruding from the surface

The splashed melt particles are first chilled and solidified and then subsequently wrapped

The material temperature is low and the confluence cannot be fused. Mold peeling flake blocks confluence fusion

Insufficient fluid supply

Uneven hot and cold shrinkage

Adjust the number, position, diameter and stiffness of the ejector pins

Increase the draft angle

Increase strength, hardness, rigidity

Filling stiffness, reduced shrinkage

Increase toughness

Increase flame retardancy

ABS (super unbreakable plastic)

PA (nylon)

PBT (electrical plastic)

PC (plexiglass)

PE-HD (hard soft rubber Kailux)

PE-LD (barrel soft rubber)

PMMA (acrylic)

POM (Saigang)

PP (100% glue)

PPO

PS (hard glue, optical special glue)

Shoulders<t

Rib height <3t Tendon spacing>2t Rib width<t

Distance from edge>max(1/4t, D); Hole spacing>max(3/4t, 3); Hole bottom thickness>(1/3t)

Wall thickness all around>(1/3t) Insert preheating to resolve differences in thermal characteristics

Anti-rotation diameter D>(1.2~1.4)d insert diameter

ST2.2 1.7 ST2.9 2.4 ST3.5 2.9 ST4.2 3.4 ST4.8 4.2 (KT-28)4X10 3.3

If the pressure is maintained for too long, the pressure will be uneven and the internal stress will be too large, resulting in deformation or even rupture. The holding pressure is too short, the volume shrinks greatly and the surface quality is poor.

Full, less energetic

Too low an underpayment; too high a decomposition

Inner mold temperature<outer mold temperature High mold temperature is beneficial to surface quality

Initial low to avoid serpentine jets Medium-term average, uniform expansion Big in the later stage, overcome the greatest resistance

Annealing: Reduce stress - within the temperature range of 10 to 20 degrees in each of the [use temperature ~ deformation temperature] windows Humidity adjustment: For materials with strong water absorption such as PA - immediately isolate the air after demoulding to achieve moisture absorption balance to stabilize size

【Note】

Underpayment Uneven thickness and different cooling rates

Internal trapped air If the cooling is not timely, gas will be produced internally.

The back of the shunt gate forms a confluence of uneven cold and heat

Divided melt cannot merge

Uneven heat shrinkage Uneven pouring impact Uneven release force

The melt decomposes when heated to produce gas Injection too fast and containing air

Cooled too quickly and was pushed leaving traces The melt front expands and advances rapidly

Shooting too fast Liquidity is too good

The melt flow changes drastically and there is gas

Holding pressure too long, holding pressure too high Gate impact stress Ejector release stress Insert thermal expansion coefficient differential stress Mold crack reproduction

The air in the mold is instantly high-pressure and high-temperature

Xenon lamp aging (outdoor)

Fluorescent UV aging (indoor)

Carbon arc lamp aging

Blue and white zinc: 24H Black zinc: 48H Color zinc: 72H Nickel plating: 24H Galvanized Nickel: 200H

Passivation: 200H

24H