Download ppt - 6.1 Checking M aximum I njection V olume 6.2 Checking I njection P ressure

6.1 Checking Maximum Injection Volume6.2 Checking Injection Pressure

6.3 Checking Clamping Force

6.4 Checking Size of Mold Parts

6.5 Checking Mold Opening stroke

6.6 Checking Ejector

Chapter Ⅵ Checking Process Parameters of Injection Machine

6.1 Checking Maximum Injection Volume

The actual injection volume should be less than 80% injection machine’s

maximum injection volume

injection volume shown by volume :

V ≤ 0.8Vm

where,

V - Total volume of plastic parts (plastic parts + gating system)

V m - Maximum injection volume of injection machine (cm3)

The injection volume shown by weight:

G ≤ 0.8G m G = p'V

where,

G - The total weight of plastic parts (plastic parts + gating system)

G m - The maximum injection volume of the injection machine (g)

p'- Plastic barrel temperature and pressure density (g/cm3)

6.1 Checking Maximum Injection Volume

6.2 Checking Injection Pressure

Check the Rated injection pressure of injection machine can meet the required pressure or not

P n ≥ P iWhere,P i - The required pressure of plastic molding injectionP n - The nominal injection pressure injection machine

P i will be affected by the gating system, the resistance of the cavity, the m

old temperature and other factors.

When P i is too big: lager flash, demolding difficult, poor surface quality,

and big internal stress

When P i is too small: can not successfully filled cavity, form inadequate

6.3 Checking Clamping Force

Where, F c – The nominal clamping force of injection machine (N) A p – The total projected area of the plastic pieces and pouring system in the parting surface(mm2) q - The average pressure of the plastic melt cavity (MPa)

The clamping force is the maximum force of the clamping device applied to the mold

Fc≥q·Ap

Nozzle size locating hole size

Rod spacing Mold closed thickness

Mounting screw

hole size


1.Nozzle size

The spherical radius of gate sets R and the spherical radius of nozzle front end R0Nozzle diameter d0 and gate sets small side hole diameter dRelationship: d = d0 + (0.5-1) mm R = R0 + (1-2) mm


2.locating hole size

h: small mold, take (8-10) mm Large mold,take (10-15) mm


3.Rod spacing Dimensions of one mold should be less than the rod spacing of the i

njection molding machine to ensure that the mold can be installed on th

e injection machine work table.


The relationship between mold size and rod spacing of the injection machine

4.Mold closed thickness

Hmax≥Hm≥Hmin


5.Mounting screw hole size

Mold lighter weight using plate fixed

Mold heavier weight using screw fixed


Single-parting surface mold: S> = H1 + H2 + (5 ~ 10) mmDouble-parting surface mold: S> = H1 + H2 + a + (5 ~ 10) mm


Checking opening stroke of single-parting mold

1-Fixed mode 2-Dynamic model

Checking opening stroke of double-parting mold1-Fixed mode 2-Flow plate 3-Dynamic model

maximum stroke of mold opening of injection machine(S) is independent of mold thickness (Hm)


maximum stroke of mold opening of injection machine(S) is independent of mold thickness (Hm)

Single parting surface mold: S0 = Hm + [H1 + H2 + (5 ~ 10)]

Double parting surface mold : S0 = Hm + [H1 + H2 + a + (5 ~ 10)]


Stroke checking of hydraulic clamping part

maximum mold opening stroke of side parting core-pulling mechanism (S)

When H4 in> H1 + H2,

S = H4 in (5 ~ 10) mm

When H4 in <H1 + H2,

S = H1 + H2 + (5 ~ 10) mm


6 .6 Checking Ejector

center eject

Sides dual mechanical eject

center hydraulic eject and side dual mechanical ejector

center eject and auxiliary fuel tank

classification of ejector :

Vertical injection machine

Horizontal injection machine

Right-angle injection machine

calculation of injection machine

Thinking and Practice

XS-ZY-500 ： means the injection machine with a maximum injection volume

of 500cm3

XS ： Plastic molding machine Z ： Injection machine Y ： Screw

S-ZY-190/90 ： The injection volume is 190cm3 、 Clamping force is 90t

SYS-30 ： means the vertical injection machine with a injection volume of

30g