Buying a Plastic Injection Molding Machine (PIMM) is not a small investment. Too much machine for the job at hand is wasteful. Too little machine does not get job done. Careful matching of the jobs needs and the attributes of a PIMM is well worth the effort.

1. How to select a Plastic
Injection Molding Machine
How to select a Plastic
Injection Molding Machine

2. Purchasing a Plastic Injection Molding Machine (PIMM) is not a
little venture. A lot of machine for the current task is a big
waste. Too little machine does not complete employment.
Watchful coordinating of the occupations needs and the
characteristics of a PIMM is definitely justified even despite
the exertion.

3. Shot weig ht
The shot weight is measured weight of the plastic infused
at the point when the spout is unattached. the plastic
utilized is for the most part polystyrene with a particular
gravity (SG) of 1.05. this is indicated in the particular as PS.
Shot weight as far as a resin= c*b/1.05 where b=SG of
leave and c = shot wt as far as PS.

4. Selecting machine
A PIMM of a predetermined shot weight can be utilized to form
articles counting the runner weighing from 35% to 85 % of the
shot weight. As far as possible originates from twisting on the
platens, barrel occupant time of the leave and electric power
utilization per kg of the prepared material.
BRT=wt of liquefy in barrel*ct/real shot wt.

5. Clamping force
Clasping power is an imperative property of the bracing unit
of a PIMM. It is the most extreme drive the machine is prepared
to do to keep the form close against cavity weight amid infusion.
Inadequate bracing power offers ascend to streak at the shape
joint.

6. Screw diameter
L/D proportion. A high L/D proportion of 22:1 or above gives better
blending and more uniform warming because of pressure in
move area of the screw.
A medium L/D proportion of 20:1 is utilized for general application
with medium necessity.
A low L/D proportion of 18:1 is utilized for low necessity where shot
weight is more overwhelming choice foundation. The infusion
weight is low.

7. Injection pressure
Infusion weight implies the most extreme weight in the barrel
amid infusion, not the maximum water powered pr. The two are
connected by the proportion of the screw cross segment territory
of the infusion chamber territory. For the most part, infusion pr.
Is higher than the maximum pressure driven pr by around 10 times.

8. Injection speed
Inj speed is the maximum speed of the screw the m/c is competent
of amid inj.
Inj speed impacts the inj time. Shaping meager divider articles
require high inj speed with the goal that dissolve does not harden
before the pit is totally filled.
Machine ought to have duplicate inj speeds.

9. Accumulator
It is an alternative to increment inj speed. A collector is an
vitality putting away that amasses pressurized water driven oil
in a period of low request to be utilized as a part of inj ( appeal)
stage. While expanding the electric engine and water powered
pump sizes increases the inj speed by 25% an
gatherer does as such with around three times increment.

10. Injection rate
As an alternative to inj speed some m/c use inj rate. Inj rate
is the max volume swept out by the screw per sec during inj.
It is expressed in cm3 /s.
Inj rate =inj speed*3.14*(d/2)2. where d=screw dia in cm.
Note that inj speed is not independent of screw dia, but inj rate is.

11. Screw surface speed
Screw turning pace is determined as a range in rpm. Screw
rotational speed without anyone else's input is not basic as
screw surface speed. The two are connected by screw dia.
SSS=0.052*screw dia*rpm.
Every plastic material has a suggested most extreme sss which
must not be surpassed. For instance PP and HDPE ought not
encounter a sss of higher than 800 mm/s.

12. Plasticizing capacity
It is the measure of PS that a PIMM can consistently plasticize in
one hour at max screw revolving speed with 0 back pr.
To check if the plasticizing limit of the PIMM is not being
surpassed compute the wt of the segment and Sprue
per shot W 9g) partitioned by screw turn time t (s) and
change over the remainder to kg/hour.
W*3600(t*1000) this must be not as much as the plasticizing limit.

13. Since ct is longer than screw rotation time the shot wt S (g)
of a m/c and its plasticizing capacity G (kg/hr) set a lower
limit on cycle time tmin (s) as follows.
T min=S*3600(G*1000).
It is particularly important to match shot wt and plasticizing
capacity in the case of fast cycling m/cs producing thin
walled or close tolerance components.

14. Mold opening stroke
It is the uprooting of the moving platen from form near
form open. Form opening stroke decides the maximum stature H
of the form part the m/c is able to do.
Shape opening stroke>=2H+sprue length L
In hot runner framework L=0

15. Mold height (thickness)
Mold stature is left over from the days when press are vertical.
In level press, a more suitable depiction is shape thickness.
In flip clam PIMM determination, form stature is communicated
as a range, from the base to greatest to the stature the
machine could suit. The distinction is shape tallness
alteration the machine is prepared to do.

16. Maximum daylight
The most extreme opening between the settled and moving
platens at the point when the clasp is completely open. It is
identified with shape opening stroke and least/greatest shape
stature as takes after.
For a flip brace m/c.
Max daylight=mold opening stroke + max shape ht.
For direct water powered cinch machine
Max daylight=mold opening stroke + least shape ht.

17. Space between tie bar
Shape width must fit inside the level space between tie
bars if the form is brought down from above. The shape length
must fit inside the vertical space between tie bars if the
form is opening in from the side. It is prompt that there is a
leeway of 25mm on each side for little shape and 50 mm
for an enormous form.

18. Tie bar diameter
On the off chance that the tie bar pressure are even, the worry
in each of them is given by
Stress= clipping power +1000/(3.14* d2) where stress is in
kg/mm2 clipping power is in tones and dia d is in mm.
High elastic has a breaking worry of more than 90kg/mm2
gentle steel 20/kg2.
Non distribute faces, on-symmetrical depression as for
Sprue and maladjustment of mold tallness component of a
flip brace m/c.

19. Platen thickness
The moving platen and settled platen must have adequate
firmness to transmit the drive of attach bar to the form with
least avoidance. For a given geometry a level platens
avoidance is corresponding to the 3D shape of its thickness.
Particularly for the moving platen, a trade off needs to
be struck amongst wt and thickness.

20. Dry cycle time
It is the form shutting time in addition to shape opening time in
addition to perfect time. Dry process duration is a definitive
process duration as there is no cooling period.
Running a m/c at max conceivable ct is not alluring if the m/c
is not running smooth and stable.

21. Electric motor ratting
The current per stage drawn by a three stage engine at
its evaluated power is
im (A)=motor control rating (kw) * 1000/(3*single stage
control voltage (V) *efficiency * control figure)
For most three stage engines efficiency=0.88to 0.91 and
control factor=0.84 to 0.88

22. Electric heater rating
Electric band radiator along the barrel gives warm up to the
tar at start up. It likewise supplements the warming by
plasticizing (when screw turns) amid the trim cycle.
A higher rating for each warmer has the benefit of shorting the
starting warmth up time.
ih (A) = electric radiator rating (kw) * 1000/(3* single stage
voltage (v)

23. System pressure
The most well-known water powered framework weight utilized
as a part of PIMM is 140 bars, which apx equivalents to 140
kg/cm2. this is restricted by vane pump.
A higher framework pr. Of 170 bar to 240 bar are utilized with
cylinder pump which requests cleaner oil to work with.
Final conclusion select PIMM
depending on article to be molded.

24. Contact Us
www.quality-mold.com
931-668-3876
QualityMoldShop,Inc.