* Four cylinder fully hydraulic clamping structure is
1. three position points on each of the
four cylinders create a very long guide for the moving platen, which is up
to 4 times of the normal machines resulting more stable movement. thus,
evenly stressed on the mold and equally wall thickness of the preform can
be realized, and eccentricity due to uneven stress during molding can be
2. without any adjustment to the mold and
oil lubrication, the machine is clean and accord with the sanitary
requirement for food packing.
3. ejector stroke is especially long and
can be enlarge to meet the automatic production demand.
4. the clamping force is uniform and the
action can be repeated under a very high precision.
5. the mold is stressed evenly, the
clamping force is controlled according to be feedback of the injection
pressure and increased up to 5 times of the injection pressure
automatically. Unclamping will not occur. The clamping force goes down
upon the injection concluded. Energy saving can be realized and heavy load
for a long time on the mold can be avoided. The longevity of the mold can
be increased by 50% at least.
6. compared with toggled machine, our
machine is faster and save more energy.
* Adopt PET special screw and big L/D ratio to plasticize
evenly, the transparent has been increased and the shrinkage of the
preform can be improved.
* Big diameter multi-component water knockout vessel is
equipped to cool the mold efficiently.
* Accurate and stable low pressure protection function to
ensure the mold will be protected even in an accident of the product
failing to fall down (this function can be tested by cotton thread).
* During the cooling stage, the clamping force decrease step
by step according to the reduction of the injection pressure down to zero
before opening to avoid the open impact. The internal stress can be
eliminated and the rupture on the neck occurred during opening can be
* The serviceable range is very large. For example, edible
oil preform can be made by PET180, and 5 gallon preform can be molded by
Model PET250 if the min. mould thickness is increased up to 100mm.
- Structure and action analysis
for clamping unit:
- (see above picture) four
piston rods (tie rods) cross through the movable platen and their
ends are fixed on the four angles of the stationary platen and the
back stand. Four cylinders are sleeve over the piston rods and
fixed on the movable platen. Two mold-moving cylinder are
assembled between the movable platen and back stand or between the
movable platen and the front stationary platen. The mold-moving
cylinder drive the movable platen to open or close the mold, and
the high pressure clamping is fulfilled during the process that
the pressure oil is filled into four cylinder.
The four bars are stressed evenly, and the force line
is shortened by 40%, the system has a good rigidity.
the clamping force repeats precisely.
The clamping force can be controlled according to the
feedback of the injection pressure.
the position of the mold can be adapted
High precise products can be molded, such as gear,
lens and CD.
- It is favorable for long core
products, and molding big products by a small Model machine can be
- compare with the
toggled type injection molding machine, the opening stroke of our
machine is 1/3 longer and can be further extended according to the
there are three position points on each of the four cylinders
enable the movable platen to conduct quite a long guide for its
smooth motion. This feature facilitates to make the long core
- the longevity of the machine
and the mold can be increased by more than 50%
- There are no wear and tear in
the pin and spindle that always occur in the toggle machines.
Low pressure protection is sensitive and reliable.
the tie bars (column bars) can bear heavier pull because they are
stressed evenly and force line shortened by 40%.
the mould is stressed evenly.
The clamping force will decrease once the injection is over.
therefore, the heavy load bearing time of the machine and the mold
will be shortened by more than 3/4.
- The speed increase by 20%, energy
saving by 10%
- with 2 mold-moving cylinder
and 4 clamping cylinders, the contradiction of the force and speed
can be resolved.
- the oil circuit between the
left and right chamber of the clamping cylinders is quite short
and resistance is very low.
- the right chamber of cylinder
is compensated by the pressure oil from the left chamber of the
same cylinder. The following trouble in the traditional
liquid-filled injection molding machines can be avoided: crawling
and time-consuming in the pressure increasing process usually
occurs as a result of insufficient vacuum oil-suction.
- The time for multiplying the
oil pressure is only 1/5 of the tradiitonal fully hydraulic
injection molding machines.
- No multiplied oil refilling
will be needed to the clamping cylinders while pressure holding is
- The action will be more
stable, more accurate and faster by four section control to the
clamping force and speed.
- Compared with the foreign
fully hydraulic machines, more than 1/3 hydraulic units have been
reduced and the energy saving of 15% is realized by an advanced
design and smart matching of the hydraulic system.
- other merits:
- no mold adjustment is needed.
- there are few wear-and-tears
in the clamping system and no lubricant is to be supplied.
- there are pnly a few stressed
parts in the clamping system. the mechanism and hydraulic systems
are quite simple. the maintenance is easy and the charges for it
can be saved a lot.
- The clamping force increase
accordingly, up to 1.5 times, with the growth of the injection
pressure during injection to ensure the mold-relieving can be
- The export standard of the
permitted leakage volume is only 1/100 of the JIS (Japanese
- There is an option of press
injection feature for multi-molding requirements.