[0001] The industrial/production environment at which this idea is aimed is the one where
machinery and equipment is utilised in the foodstuff, chemical, pharmaceutical and
non-pharmaceutical sectors to hermetically seal product-containing containers without
any risk of contamination in order to isolate the product against potentially polluting
environments by the application of a lid (either a film made from various materials
or a preformed lid).
[0002] The above sealing operation involves the use of machines and equipment consisting
of a unit hereinafter referred to as the heat sealer, and another unit hereinafter
referred to as the die.
[0003] Simplifying the description we can say that the container/s previously filled with
the product to be protected, is/are positioned between two sections of a die and placed
into a special cavity formed in the die itself and is/are sealed by the heat sealer
on which the die is mounted, by the application of a lid that is heat sealed onto
the container along a well defined line on the top edge of the container itself (heat
seal area) by applying heat and pressure for a specific period of time so as to fuse
together the respective materials of container and lid.
[0004] The described sealing operation occurs by means of machines and equipment essentially
consisting of various electromechanical units with different functions, such as the
container locating unit that positions the product-filled container correctly in the
heat sealing area, or the heat sealing unit, which consists of various synchronised
moving parts designed to apply sufficient force to seal the containers, and of the
film feeder unit.
[0005] Most heat sealers work by moving the containers along the line in an intermittent
motion. The containers are positioned in the die, then they stop, following this intermittent
motion principle. The stop position is obtained by eliminating the force that keeps
the containers in motion. In the classical type of die there is no specific component
that halts the advancing of containers, which are positioned by specially-designed
thrusters or by other components such as chains or belts.
[0006] The diagrams below show the classical container motion principle (3) whereby the
containers are positioned in the lower die section.
[0007] Figure 1 shows the situation in which the containers (3) are moving, sliding over
the lower die section (1) due to the positioning force exerted (4), and the resting
blocks (2) which, together with the lower die section (1), constitute a base on which
the containers are able to slide.
[0008] The dynamic friction force is not sufficient to slow down the movement of the containers
since it is totally overcome by the positioning force (4)
[0009] In Figure 2, no positioning force (4) is being applied and consequently the containers
(3) are only subject to the forces of friction (5) and inertia (6). When the friction
(5) force totally eliminates the inertia (6), the containers (3) will stop moving
at the pre-established point, as shown in Figure 3.
[0010] At this point the next stage of the production cycle begins, in other words the closure
of the two die sections in order to seal the containers.
[0011] This stage begins with the raising of the lower die section and the containers (3)
resting on the stop block (2), which is a fixed component that is stationary in relation
to the lower die section (1).
[0012] Figure 4 shows the container's holding position in the lower die section: 1 die,
2 stop block and 3 container centred in the die recess. At this point the operation
to locate the container in the lower die section is complete.
[0013] With this invention a system has been implemented to accurately stop the container
in the lower die section by opposing the inertia that the container has gained while
approaching the die.
[0014] This heat sealer uses positioning belts and a mobile stop block that can be adjusted
to various positions.
[0015] As the containers approach and almost reach the final position, the stop block (2)
is on the same level as the rest of the lower die section, creating a perfect sliding
plane.
[0016] When the containers (3) are approaching the final position, the stop block (2) is
positioned in such a way to be slightly lower than the lower die section (1) so that
the containers can drop into the lower die section (1) and the movement of the containers
is totally stopped by the mechanical block created by the relative movement between
the lower die section (1) and the stop block (2).
[0017] By making use of mechanical contrast to slow down the advancing of the container
rather than simply eliminating the force that was keeping the container in motion,
it means that a braking force is obtained which blocks the container into a precise
and univocal position each time. The container can therefore advance at a very fast
pace since fiction force is not required to stop the container.
[0018] The starting condition coincides with that shown in Figure 1, in which it can be
seen that the containers are advancing and the stop block (2) is level with the lower
die section (1): the containers can slide unhindered along the lower die section,
pushed along by the positioning thrust force (4).
[0019] Figure 5 illustrates how the stop block (2) is positioned inside the lower die section
(2) creating a step that acts as a locating stop for the containers. 1 lower die section,
2 stop block in lowered position, 3 container approaching, 4 positioning thrust force
[0020] Figure 6 shows how the containers (3) come to rest inside the lower die section (1)
and then stop, as shown in Figure 7.
[0021] 1 die mould, 2 stop block, 3 container dropping into the die mould, 4 positioning
thrust force.
[0022] Figure 7 illustrates the positioning phase
[0023] At this stage the stop block (2) has to move by dropping down into the lower die
section (2) thus enabling the containers to reach the final heat sealing position,
as shown in Figure 4.
[0024] Figure 8 shows the container's holding position within the lower die section. The
container is fully seated in the lower die section (1) and the stop block (2) is fully
lowered in the lower die section during the heat sealing phase.
[0025] Figures 9 and 10 show the container release phase after completing the heat sealing
phase.
[0026] Figure 9 shows the stop block (2) returning to its initial position at the same level
as the lower die section (1) to allow, as shown in figure 10, the application of the
thrusting force needed to eject the containers. The stop block in the raised position
facilitates the free passage and movement of the containers.
[0027] Figure 10 shows the end of cycle with the containers being ejected from the die
[0028] The exiting containers moving unhindered.
[0029] What is required at this stage is that the component that previously acted as a stop
to properly position the containers must now be in a different position in order to
allow the containers to be ejected from the die.
[0030] The container locked in the lower die section by means of this adjustable block or
by means of locating lugs that move in the same manner in order to ensure that the
incoming containers are properly positioned in the die and can then easily slide out
of it after completion of the sealing process.
[0031] The relative movement between the stop block and the rest of the die allows for faster
movement of the containers in and out of the die, thus improving the unit's productivity.
1. A system that accurately stops the container within the lower die section, opposing
the inertia that the container has gained during its travel towards the die.
2. With reference to claim 1, a heat sealer that uses positioning belts and a mobile
stop block that is adjustable to various positions. During the advancement phase and
almost to the point of reaching the final position, the stop block (2) is on the same
line as the rest of the die, creating a perfectly level sliding plane.
3. With reference to claim 1, in proximity of the final position the stop block is positioned
so that it is lower than the die (1) such that the containers fall into the lower
die section (1) and the movement of the containers is totally cancelled out by the
mechanical block that has been created by this relative motion between the lower die
section (1) and the stop block (2). By the use of a mechanical block opposing the
advancement of the container and not simply the elimination of the force that kept
the container in motion, a braking force is achieved that blocks the containers in
a specific and precise position every time.