Conventionally, expanded or foam plastic containers are manufactured in a moulding cycle which comprises dispensing beads or particles of a plastics material suitable for moulding expanded plastics products into a closed mould cavity defining the desired shape of the product and formed between female and male mould parts, causing the moulding material to expand within the cavity to mould the container, permitting the expanded moulding material to solidify within the cavity, and separating the mould parts to enable the moulded container to be ejected therefrom. Hereinafter, such a moulding cycle will be simply referred to as a moulding cycle of the type described. In one particular example of such a conventional moulding cycle, the beads of plastics moulding material are injected into the mould cavity and steam is introduced into the mould cavity to heat and, consequently,"cook"the plastics material. The beads comprise a thermoplastics material and a foaming agent and the term"cook"and like terminology are the terms commonly used to describe introducing steam directly into the beads disposed in the mould to achieve the necessary expansion and fusion of the beads for producing the container moulding.

Expanded plastics containers have a poor surface smoothness owing to the relatively low density of the foam material forming the containers, and the lack of surface smoothness makes it difficult to provide for acceptable printing of advertising and other printed matter on the external walls of the containers. In order to avoid this difficulty, it is desirable to bond to the external surface of the container, preferably, covering the entire external surface of the side wall of the container, a laminate of flexible sheet material, for example, paper or plastics sheet material, which is pre-printed or, alternatively, may be post-printed, on its external surface with the required advertising and other printed matter. Printing on such a laminate may be produced, effectively, with a photographic quality.

Accordingly, it is an object of the present invention to provide a method and apparatus for applying a label or other laminate of flexible sheet material to an

expanded or foam plastics container and, more specifically, to a method and apparatus for moulding an expanded plastics container with a label or other laminate of flexible sheet material affixed to an external wall of the container.

From one aspect, the present invention consists in a method of moulding an expanded plastics container having a label or other laminate of flexible sheet material affixed to a wall of the container, said method utilising a moulding cycle of the type described and being characterised by the steps of applying the laminate to the wall of one of the mould parts used for the moulding cycle whilst the mould parts are separated, said wall of said one mould part defining the wall of the container to which the laminate is to be secured, retaining the laminate on the wall of said one mould part, closing the mould parts together to form the mould cavity, and carrying out the moulding cycle to produce an expanded plastics container having the laminate disposed on the wall of the container.

Conveniently, the mould part to which the laminate is applied is the female mould part and the laminate is inserted into the female mould part and is retained on the wall of the female mould part defining an external wall of the container to which the laminate is to be affixed by the moulding cycle.

In a preferred embodiment, the laminate is transferred from a stack of laminates to a dummy male core substantially corresponding to the male mould part used for the moulding cycle and is attached to the wall of the dummy core corresponding to the relevant cavity wall of the female mould part, for example, by vacuum applied to the interior of the dummy core. The dummy core with the laminate thereon is then moved to insert the laminate into the cavity of the female part, whilst the mould parts are separated, and the laminate is transferred from the dummy core to the wall of the female mould part. Air pressure may be applied to the dummy core when the latter is inserted into the female mould cavity to transfer the laminate to the wall of the female mould and an electrostatic charge may be applied to the mould to retain the laminate on the wall of the female mould cavity.

Thereafter, the dummy core is withdrawn from between the mould parts, the latter close together to assembly the mould and the moulding cycle takes place in order to produce the container with the laminate attached to the external wall of the container. The moulding cycle may include heating the expanded plastics moulding material so as to activate expansion of the moulding material within the

mould cavity and the laminate may have a heat-activated adhesive layer on its surface adjacent the container moulding which positively adheres the laminate to the moulding and achieves a strong bond preventing separation of the laminate from the moulding.

The invention is particularly suitable for use with the method disclosed in our copending International application entitled"Expanded Plastics Containers" (Attorney's Ref: 35513) which is being filed concurrently herewith and which discloses moulding an expanded plastics container with a rim flange projecting radially outwardly about the mouth of the container. This rim flange is similar to the roll type rim flange of a cup thermo-formed from sheet plastics material, and is capable of capturing a snap-on lid. With the present invention, the container of our copending application may be moulded with a laminate entirely surrounding the side wall (s) of the container, for the full height thereof, with the edge of the laminate in abutting relation with the underside of the rim flange so that the upper edge of the laminate is concealed. The external surface of the laminate may be printed over its entire surface with advertising and other matter and, because of the surface smoothness of the laminate, results in high quality printing and an attractive product. Moreover, the laminate also serves to strengthen or reinforce the expanded plastics container, particularly, in the case where this is a thin walled product manufactured by the method described in our copending International application. The overall result is a strong, attractive plastics container which retains the insulating advantages of a foam plastics container.

From another aspect, therefore, the invention consists in an expanded plastics container in which a laminate of flexible sheet material is bonded to a surface of the expanded plastics material during the moulding process.

From yet another aspect, the invention consists in moulding apparatus which is adapted to utilise a moulding cycle of the type described to mould an expanded plastics container having a label or other laminate of flexible sheet material affixed to an external wall of the container, characterised in that the laminate is attachable to a dummy male core substantially corresponding to the core of the male mould part used for the moulding cycle, the dummy core with the laminate attached is movable into the cavity of the female mould part used for the moulding cycle whilst the mould parts are separated, means is operable to

transfer the laminate from the dummy core to the wall of the female mould part defining the wall of the moulded container to which the laminate is to be affixed, and the dummy core is removable from the female mould part, whereby the laminate is affixed to the expanded plastics material forming the external wall of the moulded container during the moulding cycle.

The dummy core may be mounted on a carriage which is able to reciprocate between a lamina pick-up station and a moulding station, the laminate being transferred to the dummy core at the pick-up station and being transferable from the dummy core to the cavity wall of the female moult part at the moulding station. In a preferred embodiment designed to mass produce the containers, the moulding station comprises a multiplicity of mould tools, the carriage mounts a multiplicity of dummy cores corresponding to the number of mould tools and the label pick-up station has means for transferring labels to all the dummy cores preparatory to the carriage advancing the dummy cores together with the labels thereon to the moulding station.

The or each mould tool at the moulding station may be constructed, as described in our aforementioned copending International application, for moulding an expanded plastics container having a rim flange projecting radially outwardly from the container side wall about the mouth of the container.

When the mould parts separate at the end of the moulding cycle, means can be provided for ensuring that a moulded container is retained on the male mould part and the carriage may include means which removes a moulded container from a male mould part as the dummy core delivers the next laminate to the associated female mould part. The removed container may then travel with the carriage on its return stroke for delivery to an inspection station adjacent the label pick-up station. This inspection station may comprise one or more inspection cores for receiving the moulded containers thereover, and means for applying a vacuum to the inspection core (s) and for detecting when the degree of vacuum applied to the container (s) is less than a predetermined amount. This indicates the presence of one of more leaking containers on the inspection core (s) and enables the leaking container (s) to be rejected.

In order that the present invention may be more readily understood, reference will now be made to the accompanying drawings, in which:-

Figure 1 is a schematic elevational view of a moulding machine embodying apparatus according to the invention for applying labels to expanded plastics cups during the moulding cycle of the cups, Figure 2 is a schematic plan view of the machine omitting the mould tools and label pick-up station, and Figure 3 is a half-sectional, half-elevational view of an expanded plastics cup manufactured by the machine.

Referring to the drawings, the machine comprises a frame 1 having a label pick-up station 2, a moulding station 3, which is spaced from the pick-up station longitudinally of the machine frame, and an inspection and collection station 4 for moulded cups disposed adjacent and below the label pick-up station 2. A carriage 5 having dummy cores 6 for transporting labels from the label pick-up station to the moulding station reciprocates along two spaced horizontal rails 7 mounted on the machine frame and extending between the stations 2,3. The carriage is reciprocated under the control of a chain drive and electrical servomotor (not shown). The moulding station 3 includes six sets of mould tools 8 for moulding expanded plastics cups aligned across the machine frame. Correspondingly, the carriage mounts six dummy cores 6 cooperating with the mould tools 8 and for receiving labels from six stacks 9 of precut labels and transferring them to the mould tools. The carriage 5 also mounts six suction cup devices for picking up moulded cups 10 at the moulding station 3 and carrying them, on the return stroke of the carriage, to six inspection cores 11 at the inspection station.

The mould tools 8 may be constructed as described in our aforementioned copending International application for producing expanded or foam plastic cups 10 having an annular rim flange. The cups may, for example, be moulded from expanded polystyrene material and the resulting moulding are thin walled products of high density foam plastics material. Each cup is of circular shape in plan and comprises a bottom wall and a side wall extending upwardly and outwardly from the bottom wall to a mouth at the top of a cup where the side wall terminates in the rim flange which projects radially outwardly from the side wall about the mouth of the container. The mould tools mould the cups with their bottom walls uppermost and their mouths directed downwardly. Each tool comprises male and female mould parts 12,13 with the male mould part 12 being

mounted at 14 in a fixed position relative to the machine frame 1 and the female mould part 13 being supported on a pneumatically reciprocated mounting 15 so that the female mould part is movable downwardly to fit over the male mould part and assemble the mould cavity preparatory to moulding a cup.

The carriage 5 has two sets of support arms 16,17 which are movable apart and together in a vertical direction and are reciprocated in this direction under the control of a pneumatic cylinder 18. The two arms 16 of the upper set project from opposite side of the carriage and mount a spindle 40 therebetween carrying rocker arms 19 for the dummy cores. The rocker arms are fixed to the spindle at one end and carry plates 41 at their opposite ends mounting the dummy cores. The spindle 40 is rocked under the control of a pneumatic cylinder (not shown) in order to rock the arms 19 between a horizontal position 20 and an upright position 21. In the upright position, the arms 19 locate the dummy cores 6 with their axes substantially horizontal and transverse to the parting axes of the mould parts 13,14 at the moulding station. Each of the dummy male cores 6 substantially corresponds in shape and dimensions to the male mould part 12 of its associated mould tool 8. It is hollow, with a perforated wall structure, and is alternatively connectable by pneumatic control mechanism of the machine to a source of vacuum or a source of air pressure.

The lower support arms 17 of the carriage mount, on their undersides at their forward end, suction pick-up cups (not shown) for removing moulded cups 10 from the male mould parts and carrying them to the inspection station 4. Under the control of the pneumatic control mechanism of the machine, vacuum and air pressure is alternatively supplied to these suction cups for the purposes of withdrawing moulded cups 10 from the male mould parts and ejecting the moulded cups from the carriage onto the inspection cores 11 at the inspection station.

The label pick-up station 2 comprises a platform 22 mounted on the machine frame 1 and supporting six open top receptacles 23 containing labels stacked in a flat condition. Mounted on the machine frame above the platform 22 is a second carriage 24 supporting pneumatically operated plungers 25 having suction pick-up heads 26 for removing individual labels from the stacks 9 and transferring them to the dummy cores 6. There are three such plungers spaced

transversely of the machine, and the carriage 24 is slidable parallel to the path of sliding movement of the carriage for transferring labels from the stacks to the dummy cores and has a limited amount of sliding movement transversely of the machine so as to enable the three plungers 25 to service the six dummy cores in two operating cycles of the carriage 24. Pneumatic cylinders 27 control the plungers 25 and the application of vacuum to the plungers is controlled by the pneumatic control mechanism of the machine.

The carriage 5 also mounts two arms (not shown) which are slightly above and adjacent opposite sides of each dummy core 6 when the latter is raised in to the position 21 for collecting labels. These arms are pneumatically operated to engage projecting portions of a label applied to the dummy core by the plunger 25 and are movable downwardly to assist wrapping of the projecting portions of the labels about the core under the action of the vacuum applied to the hollow core.

The inspection and collection station 4 includes six inspection cores 11 disposed transversely of the machine frame at positions corresponding to the mould tools 8. Each inspection core is of corresponding shape and dimensions to the male mould parts 12 and is hollow with a perforated end wall structure for alternately applying vacuum and air pressure to the inside of the bottom wall of a moulded cup deposited onto the inspection core. The inspection cores are pivotally mounted in a common horizontal shaft 28 which is rockable in opposite directions under the control of a pneumatic cylinder 29 connected to the shaft by a lever arm 30. Mounted on the machine frame 1 adjacent the inspection cores is a horizontal conveyor 31 for collecting and stacking acceptable cups discharged from the inspection cores. The inspection cores inspect the moulded cups 10 for leakages by applying vacuum to the insides of the cups deposited on the cores. If a sensing system (not shown) detects the degree of vacuum applied to the insides of the cups deposited on the cores to be correct, it causes the pneumatic cylinder 29 to be operated, via the pneumatic control mechanism, to turn the cores from the vertical position in which they receive the cups to a horizontal position 32, whereupon the vacuum is replaced by a source of air pressure in order to discharge the cups from the cores and form the stacks 33 on the conveyor 31.

The cores then return to the upward vertical position. On the other hand, if the sensing system detects the degree of vacuum to be incorrect, the system causes

the pneumatic cylinder 29 firstly to be operated to rock the inspection cores into a downward vertical position, whereupon the leaking cup or cups fall off their inspection cores owing to the loss of vacuum caused by the leakage (s).

Thereafter, the pneumatic cylinder rocks the cores back into the horizontal position 32, the acceptable cups are discharged from the cores into the stacks 33, as previously, and the cores are returned to the upward vertical position preparatory to inspecting a subsequent set of moulded cups. Leaking cups which fall off the cores when these are in the downward vertical position are rejected and removed for disposal.

The moulding machine manufactures a cup 10 of laminated construction using labels from the stacks 9. Each label is made from flexible sheet material, for example, paper or plastics sheet material printed on its outside surface with advertising or other matter, and is laminated to the external surface of the cup side wall. It is of such dimensions and configuration as to be foldable about itself into a slightly conical shape matching the side wall of the cup and to extend about the circumference of the cup for the full height of the side wall of the cup. The labels may, for example, be formed from sheet polypropylene material and are provided on their inner surfaces with heat activated adhesive.

The machine operates as follows. With the carriage in the label pick-up station 2 and the arms 19 rocked into the position 21 in which the axes of the dummy cores 6 are approximately horizontal, as are also the uppermost walls of the cores, the plungers 26 are moved by the carriage 24 so that their vacuum heads 26 pick up three labels from three alternate stacks 9, and transfer these labels to three alternate cores 6. They then return to pick up three more labels from the remaining stacks and transfer these to the remaining dummy cores.

When the labels are applied to the cores by the plungers, vacuum is removed from the vacuum heads 26 and applied to the dummy cores. At the same time, the mechanical arms operate to assist the wrapping of the labels about these cores. As a result, each label is completely wrapped about its respective dummy core and is retained thereon by the vacuum applied to the core. When the labels are secured to the cores, the relevant pneumatic cylinder operates to return the arms 19 to the horizontal position 20, thereby positioning the dummy cores with their axes vertical.

During this time, a moulding cycle is being carried out with the mould tools 8. In response to movement of the cores into the position 20, the carriage 5 advances along the rails 7 to the moulding station 3 and to the position shown in broken lines in Figure 1 and full lines in Figure 2. To permit the carriage to be moved into this position, the mould parts 12,13 have been opened at the end of a moulding cycle, with the moulded cups 10 being retained on the male mould parts 12. Hence, the carriage locates the dummy cores and the suction pick-up cups on the arms 17 between the separated mould parts and the pneumatic cylinder 18 is operated to separate the support arms 16,17, thereby inserting the dummy cores into the female mould parts 13 and locating the suction pick-up cups at the ends of the arms 17 adjacent the moulded containers on the male mould parts 12.

In this position, vacuum is removed and air pressure is applied to the dummy cores 6 to transfer the labels carried thereon to the adjacent walls of the female mould parts defining the external surfaces of the cup side walls and an electrostatic charge is applied to the female mould parts to retain the labels in the female mould parts. The labels completely surround and cover the adjacent wall of the female mould parts moulding the external surfaces of the side walls of the cups.

Whilst the labels are being transferred to the female mould parts, suction is applied to the suction cups on the support arms 17 so that the moulded cups 10 are attached to the support arms 17. Air pressure may be applied to the end of the male mould parts to assist this operation. Thereafter, the pneumatic cylinder 18 is operated to close the support arms 16 and 17 together, thereby withdrawing the dummy cores from the female mould parts and the moulded cups from the male mould parts. The carriage 5 is then moved back to the pick-up station 2 in a return stroke and the female mould parts 13 are moved in a downward stroke onto the male mould parts 12 to reassemble the mould tools 8, whereupon the next moulding cycle takes place in order to mould another batch of expanded plastics cups having the labels delivered to the female mould parts bonded to the outsides of the cups. In this moulding cycle, plastics moulding beads are injected into the mould cavities of the mould tools, steam is injected into the mould cavities to heat and cook the plastics material and achieve the necessary expansion and fusion of the beads for producing the moulded cups, and the tools are cooled to solidify the

moulding. During the cycle, the heat activated adhesive on the labels retained within the female mould parts causes the labels to be firmly bonded to the adjacent side surfaces of the cup moulding.

Upon return of the carriage to the label pick-up station, another six labels are secured to the dummy cores 6 preparatory to the next moulding cycle, and air pressure is applied to the suction cups to discharge the moulded cups 10 onto the inspection cores 11. The cups seated on the inspection cores are tested for leaks in the manner hereinbefore described, leaking cups being rejected and acceptable cups being discharged into the stacks 33 on the conveyor 31.

An example of the cups 10 produced by the machine of this invention is illustrated in Figure 3. It is an expanded or foam plastics cup of relatively thin walled construction and comprising high-density foam plastics material. It is of circular shape in plan and comprises a bottom wall 45 and a side wall 46 extending upwardly and outwardly from the bottom wall to a mouth 47 at the top of the cup where the side wall terminates in an annular rim flange 48 which projects radially outwardly from the side wall about the mouth of the container. The rim flange 48 is similar to the roll type rim flange of a cup thermo-formed from sheet plastics material and is designed to capture a lid which may be snapped onto the rim flange to close the mouth of the container. A label 49, which has its inner surface bonded to the external surface of the side wall 46 of the cup by the heat activated adhesive, completely covers the side wall of the cup. The edge 50 of the label adjacent the mouth of the cup is seated directly under the rim flange 48 so that its upper edge is concealed.