EP1401740B1

EP1401740B1 - Device for the bulk supply of polymers

Info

Publication number: EP1401740B1
Application number: EP02708906A
Authority: EP
Inventors: Nigel Hampton; Alain Pieters
Original assignee: Borealis Technology Oy
Current assignee: Borealis Technology Oy
Priority date: 2001-06-12
Filing date: 2002-03-22
Publication date: 2006-05-17
Anticipated expiration: 2022-03-22
Also published as: ES2259701T3; ATE326406T1; EP1401740A2; SE0102068D0; AU2002243167A1; WO2002051236A8; WO2002051236A3; DE60211515D1; WO2002051236A2

Abstract

A device for the buld supply of polymers is described. The device is characterised in that it includes a container and an inner polmer liner (4); the liner is attached toeh container; the container and the liner have at least on inlet opening (9); the container has a seperate outlet opening; the liner has a discharge chute (11) extending through the outlet opening; and that the wall (22) surrounding the outlet opening (3) has a circumferential groove (23) into which a location ring (24) is inserted, with the discharge chute (11) of the inner liner (4) passing between the ring and the groove. Preferably the liner (4) is atatched by means of transversal supporing bars (5, 6, 7) to the top of hte container at the front end and back end thereof, and to the bottom of the container at the front end thereof, and to the bottom of the container at the front end thereof. In addition the liner (4) is preferably attached tohe container along hte top of the two sides thereof by means of elastic bands (8) on the liner in combination with hooks on the container. To facilitate unloading of the container each of the two lower corners adjacent the outlet opening are cut-out to form tow triangular surfaces (10) inclined towards the outlet opening.

Description

Field of the invention

The present invention relates to a device for the bulk supply of polymers.

Technical background

Polymer material, typically polymer pellets, are manufactured by the polymer manufacturer at a plant and delivered to the customer such as a wire and cable manufacturer or pipe manufacturer by road and/or rail transport. In many applications such as wire and cable applications the cleanliness of the polymer material is important to ensure highly reliable long life products. Throughout the manufacturing of the polymer material at the polymer plant stringent efforts are made to avoid the presence of contaminants. In addition to these efforts it is essential that the design of the package and material handling systems for the transport of the polymer material from the manufacturing plant to the customer should be made in such a way that the risk of contamination is minimised.
A common way to package polymer material for transport from the manufacturer to the customer is the so-called Octabin which comprises a vertical octagonal container of paper board enclosing a plastic bag filled with about 500 to 1000 kg of polymer material (pellets).
The present system for packaging polymer material for transport to the customer is not optimal and suffer from disadvantages.
Conventional transport containers have a relatively small volume and a high number of connect/disconnect operations are necessary. It would be desirable to transport the polymer material in bulk, i.e. in a container holding at least about 20 tonnes, thereby minimising handling operations to an optimal level.
Conventional transport containers give rise to a large amount of packaging waste and it would be an advantage to reduce the packaging waste handling when transporting polymer material.
Conventional transport containers protect the plastic material in a satisfactory way during the transport from the manufacturer to the customer, but there is a risk of contaminating the polymer material when unloading it at the customer.
Also, handling of conventional transport containers at the customer is expensive, cumbersome and time consuming and requires access to unloading trucks and warehouses.

Summary of the invention

It is an object of the present invention to alleviate or eliminate the drawbacks of the prior art and provide a device for the bulk supply of polymers which ensures that the cleanliness attained in the manufacturing plant is maintained all the way from the manufacturer to the customer. The device should also only give rise to a minimum amount of packaging waste.
These and other objects are obtained by the present invention which provides a device for the bulk supply of polymers, characterised in that
it includes a container and an inner polymer liner;
the liner is attached to the container;
the container and the liner have at least one inlet opening;
the container has a separate outlet opening;
the liner has a discharge chute extending through the outlet opening; and that
the wall (22) surrounding the outlet opening (3) has a circumferential groove (23) into which a location ring (24) is inserted, with the discharge chute (11) of the inner liner (4) passing between the ring and the groove.
Further features of the present invention will appear from the description below and the appended claims.

Brief description of the drawings

In the attached drawings

Fig. 1 shows a perspective view of a container device according to the present invention;
Fig. 2 shows a perspective view of a plastic liner according to the present invention to be attached inside the container of Fig. 1;
Fig. 3 shows a perspective view of the plastic liner of Fig. 2 as seen from the opposite direction;
Fig. 4 shows a partial section view through the outlet opening of the device of the present invention in a transport position; and
Fig. 5 shows a partial section view similar to that of Fig. 4 through the outlet opening of the device of the present invention in a discharge position.

Detailed description of preferred embodiments of the invention

The device according to the present invention and preferred embodiments thereof will now be described in more detail with reference to the attached drawings.
As is indicated in Fig. 1, the device comprises an outer container 1. If the polymer material is transported by road the container is loaded on a truck and is preferably tiltably mounted on the truck as shown in Fig. 1. The container is preferably a conventional type container capable of holding about 20 to 30 tonnes of polymer material (pellets). The container preferably has a square form with a front, a back, a top, a bottom, and two sides. The outer dimensions of such a preferred square container are about 9 m x 2.5 m x 2.5 m. On the top of the container is provided at least one and preferably several closable inlet openings 2 for feeding polymer material into the container. A closable outlet or discharge opening 3 is provided at the lower part of the back of the container. This outlet opening will be discussed in more detail below with reference to Figs. 4 and 5. The container 1 is preferably made of a metallic material such as steel. Access to the container for inserting the plastic liner discussed below with reference to Fig. 2 and 3, cleaning, etc. is conveniently by means of doors at the back of the container (not shown). To facilitate emptying of the container as will be discussed below, the container preferably has its two lower backside corners cut-out. This is preferably made by inserting triangular internal corner plates into the two corners.
With reference to Fig. 2 and 3 a plastic liner 4 is provided inside the container 1. The liner 4 is designed to accomodate the polymer material to be transported (pellets; not shown). The liner is preferably made of the same polymer material as the polymer material to be transported, e.g. polyethylene. The liner is a separate component to the container and is preferably exchanged for a new liner before every transport of polymer material.
It is important to ensure that the liner remains safely located inside the container both during filling and unloading operations. To this end the liner is attached to the container by special fixing means on the liner and on the inside of the container. More specifically, the liner is provided with supporting bars, preferably three transversal supporting bars 5, 6 and 7, i.e. one at the top frontside, one at the top backside and one at the bottom frontside of the liner. These support bars are connected to fixing means, such as holes, at corresponding places on the inside of the container. In addition to the supporting bars the liner is provided with a number of additional fixing means, preferably in the form of elastic bands 8 that are connected to corresponding places of the container by means of fixing means, preferably hooks such as carabiner hooks (not shown) on the inside of the container. These elastic bands 8 are arranged at least along the top of the sides of the liner between the supporting bars. With the help of these fixing means it is easy to introduce the liner into the inside of the container and connect the liner to the container by means of the fixing means so that the liner stays in a proper erected position during the filling, transport, and unloading operations. When the polymer material has been unloaded from the container and the empty container has been returned to the polymer manufacturer, the used liner can readily be removed and replaced by a new liner.
For loading the container with polymer material the at least one inlet opening 2 in the top of the container is connected to corresponding inlet openings 9 in the top of the liner 4.
To facilitate smooth unloading of polymer material from the container the liner, like the container, has cut-out corners 10 at the two lower backside corners of the liner. These cut-out corners form two triangular surfaces inclined towards the outlet opening of the liner. The unloading or discharge of the polymer material is effected through a discharge chute 11 which protrudes from the lower part of the backside of the liner.
According to a particular embodiment the liner may also be provided with an air inlet sleeve 12 with a filter in order to feed filtered air into the liner after installation so that the liner is blown up with filtered air to guarantee a minimum of wrinkles in the liner.
In addition compensation air may be introduced into the liner during unloading via air inlet openings 13 in the container 1 (see Fig. 1; preferably there are two inlet openings at the front of the container and two at the back) and further via a filter 14 (preferably a polyethylene membrane) that is built into the liner 4 at the front-side thereof (see Fig. 3).
With reference to Figs. 4 and 5 these show a partial section of the outlet opening 3 of the container 1. The outlet opening is preferably cylindrical and arranged in an endplate 15 on the backside of the container. Preferably also, the endplate has a cover plate 16 and a lid that is hinged (not shown) and movable between a closed position covering the outlet opening and an open position exposing the outlet opening. For securing the cover plate 16 in position clamping means 17 are provided. As shown in Figs. 4 and 5 these clamping means preferably comprise angle bars 18 secured to the endplate 15 by means of studs 19 threaded in holes 20 in the endplate and provided with eyebolts 21 at their opposite end. To expose the outlet opening it is only necessary to open the lid, unscrew the eyebolts somewhat, turn the angle bars aside and remove the cover plate. The unscrewing of the eyebolts may be done by simply using a screwdriver, i.e. no special tool or key is required. The studs 19 are permanently connected to the endplate in the meaning that it is not necessary to unscrew them from the endplate for removal of the cover plate. However, in case the threads of the studs are damaged they may be removed and exchanged. The permanent connection of the studs to the endplate protects the internal threads of the holes 20 in the endplate and prevents dirt from entering the holes. This greatly extends the life of the steel container by eliminating the need for costly re-machining of the plate to repair damage to the screw threads caused by dirt. Additionally, it reduces the time needed to prepare the unloading thus promoting the clean unloading.
An alternative to the "angle bar" clamps shown in Fig. 4 and 5 are clamping means employing a "cam" action. Such clamping means are permanently screwed to the end plate in the same way as the shown "angle bar" clamps. Cam action clamping means must have a mechanism for securing such that the rigours of transport do not cause the cams to unlock.
The outlet opening 3 is preferably circular and has the form of a cylindrical bore 22 through the endplate 15 and the container 1. In the endplate the bore is provided with a circumferential groove 23. Into this groove a location ring 24, preferably of plastic material, is inserted. Before insertion of the location ring 24 the discharge chute 11 is drawn through the outlet opening 3 so that the discharge chute is fixed between the groove 23 and the location ring 24 when the location ring is inserted into the groove.
The peripheral outer part of the location ring 24 that is inserted into the groove preferably has a rounded or chamfered form in order to be more easily inserted into the groove. Similarly the outside edge 25 of the groove may preferably be chamfered for easy insertion of the location ring into the groove 23.
In order to fix the location ring 24 properly in the groove the location ring is provided with circumferential flanges 26 on each side so that they abut against the cylindrical wall or bore on each side of the groove 23.
It is particularly preferred that the flange towards the outside of the outlet opening has an extension that is shorter than the distance from the groove 23 to the outside or mouth of the outlet opening. In this way space is provided for the discharge chute that extends from between the outside flange 26 of the location ring and the bore 22, to be folded inwards without being squeezed between the outside flange 26 and the lid 16 when the latter is closed.
To ensure the correct insertion of the location ring, it is essential that the groove 23 is clean and free of detritus.
In order to eliminate any water or other extraneous material that may accumulate in the groove 23 it is preferred that the groove is provided with a drainage channel 27 that extends from the lower part of the groove and downwards to the exterior of the container.
The discharge chute 11 is integral with the liner 4 and is most preferably made of the same plastic material. In order to protect the protruding discharge chute it preferable comprises an inner sleeve 28 and an outer sleeve 29 as shown more clearly in Fig. 5. Preferably, the inner sleeve 28 is of a somewhat longer extension than the outer sleeve 29. The inner sleeve may e.g. have a length of about 1 m, while the outer sleeve may have a length of about 0.5 m. The reason for this is that the inner sleeve is pulled through the wall of a building and connected to a receiver station for unloading, while the outer sleeve is only connected to the outside of the wall of the building to protect the inner sleeve from dust between the container and the building.
As indicated above and shown in Figs. 4 and 5, the discharge chute 11 is fixed by means of the location ring 24 which squeezes it into the groove 23. This means that the discharge chute is stretched peripherally outwards into the groove 23. This stretching could damage the discharge chute through a thinning of the thickness and in order not to stress the discharge chute excessively the diameter of the discharge chute 11 should preferably be somewhat larger than the outside diameter of the location ring 24. The diameter of the discharge chute should not be too large, however, as then the extra thickness created must be accomodated within the groove and if this thickness is too large damage may occur due to the excessive force required to insert the location ring. It is preferred when the discharge chute has a diameter that is about 5-30 % larger than the outside diameter of the location ring. Within this range on the one hand excessive stress is not placed upon the discharge chute and on the other hand the extra thickness is not great enough to create damage when the location ring is inserted.
What has been said above for the diameter of the discharge chute is, of course, also valid for the diameters of the inner and outer sleeves.
When the inner liner is filled with polymer material to be transported to the user, the inner liner is sealed by closing the inlet openings 9 and the discharge chute 11. As indicated in Fig. 3 closing the discharge chute 11 is done by tightening a string 30 around the inner sleeve 28, sealing the outer sleeve 29, and then pushing the closed discharge chute back into the container 1. Also, the inlet openings 2 of the container are closed and the cover plate 16 is secured over the outlet opening 3 in a closed position by the clamping means 17.
When the polymer material (pellets) is to be discharged from the container, the lid is moved into an open position, the clamping means 17 are loosened and the cover plate 16 is removed from the outlet opening 3. Then the outer sleeve is opened by cutting open the seal and thereafter the innersleeve is unfolded and connected to the receiver station and finally the string is removed.
To support and guide the inner and outer sleeves of the discharge chute during unloading a guidance means (not shown) may be provided. Such guidance means preferably has the form of an adapter comprising an apertured plate to be fixed on the endplate after the lid has been opened. The aperture of the adapter plate is coextensive with the opening in the endplate and the adapter plate is fixed to the endplate by means of the same clamping means as the cover plate. Protruding from the aperture of the adapter plate is a guidance member, preferably in the form of a pipe or "half-pipe" (i.e. the semi-circular bottom half of a pipe) surrounding the extended discharge chute.
To facilitate the discharge of the polymer material the container may be tilted as shown in Fig. 1. Also, filtered air is preferably fed into the inner liner 4 via air inlet openings 13 and filter 14 so that collapse of the liner is prevented.
When the container has been unloaded it is transported back to the polymer manufacturer where it is cleaned and the used liner may be exchanged for a new one and filled with new polymer material.
From the above description it is evident that the present invention affords a very convenient device for the bulk transport of polymer pellets without the disadvantages of earlier devices used for the supply of polymer pellets.
The invention has been described above with reference to preferred embodiments thereof, but it will be recognised that the invention is not limited to these embodiments and that various modifications may be made within the scope of the invention as defined by the appended claims.

Claims

A device for the bulk supply of polymers,
characterised in that
it includes a container (1) and an inner polymer liner (4);
the liner is attached to the container;
the container and the liner have at least one inlet opening (2,9);
the container has a separate outlet opening (3);
the liner has a discharge chute (11) extending through the outlet opening; and that
the wall (22) surrounding the outlet opening (3) has a circumferential groove (23) into which a location ring (24) is inserted, with the discharge chute (11) of the inner liner (4) passing between the ring and the groove.
A device as claimed in claim 1, wherein the container (1) has a substantially square form with a front, a back, a top, a bottom, and two sides.
A device as claimed in claim 1 or 2, wherein the liner (4) is attached by means of transversal supporting bars (5,6,7) to the top of the container (1) at the front end and back end thereof, and to the bottom of the container (1) at the front end thereof.
A device as claimed in claim 3, wherein the liner (4) further is attached to the container (1) along the top of the two sides thereof by means of elastic bands (8) on the liner in combination with hooks on the container.
A device as claimed in any one of claims 1-4, wherein inside the container (1) each of the two lower corners adjacent the outlet opening are cut-out to form two triangular surfaces inclined towards the outlet opening (3).
A device as claimed in any one of claims 1-5, wherein the outlet opening (3) is cylindrical and is arranged in an endplate on the backside of the container, said endplate (15) having a cover plate (16) and a hinged lid which is movable between a closed position covering the outlet opening and an open position exposing the outlet opening.
A device as claimed in claim 6, wherein the endplate (15) has clamping means (17,18,19,21) for securing the cover plate (16) in the closed position.
A device as claimed in claim 7, wherein the clamping means (17,18,19,21) are permanently connected to the end plate.
A device as claimed in claim 1, wherein the outside edge (25) of the groove (23) is chamfered.
A device as claimed in claim 9, wherein the location ring (24) has circumferential flanges (26) on each side for contact with the surface of the cylindrical wall (22) on each side of the groove (23).
A device as claimed in claim 10, wherein the flange (26) towards the outside of the outlet opening (3) has an extension that is smaller than the distance from the groove (23) to the outside of the outlet opening.
A device as claimed in any one of claims 1-11, wherein the discharge chute (11) has a diameter that is 5-30 % larger than the outside diameter of the location ring (24).
A device as claimed in claim 12, wherein the discharge chute (11) of the inner liner (4) comprises an inner sleeve (28) and an outer sleeve (29).
A device as claimed in any one of claims 1-13, wherein a drainage channel (27) extends from the lower part of the groove (23) and downwards to the exterior of the container.
A device as claimed in any one of claims 1-14, wherein the liner (4) has at least one air inlet with a filter (12, 14).