Patent Application
20180201399
The present application relates to improvements in or relating to capsules. In particular, it relates to a weld-head and former for use in the assembly of capsules, such as beverage capsules. The application also relates to methods of assembly utilising said weld-head and former and uses of capsules produced by said methods.
Capsules for containing beverage ingredients are well known. One type of known capsule is described in U.S. Pat. No. 5,840,189 and comprises a cup-shaped capsule body having a base, a truncated conical side wall and an open mouth. The open upper mouth is hermetically sealed by a lid. The cup-shaped capsule body and lid define a capsule volume in which is located a filter element and a portion of beverage ingredients. In use, the lid and base are both pierced to allow for the injection of hot water into the capsule volume, and the delivery of an extracted beverage out of the capsule volume. The filter element serves to allow the extracted beverage to pass there through while retaining the solid residue of the beverage ingredients. In U.S. Pat. No. 5,840,189 the filter element is permanently joined to an interior surface of the conical side wall at a location adjacent to the open mouth.
U.S. Pat. No. 6,440,256 describes a method of forming and inserting a filter element into a cup-shaped capsule body of the type described in U.S. Pat. No. 5,840,189. In particular, the method first requires the folding and sealing of a filter material to form a filter element. The filter element is then transferred to the location of a cup-shaped capsule body by a first mandrel. A probe is then lowered relative to the first mandrel to strip the filter element off the first mandrel with a heated tip of the probe being used to tack weld a bottom of the filter element to the base of the cups shaped capsule body. Next, the probe is withdrawn and a shaping mandrel is inserted to radially expand the filter element against the interior side wall of the cup-shaped capsule body. The shaping mandrel is then withdrawn and a welding mandrel is inserted to effect a peripheral weld between the filter element and the side wall.
This prior art method involves a number of individual stages and require three separate mandrels. It is also unsuitable for assembling a filter element in a capsule where the filter element does not extend to the base of the cup-shaped capsule body.
According to the present disclosure there is provided a method of assembling a filter element with a cup-shaped capsule body using a combined weld-head and former, comprising the steps of:
Advantageously, the combined weld-head and former achieves, in a single operation, the multiple functions of inserting the filter element into the cup-shaped capsule body, shaping the filter element into a cup-shaped filter element, and the bonding together of the cup-shaped filter element and the cup-shaped capsule body. This allows for a less complicated and quicker assembly procedure. The method is also suitable for assembling a filter element in a capsule where the filter element does not extend to a base of the cup-shaped capsule body.
A magnitude of a peak force applied to the filter element by the sprung-loaded former may be limited by allowing the sprung-loaded former to move relative to the weld-head against a spring bias.
Typically, the filter material is made from a material having a relatively low tear strength. The present applicant has found that using a solid, non-compliant former to drive the filter element into the cup-shaped capsule body can lead to tearing of the filter element if too high a load is applied to the filter element by the former. By use of the sprung-loaded former of the present disclosure the likelihood of tearing of the filter element is lessened or avoided since the peak force applied by the former to the filter element may be moderated by the compliance of the former.
Consequently, the magnitude of the peak force applied to the filter element is preferably less than the force required to tear the cup-shaped filter element. For example, the magnitude of the peak force applied to the filter element may be less than 45N, preferably less than 40N, more preferably less than 30N.
At the end of step b), a portion of the cup-shaped filter element may be held in contact with the cup-shaped capsule body by the weld-head. Advantageously, this allows bonding of the cup-shaped filter element and the cup-shaped capsule body to take place immediately after the filter element has been deformed into the cup-shaped filter element. In other words, a single stroke of the combined weld-head and former not only inserts and deforms the filter element into the required shape but also readies the cup-shaped filter element for a bonding step. This avoids the need for a plurality of reciprocal machine movements to insert, deform and bond the filter element, which thus results in a faster assembly process.
The cup-shaped filter element may be bonded to the cup-shaped capsule body such that the cup-shaped filter element is suspended within the cup-shaped capsule body, with a base of the cup-shaped filter element being out of contact with a base of the cup-shaped capsule body.
During step d), a portion of the cup-shaped filter element may be bonded to the cup-shaped capsule body by using a heated portion of the weld-head. The weld-head may be heated by a resistive heater coil or resistive band. The heated portion may comprise a heated ceramic component.
During step d), at least a portion of the cup-shaped capsule body may be softened by the heated portion of the weld-head, thereby allowing the weld-head to move further into the cup-shaped capsule body.
The heat applied to the cup-shaped capsule body may result in softening of the material of the cup-shaped capsule body and/or may result in localised thinning of a side wall of the cup-shaped capsule body. In either case this may allow the weld-head to move further into the cup shaped capsule body since the reaction force applied to the weld-head by the cup-shaped capsule body may be reduced by the material softening.
During said further movement of the weld-head into the cup-shaped capsule body, further movement of the sprung-loaded former into the cup-shaped capsule body may be limited or avoided by allowing the sprung-loaded former to move relative to the weld-head against a spring bias.
Advantageously, even where the weld-head does move further into the cup-shaped capsule body, movement of the former further into the cup-shaped capsule body is either limited or avoided due to the former being sprung-loaded. In other words, the additional displacement of the weld-head is partially or wholly accommodated by compression of the spring bias existing between the weld-head and the former. This significantly lessens or eliminates any additional loading being applied to the cup-shaped filter element during the bonding step.
The sprung-loaded former may be slidably coupled to the weld-head, with a compression spring extending between the sprung-loaded former and the weld-head. As an alternative to a compression spring, the former may be sprung-loaded by, for example, use of an elastomeric spring, a gas spring, a gas strut, or another arrangement providing compliance between the weld-head and the former or compliance within the former itself. The element providing compliance may be a separate element or may form an integral part of either the weld-head or former. The material and/or the shape of the former may produce the compliance.
The method may further comprise the step of:
During step e) the sprung-loaded former may flex to aid decoupling of the sprung-loaded former from the cup-shaped filter element.
The former may be formed from a rigid material. In some aspects using a flexible former may reduce the risk that the cup-shaped filter element will be torn on withdrawal of the combined weld-head and former. A part or a whole of the former may therefore be formed from a flexible material. Alternatively, the former may comprise a geometric shape providing an inherent flexibility.
The present disclosure also provides a method of making a beverage capsule, comprising the steps of:
The present disclosure also provides a beverage capsule produced using the method described above.
The one or more beverage ingredients may be an extractable/infusible ingredient such as roasted ground coffee or leaf tea. The beverage ingredients may be a mixture of extractable/infusible ingredients and water-soluble ingredients. The water-soluble ingredient may be, for example, an instant spray-dried or freeze-dried coffee, a chocolate powder, a milk powder or a creamer powder. Milk powders may include dried skimmed milk, part-skimmed milk, and whole milk, dried milk protein concentrates, isolates, and fractions, or any combination thereof. Creamer powders may be manufactured from dairy and/or non-dairy food ingredients and typically contain emulsified fat, stabilized by protein or modified starch, dispersed in a carrier that facilitates drying, especially spray drying. The powdered ingredient may be agglomerated.
The present disclosure also provides a combined weld-head and former for use in assembling a beverage capsule, comprising a weld-head and a former, wherein the former is sprung-loaded.
The sprung-loaded former may be slidably coupled to the weld-head, with a spring extending between the sprung-loaded former and the weld-head.
As noted above, the spring may be a compression spring, an elastomeric spring, a gas spring, a gas strut or another arrangement providing compliance between the weld-head and the former. The element providing compliance may be a separate element or may form an integral part of either the weld-head or former.
The sprung-loaded former may comprise a forming body. At least a portion of the forming body may be flexible.
The present disclosure also provide for use of a combined weld-head and former as described above to assemble a filter element with a cup-shaped capsule body.
The cup-shaped capsule body may be formed from a polymeric material. For example, it may be formed from polypropylene, polyester, polystyrene, nylon, polyurethane, acetal, acetal grade polyoxylene methylene copolymer (e.g. Centrodal C), or other engineering plastics.
The cup-shaped capsule body may comprise a laminated material. For example, the cup-shaped capsule body may comprise a laminate of polystyrene and polyethylene. In another example, the cup-shaped body may be formed from a laminate having layers of polystyrene, ethylene vinyl alcohol (EVOH) and polyethylene.
The cup-shaped capsule body may comprise a barrier layer. The barrier layer may form one layer of a laminate structure of the cup-shaped capsule body. The barrier layer may be substantially impermeable to oxygen/air and/or moisture. Preferably the barrier layer acts to preserve the contents of the capsule from potential degradation due to exposure to oxygen/air and/or moisture. An example of a suitable barrier layer is EVOH.
Suitable materials for the filter element include heat-sealable woven and non-woven materials, paper, and cellulose as well as plastics such as polypropylene and polyethylene. The paper or cellulose material may contain fibres of another material, for example, polypropylene or polyethylene.
The sprung-loaded former may be made in whole or in part from a material which is heat resistant. The sprung-loaded former may be formed from a rigid material such as aluminium, mild steel, copper, brass or stainless steel. It may also be made from a non-metallic material such as a ceramic or a polymer. The polymer may comprise synthetic resin bonded fabric, for example, a phenol formaldehyde resin including additional woven cotton or linen fabrics. One example of such is Tufnol (RTM) available from Tufnol Composites Ltd., of Birmingham, UK. The sprung-loaded former may be made in whole or in part from a material which is flexible. One example is silicone.
Aspects of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:
A capsule 1, which may be, for example, a beverage capsule containing a portion of one or more beverage ingredients, is shown in
The cup-shaped. capsule body 2 may be formed from a laminate having layers of polystyrene, ethylene vinyl alcohol (EVOH) and polyethylene.
The lid 3 may be formed from polyethylene, polypropylene, polyesters including polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polyamides including nylon, polyurethane, paper, viscose and/or a metal foil. The lid may comprise a laminate, be metallised or formed of copolymers. In one example, the lid comprises a polyethylene-aluminium laminate.
As shown in
The combined weld-head and former 60 comprises a weldhead 70 and a sprung-loaded former 80.
The weld-head 70 comprises a generally solid body 71 having a bore 72 running there through. The bore 72 is located at a centre of the solid body 71 and orientated along a longitudinal axis of the weld-head 70. An upper end of the solid body 71 is provided with a plurality of threaded bores 75 to allow the weld-head 70 to be coupled to a mechanism (not shown) that controls movement and heating of the weld-head 70. A lower end face 73 of the weld-head 70 is perpendicular to the longitudinal axis. A welding zone 74 towards a lower end of the solid body 71 is shaped to conform with the cup-shaped capsule body 2. In the illustrated example the welding zone 74 comprises two tapered surfaces that conform in shape to inwardly tapering section 22 of the cup-shaped capsule body 2. The weld-head may be formed from a suitable material able to transmit heat energy via the welding zone 74. Examples include mild steel, aluminium, copper and brass.
The sprung-loaded former 80 comprises a forming body 86, a coupling leg 83 and a spring 84. The forming body 86 comprises a base 82 of a circular shape and a side wall 81 which extends upwardly from the base 82 and terminates in a circular rim 87. The side wall 81 has a frusto-conical shape, the inclination of which generally conforms to the inclination of the side wall 5 of the cup-shaped capsule body 2. An outer corner 85 at the junction between the side wall 81 and the base 82 is radiused to prevent any sharp edges which might tear the filter element 8. The coupling leg 83 extends upwardly from the base 82 within the side wall 81. The coupling leg 83 is cylindrical and located at a centre of the forming body 86 and is shaped and sized to be received as a sliding fit within the bore 72 of the weld-head 70. The forming body 86 is made of a rigid material, such as aluminium or copper. Alternatively, a material with a degree of flexibility, such as a silicone rubber, could be utilised.
The spring 84 is located about the coupling leg 83 and extends from an inner face of the base 82 to the lower end face 73 of the weld-head 70. The spring is a helical compression spring.
The coupling leg 83 is retained within the bore 72 by means of a threaded bolt, bore and washer arrangement 88 at an upper end of the coupling leg 83.
As assembled and viewed in the orientation shown in
The steps in assembling the filter element 8 with the cup-shaped capsule body 2 are shown in
In a first step shown in
Insertion of the combined weld-head and former 60 continues until the point is reached, shown in
Bonding of the cup-shaped filter element 56 to the cup-shaped capsule body 2 now takes place due to heat energy from the welding zone 74 causing localised fusing of the material of the filter element 8 and the cup-shaped capsule body 2. The heating of the material of the cup-shaped capsule body 2 has been found to have a tendency to soften and/or thin the cup-shaped capsule body 2. This allows the weld-head 70 to move downwards, further into the cup-shaped capsule body 2. This further inward movement of the weld-head 70 would have a tendency, if the forming body 86 were not sprung-loaded, to impart an increased force to the cup-shaped filter element 56 (which is now not free to move relative to the cup-shaped capsule body 2). However, the sprung-loaded form of the former 80 means that the further inward movement of the weld-head 70 is accommodated by compliance of the combined weld-head and former 60—specifically it is accommodated by compression of the spring 84 so as to move the forming body 86 relative to the weld-head so as to reduce the size of the gap 90.
The final stage, shown in
The assembly of the cup-shaped filter element 56 and the cup-shaped capsule body 2 may then undergo further process steps in order to fill the capsule with a portion of one or more beverage ingredients and to apply the lid 3.
As part of the assembly method described above, the spring rate of the sprung-loaded former 80 should be chosen as required depending on the particular geometry of the cup-shaped capsule body 2 and the material of the filter element 8 to ensure that the peak load imparted to the filter element a/cup-shaped filter element 56 does not exceed its tearing strength. The spring rate of the sprung-loaded former 80 depends not only on the spring rate of the spring 84 itself but also the effects of friction between the components of the former 80. In one experiment, a circular piece of filter material comprising woven paper and polyethylene of diameter 0.97 mm and thickness 0.1 mm, was bonded according to the method described above in a cup-shaped capsule body 2 having an inner face formed from polyethylene and an internal diameter at the open upper mouth 20 of 45 mm. The depth of the cup-shaped filter element 56 so formed was 33 mm. For this example a spring rate of from 2.0 to 4.0 N/mm, preferably 3.0 N/mm for the sprung-loaded former 80 was found to be beneficial. This was achieved with use of a helical compression spring having a spring rate of from 1.0 to 3.0 N/mm, preferably 2.0 N/mm.
Tests were conducted to ascertain the tearing strength of a typical filter element. The results are shown in Table 1 below. The filter element comprised a circular piece of filter material comprising woven paper and polyethylene of diameter 97 mm and thickness 0.1 mm. A forming body 86 was driven at a fixed rate of 100 mm/minute until tearing of the filter element occurred.
From this, it can be seen that, for this example, limiting the peak force applied to the filter element 8/cup-shaped filter element 56 to under 48N is preferred to reduce or eliminate the chances of tearing.
Comparative tests were then undertaken to compare the peak force applied to the filter element 8/cup-shaped filter element 56 using the method of the present disclosure (making use of a sprung-loaded former 80) compared to an assembly method using a weld-head and former that consists of a solid bung former that is not sprung-loaded relative to the weld-head. As above, the filter material comprised woven paper and polyethylene of diameter 97 mm and thickness 0.1 mm. The capsule body 2 comprised an inner face formed from polyethylene and an internal diameter at the open upper mouth 20 of 45 mm. The depth of the cup-shaped filter element 56 formed was 33 mm. For the combined weld-head and former 60, a spring rate of 3.0 N/mm for the sprung-loaded former 80 was chosen by use of a compression spring having a spring rate of 2.0 N/mm. The results are shown in Table 2 below.
Use of the sprung-loaded formed resulted in a significantly reducing peak load being applied to the filter element a/cup-shaped filter element 56 and in every case prevented tearing of the material.
In the above aspect, the forming body 86 comprises an intergral, cup-shaped, thin-walled structure. However, other forms of forming member may be used as part of the sprung-loaded former 80. For example, the forming body 86 may be formed from a plurality of separate parts. The forming body 86 may comprise a base 82 but no side wall.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1218848.8 | Oct 2012 | GB | national |
This application is a continuation of U.S. patent application Ser. No. 14/436,443, filed Apr. 16, 2015, which is a U.S. national phase application of International Application No. PCT/IB2013/002515, filed Oct. 16, 2013, which claims the benefit of Great Britian Application No. 1218848.8, filed Oct. 19, 2012, which are all hereby incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14436443 | Apr 2015 | US |
| Child | 15922361 | US |
