The Football (Soccer Ball)
4. The functions of the ball casing
Figure 8: Manufacturing of a football casing (US 5 772 545 A1).
The casing is the most exposed component of a football. It should be largely abrasion-resistant, evenly round and keep shape. Its properties should remain stable under all game and weather conditions. This demanding catalogue of requirements presented a particularly motivating challenge for inventors.
We will briefly present the components composing most of today's football casings and the required manufacturing steps, based on US patent application 5 772 545 A1 (Figure 8).
(A) shows a bladder ball 31 with mounted valve stem 32. A strengthened glue-coated thread 331 (eg. made of nylon) is evenly wound around this bladder ball until it forms a web layer (B, C) which is heated and molten to obtain strengthened bladder 30. (D) shows the polygonal panels 24, cut out of leather or synthetic leather, which are machine-sewn together (E) in such a way that the seams are on the outer side (F). The ball cover is turned right side out using remaining inlet opening 28 (G); the reinforced bladder 30 is inserted as shown by (H) and the valve stem is glued to valve hole 26 provided in one of the polygonal panels. Opening 28 is sewn together by hand. The ball is then ready to be inflated.
Sometimes a reinforced panel is provided opposite the valve segment for counterbalancing purposes (DE 196 24 020 C1).
| Publication number | Year | Title | Brief description |
|---|---|---|---|
| US 5 772 545 A | 1996 | Sportsball and manufacturing method thereof | see title |
| DE 196 24 020 C1 | 1996 | Spielball und Verfahren zu dessen Herstellung | Compensation of the adverse effect of the valve by means of a reinforced panel, provided on the football casing opposite the valve |
4.1 The seams
Stable sewing of the individual ball panels presents a particular challenge as the seams are subject to high stress. They should not be visible to avoid wear and roughness of the ball surface.
Sewing techniques include the early staggered double seams (DE-PS 354 758), seams on fabric linings of individual panels covered by adhesive tapes (DE-PS 363 800), various combined adhesive and stitching solutions (DE-PS 366 073) and loop seams (GB 384 570 A, Figure 7), and the recent self-shrinking threads (US 5 752 890 A) which should provide for an enhanced durability of the seams.
Figure 9: Sewing of football casing GB 384 570 A.
Figure 9 taken from GB 384 570 A shows the sewing process very clearly. The "loop" stitching of the panels (a [top] and I, m[bottom right] ) of a ball casing is made by means of thread q, and the panel seams are additionally glue-sealed.
| Publication number | Year | Title | Brief description |
|---|---|---|---|
| US 5 752 890 A | 1998 | Ball for ball game and method for manufacturing the same | Utilisation of self-shrinking threads for sewing football casings |
| GB 384 570 A | 1932 | A ball for games | Loop stitching of football casings |
| DE-PS 366 073 | 1922 | Verfahren zur Herstellung äußerlich unsichtbarer Nahtverbindungen an Spielballhüllen | Method for manufacturing seams on game ball casings, not visible from the outside |
| DE-PS 363 800 | 1921 | Spielhülle mit verdeckten Nähten | Game ball casing with recessed stitching |
| DE-PS 354 758 | 1920 | Naht zur Verbindung der Lederteile an Sportballhüllen | Sewing of a ball casing with staggered double seams |
4.2 The component structure
Two of the above figures show that today's footballs usually consist of three or more layers or shells (cf. DE 43 39 677 A1, EP 0 598 542 A2).
This design has been adopted to optimise the spherical shape, increase durability and achieve better bounce of the ball, eg. through lower water uptake and adapted cushioning. Over the years, artificial leather and other synthetic materials have widely replaced genuine leather for manufacturing football casings (eg. proposed in GB 733 154 A as early as in 1951).
| Publication number | Year | Title | Brief description |
|---|---|---|---|
| EP 0 598 542 A2 | 1993 | Inflatable sports ball | Multi-layered structure of a football casing |
| DE 43 39 677 A1 | 1993 | Verwendung eines Verbundstoffes zur Herstellung von Sportbällen | Multi-layered structure of a football casing |
| GB 733 154 A | 1951 | Improvements in or relating to inflatable balls | Use of plastics for football casings |
4.2.1 The carcass
The inflated bladder ball is usually bonded with a web layer made of fibres providing tensile strength. This layer provides stability to the bladder ball and prevents excessive inflating.
Figure 10: Nylon reinforcing layer of a ball casing according to US 3 219 347 A.
Textile-like materials are often used for this purpose (cf. DE-PS 480 658, fabric, 1927; US 3 219 347 A, 1927 (Figure 10) and US 3 405 018 A, nylon, 1961; US 4 333 648 A, nylon elastomer thread; WO 95/09034 A1 multi-layer nylon, 1995).
Depending on the desired properties, the other layers may include foam, latex or specifically developed elastic synthetic materials either for cushioning or for enhanced bounce capacity. This composite unit is usually bonded through vulcanisation or using adhesives. It is often referred to as the "carcass".
The final outer casing, which shows the typical panel structure, is either sewn as described above or laminated onto the carcass. This method has been increasingly used for about 15 years (eg. WO 2004/056 424 A1), although is has been known since 1913, according to DE DE - PS 281 587.Thermal bonding allows to obtain particularly smooth surfaces, since there are no seams and no bulges.
| Publication number | Year | Title | Brief description |
|---|---|---|---|
| WO 2004/056 424 A1 | 2002 | Ball for ball game and method for manufacturing the same | Adhering panels of the cover of a football |
| WO 95/09034 A1 | 1993 | Sports ball and method of manufacture of same | Football casing reinforced with nylon layers for added tensile strength |
| US 4 333 648 | 1982 | Inflatable game ball | Ball casing reinforced with nylon elastomer fabric |
| US 3 405 018 | 1961 | Method of making simulated seam reinforcing and rigidizing for air-inflated balls | Interior ball case reinforced by means of nylon thread winding layer |
| US 3 219 347 | 1961 | Air inflated ball with reinforced seams | Interior ball case reinforced by means of nylon thread winding layer |
| DE-PS 480 658 | 1927 | Nahtloser Fußball mit mehrlagiger, auf die Gasblase aufgeklebter Verstärkungshülle | Seamless football with multi-layered reinforcing casing bonded on bladder |
| DE-PS 281 587 | 1913 | Lehrform zur Herstellung von Sportbällen aus einzelnen aneinandergeklebten Teilen | Template for manufacturing sports balls composed of a plurality of adhered panels |
4.2.2 Physical properties of the layers
The specific physical properties of the individual ball casing layers have recently been the subject matter of many patent applications. The focus has been partly on the tensile strength achieved through the individual components (eg. WO 95/09034 A1) and partly on improving elasticity to optimise bounce properties.
The desired bounce is often achieved by adding elastic hollow bodies to the synthetic intermediate layers of the casing. These provide for a sort of air cushion (DE 44 08 047 A1, DE 197 32 824 A1, DE 100 42 244 A1, WO 97/17109 A1). Other applications propose the creation of graded pore sizes within a specific layer (EP 0 385 872 A2), additional fleece padding (DE 43 39 677 A1) or use of a matrix material with embedded dimensionally stable, elastic blow-moulded parts (DE 197 58 546 A1).
Use of synthetic materials has some disadvantages too. Leather adapts comparatively well to the inner pressure created by an inflated bladder, ie. it has sufficient elasticity to expand and bulge. Many laminated synthetic materials are less well adapted and need to be specifically preformed and assembled.
Figure 11: Manufacturing of plastic segments for football casings (DE 102 55 092 A1).
According to DE 102 55 092 A1 each individual panel is moulded to obtain the desired three-dimensional shape (Figure 11) which it ought to have when the ball is fully inflated. Several manufacturing steps are required for this purpose.
Backing material 10 is preformed in a press using mould 2, before being placed on a further mould 3 and laminated to pre-heated mouldable part 20; this composite piece is one of the panels that will form the outer casing of a football.
| Publication number | Year | Title | Brief description |
|---|---|---|---|
| DE 102 55 092 A1 | 2002 | Verfahren zur Herstellung von Teilstücken eines Balls | Optimum pre-forming of individual plastic panels for ball casings |
| DE 100 42 244 A1 | 2000 | Verbundmaterial für eine Ballhülle, insbesondere Fußballhülle | Ball casing padding layer consisting of synthetic foam with closed cells |
| DE 197 58 546 A1 | 1997 | Fußball | Padding layer for a ball casing, consisting of dimensionally stable, elastic blow-moulded parts |
| DE 197 32 824 A1 | 1997 | Fußball | Padding layer for a ball casing, consisting of elastic hollow bodies |
| WO 97/17109 A1 | 1996 | A ball and a method of manufacturing a ball | Elastomer material with hollow bodies as padding layer in a ball casing |
| WO 95/09034 A1 | 1993 | Sports ball and method of manufacture of same | Football casing reinforced with nylon layers for added tensile strength |
| DE 44 08 047 A1 | 1994 | Ballhülle, insbesondere für Fußbälle | Ball casing with air cushion layer consisting of bubble-shaped chambers |
| DE 43 39 677 A1 | 1993 | Verwendung eines Verbundstoffes zur Herstellung von Sportbällen | Fleece padding layer for ball casing |
| EP 0 385 872 A2 | 1990 | Ballons de sports ou de loisiers, comprenant unse couche externe en mousse à peau intégrale et leur obtention | Football casing with foam layer having graded pore sizes |
4.2.3 Perfect casings - for what purpose?
Many of the techniques and materials described above help to obtain a surface smoothness that is sometimes not desired in practice. When using nearly perfectly smooth footballs, players often complain about a lack of "football feeling" which they used to experience before.
This has somewhat reversed the previous trend towards ever smoother surfaces. Profile segments are sometimes arranged on the laminated panels. In addition to conferring the desired "feeling", they should provide for better ball control and enable the goal keeper to hold on to the ball more easily (DE 202 20 150 U1).
| Publication number | Year | Title | Brief description |
|---|---|---|---|
| WO 2006/055 781 A1 | 2006 | Dimpled inflatable game balls | Dimpled inflatable game balls |
| DE 202 20 150 U1 | 2002 | Ballhülle, insbesondere für Fußbälle | Ball casing provided with profile elements for improved ball control |
4.3 Patterns and optical aspects
Nowadays, the ball casing also has an optical function. A specific football is being created (and marketed) for nearly any major football event. Individual surface designs are not only created by means of different colours and plastic films bearing designer elements which are laminated onto the ball casing (eg. made of polyurethane, cf. WO 95/09034 A1), but also by means of individual panel patterns.
From approx. WWI until the 1970 World Cup, footballs typically had the panel pattern shown in the above figure with the "lacing fork" of 1928. Since 1970, people have expected a football to show a black-and-white pattern composed of pentagonal and hexagonal panels.
Figure 12: Football cover made of triangular and pentagonal panels(WO 01 / 83047 A1).
However, there are many other alternatives to design the cover of a football using individual panels. Some examples are shown in the documents DE-PS 804 418, DE-GM 1 723 048, DE-GM 1 723 049, DE 44 34 751 A1, DE 700 67 84 U1, DE 195 34 144 A1, DE 195 35 636 A1 and DE 195 41 395 A1.
WO 01/83047 A1 presents a configuration made of triangular and pentagonal panels (Figure 12).
| Publication number | Year | Title | Brief description |
|---|---|---|---|
| WO 01/83047 A1 | 2000 | Ball for ball game and method for manufacturing the same | Ball cover composed of triangular and pentagonal panels |
| WO 95/09034 A1 | 1993 | Sports ball and method of manufacture of same | Polyurethane film bearing designer elements, laminated onto the ball casing |
| DE 195 41 395 A1 | 1995 | Ballhülle, insbesondere für Fußbälle | Football cover consisting of pentagonal and three-pointed star segments |
| DE 195 35 636 A1 | 1995 | Hohlkörper, Ball, Sportball, insbesondere Fußball , mit bevorzugt sphärischer bis ellipsoider Hülle nach Maßgabe kreisförmiger bis elliptischer Grundmuster | Hollow body, ball, sports ball, in particular football, preferably with spherical to ellipsoid casing determined by circular to elliptic basic patterns |
| DE 195 34 144 A1 | 1995 | Hohlkörper, Ball, Sportball, insbesondere Fußball, hergestellt aus ein bis fünf verschiedenen Polygon-Facettenformen nach einem Dreiecksgrundmuster | Hollow body, ball, sports ball, in particular football, composed of one to five different types of polygon facets based on a uniform triangular pattern |
| DE 44 34 751 A1 | 1994 | Ballhülle | Football cover consisting of triangular and elongated rhombus segments |
| DE 700 67 84 U1 | 1970 | Sportball | Football cover composed of pentagons and triangles |
| DE-GM 1 723 049 | 1956 | Hülle für Fuß- und andere Spielbälle | Football cover consisting of rectangular and pentagonal segments |
| DE-GM 1 723 048 | 1956 | Hülle für Fuß- und andere Spielbälle | Football cover consisting of bone shaped segments |
| DE-PS 804 418 | 1949 | Sportballhülle aus Zuschnittsgruppen | Typical football cover of the 1950s |