A METHOD OF FORMING AN ITEM OF FOOTWEAR
The present invention relates to a method of forming an item of footwear ( 100 ) and an item of footwear ( 100 ). In particular, the item of footwear ( 100 ) is a boot formed of vulcanised rubber such as a Wellington boot. A method of forming an item of footwear ( 100 ) comprising the steps of providing a sole member ( 2 ) formed of a first rubber material having a first compressive resistance, the sole member ( 2 ) comprising a cavity ( 4 ) in an upper surface ( 2 A) of a heel region of the sole member ( 2 ); placing an insert ( 6 ) into the cavity ( 4 ), the insert ( 6 ) having a second compressive resistance lower than the first compressive resistance; and then vulcanising to thereby attach an upper part ( 8 ) formed of a second rubber material to the sole member ( 2 ) at a first temperature, wherein the insert ( 6 ) is formed of a material which is solid at the first temperature.
1 . A method of forming an item of footwear comprising the steps of:
(a) providing a sole member formed of a first rubber material having a first compressive resistance, the sole member comprising a cavity in an upper surface of a heel region of the sole member;
(b) placing an insert into the cavity, the insert having a second compressive resistance lower than the first compressive resistance; and then
(c) vulcanising to thereby attach an upper part formed of a second rubber material to the sole member at a first temperature,
wherein the insert is formed of a material which is solid at the first temperature.
2 . The method of claim 1 , wherein step (a) comprises moulding the sole member to form the cavity.
3 . The method of claim 1 , wherein the first rubber material comprises synthetic rubber in an amount of from about 4 wt % to about 6 wt % and natural rubber in an amount of from about 40 wt % to about 50 wt % based on the total weight of the first rubber material, and/or the second rubber material comprises synthetic rubber in an amount of from about 4 wt % to about 6 wt % and natural rubber in an amount of from about 40 wt % to about 50 wt % based on the total weight of the second rubber material.
4 . The method of claim 3 , wherein the first and/or second rubber material consists essentially of:
a natural rubber,
a synthetic rubber,
silicon dioxide and/or calcium carbonate, and
one or more of zinc oxide, an accelerant and an antioxidant.
5 . The method of claim 1 , wherein the insert comprises a plurality of air pockets or channels arranged within the insert.
6 . The method of claim 5 , wherein the air pockets or channels are regularly arranged within the insert.
7 . The method of claim 5 , wherein the air pockets or channels form a honeycomb structure.
8 . The method of claim 5 , wherein the insert is formed of a thermoplastic, preferably thermoplastic polyurethane.
9 . The method of claim 1 , wherein the cavity extends into at least 50% of the depth of the sole member in the surrounding area and the insert is complementarily sized and shaped.
10 . The method of claim 1 , wherein the cavity extends across at least 50% of the width of the sole member and the insert is complementarily sized and shaped.
11 . The method of claim 1 , wherein the item of footwear is a boot with a height of at least 100 mm, preferably at least 150 mm, most preferably at least 200 mm.
12 . An item of footwear produced according to the method of claim 1 .
13 . An item of footwear comprising:
a sole member formed of a first rubber material having a first compressive resistance, the sole member comprising a cavity in the heel region;
an insert arranged within the cavity, the insert having a second compressive resistance lower than the first compressive resistance; and
an upper part formed of a second rubber material attached to the sole member,
wherein the insert is formed of a material with a melting temperature greater than 140° C.
14 . The item of footwear of claim 13 , wherein the first rubber material comprises synthetic rubber in an amount of from about 4 wt % to about 6 wt % and natural rubber in an amount of from about 40 wt % to about 50 wt % based on the total weight of the first rubber material, and/or the second rubber material comprises synthetic rubber in an amount of from about 4 wt % to about 6 wt % and natural rubber in an amount of from about 40 wt % to about 50 wt % based on the total weight of the second rubber material.
15 . The item of footwear of claim 14 , wherein the first and/or second rubber material consists essentially of:
a natural rubber,
a synthetic rubber,
silicon dioxide and/or calcium carbonate, and
one or more of zinc oxide, an accelerant and an antioxidant.
16 . The item of footwear of claim 13 , wherein the insert comprises a plurality of air pockets or channels arranged within the insert.
17 . The item of footwear of claim 16 , wherein the air pockets or channels are regularly arranged within the insert.
18 . The item of footwear of claim 16 , wherein the air pockets or channels form a honeycomb structure.
19 . The item of footwear of claim 13 , wherein the cavity extends into at least 50% of the depth of the sole member in the surrounding area and the insert is complementarily sized and shaped.
20 . The item of footwear of claim 13 , wherein the cavity extends across at least 50% of the width of the sole member and the insert is complementarily sized and shaped.
21 . The item of footwear of claim 13 , wherein the item of footwear is a boot with a height of at least 100 mm, preferably 150 mm, most preferably 200 mm.
22 . The method of claim 1 , wherein the insert is formed of a thermoplastic polyurethane.
23 . The method of claim 1 , wherein the item of footwear is a boot with a height ranging from at least about 150 mm to at least about 200 mm.