Knitted compression garment, knitted fabric and method of knitting fabric
A therapeutic medical garment having a variable pressure profile along its length, and including a knitted tubular body and a knitted anti-slip portion formed proximate one end of the tubular body with an inner surface adapted for residing against a wearer's skin. The knitted anti-slip portion includes at least first, second and third yarns simultaneously knitted to form a repeat having a raised surface texture on the inner surface of the anti-slip portion. One of the first, second and third yarns is a low-friction yarn, and two of the first, second and third yarns are high-friction yarns knitted to reside on and form the raised surface texture on the inner face of the anti-slip portion. A fabric construction and a method of forming a fabric construction are also disclosed.
1. A therapeutic medical garment having a variable pressure profile along a length thereof, and comprising:
(a) a knitted tubular body;
(b) a knitted anti-slip portion formed proximate one end of the knitted tubular body with an inner surface adapted for residing against a wearer's skin;
(c) the knitted anti-slip portion including at least first, second and third yarns simultaneously knitted to form a repeat having a raised surface texture on the inner surface of the knitted anti-slip portion, wherein the first yarn is a low-friction yarn, and further wherein the second yarn and the third yarn are high-friction yarns knitted to reside on and form the raised surface texture on the inner face of the anti-slip portion such that the second yarn is covered by the third yarn at points where the third yarn locks the second yarn to the knitted anti-slip portion.
2. A therapeutic medical garment according to claim 1 wherein the first yarn has a coefficient of friction of less than 0.5 and the second yarn and the third yarn have a coefficient of friction of greater than 0.5.
3. A therapeutic medical garment according to claim 1 or claim 2 , and including:
(a) a knitted welt formed on one end of the knitted tubular body; and
(b) the knitted anti-slip portion formed intermediate the knitted tubular body and the knitted welt having a textured inner surface adapted for residing in a non-slip condition against the wearer's skin to increase the anti-slip properties of the therapeutic medical garment.
4. A therapeutic garment according to claim 3 , wherein the knitted tubular body and the knitted anti-slip portion are integrally-formed.
5. A therapeutic garment according to claim 4 , wherein the knitted tubular body is a jersey knit structure.
6. A therapeutic garment according to claim 1 , wherein the second and third yarns have a linear mass density between 20 and 5040 denier (22.2 to 5594 dTex).
7. A therapeutic garment according to claim 1 , wherein the second and third yarns are multifilament yarns selected from the group consisting of natural rubber, synthetic rubber and spandex.
8. A therapeutic garment according to claim 1 , wherein the second and third yarns are coated with a coating material selected from the group consisting of room temperature vulcanizing elastomer, liquid silicone coating, silicone rubber, and polyurethane elastomer.
9. A therapeutic garment according to claim 1 , wherein the second yarn is knit as an inlay yarn and wherein the third yarn forms part of the knit structure and acts to lock the first high-friction yarn into the repeat.
10. A therapeutic garment according to claim 1 , wherein the second yarn is knit as an inlay yarn and wherein the third yarn is knit as an inlay yarn offset to the second yarn.
11. A therapeutic garment according to claim 1 , wherein the first yarn is between 15 and 1200 denier (16.6 and 1332 dTex).
12. A therapeutic medical garment having a variable pressure profile along a length thereof, and comprising:
(a) a knitted tubular body;
(b) a knitted anti-slip portion formed proximate one end of the knitted tubular body with an inner surface adapted for residing against a wearer's skin;
(c) the knitted anti-slip portion including first, second, third and fourth yarns simultaneously knitted to form a repeat having a raised surface texture on the inner surface of the knitted anti-slip portion, wherein the first yarn and the second yarns are low-friction yarns, and further wherein the third yarn and the fourth yarn are high-friction yarns knitted to reside on and form the raised surface texture on the inner face of the knitted anti-slip portion such that the third yarn is covered by the fourth yarn at points where the fourth yarn locks the third yarn to the knitted anti-slip portion.
13. A therapeutic medical garment according to claim 12 , wherein in a repeat of the knitted anti-slip portion a ratio between an exposed length formed by a high-friction yarn defined as l fy and an exposed length formed by a low-friction yarn l by on a contact surface of the knitted fabric structure intended to contact a wearer' body is above r=0.3 ,
wherein the respective exposed lengths l x of a yarn x is defined as:
l
x
=
∑
j
(
s
J
·
k
1
,
2
,
3
)
wherein:
a) a section s j of yarn x between two points at which the yarn x is in direct contact with said contact surface, is multiplied with a factor of k 1 =1;
b) a section s j of yarn between a first point at which the yarn is in direct contact with a contact surface, and a second point at which a further yarn is arranged between the yarn and the contact surface, is multiplied with a factor of k 2 =0.5; and
c) a section s j of yarn between two points at which the yarn is not in direct contact with a contact surface, is not considered when calculating the exposed length, i.e. k 3 =0.
14. A method of forming a knitted fabric structure for a therapeutic medical garment having a variable pressure profile along a length thereof, comprising the steps of:
(a) forming a knitted tubular body including a knitted anti-slip portion formed proximate one end of the knitted tubular body with an inner surface adapted for residing against a wearer's skin, and having at least first, second and third yarns simultaneously knitted to form a repeat having a raised surface texture on the inner surface of the anti-slip portion, wherein the first yarn is a low-friction yarn, and further wherein the second yarn and the third yarn are high-friction yarns knitted to reside on and form the raised surface texture on the inner face of the anti-slip portion such that the second yarn is covered by the third yarn at points where the third yarn locks the second yarn to the knitted anti-slip portion; and
(b) providing in each repeat of the knitted anti-slip portion a ratio between an exposed length formed by a high-friction yarn defined as l fy and an exposed length formed by a low-friction yarn l by on a contact surface of the fabric structure intended to contact a wearer' body of greater than r=0.3,
wherein the respective exposed lengths l x of a yarn x is defined as:
l
x
=
∑
j
(
s
J
·
k
1
,
2
,
3
)
and further wherein:
i) a section s j of yarn x between two points at which the yarn x is in direct contact with said contact surface, is multiplied with a factor of k 1 =1;
ii) a section s j of yarn between a first point at which the yarn is in direct contact with a contact surface, and a second point at which a further yarn is arranged between the yarn and the contact surface, is multiplied with a factor of k 2 =0.5; and
iii) a section s j of yarn between two points at which the yarn is not in direct contact with a contact surface, is not considered when calculating the exposed length, i.e. k 3 =0.