Unitary absorbent multilayered core
View Patent ↗The present invention is directed to a unitary absorbent core including a first fibrous absorbent layer of (a) natural fibers, synthetic fibers or a mixture thereof, (b) a binder which is a synthetic binder fiber or powder, a hydrophilic emulsion polymer binder or a mixture thereof, the fibrous absorbent layer having an upper surface and a lower surface, the lower surface in contact, optionally coextensively in contact, with an upper surface of a synthetic carrier which has a lower surface integral with a first hydrophobic vapor-transmissive moisture barrier. The present invention is also directed to a receptacle for food incorporating the unitary absorbent core. The present invention is also directed to a filter element incorporating the unitary absorbent core.
1. A unitary absorbent core comprising:
I) a first fibrous absorbent layer comprising:
a) from about 15 to about 95 percent by weight natural fibers, synthetic fibers or a mixture thereof,
b) from 0 to about 80 percent by weight superabsorbent material; and
c) from about 5 to about 30 percent by weight of a binder which is a synthetic binder fiber or powder, a hydrophilic emulsion polymer binder or a mixture thereof, and,
the fibrous absorbent layer having an upper surface and a lower surface, the lower surface in contact, optionally coextensively in contact, with
II) an upper surface of a spunbond-meltblown-spunbond nonwoven synthetic carrier having a basis weight of from about 9 gsm to about 30 gsm, which has a lower surface integral with
III) a first vapor-transmissive moisture barrier, wherein the moisture barrier is hydrophobic or hydrophilic;
wherein the unitary absorbent core has a basis weight of about 45 gsm or greater and, wherein the unitary absorbent core has an air permeability of from about 3 to about 7 m 3/ min/m 2 (11-22 ft 3/ min/ft 2 ).
2. The unitary absorbent core of claim 1 , wherein the core further comprises in contact, optionally, coextensively in contact, with the upper surface of the first fibrous absorbent layer
IV) a second fibrous absorbent layer comprising
a) natural fibers, synthetic fibers or a mixture thereof, and
b) a binder which is a synthetic binder fiber or powder, a hydrophilic emulsion polymer binder or a mixture thereof.
3. The unitary absorbent core of claim 2 , wherein the first, second or first and second fibrous absorbent layers further comprise superabsorbent material.
4. The unitary absorbent core of claim 3 , wherein the core has an absorbent capacity of from about 10 grams/gram to about 15 grams/gram.
5. The unitary absorbent core of claim 1 , wherein the upper surface of the first or second fibrous layer which is uppermost in the core is integral with a second moisture barrier, which may be the same as or different from the first moisture barrier.
6. The unitary absorbent core of claim 1 , wherein the basis weight of the core is from about 50 to about 1000 gsm.
7. The unitary absorbent core of claim 6 , wherein the basis weight of the core is from about 75 to about 350 gsm.
8. A unitary absorbent core comprising:
I) a first fibrous absorbent layer comprising:
a) from about 15 to about 95 percent by weight natural fibers, synthetic fibers or a mixture thereof,
b) from 0 to about 80 percent by weight superabsorbent material; and
c) from about 5 to about 30 percent by weight of a binder which is a synthetic binder fiber or powder, a hydrophilic emulsion polymer binder or a mixture thereof, and,
the fibrous absorbent layer having an upper surface and a lower surface, the lower surface in contact, optionally coextensively in contact, with
II) an upper surface of a natural or synthetic carrier which has a lower surface integral with
III) a first vapor-nontransmissive moisture barrier, wherein the moisture barrier is hydrophobic or hydrophilic and wherein the unitary absorbent core has a basis weight of about 45 gsm or greater.
9. The unitary absorbent core of claim 8 , wherein the core further comprises in contact, optionally, coextensively in contact, with the upper surface of the first fibrous absorbent layer
IV) a second fibrous absorbent layer comprising
a) natural fibers, synthetic fibers or a mixture thereof, and
b) a binder which is a synthetic binder fiber or powder, a hydrophilic emulsion polymer binder or a mixture thereof
10. A receptacle for containing a food product which tends to exude fluids comprising:
(A) a tray for holding a food product; and
(B) positioned in the tray, a unitary absorbent core having a basis weight of 45 gsm or greater comprising:
I) a first fibrous absorbent layer comprising:
a) from about 15 to about 95 percent by weight natural fibers, synthetic fibers or a mixture thereof,
b) from 0 to about 80 percent by weight superabsorbent material; and
c) from about 5 to about 30 percent by weight of a binder which is a synthetic binder fiber or powder, a hydrophilic emulsion polymer binder or a mixture thereof, and,
the fibrous absorbent layer having an upper surface and a lower surface, the lower surface in contact, optionally coextensively in contact, with
II) an upper surface of a synthetic carrier which has a lower surface integral with
III) a first vapor-transmissive or vapor-nontransmissive moisture barrier, wherein the moisture barrier is hydrophobic or hydrophilic.
11. The receptacle of claim 10 , wherein the first vapor-transmissive or vapor-nontransmissive moisture barrier is vapor-nontransmissive.
12. The receptacle of claim 10 , wherein the first vapor-transmissive or vapor-nontransmissive moisture barrier is vapor-transmissive and the unitary absorbent core has an air permeability of from about 3 to about 7 m 3 /min/m 2 (11-22 ft 3 / min/ft 2 ).
13. The receptacle of claim 10 , wherein the synthetic carrier is an SMS nonwoven having a basis weight of from about 9 gsm to about 30 gsm.
14. The receptacle of claim 10 , wherein the core further comprises in contact, optionally, coextensively in contact, with the upper surface of the first fibrous absorbent layer
IV) a second fibrous absorbent layer comprising
a) natural fibers, synthetic fibers or a mixture thereof, and
b) a binder which is a synthetic binder fiber or powder, a hydrophilic emulsion polymer binder or a mixture thereof.
15. The receptacle of claim 10 , wherein the first, second or first and second fibrous absorbent layers further comprise superabsorbent material.
16. The receptacle of claim 15 , wherein the core has an absorbent capacity of from about 10 grams/gram to about 15 grams/gram.
17. A filter element comprising:
(A) a support matrix, and
(B) an absorbent core having a basis weight of 45 gsm or greater comprising:
I) a first fibrous absorbent layer comprising
a) natural fibers, synthetic fibers or a mixture thereof,
b) a binder which is a synthetic binder fiber or powder, a hydrophilic emulsion polymer binder or a mixture thereof,
the fibrous absorbent layer having an upper surface and a lower surface, the lower surface in contact, optionally coextensively in contact, with
II) an upper surface of a spunbond-meltblown-spunbond nonwoven synthetic carrier having 2 a basis weight of from about 9 gsm to about 30 gsm, which has a lower surface integral with
III) a first vapor-transmissive moisture barrier, wherein the moisture barrier is hydrophobic or hydrophilic;
wherein the absorbent core has an air permeability of from about 3 to about 7 m 3/ min/m 2 (11-22 ft 3 /min/ft 2 ).
18. The filter element of claim 17 , wherein the core further comprises in contact, optionally, coextensively in contact, with the upper surface of the first fibrous absorbent layer
IV) a second fibrous absorbent layer comprising
a) natural fibers, synthetic fibers or a mixture thereof, and
b) a binder which is a synthetic binder fiber or powder, a hydrophilic emulsion polymer binder or a mixture thereof.
19. The filter element of claim 17 , wherein the core has an absorbent capacity of from about 10 grams/gram to about 15 grams/gram.
20. The filter element of claim 17 , wherein the core contains superabsorbent material and the core has an absorbent capacity of from about 20 grams/gram to about 110 grams/gram.
21. The unitary absorbent core of claim 17 , wherein the core contains superabsorbent material and the core has an absorbent capacity of from about 20 grams/gram to about 50 grams/gram.