Glass compositions

1. A glass fiber mat comprising:

a mat of glass fibers comprising from about 0.5 to about 30 weight percent bismuth oxide and from about 0.1 to about 3 weight percent ZrO 2 .

2. A glass fiber mat comprising:

a mat glass fibers comprising from about 9 to about 15 weight percent bismuth oxide and from about 50 to about 75 weight percent silicon oxide.

3. A glass fiber mat comprising:

at least one mat formed of glass fibers wherein the glass fibers comprise from about 0.5 to about 30 weight percent bismuth oxide, from about 56 to 69 weight percent silicon oxide, substantially no boric oxide, from about 0 to about 2 weight percent barium oxide, from about 9 to about 20 weight percent R 2 O, wherein R 2 O is a mixture of sodium oxide and potassium oxide, from about 1 to 5 weight percent alumina, from about 3 to about 7 weight percent calcium oxide, from about 1 to about 5 weight percent magnesium oxide, from about 0 to about 5 weight percent zinc oxide, and from about 0 to about 1 weight percent fluorine.

4. The glass fiber mat of claim 3 , wherein the glass fiber mat forms at least a portion of a filter.

5. A glass fiber mat comprising:

at least one mat formed of glass fibers wherein the glass fibers comprise from about 0.5 to about 30 weight percent bismuth oxide, substantially no boric oxide, from about 0 to about 2 weight percent barium oxide, from about 9 to about 20 weight percent R 2 O, wherein R 2 O is a mixture of sodium oxide and potassium oxide, from about 1 to 5 weight percent alumina, from about 3 to about 7 weight percent calcium oxide, from about 1 to about 5 weight percent magnesium oxide, from about 0 to about 5 weight percent zine oxide, and from about 0 to about 1 weight percent fluorine.

6. A glass fiber mat comprising:

at least one mat formed of glass fibers wherein the glass fibers comprise from about 9 to about 15 weight percent bismuth oxide, from about 56 to 69 weight percent silicon oxide, from about 0.01 to about 2 weight percent zinc oxide, from about 2 to about 4 weight percent Al 2 O 3 , less than about 0.0001 weight percent lead, and wherein the glass fiber mat is capable of absorbing at least about 90 percent of X-rays emanating from an X-ray source having an energy level of about 22kV and such source being position about 25 cm from the glass fiber mat, when the mat of glass fibers has a basis weight of about 170 g/m 2 .

7. The glass fiber mat of claim 6 , wherein the glass fibers are woven.

8. The glass fiber mat of claim 6 , wherein the glass fiber mat further comprises the mat formed into the shape of an apron or blanket, the glass fiber mat being capable of being draped over a person as an X-ray shield for use during X-ray exposure.

9. The glass fiber mat of claim 6 , wherein the glass fiber mat further comprises a veil mat attached to a rigid substrate for constructing an X-ray shielded room.

10. The glass fiber mat of claim 6 , wherein the glass fiber mat further comprises a veil mat attached to hardboard.

11. The glass fiber mat of claim 6 , wherein the glass fiber mat further comprises the mat attached to or mixed with a reinforcement material.

12. The glass fiber mat of claim 11 , wherein the reinforcement material is metal, plastic, rubber, ceramic, gypsum, or mixtures thereof.

13. The glass fiber mat of claim 6 , wherein the glass fiber mat further comprises the at least one mat being covered with or attached to fabric to form apparel.

14. The glass fiber mat of claim 6 , wherein the glass fiber mat comprises insulation material in X-ray equipment or packing material for packaging X-ray equipment.

15. The glass fiber mat of claim 6 , wherein the glass fiber mat comprises at least a portion of a container capable of holding film and protecting the film from X-rays emitted by a security screening system.

16. A glass fiber mat comprising:

at least one mat formed of glass fibers wherein the glass fibers comprise from about 0.5 to about 30 weight percent bismuth oxide, from about 0.01 to about 2 weight percent zinc oxide, from about 2 to about 4 weight percent Al 2 O 3 , and having an average diameter of about 0.8μm;

wherein the glass fibers have a leaching constant for Bi 2O 3 of from about 7 ng/cm 2 h to about 650 ng/cm 2 h when 1 gram of the glass fibers is boiled for three hours in 100 ml of H 2 SO 4 having a specific gravity of 1.26 g/cm 3 ; and

wherein the glass fiber mat forms at least a portion of a filter.

17. The glass fiber mat of claim 16 , the glass fibers further comprising from about 56 to 69 weight percent silicon oxide.

18. The glass fiber mat of claim 17 , wherein the glass fibers have a softening point of less than about 703° C.

19. The glass fiber mat of claim 17 , wherein the glass fibers have an average diameter of about 1.4 μm, a basis weight of from about 203 to about 236 g/m 2 and have a total tensile strength/gsm of greater than about 0.016.

20. The glass fiber mat of claim 17 , wherein the glass fibers further comprise from about 9 to about 15 weight percent bismuth oxide, have an average diameter of about 1.4 μm, a basis weight of from about 125 to about 145 lbs/3000 ft. 2 and a puncture endurance of greater than about 0.4 kg when dry and greater than 0.3 kg when wet.

21. The glass fiber mat of claim 16 , wherein the glass fibers include from about 0 to about 1 weight percent boric oxide.

22. The glass fiber mat of claim 17 , wherein the glass fibers form a filter having a Kdis value of from about 50 to about 150 ng/hcm 2 .

23. The glass fiber mat of claim 17 , wherein the glass fibers form a filter having a density of from about 2.5 to about 2.85.