Process for manufacturing mica sheet composites

Claim 3

The method as set forth in claim 1 wherein in step (a) a thixotropic colloid agent selected from the group consisting of xantham gum, hydroxyalkyl guar, sodium silicate, potassium silicate and calcium sulfate is mixed with water and the platelets.

Claim 4

reducing lateral movement of said platelets toward said drain while liquid carrier is being removed through said drain, and

Claim 5

reducing lateral movement of said platelets toward said drain while liquid carrier is being removed through said drain, and

Claim 6

enabling the formation of a mica sheet of uniform thickness by preventing the channeling of platelets toward the drain.

Claim 7

enabling the formation of a mica sheet of uniform thickness by preventing the channeling of platelets toward the drain.

Claim 8

The method as set forth in claim 1 wherein in step (a) a thixotropic colloid agent which is a xanthan gum having the formula

Claim 9

The method as set forth in claim 1 including the steps of drying and pressing the mica sheet.

Claim 10

In method for manufacturing a mica sheet of uniform thickness in which a resin is applied to mica platelets as a binder which strengthens the sheet wherein the improvement comprises: a. grinding a dry mica starting material to yield mica platelets; b. mixing a quantity of the mica platelets with water and a thixotropic colloid agent; c. delivering the mixture of water, thixotropic colloid agent and mica platelets to a sheet forming mold having a drain on the bottom thereof and a screen for passing water and retaining platelets positioned between the mixture and the drain; and d. removing the water from the mold through the drain to yield a mica sheet on said screen; said thixotropic colloid agent causing said mica platelets to remain in suspension after said mixture of water, thixotropic colloid agent, and mica platelets are delivered to said mold, reducing lateral movement of said platelets toward said drain while water is being removed, and enabling the formation of a mica sheet of uniform thickness by preventing the channeling of platelets toward the drain.

Claim 11

In method for manufacturing a mica sheet of uniform thickness in which a resin is applied to mica platelets as a binder which strengthens the sheet wherein the improvement comprises: a. grinding a dry mica starting material to yield mica platelets; b. mixing a quantity of the mica platelets with water and a thixotropic colloid agent; c. delivering the mixture of water, thixotropic colloid agent and mica platelets to a sheet forming mold having a drain on the bottom thereof and a screen for passing water and retaining platelets positioned between the mixture and the drain; and d. removing the water from the mold through the drain to yield a mica sheet on said screen; said thixotropic colloid agent causing said mica platelets to remain in suspension after said mixture of water, thixotropic colloid agent, and mica platelets are delivered to said mold, reducing lateral movement of said platelets toward said drain while water is being removed, and enabling the formation of a mica sheet of uniform thickness by preventing the channeling of platelets toward the drain.

Claim 12

The method as set forth in claim 5 wherein in step (b) the thixotropic colloid agent that is mixed with the water and platelets is xanthan gum having the formula

Claim 13

The method as set forth in claim 5 wherein a suction is applied to said drain to withdraw water from said sheet forming mold.

Claim 14

The method as set forth in claim 7 including the step of covering the mica platelets in said sheet forming mold with a waterproof cover to facilitate removal of water and applying a suction to said drain while said mica platelets are covered with said cover.

Claim 15

The method as set forth in claim 7 including the step of applying a binder resin to said mica platelets prior to mixing said mica platelets with water and a thixotropic colloid agent in step (b).

Claim 16

The method as set forth in claim 7 including the step of applying a binder resin to the mica sheet after a sheet is formed in the sheet forming mold.

Claim 17

The method as set forth in claim 9 also including the steps of drying and pressing the mica sheet formed in said sheet forming mold.

Claim 18

The method as set forth in claim 10 also including the steps of drying and pressing the mica sheet formed in said sheet forming mold.

Claim 21

The method as set forth in claim 13 wherein in step (b) a xanthan gum having the formula