Method of forming sieve unit for screening machine

Claim 1

A method of making a rectangular sieve unit for removable mounting in a screening machine, comprising the steps of: (a) forming a substantially rectangular frame body of a synthetic resin or elastomeric material with a reinforcement received therein, said frame body having a substantially rectangular window surrounded by said frame body; (b) uniformly heating a substantially rectangular screen layer of synthetic resin or elastomeric material with original length and width dimensions in excess of those of said window over the entire area of said screen layer thermally to elongate said screen layer in its length and with dimensions; (c) thereafter affixing said screen layer to said frame body across said opening all around the peripheries of said screen layer and said frame body; (d) thereafter cooling said screen layer while said screen layer is affixed to said frame body to contact said screen layer is its length and width dimensions and develop a screening tension in said layer of the sieve unit formed by said frame body and said layer and; (e) mounting said sieve unit in a screening machine for the screening of material by vibration of said layer.

Claim 2

A method of making a rectangular sieve unit for removable mounting in a screening machine, comprising the steps of: (a) forming a substantially rectangular frame body of a synthetic resin or elastomeric material with a reinforcement received therein, said frame body having a substantially rectangular window surrounded by said frame body; (b) uniformly heating a substantially rectangular screen layer of synthetic resin or elastomeric material with original length and width dimensions in excess of those of said window over the entire area of said screen layer thermally to elongate said screen layer in its length and with dimensions; (c) thereafter affixing said screen layer to said frame body across said opening all around the peripheries of said screen layer and said frame body; (d) thereafter cooling said screen layer while said screen layer is affixed to said frame body to contact said screen layer is its length and width dimensions and develop a screening tension in said layer of the sieve unit formed by said frame body and said layer and; (e) mounting said sieve unit in a screening machine for the screening of material by vibration of said layer.

Claim 6

The method defined in claimed 4 wherein said frame is a steel or glass-fiber-reinforced synthetic resin frame embedded in the material of said body.

Claim 16

A method of screening wetted fine-grained materials which prevents the caking-up of the materials on a screening surface comprising feeding of said wetted fine-grained materials to said screening surface of a rectangular sieve unit removably mounted in a screening machine and vibrating said surface, said rectangular sieve unit being constructed through the steps comprising: (a) forming a substantially rectangular frame body of a synthetic resin of elastomeric material with a reinforcement received therein, said frame body having a substantially rectangular opening surrounded by said frame body; (b) uniformly heating a substantially rectangular screen layer of synthetic resin or elastomeric material with original length and width dimensions in excess of those of said opening uniformly over the entire area of said screen layer thermally to uniformly elongate said screen layer in its length and width dimensions; (c) thereafter affixing said screen layer to said frame body across said opening all around the peripheries of said screen layer and said frame body; (d) thereafter cooling said screen layer while said screen layer is affixed to said frame body to contract said screen layer in its length and width dimensions and develop a screening tension permitting vibration in said layer of the sieve unit formed by said frame body and said layer; and (e) vibrating said layer to screen material therewith.

Claim 17

A method of screening wetted fine-grained materials which prevents the caking-up of the materials on a screening surface comprising feeding of said wetted fine-grained materials to said screening surface of a rectangular sieve unit removably mounted in a screening machine and vibrating said surface, said rectangular sieve unit being constructed through the steps comprising: (a) forming a substantially rectangular frame body of a synthetic resin of elastomeric material with a reinforcement received therein, said frame body having a substantially rectangular opening surrounded by said frame body; (b) uniformly heating a substantially rectangular screen layer of synthetic resin or elastomeric material with original length and width dimensions in excess of those of said opening uniformly over the entire area of said screen layer thermally to uniformly elongate said screen layer in its length and width dimensions; (c) thereafter affixing said screen layer to said frame body across said opening all around the peripheries of said screen layer and said frame body; (d) thereafter cooling said screen layer while said screen layer is affixed to said frame body to contract said screen layer in its length and width dimensions and develop a screening tension permitting vibration in said layer of the sieve unit formed by said frame body and said layer; and (e) vibrating said layer to screen material therewith.