US 12,337,519 B2
Screw for an extruder and extruder device
Giorgio Maccagnan, Castronno (IT); Simone Maccagnan, Castronno (IT); and Davide Fedeli, Jerago County Orago (IT)
Assigned to GIMAC DI MACCAGNAN GIORGIO, Castronno (IT)
Appl. No. 17/263,588
Filed by GIMAC DI MACCAGNAN GIORGIO, Castronno (IT)
PCT Filed Oct. 7, 2019, PCT No. PCT/IB2019/058514
§ 371(c)(1), (2) Date Jan. 27, 2021,
PCT Pub. No. WO2020/075037, PCT Pub. Date Apr. 16, 2020.
Claims priority of application No. 102018000009362 (IT), filed on Oct. 11, 2018.
Prior Publication US 2021/0283815 A1, Sep. 16, 2021
Int. Cl. B29C 48/50 (2019.01); B29C 48/505 (2019.01); B29C 48/68 (2019.01)
CPC B29C 48/509 (2019.02) [B29C 48/6803 (2019.02)] 10 Claims
OG exemplary drawing
 
1. A screw for an extruder, said screw (1) comprising:
a screw body (2) having an external surface (3) coated by an external functionalization coating (4), the screw body (2) and the external surface (3) thereof is a metal material, the external functionalization coating (4) is in a material which is compatible, from the point of view of the chemical and physical interactions, with an extruding material and with the end use of the same, and
a wear detection-quantification coating (5) at least partially coating said screw body and arranged between said external surface (3) and said external functionalization coating (4), a chosen color of said wear detection-quantification coating (5) being visually distinguishable from a color of said external functionalization coating (4) to identify wear without the use of a measuring apparatus or an analyzing process,
wherein the wear detection-quantification coating (5) is made of a material selected among filler materials, nitrides, carbides, carbonitrides, crystalline materials, and diamond,
wherein the wear detection-quantification coating (5) has a hardness greater than 1500 HV, and
wherein the wear detection-quantification coating (5) comprises at least two wear detection layers, with each wear detection layer being of a color different from other wear detection layer(s) thereof to thereby determine an amount of wear detection-quantification coating lost during extrusion.