Yogesh K Trivedi

US Patent:

59286741, Jul 27, 1999

Filed:

Oct 20, 1997

Appl. No.:

8/954592

Inventors:

Thomas N. Hall - Hackettstown NJ
Yogesh C. Trivedi - Grosse Ile MI

International Classification:

C08J 922

US Classification:

425 4C

Abstract:

The subject invention pertains to an apparatus with the continuous expansion of thermoplastic minipellets, particularly polypropylene. The apparatus comprises a mixing means for mixing the thermoplastic minipellets in water to form a slurry, which is connected to a pressurizing means to form a flow of pressurized slurry to a junction which in trains a blowing agent to form a pressurized slurry mixture, which is connected to a heating means to heat the pressurized slurry mixture. Once the pressurized slurry mixture is impregnated with the blowing agent, it flows through water more orifice plates for expansion of thermoplastic minipellets into an expansion vessel.

US Patent:

55805035, Dec 3, 1996

Filed:

Jun 3, 1994

Appl. No.:

8/253889

Inventors:

Thomas N. Hall - Mount Olive NJ
Yogesh C. Trivedi - Grosse Ile MI

Assignee:

BASF Corporation - Mount Olive NJ

International Classification:

C08J 914

US Classification:

264 53

Abstract:

The subject invention pertains to a continuous process for expanding thermoplastic minipellets, particularly polypropylene. The minipellets are continuously expanded by continuously charging and mixing water and minipellets in a slurry tank to form a slurry which is subsequently pressurized. A blowing agent such as butane is entrained into the pressurized slurry flow, which said slurry is then heated by a heating means, such as a shell and tube heat exchanger, to the softening point of the minipellets. The heated minipellets are given the time necessary for impregnation by permitting them to flow through one or more impregnation vessels. The impregnated minipellets are released through an orifice into an expansion vessel where the blowing agent flashes off, thereby expanding the minipellets.

US Patent:

57531579, May 19, 1998

Filed:

May 27, 1997

Appl. No.:

8/863269

Inventors:

Thomas N. Hall - Mount Olive NJ
Yogesh C. Trivedi - Grosse Ile MI

Assignee:

BASF Corporation - Mount Olive NJ

International Classification:

C08J 914

US Classification:

264 53

Abstract:

The subject invention pertains to a continuous process for expanding thermoplastic minipellets, particularly polypropylene. The minipellets are continuously expanded by continuously charging and mixing water and minipellets in a slurry tank to form a slurry which is subsequently pressurized. A blowing agent such as butane is entrained into the pressurized slurry flow, which said slurry is then heated by a heating means, such as a shell and tube heat exchanger, to the softening point of the minipellets. The heated minipellets are given the time necessary for impregnation by permitting them to flow through one or more impregnation vessels. The impregnated minipellets are released through an orifice into an expansion vessel where the blowing agent flashes off, thereby expanding the minipellets.