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Pulping, Bleaching and Fiber Modification


Herty is committed to supporting Pulp, Paper and Fiber-based Packaging by continually expanding and upgrading our pulping and bleaching processing capabilities to produce advanced pulp fibers that can meet the most demanding customer specifications.

The Herty Center’s pulp processing area include capabilities for chemical pulping and bleaching. Depending on the fiber type, chemical pulping can be conducted in either a 25-liter vertical batch digester, a 25-liter rotating digester, a 500-liter Continuously Stirred Tank Reactor (CSTR) or a 2500-liter vertical batch digester. Each digester is computer controlled to allow precise temperature ramps and controlled H-factor pulping. Digesters are equipped with (heated) liquor recycling. In addition, the 2500-liter digester allow for controlled liquor withdrawal and addition (liquor profiling). Digesters can be configured to discharge to blow tanks. Capabilities are available for pulp washing and screening to determine total and screened pulp yields. Full sequence batch-wise bleaching can be conducted in either the 7-liter Parr reactor (with or without continuous mixing) or Herty’s 500-liter CSTR. The wetted parts of both of these high-pressure rated reactors are made of Hastelloy®, which allows processing over the entire pH range. The 7-liter Parr reactor is ideally suited for quick scoping trials to define a bleaching sequence or stage-by-stage chemical applications, while the 500-liter CSTR enables pilot-scale or production bleaches. Brownstock or bleached pulps can refined using PFI, Valley, pilot refiners and handsheets produced allowing for the full range of physical and optical testing (TAPPI).

Pulping, Bleaching, and Fiber Modification Question 1
Whether it is modification of an existing process or a new process to modify fiber functionality, let Herty work with you to design an experimental program that can isolate the impact of process modifications on yield, fiber properties and end-use performance.

Pulping, Bleaching, and Fiber Modification Question 2
Herty can assess the impact of pulping conditions on yield and fiber morphology. Downstream process and integration with Herty’s papermachines allows clients to produce roll stock for customer evaluation.

Pulping, Bleaching, and Fiber Modification Question 3
Herty can assess the impact of bleaching conditions on key pulp properties, such as brightness, viscosity and degree of polymerization. Bleaching trials can be conducted at lab or pilot-scale conditions and integrated with Herty’s papermaking capabilities.

Pulping, Bleaching, and Fiber Modification Question 4
Let Herty design a bleaching sequence that is tailored to meet your end-use performance criteria.

Pulping, Bleaching, and Fiber Modification Question 5
Herty can produce ton quantities of brownstock for direct evaluation in paper, nonwoven and composite applications. Herty can also bleach brownstock to meet client’s needs and produce roll stock for downstream converting and validation.

Pulping, Bleaching, and Fiber Modification Question 6
Herty has expertise on the pulping of non-wood species, such as hemp, kenaf and bagasse. Let us evaluate the potential of your feedstock!

For more information please contact Dr. Omar Ali.

Pulping and Bleaching Systems
Equipment Make/Model Use
2500-L Digester Herty Proprietary Large-scale chemical digester and reaction vessel. Perfect for process validation. Option for recirculation of liquors and steam explosion direct discharge.
500-L High Pressure Reactor System

Herty Proprietary

(All Hastelloy® Wetted Parts)

A versatile high temperature reactor system, capable of high pressure and full vacuum conditions. Direct reactant injection and direct sampling. Used for both pulping and bleaching (ECF and TCF). Ideal for process validation and small-scale production.
25-L Digesters Herty Proprietary High pressure digesters (vertical and with the option of steam explosion direct discharge).
7-L High Pressure Reactor System

Parr Model 4580

(All Hastelloy® wetted parts)

A versatile reactor system used for small-scale pulping and bleaching studies to produce kg quantities.

Complete Equipment List

Last updated: 5/16/2017