Galls - Oak Galls
Galls - Oak Galls
Mechotech designs and manufactures turnkey natural colour extraction plants for oak galls. In the Mechotech catalogue, Galls - Oak Galls is listed in the Grey to Black Colour group alongside Leaves - Sumac, Hulls - Walnut, Roots - Iris, Dried Bean - Black Beans, Grains - Black Rice and Vegatables - Balck Carrot / Black Currant. Mechotech’s article on oak galls describes them as among the richest natural sources of hydrolysable tannins (gallotannins). The grey-to-black colour is not a single pigment extracted from the plant: it forms as iron-tannate when the tannin liquor reacts with iron salts, the chemistry behind iron-gall ink, grey and black natural dyeing and traditional leather tanning.
Mechotech’s Oak Galls plant is configured around the raw material and the target colour extract. It is built in SS 316L with integrated solvent recovery, automation and full documentation, and is delivered as a commissioned turnkey system. The tannin extract can be taken as a tannin liquor, concentrate or powder, or developed with iron to a grey-to-black shade; the target form is confirmed during process development. Final parameters are established during process development and pilot validation.
Technical Specifications
| Product | Galls - Oak Galls Natural Colour Extraction Plant |
|---|---|
| Raw Material | oak galls |
| Plant Part / Feed Form | Galls (oak galls; crushed or powdered form confirmed with the client) |
| Colour Group | Grey to Black Colour |
| Pigment Class | Hydrolysable tannins (gallotannins); grey-to-black colour develops when the tannin extract reacts with iron |
| Extract Type | Natural colour extract (liquid concentrate or dried powder, per specification) |
| Extraction Method | Closed jacketed SS 316L extraction with food-grade solvent (alcohol / aqueous), multiple cycles at controlled temperature |
| Product-contact Material | SS 316L |
| Filtration System | Plate-and-frame filter press with cartridge polish filters |
| Concentration System | Falling-film / vacuum evaporator with solvent recovery |
| Drying System | Spray or vacuum dryer |
| Automation | PLC-based |
| Plant Capacity | Configured to requirement |
| Utility Requirements | Steam, chilled/cooling water, compressed air and power (project-specific) |
| Compliance | GMP hygienic design; full documentation for qualification |
| Final Product Form | Natural colour extract (grey to black colour group) |
Plant Capacities
| Plant Scale | Raw Material Throughput | Typical Use |
|---|---|---|
| Pilot | Configured to your feedstock and trial plan | Product development, parameter validation |
| Semi-Commercial | Configured between pilot and commercial scale | Scale-up trials, contract manufacturing |
| Commercial | Configured to raw-material supply and confirmed buyer volume | Commercial production |
Capacity is configured to raw-material supply, confirmed buyer volume and investment timeline; a pilot plant is recommended to validate parameters before scaling.
Manufacturing Process
Raw Material Preparation
Dried oak galls are inspected, cleaned and crushed or powdered to expose surface area before extraction.
Extraction
The prepared oak galls is extracted with food-grade solvent (alcohol / aqueous) in closed jacketed SS 316L extractors at controlled temperature and over multiple cycles to recover the target colour compounds.
Filtration
The extract (miscella) is clarified through a plate-and-frame filter press followed by cartridge polish filters.
Concentration & Solvent Recovery
The miscella is concentrated in a falling-film / vacuum evaporator, with solvent recovered through the condenser return system so that heat exposure of the pigment stays low.
Standardisation
The concentrate is assayed for colour strength and adjusted to the declared target specification before the final finishing step.
Drying & Quality Control
The standardised Galls - Oak Galls extract is spray- or vacuum-dried where a powder is required, then released after the agreed assay, residual-solvent, heavy-metal, microbial and moisture tests.
Major Plant Equipment
- Raw material cleaning and size-reduction system
- Closed jacketed SS 316L extraction vessels
- Solvent storage tanks
- Plate-and-frame filter press
- Cartridge polish filtration
- Falling-film / vacuum evaporator
- Solvent recovery unit and condensers
- Standardisation / blending vessel
- Spray or vacuum dryer
- CIP system
- Automation and instrumentation
Plant Output
Applications
- Natural colour and dye ingredient supply
- Food and beverage colour applications (subject to approval of the specific colour in each market)
- Cosmetic and personal-care colour applications
- Nutraceutical and Ayurvedic / herbal formulations
- Pharmaceutical standardised ingredient supply
Key Features
SS 316L Construction
Electropolished SS 316L product-contact surfaces with CIP operation between batches.
Closed-Loop Solvent Recovery
Integrated condenser-return recovery reuses solvent between batches and reduces solvent loss.
Tannin-Rich Feedstock Handling
Crushing and extraction are configured for hard, tannin-rich galls, with water or alcohol-based extraction evaluated against the target extract form.
Standardised to Specification
In-process and batch-release assay are used to check the finished extract against its declared target specification.
Gentle Concentration
Vacuum concentration keeps heat exposure low for temperature-sensitive colour compounds.
Scalable Batch Capacity
Plants are configured to requirement from pilot scale upward, with modular expansion.
Frequently Asked Questions
Does Mechotech supply the complete machinery for Galls - Oak Galls?
What specification can the Galls - Oak Galls plant achieve?
What production capacities are available for the Galls - Oak Galls plant?
Which raw material is processed in the Galls - Oak Galls plant?
How does the Galls - Oak Galls extraction process work?
How is grey-to-black colour obtained from oak galls?
Is the iron development step part of the standard plant?
How does this page differ from other tannin and brown-colour pages?
Which related colour pages does Mechotech list with Galls - Oak Galls?
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