Pre WWII German sources Decatizing for Wool Soft Felt Hats

[habigman]

According to pre WWII German sources Decatizing was especially important for Wool Soft Felt Hats.  C.G. Wilke Guben were the first to use this process on Wool Soft Felt Hats in the mid 19th Century.

This is explanation is from "Der Filzhut (The Felt Hat), seine Geschichte und seine Herstellung (Its History and Preparation), Hrsg.v.d. Deutschen Hutmacher-Zeitung (German Hat Maker Newspaper), 1936".

"Molding Shop or Matrix Drawing and Decaturation

From now on, man must often replace the machine, skill and expertise now play a major role. Now the experience of the old art of hat making comes into its own (the die-making and decatur are closely related). The process is as follows: take the stumps, moisten them slightly and heat them under the so-called drawing hood (see illustration).

This hood is made of copper and comes into contact with a large sieve that allows vapors to pass through from below. Above this there is usually an exhaust system which extracts the water vapor. The worker places the mold, which usually has a loose head and rim, on this sieve. In contrast to the past, when only wooden molds were used, aluminum alloy molds are now used, which have the advantages of durability and reusability. The stump is attached to the rim by wrapping a cord around it and the head is firmly pressed or screwed into place by means of a large iron screw. Women's hats are left to dry on the mold, men's hats are now ready for decaturation, i.e. the product is made resistant to the weather and durable. One of the first experts to use this process in practice was Wilke, Guben.  Just as we said with carbonization that furnaces with trolleys were used (see illustration), which could be pushed out and also replaced, similar apparatus, decatizing kettles, are also used for decaturation; these are mainly supplied by the companies Meyner, Altenburg, and Johst, Luckenwalde.

For technical reasons, it is advisable to insulate the decatizing kettles with a mixture of sand and diatomaceous earth, which is connected by a bandage. The actual decatizing process is as follows: the goods are pre-dried on the mould in the kettle for approx. 1 hour, then the kettle is firmly closed by tightening wing screws on the front wall and the kettle and heating coil are pressed to 1-3 atmospheres. It is then blown off through a venting valve and emptied through an exhaustor. After this process, the boiler is left to dry for 4 hours, opened, allowed to cool down and the decaturation is complete."

This is from "25 Berlin - Gubener Hutfabrik (Hat Factory), Actiengesellschaft (Public or Private Company) vorm. A. Cohn, Guben", 1913:".

DECATIER APPARATUS FOR SOFT HATS

"The station to which the hat is now brought is the raw decatur. The term "decatizing" has its origin in the French word "cati", i.e. to press. In the original conception, decatizing meant nothing more than freeing the fabric from the pressed sheen; a manipulation that was first used in cloth manufacturing.

The cloth industry also used this term for a whole number of much wider cloth industrialists soon discovered that these treatments on the fabric maintained a matt sheen, a going treatment of the fabric with steam. The inventive, ambitious mind of the soft, mollusc-like feel, a fine, long-lasting stroke was achieved; above all, however, this treatment made the cloth shrink-free, i.e. it was prevented from shrinking or changing its structure at all when worn due to the effects of the weather. For a long time, the woollen hat industry knew nothing about this manipulation, which was widely used in cloth manufacture, until a hat manufacturer from Guben continued his experiments and achieved useful and, as it turned out after further elaboration of the original system, extremely important results.

Today, the woolen hats are drawn onto precisely fitting molds, two at a time, with the right sides of the hats lying on top of each other, the outermost edges stretched onto corresponding rings and subjected to a steam process, i.e. the decatizing effect. For this purpose, the hats are placed on an iron frame, pushed into a large boiler which is hermetically sealed and inside which hot, dry steam is let in and pressure is generated by an atmosphere. The goods are exposed to this steam pressure for a period of time (20-40 minutes). In order to protect them from any water droplets, the racks are covered by covers and, after the steaming process is complete, the steam used is extracted by ventilation before the boiler is opened.

The decatur is therefore of extraordinary importance for the woolen hat. Just as the Fulling means the soul of the Stumpen / Hood, so the Decatur imprints the character of the hat, it makes it stable and solid."

Here is an 1930s Wool Soft Felt Hat that was made by Brüder Böhm that is marked "Guaranteed Decateered".

https://germanaustrianhats.invisionzone.com/topic/7-brüder-böhm-hutfabrik/?do=findComment&comment=798

Here is a Bahner Plaiting Machine, Decatising Machine (306)

https://hatmachines.com/our-fabrications-and-products/new-machines/plaiting-machine-decatising-machine-306/

[habigman]

This is a more detailed description from "Der Hut" Gustav Menschel  Copyright © 2009 by Eigenverlag, Wien

1.1 Decatizing

The foundation stone for a weather-resistant wool felt hat was laid around 1850 by hat maker Carl Gottlob Wilke from Forst, who also founded the first German hat factory in Guben in 1864 and patented the decatizing process at the same time. Pre-decaturation and decaturation significantly improve the dimensional stability of wool felts and reduce their weight. For cost reasons, only high-quality woolen hats are decatized. Since wool is severely attacked at higher temperatures and especially over longer exposure times, special attention must be paid to the temperature when decating. Fiber damage can be easily recognized visually by the discoloration of white wool felts. Bortfeldt mentions the following study in his book: Some sections of such felts were exposed to a higher air temperature for 15 minutes each and showed no change at 100 °C, a slight yellowing at 105 °C, and a noticeable gold at 110 °C , browning begins at 120 °C and charring at 150 °C; while after a stay of 20 seconds there was no noticeable change.

Decatering Kettle made by Zimmermann

Stiff wool hats are pulled over saddles and nailed before being placed in the decaturation machine. Soft, good quality wool stumps are usually decated for the first time before stiffening. Two stumps, ground or unground, possibly with shiny surfaces, are placed with their right sides on top of each other, pulled tightly onto the oval head shapes and tied at the band point with a shaping cord. After the steam-heated rack is fully loaded, the stumps are moved into the decaturation kettle. The frame is connected to the steam pipe using a bayonet lock and, like the casing of the previously closed boiler, is preheated well. Preheating prevents the formation of water droplets from the direct decaturation steam and avoids irreparable decaturation stains. Now the decaturation steam is allowed to enter and decaturation is carried out for ½–1 hour at a maximum of 1 bar overpressure (100 °C). Steam tensions higher than 1 bar should be avoided because the associated increase in temperature severely attacks the wool felt. After the treatment is finished, in order to quickly remove the steam and cool the stumps, the one at the back of the kettle installed vent is switched on.

After removal, the stumps are stiffened and shaped into a hat. This is followed by the actual decaturation with completely dry goods. If the hats are wet, direct contact with the molds, which are usually made of aluminum alloys, could destroy reducible dyes and thus cause staining. To be on the safe side, cover the shapes with cotton fabric or thin felt (Manchons). The chassis and the casing of the decaterator must be preheated well for ¼ hour before loading. This means that the metal molds can be heated easily and the coloring is prevented from being affected by condensation of water vapor on their surface (sweating of the molds). The molds covered with two hats are decated for 20-30 minutes at ¾-1 bar, as described for the pre-decating. Cheap hats that have not been subjected to pre-decating must be decated at at least 1 bar, otherwise they will very quickly lose their shape when used, especially in rainy weather.