The confusion about whether we deal here with chalky paper?

[Rein]

indirect typo; coated paper:




direct typo; coated paper with no or hardly any pit; called by most "ordinary paper":




to be continued ...

[Rein]

The whole idea of having a special type of paper introduced in 1905 was to prevent the re-cycling of stamps after the re-moval of the cancellations. A problem much dealt with by the Netherlands Indies postal authorities in the pre-1942 period.

The use of surfaced or coated paper was supposed to prevent such re-cycling! It did not as the N.E.I. 1930-ies destructive cancellations prove!

Furthermore, there is NO reason to believe that the coating HAD to contain a substance that SHOULD react to the SILVER TEST!

And this is when and where our philatelic grandparents let us inherit a destructive method for recognize these coated stamps instead of providing us with adequate, non-destructive methods!

J'ACCUSE!

to be continued ....

[Rein]

Stanley Gibbons in its 1840-1952 Commonwealth Catalogue gives us an introduction to paper!



WHY not simply call this paper "coated paper" versus "uncoated paper" instead of making us believe or confuse that "ordinary paper" had no coating?!?!?!?!? And how to call this "unsurfaced" or "uncoated" paper? Ordinary as well????

The paper used during the Second World War for high values, as in Bermuda, the Leeward Islands, etc., was thinly coated with some kind of surfacing which does not react to silver and is therefore regarded (and listed) as "ordinary".

"therefore regarded" - such an ARROGANCE !!!

to be continued ....

[Rein]

The thinly coated paper was not just for high values!?










All direct typography...

to be continued .....

[Rein]

Although the catalogue listings want us to believe otherwise the 1935-1957 typographed De La Rue printings show at least three different types of paper!

- the coated paper with a flat surface and/or scattered with pits! The coating is relatively thick.
- the coated paper with a surface that is often showing an irregular craquele and occasionally some pits! The coating is very thin!
- the uncoated paper - not coming from the De La Rue printings but from the wartime emergy measures - after the bombing of the DLR premises of 29.12.1940 -when other printing houses helped them out and did the job [Harrison & Sons, Bradbury Wilkinson, Williams Lea]

The first type is supposed to have chalk contained in the coating! And is therefore called chalky paper!
The other two types are supposed to have no chalk at all - and why should one have with no coating at all. Therefore called ordinary paper!





to be continued ....

[Otin]

Rein:
I´ve been reading the long discussion about chalky paper and want to add my humble point of view. I think the silver test have had its reason on the fact that early coatings had a great proportion of kaolin as pigment (and casein as adhesive) its nature similar to lime, thus giving the dark chemical raction applied to detect "chalky" paper.
Concerning specs on the coating layers, it should be consider the coating processes, i.e brush, printing cylinder and air knife (translation to English of "cuchilla de aire" in Spanish) Each one of these processes have its own and ultimate charateristics on the finished coating.
By the evidence I posses I can say our coated matt paper has been done by the cuchilla de aire process. I have blocks of four of stamp MT 1169 showing, under UV light; the entire block glowing, then another one showinh large dark spots indicating lack of coating in those pats, then another one showing glowing spots like an star studded sky and a last one totally with no glow at all ("neutro" because of lack of fluorescent coating). I have no doubt this is the result of exhation of coating material.
Concering WT "satinado" paper I tell you once more is a thin paper (55gr/m2) coated as all the rest with different thicnesses delivered by that firm as from 1950, manufactured with a new wire mesh and a new dandy roll. WT papel rayado horizontal mate y tizado. Saludos.
José

[Rein]

José,

el estucado por cuchilla de aire (técnica) · das Luftrakelstreichverfahren (Technik) ...

http://www.freepatentsonline.com/DE10323460A1.html

7. Verfahren zur Herstellung des Laminats
Das Laminat gemäß der vorliegenden Erfindung kann durch Verteilung und Trocknung einer Harzlösungszusammensetzung auf Polysulfon-Basis auf einem Basisfilm hergestellt werden. Sie kann beispielsweise durch Walzenbeschichtung, Sprühbeschichtung, Schmelzbeschichtung, Rakelstreichverfahren, Luftrakelstreichverfahren oder Drahtbarrenbeschichtung verteilt werden.

http://www.cep-plasticos.com/es/diccion ... =&page=400

Recubrimiento por cuchilla al aire - Coating, air knife - Enduction à la râcle à l'air - Luftrakel streich-maschine

Este proceso es especialmente recomendable para finos recubrimientos sobre plástico, metal, papel, etc., para obtener una película adhesiva.

Recubrimiento por electrodeposición - Electrodeposition coating - Revêtement par électrodeposition - Elektrotauch anstrich

La precipitación de un material sobre un electrodo, como resultado del paso de una corriente eléctrica a través de una solución o suspensión del material, por ejemplo, películas de plástico sobre un metal, etc. El electrodo tiene la forma del producto deseado. A este proceso se le conoce también con el nombre de electrodeposición.

Recubrimiento por extensión - Spread coating - Revetement par nappage - Streichen

En este proceso el material (película, lámina, etc.) para ser recubierta pasa sobre un cilindro y bajo una larga hoja o cuchilla. El compuesto plástico de recubrimiento se sitúa sobre el material exactamente delante de la cuchilla y es extendido sobre el material. El espesor del recubrimiento es controlado por la velocidad del material que pasa bajo la cuchilla y por la posición y espacio de la cuchilla sobre el material. Sinon: recubrimiento por cuchilla.

Recubrimiento por extrusión

Extrusora, recubrimiento, película, lámina

Recubrimiento por fluido - Flow coating - Enduction coulant - Fluten

Proceso de recubrir un producto a causa del deslizamiento del fluido sobre su superficie y permitiendo su drenaje.

Recubrimiento por inmersión - Dip coating - Revetement au trempé - Tauchbeschichtung

Procedimiento de recubrimiento, según el cual el soporte es sumergido en un fluido polimérico, una solución o una dispersión. Posteriormente se extrae y se somete a calentamiento o a secado para solidificar la capa fina depositada.

Recubrimiento por proyección con llama - Flame spray coating - Revêtement au pistolet à flamme

Procedimiento de recubrimiento según el cual un polímero en forma de polvo se calienta hasta la temperatura de fusión mediante el cono de una llama, situada entre el orificio de proyección y el soporte a recubrir.

Recubrimiento por proyección electroestática - Electrostatic spray coating - Revêtement au pistolet
éléctrostatique - Elektrostatikspritzen anstrich

En este proceso un polvo seco de recubrimiento plástico es proyectado mediante una corriente de aire y electroestáticamente cargado mediante el campo de alto voltaje creado en la corona de una pistola de pulverizar. Las partículas cargadas se fijan sobre el producto (metálico o plástico con superficie conductora) a ser recubierto por la atracción electrostática. El sustrato recubierto se coloca en un horno para que el recubrimiento funda en forma de película continua. El grueso de recubrimiento es del orden de 0,08 a 0,8 mm.

Recubrimiento por radiación - Radiation coating - Enduction par radiation

Desde aproximadamente 1950 se conoce que una sensitiva película plástica se forma sobre las paredes de un frasco conteniendo metil-metracrilato irradiado con luz ultravioleta. El mecanismo de polimerización comprende dos fases: el monómero gaseoso primero se adhiere a las paredes de la vasija por absorción química o física y entonces se activa con la luz ultravioleta.

Recubrimiento por rodillo - Roll coating - Revetement au rouleau - Walzenauftrag

Procedimiento de recubrimiento según el cual un material de recubrimiento es transferido al soporte, por medio de un rodillo sobre el cual el material fluido se ha extendido.

Quite a selection!!


to be continued ...

[Rein]

Rein:
I´ve been reading the long discussion about chalky paper and want to add my humble point of view. I think the silver test have had its reason on the fact that early coatings had a great proportion of kaolin as pigment (and casein as adhesive) its nature similar to lime, thus giving the dark chemical raction applied to detect "chalky" paper.
Concerning specs on the coating layers, it should be consider the coating processes, i.e brush, printing cylinder and air knife (translation to English of "cuchilla de aire" in Spanish) Each one of these processes have its own and ultimate charateristics on the finished coating.
By the evidence I posses I can say our coated matt paper has been done by the cuchilla de aire process. I have blocks of four of stamp MT 1169 showing, under UV light; the entire block glowing, then another one showinh large dark spots indicating lack of coating in those pats, then another one showing glowing spots like an star studded sky and a last one totally with no glow at all ("neutro" because of lack of fluorescent coating). I have no doubt this is the result of exhation of coating material.
Concering WT "satinado" paper I tell you once more is a thin paper (55gr/m2) coated as all the rest with different thicnesses delivered by that firm as from 1950, manufactured with a new wire mesh and a new dandy roll. WT papel rayado horizontal mate y tizado. Saludos.
José

José,

what is interesting is to find out when and for which countries issuing stamps the various ways of coating paper had been used!!

The very thin coating as in the 1939 -1951 Argentina stamps is hardly known in other parts of the world it seems! The Anglosaxon world refusing to give it any attention telling it is NOT chalky paper (hence, just ordinary paper) does not help much.... The UK manufacturers only started to apply thin coating in the war-time period and that is probably why we have Wiggins Teape involved here. But where does the 1939 coated paper come from as no other country had this applied to stamp paper???

to be continued ..

[Otin]

Rein:
I remind you the 1939 coted paper used in Argentina is said to be prvided by an USA mill. The CdM museum posess in a frame a whole sheet of the 5c typographic Moreno in which one of its margins with the handwritten inscription "papel norteamericano". The WT coated paper to appear was the 40c Caña de Azúcar on base paper rayado verical by 1944.
And thanks very much for the coting methods of your previous post, which I´ll copy right away!!!. The books I got on paper manufacture describe only a few methods. Thus I ignore the many methods you transcribed. Thanks again,
José