| charles UREA FORMALDEHYDE POWDER RESIN Powdered Adhesives for Wood Products For Manufacturing Plywood Boards
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| Ufores 201 P is a powder Urea
Formaldehyde resin, which must be dissolved in water prior to use. When used with the
hardener, it provides an excellent adhesive for plywood gluing. .
Dissolving the Resin: Prior to use, the resin is mixed with water to convert into solution. A mechanical stirrer may be used for this purpose. When using a high speed mixer, all the water may be placed first and then resin may be added while the mixer is running. If low speed mixer is used, it is better to make a homogenous mix of the resin with about 2/3 of water, and rest of the water may be added later. The temperature of the water may be 20-30o C, because with lower water temperature, mixing is more time consuming. Reconstitution can be carried out in simple mixing equipment as follows:
Choice of Reactivity: The choice of reactivity would normally depend upon the local conditions. The reactivity of the glue can be adjusted over a wide range by varying the composition and amount of hardener. The reactivity of the glue is expressed in terms of gelation at 100 oC Typical Glue Formulations: a. The formulation below would meet with
the requirements of B. S. 6566 for
b. The glue mix below would meet with the
requirements of B. S. 6566 for INT grade. The gel time of the glue mix below at 100oC
would be 40 seconds. While pot life can be adjusted to the desired level by addition of
retarders like Ammonia or
Pressing Conditions: The pressing time would depend upon the press temperature, glue mix reactivity, wood density, veneer thickness and moisture content of the veneers. The temperature for good glue setting normally varies between 90 - 120oC. Pressure would depend upon the wood quality, being higher for hard wood species as compared to soft wood. The glue is spread to one surface. The veneer surface should be clean and free from dust and other contamination. The consumption of glue generally would be 140 - 200 gms per square meter. The equipment can be cleaned with warm water and this should be done before the glue has completely cured. Like any formaldehyde product, Ufores 201 P contains free formaldehyde. This may cause dermatitis, when it comes into contact with skin of sensitive persons. Skin contact with powder or liquid resin should be avoided. Hands should be thoroughly washed with soap and hot water at the end of the working day and before meals. A dust mask should be worn, while emptying the bags. Storage: The powdered resin should be stored in the original bags in a cool place protected from heat. Care should be taken that powder does not absorb moisture and water. The bags, which have been opened, should be carefully closed before storage. When stored in original bags at 20oC, shelf life would not be less than one year. © Saudi Formaldehyde
Chemical Company Ltd. 1999 |
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