WINDBOND PF is a Phenol Formaldehyde Resin Powder specially developed for the manufacturing of BWR and BWP grade Plywood, Block Board, Flush Door etc. It meets all the requirements for the preparation of Boiled Water Proof adhesive and used in the manufacture of exterior and marine grades Plywood. It is used in the hot bonding process.
PHYSICAL PROPERTIES AND SPECIFICATIONS FOR RESIN POWDER
|APPEARANCE||REDDISH-BROWN FREE FLOWING POWDER|
|VISCOSITY (1:1) AT 30°C||25-45 BY B4 CUP|
|pH OF 50% SOLUTION AT 30°C||11.0-12|
|GEL TIME AT 140°C||180-300 SECS|
|BULK DENSITY||0.45 TO 0.5 GMS PER CC|
|SOLUBILITY||EASILY SOLUBLE IN WATER|
|SP.GR. (1:1) AT 25° C||1.20-1.24|
|PREPARATION OF GLUE MIX||BWR Grade||BWP Grade|
|POWDER||100 PARTS BY WEIGHT||100 PARTS BY WT.|
|WATER||120 PARTS BY WT.||100 PARTS BY WT.|
|WHEAT FLOUR||5-8% BY WT. OF POWDER||NIL|
|CSP||5-8% BY WT. OF POWDER||NIL|
|ADDITIVE||NIL||15 PARTS BY WT.|
GLUE MAKING PROCEDURE
Take 50% of the total water in glue mixer. Add resin powder and required the quantity of wheat flour and CSP. Mix well for 15-20 minutes until all powder dissolved and lump free paste is prepared. Then add rest of water and mix well for 10 minutes. The temperature may be maintained at 20-35°C.
After addition of all ingredients and subsequent mixing, check viscosity, if needed some water may be added to maintain the required viscosity 12-22 seconds in B6 cup.
REACTIVITY OF GLUE
Local conditions determine the selection of reactivity. The reactivity of the glue can be adjusted over a wide range by varying the composition and quantity of hardener.
Glue should be used within 24 hrs. of its preparation. Longer storage will increase viscosity and reduce its bonding strength. To adjust the viscosity, water, and filler quantity may be adjusted.
The veneer surface should be properly cleaned and free from dust and other contamination. Veneer should be flat with uniform thickness. The moisture content of the veneers should be within the range of 6-8%. Higher moisture content increases the risk of blisters and bleedthrough, whereas over dried veneers may cause poor face bonding and starved joints. In general, the consumption of glue varies between 300 to 450 Gms per square meter based on manufacturing condition and veneer quality.
Open Assembly Time should be kept as short as possible, particularly under hot and dry conditions. Over-dried glued veneer results in poor wetting of the opposite veneer, which results in weak bonding.
HOT PRESSING CONDITION
Hot pressing time and pressure varies for different wood density. Normally wood density varies from than 500 to 600 kg/cubic meter
For wood density less than 550 kg/cubic meter, Hot Press pressure 8-12 Kg/sq.cm and for wood density more than 550 kg/cubic meter, Hot Press pressure 14-16 Kg/sq.cm
Hotpress temperature to be maintained between 130 to 145°C depending on the thickness of veneer and Hot Press pressure. Hot pressing time = Basic setting time at 135°C (3.5 minutes) (equivalent to gel time) + Heat transfer time to the farthest glue line (normally 0.8 to 1 minute per mm; such as for 6 mm thickness, farthest glue line is 3 mm, so ht. transfer Time to the farthest glue line is 2.4 to 3 minute.) Since the rate of heat transfer is dependent on the wood species and the moisture content, the above information can only serve as a guide.
The equipment like glue mixer, spreader should be cleaned with warm water and this should be done before the glue is completely cured.
MAJOR APPLICATION AREAS
Glue for the manufacture of BWP grade plywood, Block Board and to prepare boards which are to be used in the highly humid area.
Glue for the exterior application
25 Kg packing available in HDPE bag with polyethylene liner. Also it is available in 25 Kg multi wall paper bag with polyethylene liner.
WINDBOND PF-101L contains the small amount of Formaldehyde. Hence, direct skin contact with the resin should be avoided. There should be enough ventilation in work areas for glue preparation and pressing is done.
Store in original bags in a cool and dry place to protect from heat and moisture absorption. The resin is hygroscopic in nature, so it should be stored in a moisture free area. The limitation of the resin is the viscosity which will increase with time. Also, the rate of increase of viscosity is dependent on storage temperature. Shelf Life at 20° C is 6 months.