GENERAL PROPERTIES OF PLIOBOND
Pliobond, a use-proved product, has many applications in the adhesive field. Pliobond will bond all sorts of surfaces. Its strength is such that often the materials being bonded will break or tear before the glue-line fails.
Pliobond forms a thin yet flexible bond which is effective over a wide temperature range. It resists water, weather, chemical attack and fungus, and may be used in contact with oil or gasoline without materiaL effect on the coating.
Pliobond is versatile adhesive. It may be employed by various means, depending upon conditions.
The wet bond method.
the solvent reactivation method.
The hot bond method.
The wet bond method is the simplest to use and is adaptable wherever there is sufficient porosity in one or both surfaces to allow solvent to escape, and where maximum bond strength is not necessary.
The solvent reactivation method may be used where there is some porosity in the surfaces being bonded and where a fairly high immediate bond is necessary.
The hot bond method is used where there is little or no porosity through which solvent can escape, or where the strongest immediate bond is required.
Surfaces to be bonded should be clean and dry. Metal, glass, ceramics and certain plastics can be cleaned with solvent or solvent vapor, or with suitable detergents. A solution of 6 oz. of Oakite to a gallon of water at a temperature of 150°F makes a good degreaser. Surfaces to be cleaned should be immersed in this solution for ten minutes then rinsed with hot water and dried in an oven.
Wood should be sanded to a smooth fiat surface. Leather or rubber can be buffed. Rubber surfaces can be chlorinated quickly and easily for improved bond strength. The surface is first wiped with solvent to remove grease or wax and is then dipped for 2 minutes in Clorox or its equivalent. Whenever dipping is impossible or impractical, the Clorox may be applied with a brush. The rubber is then rinsed with water and allowed to dry
It is preferable to have surfaces warm before applying cement. This insures dryness, and also assists in solvent removal.
PLIOBOND can be brushed, sprayed, spread or roller coated. It is available in two grades called PLIOBOND 20 and PLIOBOND 30, which are respectively 20% and 30% solids. PLIOBOND 20 is used in normal applications while PLIOBOND 30 is used where the porosity of one or both surfaces is such that penetration must be avoided. There is no difference in the cements other than in percent solids and in the resulting viscosity.
The solvent used in PLIOBOND is methyl ethyl ketone. This solvent can be used for thinning when necessary. or for cleaning PLIOBOND off work tools. If methyl ethyl ketone is unavailable, ethyl acetate can be used.
PLIOBOND should be stirred before using in order to insure uniform consistency. Apply an even coat to both surfaces after cleaning as directed. In the wet bond method allow PLIOBOND to reach a state of maximum tack, which will take three to five minutes, and then press together for from 15 minutes to overnight at the highest ava1lable uniform pressure – say 25 to 200 pounds per square inch. However only mi1d pressures should be used when bonding rubber since distortion in the rubber may result in a weak bond.
In either the solvent reactivation method or the hot bond method thorough drying of both surfaces after application of PLIOBOND is necessary. This may be accomplished by using one of the following drying schedules:
24 to 48 hours at room temperature.
8 to 24 hours at 110° F.
3 to 2 hours at 150° F.
10 to 20 minutes at 200° F.
5 to 10 minutes at 300° F.
In the solvent reactivation method, one or both of the cemented and dried surfaces should be wiped lightly with solvent or given a light spray coat of solvent. They are then immediately brought together under pressure as in the wet bond method.
In the hot bond method drying is accomplished as above. Pieces are then assembled and bonded in a hot press under maximum available time temperature and pressure within the following schedule:
Time : 5 to 25 minutes
Temperature : 225°F to 325°F
Pressure : 25 to 500 pounds per square inch
Heat or pressure to be used may depend upon the materials being bonded. The thickness or heat conductivity of the materials should also be considered, as it is only the temperature in the glue line which affects the bond strength. Assemblies may be discharged hot from the press.
Oven bonding, and adaptation of the hot bond method, can be accomplished under pressure of clamps with small assemblies according to one of the following schedules:
1 to 2 hours at 220°F
20 to 45 min. at 250°F
15 to 30 min. at 300°F
It is generally feasible to leave assemblies in clamps after removal from the oven until cold.