The overall goal of this video is to demonstrate a basic procedure to prepare and test plant seed based products as wood adhesives. This is accomplished by first preparing the adhesive slurry using a working plant seed, meal, and water. The second step is to apply the adhesive slurry onto one end of two wood veneer strips.
Next, bond the two wood strips by overlapping their tacky adhesive coated areas, and then hot pressing them after conditioning. The final step is to measure the tensile shearer strength at break of the bonded wood pairs. Ultimately, the shearer strength at break is reported as the adhesive strength with the treatment conditions indicated.
This method of provides a simple way to prepare on the taste prime, say based products as wood adhesives. It would be helpful in effort in seeking economic and environment friendly formulations of bio-based wood adhesives. Also demonstrating the procedure will be dosing in chapter claims from my laboratory.
The first step is to prepare the water washed meal. Begin with commercially available def fated cotton seed meal. Use a cyclone sample meal to produce the working meal by grinding the def fatted meal through a 0.5 millimeter steel screen.
Retrieve the working meal from the grinder's outlet. Use a portion of the working meal to prepare the water washed meal. Measure a quantity of working meal and place it in the jar of a blender for every 25 grams of meal in the vessel.
Add 200 milliliters of water, mix the water and meal for three minutes. The resulting mixture is centrifuged and freeze dried to separate the water insoluble fraction. This is an example of the final product referred to as the water washed meal.
To prepare the adhesive slurry place water washed meal in a vessel. For this experiment, about three grams is needed for 91 square inch surfaces. For every three grams of meal, add 25 grams of deionized water to the vessel.
Add a stir bar, seal the beaker with paraform, and stir the mixture for two hours. When the slurry is ready, take it for immediate use bonding specimens. The next step is to prepare the bonded wood specimens for testing.
Use commercially available wood veneers to create wood veneer strips. Prepare five to 10 pairs of strips for each testing variable. The strips should measure 25.4 millimeters wide, 88.9 millimeters long, and 1.59 millimeters thick with the length being parallel to the wood grain.
Use a pencil to mark a line across the wood grain, 25.4 millimeters from one end of each strip. Also ensure the strips are labeled appropriately for later identification. Unseal the adhesive slurry and work with pairs of wood veneer strips.
Use a brush to apply the slurry onto the marked region of each pair. Allow them to air dry for 10 to 15 minutes or until they're tacky. When they are ready, brush a second layer of the adhesive slurry on top of the first and let them air dry again as the strips dry.Ready.
A benchtop heated press to operate at 100 degrees Celsius and apply a force that will yield 400 pounds per square inch in the overlap region of the specimens when the strips are dry. Work with each pair overlap the adhesive coated regions of the two strips. Place the specimens in the press.
Proceed by hot pressing them for 20 minutes. Recover the press specimens from the press and place them in an incubator. The temperature should be maintained at 22 to 23 degrees Celsius, and with a relative humidity of 50 to 60%The specimens should remain there for 48 hours.
Specimens are prepared in different manners depending on the measurement. To prepare specimens for measurement of wet strength, put room temperature water in a glass jar, get specimens that have been conditioned and immerse them in the water for 48 hours. The specimens should be tested immediately after they're removed from the water.
To prepare specimens for measurement of soaked strength, fill a water bath with water at 63 degrees Celsius. Get specimens that have been conditioned and immerse them in the bath for four hours. At the end of four hours, recover the specimens and dry them.
Met room temperature about 22 degrees Celsius relative humidity, 50 to 60%for 18 to 20 hours After drying, immersed the specimens in another 63 degrees Celsius water bath for four hours, after which it should dry for 48 hours before testing. The sheer strength measurements will be conducted on a materials testing machine. Set the gripping pressure to seven megapascals and the cross speed to one millimeter per minute.
Measure and record the sheer strength at break for each specimen. Average multiple measurements for each test variable. Secure the bonded wood specimen into grips with a width wider than the specimen, and a length that is comparable here.
30 millimeters by 25 millimeters in this photo are several types of broken wood pairs after the tensile shear test. Examples of predominantly wood substrate failures are on the left. For these, the meal product adhesive strength is higher than the substrate in the center are.
Examples of cohesive failure at Wright are adhesive bond failures, for which the measured shear strength represents the adhesive strength of the plant seed meal. Under testing conditions. Here are the measured shearer strengths found following the protocol with Maplewood strips.
Adhesives were made with cotton seed and soy meal for the test conducted following the protocol. The water washed cotton seed meal adhesive is comparable in strength to that of the cotton seed protein isolate. The water washed soy adhesive is not comparable in strength to its protein.
Isolate tests were performed following the protocol with cotton seed meal and using four different wood types. The sheer strength of dry specimens is consistently greater than the others. The soaked specimen sheer strength is consistently greater than that of the wet specimen.
This indicates that the adhesive bond is weakened by the presence of water. After watching this video, you should have a good understanding of how to prepare and test plant seed based products as wood adhesives.
