Test of main indexes of adhesive for wood-based panel and woodworking
Guide: Wood based panel and wood adhesive glue is a kind of material with good adhesion performance. It plays the role of connecting objects through adhesion and cohesion.
◆ Appearance
It refers to color, state, macro homogeneity, mechanical impurities, etc. It can directly evaluate the quality of wood-based panels and wood adhesives. Test method: a. Pour the sample of wood-based panel and wood adhesive glue into the beaker, stir it with a glass rod, and observe whether the glue is uniform and contains other mechanical impurities or condensation. b. Tilt the wood-based panel and wood adhesive glue into the vertical bottle, and observe whether the glue flows evenly from the top of the bottle along the glass bottle wall.
◆ Density
Density is the mass of material per unit volume at a specific temperature, and its unit is mg/m3. It can reflect the uniformity of the mixing of wood-based panels and wood adhesives. Determination method: a. Pycnometer method b. Pycnometer method c. Injector method ◆ Viscosity viscosity is a characteristic that blocks the relative flow of wood-based panel and wood adhesive glue inside, and it is an important index to evaluate the quality of wood-based panel and wood adhesive glue. Determination method: a. rotary viscometer method b. viscosity cup method ◆ nonvolatile content All wood-based panels and wood adhesives containing solvents must be measured for nonvolatile content in components. Calculation formula of non-volatile matter content (X%): X=(G1/G) * 100% Note: G1 – mass of sample after drying (g) G – mass of sample before drying ◆ pH value test pH value can know the acid and alkali value of wood-based panel and wood adhesive glue. The smaller the pH value, the stronger the acid; The higher the pH is, the stronger the alkalinity is. If acidic substances are contained, metal corrosion will be caused. Attention must be paid to the selection. Determination method: The simplest method for testing is to use pH test paper, but this method is only applicable to water-based or lotion wood-based panel and wood adhesive glue, and is not accurate enough. The glass electrode acidimeter method is the most accurate method for testing. It is applicable to water-soluble, dry or non aqueous media, wood-based panels and wood adhesives that can be dissolved, dispersed and suspended in water. ◆ Applicable period The applicable period of wood-based panel and woodworking adhesive glue is the time when the prepared wood-based panel and woodworking adhesive glue can maintain their available performance. It is an important industrial index of chemical reaction type wood-based panel and wood adhesive glue, double liquid type rubber wood-based panel and wood adhesive glue. ◆ Curing time The curing speed of wood-based panel and wood adhesive glue is the main data for studying the curing conditions of wood-based panel and wood adhesive glue, which can be used as a simple method to check whether the performance identification formula of the finished wood-based panel and wood adhesive glue is correct. ◆ Storage period The storage period of wood-based panel and wood adhesive glue is that under certain conditions, the wood-based panel and wood adhesive glue can still maintain their operating performance and the storage time of specified strength. The purpose of measuring the storage period is achieved by measuring the changes of viscosity and adhesive strength of wood-based panel and wood adhesive glue before and after storage. ◆ Chemical reagent resistance Chemical medium resistance is one of the durability indicators for the use of wood-based panel and wood adhesive glue. The reduction of the bonding strength of metal samples bonded with wood-based panel and wood adhesive glue after immersion in a certain test liquid at a certain temperature for a specified time is used to measure the chemical reagent resistance of wood-based panel and wood adhesive glue. ◆ Aging test of wood-based panel and woodworking adhesive glue During the use of wood-based panel and woodworking adhesive glue, due to various environmental factors and the role of media, the performance of wood-based panel and woodworking adhesive glue will be reduced and damaged, thus aging phenomenon will occur. Test method. b. Atmospheric accelerated aging test: the atmospheric accelerated aging test can shorten the test cycle and improve the test level. The test is carried out on a specially made aging test machine, which is an automatic insolator for outdoor use and tracking the sun all day long. c. Damp heat aging test: The simultaneous action of high temperature and high humidity is the main reason for the aging of wood-based panels and wood adhesives. The damp heat aging test is generally carried out in a temperature regulating box. D. Artificial simulated climate accelerated aging test: artificial simulated aging light source is used to replace sunlight for accelerated aging test. At present, the test light sources are mainly ultraviolet carbon arc lamp, sunlight carbon arc lamp and xenon lamp. e. Salt spray corrosion test: This test is mainly used to test the corrosion of glued materials caused by aging due to the penetration into the adhesive layer and acceleration of electrochemical corrosion reaction. The test is mainly carried out in various salt spray corrosion test chambers.
