Plywood glue 709

Plywood glue 709 is a kind of Urea formaldehyde adhesive.Application 709 green plastic is a modified urea-formaldehyde resin adhesive for plywood, block boards, box board production line GB/T9846.1-9846, GB/T18580-2001 standard plywood and other technical requirements. Product index appearanceMilky whitePH value7.0 ± 0.2Viscosity250 ± 50cpsDensity1.195 1.230g/cm ³Solid content(51 ± 2)%Curing time200 ± 50secFree formaldehyde0.16% 0.20%Water mixed (times)<0.5 Store Resin as a low temperature, underground storage in the absence of penetration (at) plastic tank or storage tank, to avoid direct sun exposure, can be stored for 10 days by the following of 30 . The higher the temperature, the shorter the storage period (based by the initial plastic viscosity degree); viscosity with time and increased the rate of increase depends on temperature. And our proposal is that in accordance with the principle “first come first use", to ensure that the glue used in the storage period, so as not to affect the use of glue effect. Proposed transfer adhesive process (weight): A/B/C A709 # plastic100 BCuring agent (NH4Cl) SummerAmmonium chloride0.1 0.2 WinterAmmonium chloride0.6 0.8 Composite curing agent of0.2 0.8 CFiller (flour)20 30 Plastic viscosity after the proposed transfer 3800 5500cps, adjust the viscosity of gum after filling by adding the amount to adjust the dose. Glue preparation methods: Suitable for high speed mixer, production of plywood, the starting blender then added to the A, B and C, mixing 10 15min, stir well before use to ensure, that there is no resin until the dough. Tuned plastic should be used within 45min to avoid wastage. Activity Experience temperatures below 35 activity of more than 4 hours. Veneer requirements Veneer surface should be smooth and clean, no dust and resin material. Veneer thickness shall be the same. Veneer moisture content should be ≤ 14%, higher moisture content will increase the bubbling, glue seepage and lack of gel dangerous Adhesive According to different quality veneer, double-sided adhesive capacity of 280 320g / m², usually rough veneer surface, needs more than the amount of adhesive thin veneer. Single thin plastic sheet coating is timely to maintain the lower volume to avoid bubbling through the glue, especially when moisture content is high should pay attention. Clean Glue preparation and coating equipment shall be cleaned before the adhesive curing, rubber is insoluble once cured, and should be better use of hot water; other adhesive residue and for clean water is ranked into the sewer, which would cause pollution. Therefore, they should take appropriate measures to deal with. Preloading There is evidence that preloading can improve the bonding quality, shorten the hot cycle, because the slab after preloading the Maintenance and hot plate when the loading easier. Group blank time must be as short as possible to ensure the group blanks in the first veneer film has sufficient initial adhesion to plastic in the pre-press operations to flow to the opposite of the single-board, compared with no preload, but should pay attention to the danger of too dry layer. The reason is that when the slab when the direct hot melt glue hot press in the flow of development, but in the cold press is too dry in even greater danger, especially in the dry climate circumstances. Preloading pressure should be lower than the hot pressing pressure, according to local conditions and repeated tests to determine the most appropriate pressure. Experience has shown that pressure is 9 10kg/cm ² better. Depending on treatment conditions, pre-press time is usually 60-90 minutes. Heat stress Best of the pressure the density of species from the veneer, when the tree density of less than 550kg / m³ time is 10 12kg/cm ², when the tree density is higher than 550kg / m³ time is 12 16kg/cm ². Pressing time hot glue layer in the hot pressing time and temperature under pressure to complete the time line with quality requirements of the proposed bonding pressing time: 1min/mm (slab thickness) +2 min Recommend pressing temperature 100 105