PVA Adhesive Stick

PVAAdhesive Stick is a kind of Urea formaldehyde adhesive.Application It is suitable for ordinary plywood, block boards, packaging board production.It meets the plywood technology standards, such as GB/T9846.1-9846, GB/T18580-2001 otherProduct index AppearanceMilky whitePH value / 25 °C7.5 ± 0.5Viscosity / 25 °C(3500 ± 1500) mpa.sSolid content(57.5 ± 7.5)%Storetime /25 °C(1.5 ± 0.5) monthsStore1. To avoid sunlight2. Stored in dry storage at low temperature3. Viscosity time although the increase of time4. Recommendation: the principle of first come first use5. Storage period shortened with increasing temperature.Proposed transfer adhesive process Substance nameDose ratioPVA Adhesive Stick100Ammonium ChlorideSummer0.2±0.1Winter0.65±0.15Fillers(Flour)25±5Plastic viscosity after the proposed transferAfter the viscosity of gel preparation is between2000 to 5000mpa.s, and its amount according the fillers’ dose ratio to adjusting.Gel preparation methodsWhen produce plywood, start blender by high or low speed, then added to the Environmental protection adhesive, Ammonium Chloride and Fillers. After mixing 10 to 15 minutes, ensure stir well before use, until the dough haven’t the resin. Template plastic should be used within 45 minutes, so as to avoid wastage. Changing according the temperature, the level of moisture content was adjusted curing agent and the amount of flour to meet the pre-press and production requirements.Activity of In general, the temperatures below 35 degrees Celsius, the product of the activity of more than 4 hours.Veneer requirements Veneer surface should smooth and clean, no dust and resin material. Veneer thickness shall be the same. Moisture content was to be 12% to 16%; higher moisture content will increase the bubbling, glue seepage and lack of gel dangerous.AdhesiveAccording to veneer’s quality, double-sided adhesive capacity of 280 to 320g / m², veneer surface is usually rough, needs more amount adhesive thin veneer. Thin veneer glued should to remain low when the amount of adhesive to avoid gum and bubble through, especially when moisture content is high should be pay attention.Clean The glue and adhesive equipment should be cleaning before rubber by hot water, once cured rubber is insoluble. If the glue residue and for clean water is ranked into the sewer, which would cause pollution, Therefore, we should deal with the appropriate measures.Preloading 1. The pressure is 7 to 12kg/cm ².2. Pre-press time is 30 to 90 minutes or so.3. Preloading pressure should be lower than the hot pressing pressure4. When the moisture content veneer lower the amount of adhesive is low, this layer had dried in greater danger, especially in the dry climate circumstances.5. Preloading can improve the bonding quality, shorten the hot cycle, because the slab after preloading the Maintenance and hot plate when the loading easier.6. 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, with no hot compared to more should be noted that the risk is 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 kind of can not restore the flow of adhesive.Heat stress The density of the veneer-treeGlue stress≤550kg/m3(10±2)kg/cm2≥550kg/m3(14±2)kg/cm2Glue pressing time1min/mm (slab thickness) + 2minGlue pressing temperature 100 to 105 degrees Celsius