How does the pulp solidify? What additives do you need? Curing agents? Or what binders are needed? Will the curing process require high temperature or what?
(1) urea formaldehyde moulding powder;The resin powder of urea formaldehyde resin, commonly known as electric jade powder, is produced by wet process, such as tree ester, curing agent, filler, colorant, lubricant, stabilizer, plasticizer and so on1 Components(1) resin used for urea formaldehyde resin molding powder by condensation reaction degree is relatively shallow, the resin with low viscosity, easy dipping filler, and can ensure the long production cycle and drying after proper fluidity, condensate in the industrial use of urea and formaldehyde at low temperature (a mixture of dimethylol urea, urea and formaldehyde) are usually used. The ratio of 1:1.5 (molar ratio), the PH=8 (and temperature) 30 - 35 of all dissolved, adding urea oxalate was 0.3% - 0.33% and 0.88% - 0.54% of the oxalic acid, then the occurrence of exothermic reaction, temperature rise, temperature in 55 - 60 degrees, and strictly control the PH=5.5 - 6.5, 60 - 75min by urea formaldehyde resin is required. Because the condensation degree is low, in fact just over addition reaction, condensation reaction is mainly in the curing process.(2) the curing agent used in curing agent and pressing powder requires latent, usually oxalic acid, phthalic acid, two formic acid, benzoic acid, chloroacetic acid, etc.(3) packing material is the most commonly used pulp, followed by wood powder or inorganic fillers (glass fiber, asbestos, mica etc.). The pulp is wood as raw material, with sodium bisulfite, non soluble cellulose impurities to the wood, and then byThat is the pure cellulose bleaching. The amount of filler material for the total amount of 25%-32%, the amount is too small, the pressure of plastic powder fluidity big, product strength is low; on the contrary, the amount of excessive pressure, plastic powder fluidity decreases, the product surface is not smooth, water
The industry with alkali as catalyst, the reaction temperature of about 95, the molar ratio of formaldehyde to urea as 1.2.0, to ensure that the resin can be cured. The first step of the reaction and generate a dimethylol urea, then hydroxymethyl amino and soluble resin by further condensation, if by acid catalysis, easily lead to storage products need to gel. In the neutral conditions under the linear urea formaldehyde resin with ammonium chloride as curing agent can be cured at room temperature. The molding powder at 130 to 160 DEG C heat curing accelerators such as zinc sulfate, trimethyl phosphate, two oxalic acid ethyl ester can accelerate the curing process. The urea formaldehyde resin is mainly used in the manufacture of molded plastic manufacturing, daily life products and electrical components also can be used as adhesive, paper sheet and fabric size, veneer, decorative board and so on. Because of its light color and easy coloring, products often colorful and magnificent.
Urea formaldehyde resinUre-aformaldehyde resinsUrea formaldehyde polymer. Also called urea formaldehyde resin. The cross-linking English abbreviation UF. molding, the product is insoluble and infusible thermosetting resin, urea formaldehyde resin cured phenolic resin than the color of light, translucent resistance, weak acid and weak alkali, good insulation properties, excellent wear resistance, low price but, in case of strong acid and strong alkali decomposition, weather resistance is poor. The name Beetle. urea and 37% formaldehyde aqueous solution can be obtained by the polycondensation of linear urea formaldehyde oligomer in the catalysis of acid or alkali,
