90results about How to "Reduce free formaldehyde" patented technology

The invention relates to a production technology of furan resin, particularly to a production technology of the furan resin for casting, comprising the following steps: charging, heating up, dehydrating, opening a steam valve, heating up to 80-108 DEG C in 20-30 min, preserving heat for 60-90 min, discharging, packaging, and warehousing. According to the invention, a product with low free formaldehyde and high strength can be provided by the technology, and the production process has no generation of three wastes and is green.

The invention discloses a single-side surface layer densification processing method and a product for wood. The method includes dipping treatment; a dried board base material is dipped into a dipping tank filled with agents, the dipping thickness of the surface of the board base material is controlled through control of the dipping depth of the board base material into the liquid level of the agents, the agents include urea resin and nano calcium carbonate granules, and the nano calcium carbonate granules enter the pores of the board base material during the dipping. A floorboard produced through the processing method is composed of a densification layer and the board base material, and the lower surface of the densification layer is connected with the upper surface of the board base material. According to the processing method, the dipping thickness of the floorboard is controlled through the increase and decrease of the liquid level height of the agents, only the surface of the floorboard contacts with the agents, therefore the agents are saved; drying after dipping is not needed, and quality problems caused by the dipping and drying can be avoided, processing steps are reduced, and outturn percentage is improved.

The invention discloses a method for manufacturing an ultra-low formaldehyde emission medium-to-high density fiberboard, and relates to the technical field of chemical engineering. The method comprises the steps of timber chipping, washing, stewing, softening, grinding the chipped timber into a fiber in a hot mode, adding a mixed curing agent of a super E0 tackiness agent, urea and ammonium chloride, drying, winnowing, paving and forming, hot-pressing, cross sawing, cooling, sanding, edge cutting and identifying and packaging a sawn stock board according to the demand. In the process of manufacturing the fiberboard, the mixed curing agent of the super E0 tackiness agent, the urea and the ammonium chloride is added, the formaldehyde emission conforms to the standard, and ammonia smoking can be carried out without additionally installing equipment so that the problems that investment is increased and power is consumed cannot happen; the problems that the physical properties of the fiberboard are poor and the appearance of the fiberboard is defective do not exist, and ammonia gas and other pungent smells cannot be produced.

The invention relates to a novel formaldehyde removing composite agent, with low cost, non secondary pollution and formaldehyde removing function. The inventive agent comprises at least one imidazolidinyl, at least one alkali compound and a solvent, wherein, the mass ratio between the imidazolidinyl and the alkali compound is 500:1-50:1, and the solvent mass is 0-99%. The inventive removing agent can be uniformly dissolved in general aquosity or oil paint, with excitation on the human body. And the inventive agent can be dissolved into solution to be added into the processed decorative material, or be plated on the face of object and around air, therefore, the free imidazolidinyl in air and material is reduced under 0.08mg/m2 as national standard.

The invention discloses a method for preparing a urea-melamine-formaldehyde resin adhesive for an E0-level floor. In the first step, formaldehyde solution, melamine and urea are mixed, the pH value of the mixture is regulated, the temperature is raised to 80-95 DEG C, and the reaction lasts 40-60 minutes, wherein, the mol ratio between formaldehyde and the total amount of the urea and the melamine is 2.05-2.12 : 1; in the second step, the pH value is regulated to be 5.0-6.0, and the reaction is underway till the turbidity point; in the third step, the pH value is regulated to be 6.0-6.9, the urea and the melamine are added, and the mol ratio between the formaldehyde and the total amount of the urea and the melamine which are added in the first step and the second step is 1.48-1.74 : 1, and the reaction lasts 30-70 min at a temperature of 90 DEG C; in the fourth step, the pH value is regulated to be 7.5-9.0, the melamine is added, and the reaction lasts 20-80 min at a temperature of 80-90 DEG C; and in the fifth step, the urea is added, the mol ratio between the formaldehyde and the total amount of all the urea and all the melamine is 1.02-1.30 : 1, and the material is cooled and discharged after the reaction is finished. A veneer formed by pressing the resin adhesive has good boiled-water resistance and low formaldehyde release, and the reaction is gentle and also easy to control.

The invention discloses an adhesive with ultralow formaldehyde release amount and a preparation method of the adhesive, and relates to the technical field of adhesives for artificial boards. The adhesive comprises the following raw materials: 990 to 1,000 parts of formaldehyde, 810 to 840 parts of urea, 38 to 45 parts of melamine, 28 to 32 parts of sodium hydroxide, 6 to 8 parts of formic acid, 2 to 3 parts of triethanolamine and 1.5 to 2.5 parts of polyvinyl alcohol. According to inspection, the formaldehyde release amount of the adhesive provided by the invention is 2.0 to 3.0 mg/100 g (0.1 to 0.3 mg/L by a dryer method), and the adhesive strength and the transverse static bending strength accord with the national standard, so damage of artificial boards manufactured by the adhesive to a human body is close to zero, the indoor air quality is good and the preparation process is simple.

The melamine resin prepared with formaldehyde and melamine as main material and in the presence of Lewis acid or alkali has free formaldehyde content of about 0.1 %. The adhesive possesses excellent expansion performance during formation and is suitable for use in producing various kinds of board. The products with the adhesive have low formaldehyde release amount, excellent mechanism performance, excellent weather resistance, etc. The liquid resin may be spray dried to prepare melamine adhesive powder capable of maintaining reaction activity for long time. The adhesive of the present invention has no need of adding formaldehyde trapping agent.

The invention discloses a method for producing total-eucalyptus plywood by adopting moisture-proof composite urea resin. The method comprises the following steps: rotatably cutting wood boards; drying each board; gluing; performing cold pressing for three times; stewing and conditioning; performing hot pressing for three times; cooling and conditioning; determining the thickness of a board blank and sanding the board blank. The key points of the production method disclosed by the invention are that melamine modified urea resin is adopted as a main material of an adhesive and is added with oxidized starch to form a viscous compound, polyvinyl alcohol is taken as a toughening agent, magnesium oxide is taken as an antiaging agent, hexamine and triglycidyl isocyanurate are taken as a curing agent, isobutyl triethoxy silane is taken as a bridging agent, phenolated lignin is taken as a formaldehyde catcher and aliphatic polyurethane acrylate is taken as a moisture-proof agent to prepare the composite urea resin; the composite urea resin has the advantages of being low in formaldehyde residual volume, good in water resistance and good in moisture resistance; therefore, the produced total-eucalyptus plywood is low in formaldehyde residual volume, hard to expand after absorbing water and hard to arch and deform, and a wear-resistant layer is hard to damage.

The present invention discloses a formaldehyde-reducing process in the production process of veneered strip-glued board and its equipment. Said equipment mainly includes ventilating ducts and fan, and its formaldehyde-reducing process includes the following steps: spaced stacking the adhesive-coated mechanically-matched or hot-pressed board blanks, making the air inlets of ventilating ducts be positioned at two sides of board blank stack respectively, making the air outlets of ventilating ducts be positioned in the exterior of processing field, under the action of the fan a negative pressure action is formed around the board blank stack, so that the peripheral air of the board blank stack can be led out to the exterior of processing field so as to quickly discharge out free formaldehyde produced in the adhesive-coating process, and effectively prevent the free formaldehyde from being absorbed by board core and finished product board and can reduce formaldehyde content in the product obviously.

The invention discloses a preparation method of E0-level melamine modified urea formaldehyde resin. The E0-level melamine modified urea formaldehyde resin is prepared by the following steps of feeding urea by three batches, and feeding melamine by three batches. The invention also discloses the E0-level melamine modified urea formaldehyde resin and an E0-level melamine modified urea formaldehyde resin adhesive. The method has the advantages that the distribution of the internal molecular structure of the urea formaldehyde resin is changed by the multi-batch feeding type, the prepared resin is added into an adhesive mixer, a formaldehyde removing agent, a reinforcing agent, an acid curing agent and industrial flour are stirred until all the components are uniformly mixed, so as to obtain a mixed adhesive, and the obtained mixed adhesive is applied into the production of parquets; the hot pressing cycle can be shortened, the hot pressing time is shortened from conventional 70-79s/mm to 30-35s/mm under the condition of no change of pressure and temperature parameters, and the utilization rate and production efficiency of a hot press are greatly improved; the release amount of formaldehyde in the prepared plate reaches superE0 level.

The invention relates to a preparation method of a urea-formaldehyde resin from a straw ethanol byproduct, which comprises the following steps: 1. adding a formaldehyde solution, water, a prepressing modifier, a first batch of urea, a first batch of melamine and a first batch of straw ethanol byproduct into a reactor, regulating the pH value, and heating to react; 2. regulating the pH value and controlling the temperature to react to a cloud point; 3. adding a second batch of urea, a second batch of melamine and a second batch of straw ethanol byproduct, regulating the pH value and controlling the temperature to react; 4. adding a third batch of melamine and a third batch of straw ethanol byproduct, regulating the pH value and controlling the temperature to react; and 5. cooling, adding a third batch of urea to react, cooling and discharging. The straw ethanol byproduct used by the method has the advantages of lower ash content and lower sugar content, and the lignin molecule structure maintains multiple phenolic hydroxyl groups, alcoholic hydroxyl groups and replaceable active hydrogen. By using the straw ethanol byproduct instead of part of the urea or phenol to prepare the adhesive, the method can save the petroleum resources and implement waste recovery.

The invention belongs to the technical field of adhesives, and relates to a modified urea-formaldehyde resin with a low content of formaldehyde. The modified urea-formaldehyde resin with a low content of formaldehyde comprises urea-formaldehyde resin and propyl benzoate. The invention also relates to a preparation method of the modified urea-formaldehyde resin, and a use of the modified urea-formaldehyde resin in production of fiberboards. The modified urea-formaldehyde resin can be used in the fields of building, decoration and industrial manufacturing, and can be used in bonding sheets, ceramics and plastics as an adhesive.

The invention belongs to the technical field of urea-formaldehyde resin preparation, and particularly relates to a preparation method of a nano silicon dioxide/rosin modified urea-formaldehyde resin. The method comprises the following steps: preparing a urea-formaldehyde resin from urea and formaldehyde by a weak alkali-weak acid-weak alkali technique, and modifying with nano silicon dioxide and rosin to obtain the nano silicon dioxide/rosin modified urea-formaldehyde resin. The method has the advantages of simple technique and accessible raw materials, and is suitable for industrialized mass production. The prepared urea-formaldehyde resin has the advantages of favorable viscosity, high softening point, low free formaldehyde content, environment friendliness, higher water resistance, favorable toughness and improved aging resistance, is suitable for artificial board production, and can be used as an adhesive in material binding, bamboo/wood processing, paper binding, steel paints, multicolor pattern paints and other industries.

The invention relates to the technical field of synthesis of phenol-formaldehyde resin, in particular to the phenol-formaldehyde resin which is thermosetting resin. Bisphenol type compounds and aldehyde compounds 1 are mixed and subjected to a constant-temperature reaction under certain pressure under the action of a catalyst, and an intermediate body is obtained; the intermediate body and aldehyde compounds 2 are subjected to a constant-temperature reaction under certain pressure under the action of the catalyst, and the phenol-formaldehyde resin is obtained. The phenol-formaldehyde resin is obtained through the reactions at different temperatures under different pressures in combination of the adding quantity of catalysts and formaldehyde, the obtained phenol-formaldehyde resin is the thermosetting resin, and the phenol-formaldehyde resin can be cured at the high temperature without a curing agent; fabric, paper and boards prepared from the phenol-formaldehyde resin have lower free formaldehyde content, are more environment-friendly and have lower odor, and the use environment is more excellent.

The invention discloses a method for adopting high-temperature-resisting composite urea resin for producing a whole-eucalyptus solid wood composite floor. The method includes the steps of board rotary slicing, veneer drying, gluing, three times of cold pressing, standing maintaining, three times of hot pressing, heat dissipating maintaining, slab fixed-thickness sanding, base material surface layer gluing, maintaining grooving and paint spraying, drying and sizing. The production method is characterized in that the high-temperature-resisting composite urea resin is prepared by adopting melamine modified urea resin as the main material of an adhesive, adding oxidized starch as a viscosity complexing agent, adopting polyvinyl alcohol as a toughening agent, adopting hydrogenated rosin as an antioxidant, adopting polyisocyanate as a curing agent, adopting isobutyl triethoxy silane as a bridging agent, adopting phenolate lignin as a formaldehyde catching agent and adding high-temperature-resisting filler. The high-temperature-resisting composite urea resin prepared through the method is used for producing the whole-eucalyptus solid wood composite floor so that the whole-eucalyptus solid wood composite floor can have good heat resistance performance, no obvious crack phenomenon happens under high-temperature and high-strength ultraviolet irradiation or long-time ultraviolet irradiation, and economic losses are reduced.

The invention relates to an alkali lignin oxidized starch modified urea-formaldehyde glue which is prepared by the following raw materials according to the mix proportion by weight parts: 235-245 parts of industrial formaldehyde with the purity of 37 percent, 133-159 parts of industrial urea, 0.5-1.5 parts of polyvinyl alcohol, 5-7 parts of ammonia water, 30-50 parts of industrial water, NaOH solution with the amount which can respectively regulate pH value to 7-7.5 and 8.5-9 in two times and 100-300 parts of alkali lignin oxidized starch modifier. The modified urea-formaldehyde glue is brown colloidal fluid, the coating 4 cups viscosity at the temperature of 25 DEG C is 40-50s, the density is 1.10-1.25g/cm, the solid content is 40 percent-50 percent and the average formaldehyde release amount is 1.2mg/L and the modified urea-formaldehyde glue achieves E1 level. The production of the modified glue adopts three steps of: 1) purchasing or self-making the modifier; 2) preparing the other various raw materials; and 3) adding the materials in a reaction kettle for reaction and production. The modified glue has low cost, small free formaldehyde release amount, good water resistance and good stability.

The invention belongs to the technical field of adhesive, and relates to a modified urea-formaldehyde resin prepared from urea-formaldehyde resin and propyl p-hydroxybenzoate. The invention also relates to a preparation method and applications of the modified urea-formaldehyde resin in manufacturing fiberboard. The modified urea-formaldehyde resin can be used for bonding materials such as sheet material, ceramic, and plastic in the field of building, decoration, and industry.

The invention provides a preparation method of full-alkaline synthetic melamine urea-formaldehyde resin and a wood impregnation method thereof. The preparation method comprises the following steps: adding 900-1200 parts by weight of a formaldehyde solution, 4-8 parts by weight of a sodium hydroxide solution, 20-120 parts by weight of melamine and 225-500 parts by weight of urea, then adjusting thetemperature to 60-90 DEG C, carrying out a constant-temperature reaction for 0.5-5 hours, and keeping the pH value to be 7-10; keeping the temperature of the constant-temperature reaction to be 60-90DEG C, then adding 150-475 parts by weight of urea and 90-300 parts by weight of maltodextrin or polyvinyl alcohol or starch, and carrying out a reaction for 0.5-5 hours; and adding 10-300 parts by weight of ammonia water and 2-30 parts by weight of triethylene tetramine, carrying out stirring for 5-20 minutes, and carrying out cooling to room temperature for discharging. During use, wood blocksobtained after log sawing are put into a kiln for drying, sodium borate, ammonium borate and quaternary ammonium copper are added into the melamine formaldehyde resin impregnation liquid obtained by the method, adding the dried wood blocks into the mixed solution obtained by the method for impregnation; and drying the impregnated wood block samples to finally obtain a finished product.