CN100389940C - A kind of method adopting isocyanate resin spray sizing glued wooden plank - Google Patents

Abstract

The present invention relates to a method for spraying and gluing veneer wood boards by using isocyanate resin, which has the manufacture procedures that before bamboo wood and wood are glued, the porosity of the surfaces of the bamboo wood and the wood are reduced; the bamboo wood and the wood are processed mechanically to present the shapes of a bamboo bar and a solid wood bar; the isocyanate resin is sprayed on end heads in the length direction of the bamboo bar and two lateral faces in the width direction of the bamboo bar; the isocyanate resin is sprayed to end heads in the length direction of the solid wood bar and two lateral faces in the width direction of the solid wood bar likewise; a plurality of bamboo splicing boards are sprayed and adhered by the isocyanate resin to be used as an upper and a lower surface layers, a plurality of solid wood splicing boards are sprayed and adhered by the isocyanate resin to be used as a core layer, and the upper surface layer, the lower surface layer and the core layer are veneered by hot pressing technology. Consequently, the glue spread quantity can be reduced to 10g/m 2 to 40g/m 2. Compared with a traditional gluing method, the glue spread quantity of the present invention can be reduced by two to three times. Moreover, the moisture resistant performance of the present invention is good without the release of free formaldehyde.

Description

A kind of method adopting isocyanate resin spray sizing glued wooden plank

technical field

The invention relates to a method for gluing wooden boards by spraying and sizing isocyanate resin.

Background technique

该种树脂具有胶合性能好，胶层耐水性强的特点，在木材工业中已经应用的范围包括胶合板、华夫板、刨花板以及木材的拼接和薄膜的胶合中。MDI应用于木质板材(竹材、木材)的胶合仍存在有两个问题需要解决，一是MDI树脂本身价格比较昂贵，而常规的涂胶方法又要求单位面积的涂胶量在60g/m²以上，涂胶量导致板材的成本增加巨大，涂胶过程中涂胶工具清理困难，生产效率降低；二是MDI树脂在热压胶合状态下，粘度急剧降低，而木材，竹材本身又是多孔型材料，使得树脂在受热状态下急速渗透到木质材料中去，从而对胶合强度形成不良影响。另外，采用MDI胶合的木质板材制品由于具有优良的胶合性能和良好的耐水、耐潮性能，市场上有着广泛的需求。由于木材、竹材本身都是多孔型生物质材料，经过加工的竹条或木条表面都有大小不等的空隙存在。在胶合过程中由于这些孔隙的存在，往往会引起胶粘剂在胶合表面的过分渗透，这样往往导致两个后果，一是施胶量增大，生产成本增加；二是胶粘剂过分渗透到空隙中，导致胶合不良。而目前主要是通过提高胶液的粘度、或者向胶粘剂里加入各种填料增加胶的粘稠度，来防止上述现象的发生。At present, isocyanate (MDI), also known as 4,4'-diphenylmethane diisocyanate, its molecular formula is

This kind of resin has the characteristics of good gluing performance and strong water resistance of the glue layer. It has been used in the wood industry including plywood, waffle board, particle board, wood splicing and film gluing. There are still two problems to be solved when MDI is applied to the gluing of wooden boards (bamboo, wood). One is that the price of MDI resin itself is relatively expensive, and the conventional gluing method requires the amount of gluing per unit area to be ^above 60g/m2 , the amount of glue applied leads to a huge increase in the cost of the board, and it is difficult to clean the gluing tools during the gluing process, and the production efficiency is reduced; the second is that the viscosity of MDI resin decreases sharply in the state of hot pressing and gluing, and wood and bamboo are porous materials. , so that the resin rapidly penetrates into the wood material in the heated state, thereby adversely affecting the bonding strength. In addition, the wood panel products glued by MDI have a wide demand in the market because of their excellent glue performance and good water resistance and moisture resistance. Since wood and bamboo themselves are porous biomass materials, there are gaps of different sizes on the surface of the processed bamboo or wood strips. Due to the existence of these pores in the gluing process, it often causes excessive penetration of the adhesive on the gluing surface, which often leads to two consequences. One is that the amount of glue applied increases, and the production cost increases; Poor gluing. And at present, mainly by increasing the viscosity of the glue, or adding various fillers in the adhesive to increase the viscosity of the glue, to prevent the occurrence of the above phenomenon.

Contents of the invention

The object of the present invention is to provide a kind of method that adopts spray sizing of isocyanate resin to glue wooden boards, under the premise of ensuring to reach the national standard GB50206-2002 of "glued wood structure" and the standard of outdoor structural plywood, with a small amount of The isocyanate resin is sprayed onto the surface of the veneer (or solid wood strip). In addition, the surface of the bamboo and wood is treated (surface compaction, superfine powder for surface sealing, and surface spraying of water mist). By reducing and reducing The method of opening pores on the surface of bamboo and wood can prevent the excessive penetration of isocyanate resin on the surface of bamboo and wood. The boards glued by this method will not release free formaldehyde during use and will not pollute the indoor air.

The present invention is to provide a kind of method that adopts isocyanate resin spray sizing to glue wooden panels, and its characteristic manufacturing steps are,

1. Before gluing, it is necessary to reduce the porosity of the bamboo and wood surfaces;

2. Machining bamboo and wood into shapes of bamboo strips and solid wood strips;

3. Spray the isocyanate resin to the end of the length direction of the bamboo strip, and carry out butt joint in the length direction, then spray the isocyanate resin to the both sides of the width direction of the bamboo strip, and splice the bamboo strip in the width direction to form a piece Bamboo panel; spray isocyanate resin to the end of the length direction of the solid wood strips, and carry out butt joint in the length direction, then spray isocyanate resin to both sides of the width direction of the solid wood strips, splice the solid wood strips in the width direction To form a solid wood panel, the glue amount ranges from 10 grams per square meter to 40 grams per square meter on the glue layer; the pressure range of the hot pressing process between the upper and lower surface layers and the core layer is 5 to 30 kilograms per square meter. square centimeter; the hot-pressing temperature is 80-200 degrees, and the hot-pressing time is 1-3 minutes/mm.

4. Then use isocyanate glue spray bonding of several bamboo panels as the upper and lower surface layers, and use isocyanate glue spray bonding of multiple solid wood panels as the core layer. Isocyanate resin is sprayed on the surface, and the boards are glued between the upper and lower surface layers and the core layer by hot pressing to form a final product.

The present invention provides a method for gluing wooden boards by spraying and sizing isocyanate resin. The above-mentioned treatment method for reducing porosity is to perform compaction treatment on the surface of bamboo and wood by hot pressing or rolling.

The present invention provides a method for gluing wooden boards by spraying and sizing isocyanate resin. The above-mentioned treatment method for reducing porosity is a sealing method for bamboo and wood surfaces using ultrafine powder as a sealing agent.

The present invention is to provide a method of spraying and gluing wooden boards with isocyanate resin. The above-mentioned treatment method for reducing porosity is to use surface humidification or spray catalyst on the surface of bamboo and wood.

The present invention is to provide a method for gluing wooden boards by using isocyanate resin spray sizing, wherein the above-mentioned isocyanate glue spray adopts airflow spray sizing.

The present invention is to provide a method for gluing wooden boards by spraying and sizing isocyanate resin, wherein the thickness of the bamboo strips ranges from 2mm to 6mm; the width ranges from 10mm to 30mm;

The present invention is to provide a method of spraying and gluing wooden boards with isocyanate resin, the thickness of the above-mentioned solid wood strips is 2mm-30mm; the width range is 10mm-40mm;

The sizing amount of the invention can be reduced to 10-40g/m ² , which is 1-2 times lower than the sizing amount of the traditional gluing method, and the manufacturing cost of the product is reduced; and the moisture resistance is good, and no free formaldehyde is released.

Description of drawings

Fig. 1 is a product sectional view of a typical embodiment of the present invention.

Fig. 2 is a finger joint perspective view of the end of the length direction of the veneer of the present invention.

Fig. 3 is a perspective view of the end of the length direction of the veneer of the present invention.

Detailed ways

The manufacture steps of wooden board (bamboo and timber) of the present invention are as follows:

1. Before gluing, it is necessary to reduce the porosity of the bamboo and wood surfaces. The treatment methods mainly include the following points: One is to perform surface densification treatment on the bamboo and wood surfaces, that is, use hot pressing or rolling to reduce or reduce the porosity. Eliminate the pores on the wood surface (the temperature of hot pressing or rolling is 50-180°C, the pressure is 0.5-2.0MPa, and the time is 15-120 seconds). The main purpose of this treatment is to prevent the isocyanate resin from Excessive penetration of the surface leads to poor gluing; the second is to use the method of sealing the surface of bamboo and wood, that is, the sealing agent uses ultra-fine powder or other types of sealing substances, and the ultra-fine powder (200 mesh ~ 20 mesh) will It is evenly brushed or sprayed on the surface of the glued body to close the pores on the surface of the glued body (the spraying amount of ultra-fine powder is 15-60g/cm ² .), to reduce the pores between bamboo and wood fiber tissues , to prevent excessive penetration of the resin on the surface of bamboo and wood; the third is to use surface humidification or spraying catalysts to treat the surface, and to seal the pores on the surface of the glued body by spraying water mist on the surface of the glued body. The spray amount of mist is 15-45g/cm ² . To promote the surface gluing of bamboo and wood.

2. Machining bamboo and wood into the shape of veneer and veneer strips (bamboo strips or solid wood strips); the thickness of the bamboo strips ranges from 2mm to 6mm; the width ranges from 10mm to 30mm; the thickness of the solid wood strips ranges from 2mm to 30mm ;The width ranges from 10mm to 40mm;

3. Spray (i.e. sizing) the isocyanate resin to the end of the length direction of the bamboo strip (finger joint or termination point), and carry out butt joint in the length direction, and then spray the isocyanate resin to the two ends of the width direction of the bamboo strip. On the side, the bamboo strips are spliced in the width direction to form a bamboo panel; the isocyanate resin is also sprayed (ie sizing) to the end of the length direction of the solid wood strip (finger joint or terminal point), and in the length direction. Butt jointing, then spray the isocyanate resin to the two sides of the width direction of the solid wood strip, splice the solid wood strip in the width direction to form a solid wood panel;

The above-mentioned isocyanate resin spray isocyanate glue spray adopts the method of airflow spray sizing, and the amount of glue sprayed and the degree of atomization of glue droplets are controlled by controlling the spray time and the pressure of the spray airflow. This spray sizing method requires a special spray sizing method The glue room is equipped with forced ventilation equipment to avoid the spread of glue mist and cause respiratory system damage to glue workers.

It is characterized by uniform sizing and small amount of sizing, which ranges from 10 g/m2 to 40 g/m2 on the sizing level. This method not only reduces the sizing amount by 1 to 2 times compared with the traditional gluing method (50-100g/m ² ), but also avoids the large amount of gluing caused by the gluing machine and the cleaning of the gluing equipment. The disadvantage of low work efficiency.

4. Then use isocyanate glue spray bonding of multiple bamboo panels as the upper and lower surface layers, and multiple solid wood panels with isocyanate glue spray bonding as the core layer. The isocyanate resin is sprayed on the surface, and the boards are glued between the upper and lower surface layers and the core layer by hot pressing. The hot pressing pressure range is 5-30 kg/cm2; The time is 1-3 minutes/mm; the final product is bamboo-wood composite plywood or bamboo-wood glulam.

According to the above-mentioned same implementation method, it is also possible to simply glue the layers of bamboo panels or simply glue the layers of solid wood panels, and the final product is bamboo plywood, glulam, or wood plywood, wood glulam.

Moreover, the bamboo, wood or bamboo-wood composite products glued by the above-mentioned process method also have excellent gluing performance, good moisture resistance, and no release of free formaldehyde.

Claims (7)

1. method that adopts the isocyanate resin spraying and glue blending to glue woody sheet material, the making step of its feature be,

One, needs bamboo wood and wood surface are reduced the processing of porosity before the gummed;

Two, bamboo wood, timber machining are become the shape of bamboo bar, solid wood bar;

Three, isocyanate resin is sprayed to the termination of the length direction of bamboo bar, and docks in the longitudinal direction, then isocyanate resin is sprayed to the two sides of the width of bamboo bar, be spliced to form a bamboo jigsaw at width at this bamboo bar; Equally isocyanate resin is sprayed to the termination of the length direction of solid wood bar, and dock in the longitudinal direction, then isocyanate resin is sprayed to the two sides of the width of solid wood bar, be spliced to form the solid wood jigsaw at this solid wood bar at width, its resin added scope is 10 grams/square metre to 40 gram/square metre applying glue aspects; Adopt pressure limit 5～30 kg/cm of heat pressing process between above-mentioned upper and lower superficial layer and the sandwich layer; Hot pressing temperature is at 80～200 degree, and hot pressing time was at 1～3 minute/mm.

Four, again that polylith bamboo jigsaw is bonding as upper and lower superficial layer with the isocyanate glue spraying, bonding as sandwich layer polylith solid wood jigsaw with the isocyanate glue spraying, the isocyanate resin of on the facing surfaces of bamboo jigsaw, solid wood jigsaw, all spraying again, between upper and lower superficial layer and sandwich layer, adopt heat pressing process to carry out the sheet material gummed, finally form product.

2. a kind of method that adopts the isocyanate resin spraying and glue blending to glue woody sheet material according to claim 1, it is characterized in that the processing method of above-mentioned reduction porosity is bamboo wood, wood surface to be carried out the surface adopt the densification of the mode of hot pressing or roll-in to handle.

3. a kind of method that adopts the isocyanate resin spraying and glue blending to glue woody sheet material according to claim 1 is characterized in that, the processing method of above-mentioned reduction porosity is that bamboo wood, wood surface are adopted superfines is the enclosure method of sealer.

4. a kind of method that adopts the isocyanate resin spraying and glue blending to glue woody sheet material according to claim 1 is characterized in that, the processing method of above-mentioned reduction porosity is that bamboo wood, wood surface are adopted surperficial humidification or spray the catalyst method.

5. a kind of method that adopts the isocyanate resin spraying and glue blending to glue woody sheet material according to claim 1 is characterized in that, the air-stream spraying applying glue is adopted in above-mentioned isocyanate glue spraying.

6. a kind of method that adopts the isocyanate resin spraying and glue blending to glue woody sheet material according to claim 1 is characterized in that, above-mentioned bamboo bar thickness range is at 2mm～6mm; Width range is at 10mm～30mm.

7. a kind of method that adopts the isocyanate resin spraying and glue blending to glue woody sheet material according to claim 1 is characterized in that, above-mentioned solid wood bar thickness is 2mm～30mm; Width range is at 10mm～40mm.

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