As a building template, bamboo curtain plywood is divided into plain board and laminated board. Since it passed the technical appraisal of Hunan Science and Technology Commission in 1991, it has developed rapidly in more than 10 years. According to the China Association of Formwork, there are more than 200 manufacturers, and more than 300 production lines have been established, with an annual production capacity of 70 million m2. It is not only an important variety of bamboo wood-based panels, but also a variety of architectural templates with Chinese characteristics. However, there are still many problems, such as the decline in product prices, the decline in quality, the stagnation of process technology, and the lack of technological innovation. In the face of fierce market competition, the operators of enterprises often adopt the strategy of selling at a reduced price and fight the price war. For example, the average selling price of plastic-coated bamboo plywood before and after 1994 is about 5,500 yuan/m3, currently only about 3,000 yuan/m3, and the price reduction is 45%. Due to the large drop in sales prices, in order to protect the majority of manufacturers to operate at the expense of quality, it has seriously affected the market reputation and market share, which in turn caused the price to decline, forming a vicious circle. Although there are many achievements in scientific and technological innovation, due to the lack of translation funds, the promotion and application are not enough. We believe that as a manufacturer to be in an invincible position in the market competition, we must establish the idea of ​​quality first, brand first, and credit first. Transform the current price war on the market into a brand strategy. As a university and research institute, we must continuously carry out scientific and technological innovation, and vigorously promote the application of scientific and technological innovations, transform it into productivity, and greatly improve the performance/price ratio, thereby improving the scientific and technological content of the bamboo plywood itself and enhancing it in the building formwork. The competitiveness of many varieties.
Bamboo curtain plywood is a resource utilization product. Its technological innovation includes efficient utilization of bamboo resources, improvement of product structure, innovation of process and equipment, reduction of energy consumption and product cost, and improvement of product use characteristics. Based on the scientific research achievements and production practice experience in the past 11 years, the paper puts forward the conception and comprehensive system implementation plan of bamboo curtain plywood technology, in order to make the production of bamboo plywood leap to a new level and continue more effectively through its implementation. moving forward.
1 All-round utilization of bamboo resources and efficient processing of bamboo materials
Although the processing and utilization of bamboo is in the leading position in the world, the proportion of industrial use of bamboo has also increased year by year, but it mainly refers to bamboo with large diameter, small and medium-sized bamboo, except for a small amount of raw materials for papermaking and bamboo scraping. It has not been industrially utilized, and even the processing utilization rate of bamboo is not high. In the case of a long-term shortage of timber resources in China, it is of great significance to use all-round and high-efficiency processing of bamboo resources to make up for the shortage of timber resources. The so-called all-round processing and utilization of bamboo resources requires the effective industrial use of various bamboo species with economical value, regardless of their size. The efficient processing and utilization of bamboo requires seeking a high yield and processing efficiency. High industrial performance methods with high product performance. The radial bamboo curtain composite panel series developed by our institute in 1999 using radial sectioning and radial gluing method is a concrete example of exploring the all-round and efficient processing and utilization of bamboo resources. Of course, there are still many methods, but long-term technological innovation is needed to achieve this goal.
The bamboo raft processing of the radial bamboo drapes composite panel series adopts the radial sectioning of the bamboo material to replace the traditional chord sectioning. Because the radial bamboo raft can effectively perform radial gluing without removing bamboo green and bamboo yellow, it overcomes the string-type gluing of bamboo plywood at home and abroad, and must remove the bamboo green which is difficult to glue on both sides of the bamboo string. Bamboo yellow, the disadvantage of reducing the utilization rate of bamboo. The utilization rate of the bamboo in the radial section can be increased from about 65% of the chord to about 90%, and the radial sectioning machine equipped with the tapered cutter wheel can realize the mechanized sectioning, which greatly improves the cutting efficiency. . More importantly, the radial sectioning can adapt to the bamboo processing of different bamboo species and different diameter grades, which not only increases the amount of bamboo resources used in industrialization, but also realizes the full utilization of bamboo resources.
2 Product structure improvement
For a long time, the structure of the bamboo plywood is a core layer with a chord-to-bamboo curtain as the main material, and a bamboo mat is a surface layer. This kind of structure has two shortcomings. First, the bamboo utilization rate of the bamboo curtain is low, which makes the bamboo cost of the product remain high. Second, the surface bamboo mat is difficult to process, and it is not conducive to product quality, such as: surface layer. The bamboo chord has a thickness of only 0.5mm, and the cutting work is large; the bamboo mat weaving can only be used by hand and the efficiency is low; the bamboo mat sizing is difficult to achieve uniformity by roller coating, shower coating or dipping method; The latitude and longitude cross structure of the mat makes the surface still have irregularities after hot pressing, which seriously affects the appearance of the sheet, that is, using the impregnated paper to perform a hot pressing of the reconstituted bamboo curtain plywood, and the unevenness of the board surface and the color shade are also different. Defects. In view of the above shortcomings of bamboo curtain plywood, it is believed that the product structure can be improved in the following two aspects: First, the radial bamboo curtain is used instead of the string bamboo curtain as the main material of the sheet to improve the utilization of bamboo. The second is to replace the surface bamboo mat with wood veneer. The wood veneer can be a soft material of the artificial fast-growing veneer. Because the material is soft, the groove can be filled by the bamboo curtain when the plate is hot pressed, so that the plate surface is smooth and smooth, and the plate surface is also favorable. Equal thickness sanding to improve board quality and reduce thickness deviation. In addition, the grain direction of the wood veneer is perpendicular to the core bamboo curtain, that is, the length of the wood veneer is the width of the plate, so that the production and supply of the wood veneer are more easily solved. With this product structure, the advantages compared to the existing structure are obvious.
3 Reduce the density of the board and improve the overall performance
The density of bamboo curtain plywood is mostly 0.95-1.05g/cm3, which is not only much higher than the density of wood-based panels, but also higher than the density of bamboo plywood and bamboo flooring. Although the high density of the sheet has the advantage of high mechanical strength, there are many negative effects. If the density is reduced under the premise of ensuring a certain mechanical strength, the following benefits will be brought to the product.
3.1 Reduce the consumption of raw materials per unit of product
When the density of the bamboo plywood is reduced from 1.0g/cm3 to 0.8g/cm3, the amount of bamboo curtain per unit product can be saved by 20%. According to the rough calculation, the cost of bamboo can be reduced by about 400 yuan per m3 of finished product.
3.2 Improve the physical properties of the product
The bamboo curtain plywood with high density has a large difference in density among the plates due to the thickness deviation of the slab. After moisture absorption or water absorption during storage and use, the difference in thickness expansion ratio is inevitably caused, and the thickness of the dense portion is expanded. The rate is large, and the reverse is small, so that it is easy to cause warpage deformation and unevenness of the sheet. This will seriously affect the processing properties of the steel frame bamboo plywood formwork and cannot be used. If the product density is reduced and the sanding is equal, the dimensional stability and shape stability of the sheet can be improved, which will undoubtedly benefit the application of the sheet.
3.3 Improve product performance
There are two problems in the use of high-density plates: one is too cumbersome to increase the labor intensity of workers; the other is that it is difficult to carry out cutting and nailing at the construction site, which increases the difficulty of operation. High-density bamboo plywood can be nailed even with steel nails or pre-drilled holes. When the density is reduced to 0.8 g/cm3 or less, the "four difficulties" of the sheet which is difficult to saw, difficult to plan, difficult to nail, difficult to handle and load and unload will be solved. As the use of the board is greatly improved, it will be welcomed by the construction unit and the construction operator.
4 Process innovation to improve economic efficiency
4.1 Adjust the process
The current process of bamboo curtain plywood is that the dried bamboo curtain is dipped and then dried, then the composite is assembled and then hot pressed into a plate. The shortcomings of this process: First, the process can not be continuous; Second, the wet bamboo curtain is dipped and then returned to the same dryer for the second drying, which not only causes the semi-finished products to return to the head, but also affects the smooth flow of the workshop. The important thing is to make the dryer load too large. Third, the jet dryer has a large investment and high energy consumption, which makes the drying cost of the bamboo curtain high. In order to overcome the above drawbacks, the adjusted process is as follows: dry bamboo curtain dipping stacking code dry - 4 set blank - 4 preheating hot pressing. It is characterized by the elimination of the second drying of the bamboo curtain, which is replaced by the stacking of the bamboo curtain and the preheating of the slab. The preheating of the slab is carried out on a special structure of the plate loader. The advantages of this process are as follows: 1 can greatly save the drying cost of the dipped bamboo curtain, and because the drying process is reduced, the bamboo curtain is not easily damaged, thereby facilitating the improvement of the assembly efficiency and the slab quality; The phenomenon of turning back is conducive to the orderly circulation of materials in the workshop, and also reduces the workload of material handling; 3 after the preheated slab enters the hot press, the hot pressing time can be shortened and the productivity of the hot press can be improved.
4.2 Design multi-functional production lines, using different plate making methods to produce multiple product varieties
The existing bamboo plywood production line can be designed into a multi-functional production line through technical transformation, overcoming the limitations of only producing two types of plain and laminating plates. In the newly designed multi-functional production line, according to the needs of different periods of the market, a variety of product grades of different grades can be produced by one hot pressing and secondary processing, such as one-time plastic bamboo plywood and impregnated paper stickers. Bamboo curtain plywood, coated bamboo curtain plywood and plain board. The secondary processing plate can eliminate the defects of the surface color difference and the thickness deviation of the hot pressing plate, and greatly improve the product grade, thereby creating conditions for the export of the product.
4.3 Improve the hot press bonding process, increase production and reduce energy consumption
Bamboo curtain plywood's current hot-pressing and gluing process, both plain and laminating plates adopt cold-hot-cold process, which has the advantage that the plate is flat and not warped, the surface quality is good and shiny, and drums are not generated when pressure is released. Bubble defects. The disadvantage is that the hot pressing cycle is long, the productivity of the hot press is reduced, and a large amount of steam and cooling water are consumed, which increases the product cost. In order to change this situation, a large number of thermal-thermal bonding processes have been studied. The results show that the hot-hot gluing process is completely feasible when using a medium temperature fast curing (115-125 ° C) phenolic resin glue, stepping pressure relief and immediate compaction pressure after unloading the plate. . This not only doubles the productivity of the hot press, but also saves a lot of steam and cooling water. If the slab preheating process is combined with the hot-hot gluing process, the hot pressing time will be shortened and the hot press productivity will be further improved.
5 Develop special equipment to improve processing efficiency
In order to realize the needs of process technology innovation, we design and manufacture the following special equipments to improve the processing efficiency.
5.1 Radial bamboo processing equipment
Radial bamboo raft has the advantage of high utilization rate of bamboo cuttings. In order to improve the processing efficiency, it is necessary to develop a bamboo tube to the inner section machine and the radial sectioning machine. Although the two types of equipment are simple in structure, the design and processing of the cutter head is difficult, because the bamboo material is a gramineous plant fiber material, and each bamboo has different shapes. The structure of the cutter head is required from the machining process to adapt to the change in the degree of curvature, sharpness and out-of-roundness of the length of the 2600 mm bamboo tube. At present, the design of these two devices has been completed and the prototype is being trial-produced. The structure of the blade of the bamboo tube to the inner section and the radial cutter head of the tapered cutter wheel are shown in Figs. 1 and 2. After the two devices are put into use, the radial section will increase the efficiency of the artificial section by more than 10 times.
5.2 Horizontal feeding curtain machine
Various types of bamboo quilting curtain machines are currently completed by the combination of two vertical movements of bamboo rafts and warp crossings. For the long bamboo curtain, since the bamboo raft is as long as 2600 mm, although the feeding speed is high, the feeding time of each bamboo raft is still long, thus affecting the production efficiency of the looms. We have designed the bamboo raft horizontal feeding looms. Since the stroke of the bamboo stalks is greatly shortened compared to the longitudinal feeding stroke, the feeding time is also reduced accordingly, and the production efficiency can be greatly improved.
5.3 slab preheating device
In order to realize the adjustment of the bamboo curtain plywood process and the slab preheating process, we designed the slab preheating device. This type of device has two structural solutions, one of which is modified on the basis of the existing plate loading machine. It consists of installing a radiator and a top-mounted axial fan on both sides of the loader; installing sealing and thermal insulation around the top and top of the trigger. This structure needs to solve the normal working problem of the cylinder at an ambient temperature of about 90 °C. Another structure uses a chain to drive the crossbar for lifting the plate, and the pusher is also pulled by a chain. The air heating and air circulation device, the sealing and thermal insulation device are basically the same as the former structure.
6 Strengthening applied research, expanding product application areas, and opening up new markets for products
At present, China's bamboo plywood is mainly used as a building formwork, and the template market is highly competitive. The selling price has been declining, the profit margin is getting smaller and smaller, and even threatens the survival of the enterprise. Therefore, it is necessary to strengthen its application research and expand the product. Application area. According to the physical and mechanical properties of bamboo curtain plywood, we believe that it is not only a building formwork, but also can be used as a packaging material for heavy machinery, car floor and container floor of cars, trains, and the application amount in these fields is very large. Even as a building template, there is a problem of broadening the product market. We want to make this building template with Chinese characteristics from the domestic market to the international market, because there is no bamboo plywood template abroad, and its mechanical strength is much higher than that. The world-famous Visa template, as long as the secondary processing method is used to eliminate the two disadvantages of thickness tolerance and board color difference, it is entirely possible to enter the international market. As far as the domestic market is concerned, the application of bamboo plywood formwork is still limited to some large and medium-sized cities, and has not been extended to all large and medium-sized cities. For example, the scale of construction in Shanghai is so large, but the amount is very small, not to mention Thousands of small county towns and rural market towns have basically no application, so there is a lot of room for development. In addition, bamboo plywood formwork is currently used primarily in building construction, with only a small number of high quality bamboo plywood formwork used as highway, rail, bridge and tunnel formwork. With the expansion of China's infrastructure construction and the strengthening of western development, the market potential of such templates is enormous. It is hoped that entrepreneurs with strength and vision will increase their investment in technological transformation and actively create conditions to produce high-grade bamboo plywood templates to meet the needs of domestic bridge templates and strive to open up the international market. At present, several manufacturers in Zhejiang have been producing bridge templates, and the economic benefits are good, such as the West Lake template of Hangzhou Bamboo Formwork Associates, the Maosen template of Maohua Bamboo Company of Fenghua City, Zhejiang Province, and the Yanxiang card template of Zhejiang Yanjie Company. At the China Template Association Xiamen Conference in 2002, China Construction International Construction Co., Ltd. proposed a research report on the development and application of the "95 series steel frame plywood large formwork". The report concluded that the use of bamboo (wood) plywood and steel frame to produce steel frame plywood Large templates are widely used in the world and have more advantages than all-steel large templates. This also opens up new applications for the application of bamboo plywood. We must seize these opportunities.
The bamboo curtain plywood has developed rapidly in a short period of 11 years. It is the need of national construction and the result of many years of hard work by the bamboo industry and construction industry colleagues. However, it is facing a severe market situation. Under the great attention and support of the development of bamboo industry, by strengthening scientific and technological innovation and enterprise management, and striving to improve product quality and open up new application fields, the production of bamboo curtain plywood in China will surely leap to a new level, and a new product will appear. Situation.
Bamboo curtain plywood is a resource utilization product. Its technological innovation includes efficient utilization of bamboo resources, improvement of product structure, innovation of process and equipment, reduction of energy consumption and product cost, and improvement of product use characteristics. Based on the scientific research achievements and production practice experience in the past 11 years, the paper puts forward the conception and comprehensive system implementation plan of bamboo curtain plywood technology, in order to make the production of bamboo plywood leap to a new level and continue more effectively through its implementation. moving forward.
1 All-round utilization of bamboo resources and efficient processing of bamboo materials
Although the processing and utilization of bamboo is in the leading position in the world, the proportion of industrial use of bamboo has also increased year by year, but it mainly refers to bamboo with large diameter, small and medium-sized bamboo, except for a small amount of raw materials for papermaking and bamboo scraping. It has not been industrially utilized, and even the processing utilization rate of bamboo is not high. In the case of a long-term shortage of timber resources in China, it is of great significance to use all-round and high-efficiency processing of bamboo resources to make up for the shortage of timber resources. The so-called all-round processing and utilization of bamboo resources requires the effective industrial use of various bamboo species with economical value, regardless of their size. The efficient processing and utilization of bamboo requires seeking a high yield and processing efficiency. High industrial performance methods with high product performance. The radial bamboo curtain composite panel series developed by our institute in 1999 using radial sectioning and radial gluing method is a concrete example of exploring the all-round and efficient processing and utilization of bamboo resources. Of course, there are still many methods, but long-term technological innovation is needed to achieve this goal.
The bamboo raft processing of the radial bamboo drapes composite panel series adopts the radial sectioning of the bamboo material to replace the traditional chord sectioning. Because the radial bamboo raft can effectively perform radial gluing without removing bamboo green and bamboo yellow, it overcomes the string-type gluing of bamboo plywood at home and abroad, and must remove the bamboo green which is difficult to glue on both sides of the bamboo string. Bamboo yellow, the disadvantage of reducing the utilization rate of bamboo. The utilization rate of the bamboo in the radial section can be increased from about 65% of the chord to about 90%, and the radial sectioning machine equipped with the tapered cutter wheel can realize the mechanized sectioning, which greatly improves the cutting efficiency. . More importantly, the radial sectioning can adapt to the bamboo processing of different bamboo species and different diameter grades, which not only increases the amount of bamboo resources used in industrialization, but also realizes the full utilization of bamboo resources.
2 Product structure improvement
For a long time, the structure of the bamboo plywood is a core layer with a chord-to-bamboo curtain as the main material, and a bamboo mat is a surface layer. This kind of structure has two shortcomings. First, the bamboo utilization rate of the bamboo curtain is low, which makes the bamboo cost of the product remain high. Second, the surface bamboo mat is difficult to process, and it is not conducive to product quality, such as: surface layer. The bamboo chord has a thickness of only 0.5mm, and the cutting work is large; the bamboo mat weaving can only be used by hand and the efficiency is low; the bamboo mat sizing is difficult to achieve uniformity by roller coating, shower coating or dipping method; The latitude and longitude cross structure of the mat makes the surface still have irregularities after hot pressing, which seriously affects the appearance of the sheet, that is, using the impregnated paper to perform a hot pressing of the reconstituted bamboo curtain plywood, and the unevenness of the board surface and the color shade are also different. Defects. In view of the above shortcomings of bamboo curtain plywood, it is believed that the product structure can be improved in the following two aspects: First, the radial bamboo curtain is used instead of the string bamboo curtain as the main material of the sheet to improve the utilization of bamboo. The second is to replace the surface bamboo mat with wood veneer. The wood veneer can be a soft material of the artificial fast-growing veneer. Because the material is soft, the groove can be filled by the bamboo curtain when the plate is hot pressed, so that the plate surface is smooth and smooth, and the plate surface is also favorable. Equal thickness sanding to improve board quality and reduce thickness deviation. In addition, the grain direction of the wood veneer is perpendicular to the core bamboo curtain, that is, the length of the wood veneer is the width of the plate, so that the production and supply of the wood veneer are more easily solved. With this product structure, the advantages compared to the existing structure are obvious.
3 Reduce the density of the board and improve the overall performance
The density of bamboo curtain plywood is mostly 0.95-1.05g/cm3, which is not only much higher than the density of wood-based panels, but also higher than the density of bamboo plywood and bamboo flooring. Although the high density of the sheet has the advantage of high mechanical strength, there are many negative effects. If the density is reduced under the premise of ensuring a certain mechanical strength, the following benefits will be brought to the product.
3.1 Reduce the consumption of raw materials per unit of product
When the density of the bamboo plywood is reduced from 1.0g/cm3 to 0.8g/cm3, the amount of bamboo curtain per unit product can be saved by 20%. According to the rough calculation, the cost of bamboo can be reduced by about 400 yuan per m3 of finished product.
3.2 Improve the physical properties of the product
The bamboo curtain plywood with high density has a large difference in density among the plates due to the thickness deviation of the slab. After moisture absorption or water absorption during storage and use, the difference in thickness expansion ratio is inevitably caused, and the thickness of the dense portion is expanded. The rate is large, and the reverse is small, so that it is easy to cause warpage deformation and unevenness of the sheet. This will seriously affect the processing properties of the steel frame bamboo plywood formwork and cannot be used. If the product density is reduced and the sanding is equal, the dimensional stability and shape stability of the sheet can be improved, which will undoubtedly benefit the application of the sheet.
3.3 Improve product performance
There are two problems in the use of high-density plates: one is too cumbersome to increase the labor intensity of workers; the other is that it is difficult to carry out cutting and nailing at the construction site, which increases the difficulty of operation. High-density bamboo plywood can be nailed even with steel nails or pre-drilled holes. When the density is reduced to 0.8 g/cm3 or less, the "four difficulties" of the sheet which is difficult to saw, difficult to plan, difficult to nail, difficult to handle and load and unload will be solved. As the use of the board is greatly improved, it will be welcomed by the construction unit and the construction operator.
4 Process innovation to improve economic efficiency
4.1 Adjust the process
The current process of bamboo curtain plywood is that the dried bamboo curtain is dipped and then dried, then the composite is assembled and then hot pressed into a plate. The shortcomings of this process: First, the process can not be continuous; Second, the wet bamboo curtain is dipped and then returned to the same dryer for the second drying, which not only causes the semi-finished products to return to the head, but also affects the smooth flow of the workshop. The important thing is to make the dryer load too large. Third, the jet dryer has a large investment and high energy consumption, which makes the drying cost of the bamboo curtain high. In order to overcome the above drawbacks, the adjusted process is as follows: dry bamboo curtain dipping stacking code dry - 4 set blank - 4 preheating hot pressing. It is characterized by the elimination of the second drying of the bamboo curtain, which is replaced by the stacking of the bamboo curtain and the preheating of the slab. The preheating of the slab is carried out on a special structure of the plate loader. The advantages of this process are as follows: 1 can greatly save the drying cost of the dipped bamboo curtain, and because the drying process is reduced, the bamboo curtain is not easily damaged, thereby facilitating the improvement of the assembly efficiency and the slab quality; The phenomenon of turning back is conducive to the orderly circulation of materials in the workshop, and also reduces the workload of material handling; 3 after the preheated slab enters the hot press, the hot pressing time can be shortened and the productivity of the hot press can be improved.
4.2 Design multi-functional production lines, using different plate making methods to produce multiple product varieties
The existing bamboo plywood production line can be designed into a multi-functional production line through technical transformation, overcoming the limitations of only producing two types of plain and laminating plates. In the newly designed multi-functional production line, according to the needs of different periods of the market, a variety of product grades of different grades can be produced by one hot pressing and secondary processing, such as one-time plastic bamboo plywood and impregnated paper stickers. Bamboo curtain plywood, coated bamboo curtain plywood and plain board. The secondary processing plate can eliminate the defects of the surface color difference and the thickness deviation of the hot pressing plate, and greatly improve the product grade, thereby creating conditions for the export of the product.
4.3 Improve the hot press bonding process, increase production and reduce energy consumption
Bamboo curtain plywood's current hot-pressing and gluing process, both plain and laminating plates adopt cold-hot-cold process, which has the advantage that the plate is flat and not warped, the surface quality is good and shiny, and drums are not generated when pressure is released. Bubble defects. The disadvantage is that the hot pressing cycle is long, the productivity of the hot press is reduced, and a large amount of steam and cooling water are consumed, which increases the product cost. In order to change this situation, a large number of thermal-thermal bonding processes have been studied. The results show that the hot-hot gluing process is completely feasible when using a medium temperature fast curing (115-125 ° C) phenolic resin glue, stepping pressure relief and immediate compaction pressure after unloading the plate. . This not only doubles the productivity of the hot press, but also saves a lot of steam and cooling water. If the slab preheating process is combined with the hot-hot gluing process, the hot pressing time will be shortened and the hot press productivity will be further improved.
5 Develop special equipment to improve processing efficiency
In order to realize the needs of process technology innovation, we design and manufacture the following special equipments to improve the processing efficiency.
5.1 Radial bamboo processing equipment
Radial bamboo raft has the advantage of high utilization rate of bamboo cuttings. In order to improve the processing efficiency, it is necessary to develop a bamboo tube to the inner section machine and the radial sectioning machine. Although the two types of equipment are simple in structure, the design and processing of the cutter head is difficult, because the bamboo material is a gramineous plant fiber material, and each bamboo has different shapes. The structure of the cutter head is required from the machining process to adapt to the change in the degree of curvature, sharpness and out-of-roundness of the length of the 2600 mm bamboo tube. At present, the design of these two devices has been completed and the prototype is being trial-produced. The structure of the blade of the bamboo tube to the inner section and the radial cutter head of the tapered cutter wheel are shown in Figs. 1 and 2. After the two devices are put into use, the radial section will increase the efficiency of the artificial section by more than 10 times.
5.2 Horizontal feeding curtain machine
Various types of bamboo quilting curtain machines are currently completed by the combination of two vertical movements of bamboo rafts and warp crossings. For the long bamboo curtain, since the bamboo raft is as long as 2600 mm, although the feeding speed is high, the feeding time of each bamboo raft is still long, thus affecting the production efficiency of the looms. We have designed the bamboo raft horizontal feeding looms. Since the stroke of the bamboo stalks is greatly shortened compared to the longitudinal feeding stroke, the feeding time is also reduced accordingly, and the production efficiency can be greatly improved.
5.3 slab preheating device
In order to realize the adjustment of the bamboo curtain plywood process and the slab preheating process, we designed the slab preheating device. This type of device has two structural solutions, one of which is modified on the basis of the existing plate loading machine. It consists of installing a radiator and a top-mounted axial fan on both sides of the loader; installing sealing and thermal insulation around the top and top of the trigger. This structure needs to solve the normal working problem of the cylinder at an ambient temperature of about 90 °C. Another structure uses a chain to drive the crossbar for lifting the plate, and the pusher is also pulled by a chain. The air heating and air circulation device, the sealing and thermal insulation device are basically the same as the former structure.
6 Strengthening applied research, expanding product application areas, and opening up new markets for products
At present, China's bamboo plywood is mainly used as a building formwork, and the template market is highly competitive. The selling price has been declining, the profit margin is getting smaller and smaller, and even threatens the survival of the enterprise. Therefore, it is necessary to strengthen its application research and expand the product. Application area. According to the physical and mechanical properties of bamboo curtain plywood, we believe that it is not only a building formwork, but also can be used as a packaging material for heavy machinery, car floor and container floor of cars, trains, and the application amount in these fields is very large. Even as a building template, there is a problem of broadening the product market. We want to make this building template with Chinese characteristics from the domestic market to the international market, because there is no bamboo plywood template abroad, and its mechanical strength is much higher than that. The world-famous Visa template, as long as the secondary processing method is used to eliminate the two disadvantages of thickness tolerance and board color difference, it is entirely possible to enter the international market. As far as the domestic market is concerned, the application of bamboo plywood formwork is still limited to some large and medium-sized cities, and has not been extended to all large and medium-sized cities. For example, the scale of construction in Shanghai is so large, but the amount is very small, not to mention Thousands of small county towns and rural market towns have basically no application, so there is a lot of room for development. In addition, bamboo plywood formwork is currently used primarily in building construction, with only a small number of high quality bamboo plywood formwork used as highway, rail, bridge and tunnel formwork. With the expansion of China's infrastructure construction and the strengthening of western development, the market potential of such templates is enormous. It is hoped that entrepreneurs with strength and vision will increase their investment in technological transformation and actively create conditions to produce high-grade bamboo plywood templates to meet the needs of domestic bridge templates and strive to open up the international market. At present, several manufacturers in Zhejiang have been producing bridge templates, and the economic benefits are good, such as the West Lake template of Hangzhou Bamboo Formwork Associates, the Maosen template of Maohua Bamboo Company of Fenghua City, Zhejiang Province, and the Yanxiang card template of Zhejiang Yanjie Company. At the China Template Association Xiamen Conference in 2002, China Construction International Construction Co., Ltd. proposed a research report on the development and application of the "95 series steel frame plywood large formwork". The report concluded that the use of bamboo (wood) plywood and steel frame to produce steel frame plywood Large templates are widely used in the world and have more advantages than all-steel large templates. This also opens up new applications for the application of bamboo plywood. We must seize these opportunities.
The bamboo curtain plywood has developed rapidly in a short period of 11 years. It is the need of national construction and the result of many years of hard work by the bamboo industry and construction industry colleagues. However, it is facing a severe market situation. Under the great attention and support of the development of bamboo industry, by strengthening scientific and technological innovation and enterprise management, and striving to improve product quality and open up new application fields, the production of bamboo curtain plywood in China will surely leap to a new level, and a new product will appear. Situation.
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