Major Production Equipment and Type Selection of Plate Furniture
Plate furniture is a common form of furniture in the furniture industry. Because of the versatility and interchangeability of its components, it is suitable for mass production. Because of the high requirement of parts processing accuracy, the production of panel furniture requires higher equipment accordingly. Therefore, it is very important to select the type of panel furniture equipment and configure the appropriate equipment according to the requirements of product positioning and productivity. The types of main equipment of panel furniture are shown in Table 1.
I. Opening Equipment
- Electronic cutting saw
电子开料锯 是对板材进行批量裁切加工的设备，由于采用稳定的锯座运动方式，锯座运动速度可以达到60m/m in，采用大直径锯片，锯片升起较高，一般可以达到100mm，可以同时对几件板材进行同规格部件的切割，具有很高的锯切加工效率。电子开料锯普遍采用电脑进行锯切的计算和控制，可以使板材利用率得以提高。由于锯切是在封闭空间进行的，因此又具有很高的操作安全性。
Electronic cutting saw is a kind of equipment for batch cutting of sheet metal. Because of the stable movement mode of the saw seat, the movement speed of the saw seat can reach 60 m/m in. With large diameter saw blade, the saw blade rises higher, generally up to 100 mm. It can cut several pieces of sheet metal with the same specifications at the same time, and has high sawing efficiency. Computer is widely used to calculate and control the cutting of electronic cutting saw, which can improve the utilization ratio of sheet metal. Because sawing is carried out in closed space, it has high operational safety.
In the selection of electronic saw, we should pay attention to the following parameters:
One is specifications. Specification refers to the largest size of sawing board. Generally speaking, the domestic plate size is 2440 *1220 mm. All electronic saws can cut the board of this specification. However, for some imported plates, such as 3048 * 1220 mm, 3658 * 1830 mm and other large-scale plates, cutting is necessary, which should be considered in the selection.
Table 1 Types of Major Processing Equipment for Panel Furniture
Second, sawing height. The sawing height of general electronic saw is 80 mm, 100 mm, 120 mm, 150 mm, etc. Sawing height of larger models, the number of lumber sawn at a time is also more, but the quality and speed of sawing may be affected, so it is not the higher the sawing height, the better, generally 100-120 mm is appropriate.
Third, the feed speed of the saw blade. The higher the speed, the faster the sawing speed. However, in actual use, considering the variety and quality requirements of sawn board, it is generally appropriate to use 20-30m per minute.
Fourth, sawing software. Require the interface of the software to use Chinese, which can facilitate the training and actual operation of the operator, and reduce the possibility of operation errors. Require software to have automatic typesetting function, which can improve material utilization and sawing efficiency; Require software to have storage and networking function, which can make the programming completed by a dedicated person in the office, reduce the cultural requirements of operators, thereby improving production efficiency.
- Precision pusher saw
Precision pusher saw (as shown in Figure 2) is a flexible cutting equipment for sheet metal. The precise aluminum alloy pusher driven by the operator moves along the direction of sawing to produce sawing. The sawing specifications are adjusted conveniently and quickly. It is a common sawing equipment for panel furniture components.
The following parameters should be paid attention to in the selection of precision pusher saw:
One is the form of guidance platform. Guidance platform must have high stability, flexibility and accuracy. In order to achieve this goal, precision push-table saw guidance platform generally adopts large-scale dual-roller vertical guidance system. The difference lies in the form of guideway, generally there are two kinds: one is the use of high-pressure resin special-shaped guideway, the other is the use of high-strength linear circular rail. Because the quality of high-pressure resin special-shaped guide is difficult to control, attention should be paid to the selection.
Fig. 2 Precision pusher saw
Fig. 3 The form of guide table for precision push-table saw
二是电机功率。一般精密推台锯的电机功率有3 KW、4.5KW两种，对于切割刨花板和厚度相对比较大的板材，宜选择4.5 KW的电机。
The second is motor power. Generally, the motor power of precision push saw is 3 KW and 4.5 KW. For cutting particleboard and plate with relatively large thickness, 4.5 KW motor should be selected.
The third is whether the sawing angle can be adjusted and how to adjust it. In actual production, some workpieces need to be cut into a certain angle, so we need to choose the model with adjustable sawing angle. Generally, the sawing angle can be adjusted up to 45 degrees. The adjusting mode can also be selected by manual and electric, and the electric one can be easily adjusted.
In the actual configuration process, generally configure 1-2 angle adjustable models, other choice of non-adjustable models, can reduce investment costs.
- Wood Shearing Machine
Micro-thin wood is a common decorative material in high-grade furniture. The wood shear machine (shown in Figure 4) is a precise cutting equipment for micro-thin wood, such as edge leveling and cutting head. When working, the special cutter cuts the thin wood under the drive of the hydraulic mechanism, and can process dozens of superimposed thin wood at one time. The parameters to be noticed in the wood shear are usually the maximum processing length, commonly used is 2600 mm.
Fig. 4 Bark shearing machine
- Wooden Bark Sewing Machine
Because most of the natural thin wood is small in width, it is not suitable to cover directly on the surface of the base material. If it is directly covered on the surface of the base material, the gap between them is also difficult to control, which makes the surface quality of the workpiece after the cover poor. This equipment uses fast-drying adhesives or special sewing thread to splice the precisely cut micro-thin wood to form large-scale micro-thin wood. After processing with this equipment, continuous and compact veneer can be formed on the surface of the board.
The selection of wood veneer sewing machine should pay attention to the selection of sewing mechanism. There are two kinds of sewing mechanism.
One is to use special sewing glue thread, which is operated by feeding device and heating and supplying device. A continuous S-shaped track is formed at the joints of the thin wood (as shown in Fig. 5), and the thin wood is joined together. Because it is a point connection with discontinuous regular distances, it is easy to cause cracking and off-line defects in the process of moving and pressing the jointed thin wood. Moreover, the glue thread itself has a certain thickness. When hot-pressing, the thin wood with glue thread is extruded, which will produce the phenomenon that the density is greater than that of other places. In the dyeing stage of subsequent paint processing, the phenomenon of non-uniform absorption of dyes occurs. Sometimes, S-shaped trajectory of splicing can be clearly seen, which affects the decorative effect of products, as shown in figs. 6 and 7. This kind of sewing machine is called glue sewing machine, which is cheap.
Fig. 5 The S-shaped trajectory of the glue thread when the sewing process is completed
Fig. 6 The actual state of the glue thread when the sewing process is completed
Fig. 7 Density change of veneer caused by glue thread after hot pressing
Another mechanism is to use adhesive to coat the end of the thin wood, and to bond the edges of the two thin wood tightly together. The quality of the thin wood spliced by this mechanism is stable, and there will be no processing defects in the subsequent processing. This sewing machine is called automatic continuous longitudinal splicing machine (as shown in Figure 8), but its price is relatively high.
IV. Glue Coating Machine
The glue coating machine (as shown in Figure 9) is equipped to coat the glue evenly and continuously on the surface of planar workpiece. Generally, the two steel rollers rotate relative to each other. The glue is laid between the steel rollers. The gap between the steel rollers causes the glue film to form on the lower surface of the steel rollers. Then the glue film is transferred to the surface of the workpiece, which can be divided into one-sided glue coating and two-sided glue coating. Because of the uniform gap between the steel rollers and the controllable movement speed of the steel rollers, the rubber film can be formed uniformly and rapidly on the surface of the substrate. In the process of veneer veneer, the amount of veneer can also be controlled by gluing machine, so that the glue will not leak into the surface of veneer and affect the surface effect after finishing.
Figure 8 Automatic continuous longitudinal veneer sewing machine
Figure 9 Double-sided gluing machine
The following parameters should be paid attention to in the selection of glue coating machine:
One is single-sided and double-sided gluing. Double-sided glue coating has high efficiency and large output, and single-sided glue coating is uniform and stable.
The other is the form of cots. Generally, there are three forms of double steel rollers, rubber rollers and steel rollers combination, double rubber rollers. The double steel rollers gluing machine has an effect on the uniformity of gluing of sheets with certain thickness deviation. The combination of rubber rollers and steel rollers and double rubber rollers have certain elasticity, which can adapt to the thickness change within a certain range, and the uniformity of gluing is better. Cots can also be divided into smooth surface and grooved cots. The grooved cots can control the sizing amount accurately, but the cleaning and maintenance are much more complex and suitable for mass production.
Third, the maximum processing width and thickness. It has an effect on the coating of the thickened plate.
V. Hot Press
Hot press (as shown in Fig. 10) is used for hot-pressing overlay of thin wood and base material. Porous steel plate is generally used to heat the steel plate by introducing the electrically heated heat conducting oil into the steel plate through a pipeline. Workpieces are usually placed between two layers of steel plates. The steel plates and workpieces are pressurized by hydraulic devices. The heat can quickly solidify the glue through thin wood to form a beautiful overlay material.
Because the glue dries and solidifies quickly at high temperature, it takes a certain time to place all the small size workpieces in the press. Therefore, if both sides are pasted at the same time, the lower surface of the workpiece put into the press is heated by contact with the pressing plate of the press. When the last small size workpiece is placed, the small surface glue of the workpiece put in first has been heated for too long in the pressure-free state, and the glue has solidified or partially solidified. After this pressing, the workpiece put in first is easy to produce defects such as bubbling and delamination of veneer thin wood. Therefore, for small size workpiece, multi-layer press can only be used as a single-layer press, while large size workpiece (whole sheet) has little impact on the quality of pressing due to the speed of putting into the press.
Figure 10 Three-Layer Hot Press
It can be seen from the above that for the production line with small parts as the main specification, the single-layer press is the best choice for the hot press, and for the production line with large parts as the main specification, the multi-layer hot press is the best choice.
In addition, for small size workpieces, the glue machine can be used for one-sided glue coating, and then the workpiece is placed on a whole splint, pushed into the press together. In this way, both single-layer press and multi-layer press can be used, and the work piece can be placed synchronously with the press work, which effectively improves the work efficiency.
There are not many parameters to be paid attention to in the selection of hot press, such as pressure, temperature, plate specifications and so on.
- Automatic Linear Edge Sealer
The end face of sawing plate in panel furniture must be protected and beautified by edge sealing. Fully automatic linear edge sealing machine (as shown in Figure 11) is a device that seals solid wood, PVC and other edge sealing materials on the edge of the board. The equipment coats the melted hot melt adhesive on the end face of the workpiece, and then press the sealing material on the workpiece. The hot melt adhesive solidifies quickly to form adhesive force, and combines the sealing material with the workpiece. After that, the end face of the workpiece is protected beautifully by end cutting, trimming, scraping, polishing and sanding.
Fig. 11 Automatic Linear Edge Sealer
The selection of edge-sealing machine mainly depends on the shape characteristics of the workpiece to be processed, the types of edge-sealing materials, as well as productivity and quality.
The selection of edge sealing machine should pay attention to the following functions:
- Linear Edge Sealing
Linear edge-closing configuration mainly considers the characteristics of edge-closing, and carries out some functions of addition or subtraction. Glue coating, end cutting and rough trimming are generally used as basic configurations, while pre-milling cutter, scraping, polishing, tracking trimming and other functions are selected as independent parts. For example, scrapers should be installed on the sealing materials such as PVC or ABS; fine trimming knives and sanding devices should be added to the solid wood trimming strips; in order to ensure that the quality of edge sealing is not affected by the low temperature in winter, it is better to choose the edge-sealing machine equipped with far-infrared preheating device or laser preheating device and preheating the processing end surface; there are many other optional additional configurations, such as automatic tracking round corner trimming. Function, milling cutter device, etc.
The processing performance and quality of the edge sealing machine have a great influence on the beauty and quality of the workpiece. Advanced edge-sealing machines usually install pre-milling devices at the front end, and use a pair of relatively high-speed rotating milling cutters to milling the end face of the sheet, so that the end face forms a concave profile inward, making the edge of the edge-sealing material closely adhere to the sheet, and the gap between the edge-sealing material and the sheet is very small, making the sheet parts perfect.
Thicker edge-sealing materials (2-3mm) are generally used for door panels, countertops and other components. The edge-sealing machine is also required to have the function of tracking and trimming, so that the corner parts of the workpiece can be refined.
Ordinary linear edge-sealing machine can not further modify the ends of the sawn edge-sealing band (such as the ends of the duck-billed desktop edge-sealing strip) (as shown in Figure 12), and the tracking trimming device can modify such edges (as shown in Figure 13). It can be said that the ordinary linear edge-sealing machine can only trim the upper and lower edges of the edge-sealing strip. When the tracking edge-trimming device is added, the edge-sealing strip can be corrected all around (as shown in Figure 14). As we all know, when the quality of products is improved to a certain level, it is difficult for the whole batch of products to be handled consistently by hand. It is necessary to adopt the equipment to handle the edges and corners of the products very delicately, which also reflects the quality of the products. Therefore, the tracking trimming device provides a guarantee for improving the quality of products and the added value of products.
Fig. 12 End face of common edge sealing machine
Fig. 12 End face of common edge sealing machine
Figure 13 Tracking trimming component of edge sealing machine
The feeding speed is usually constant in the process of tracking trimming. The feeding speed of various models is different, but when the feeding speed changes, the effect of tracking trimming is poor, or the trimming can not be tracked.
For the 0.4-0.8mm thickness edge-sealing belt, the tracking trimming effect is not great. These edge-sealing belts are thin and can be treated with fine sand paper. The 2-3mm thickness edge-sealing belt has the best effect of tracking trimming. The tracking trimming device with the thickness of the edge-sealing belt greater than 3mm is powerless. The trimming knife of the tracking trimming device is generally circular R=3mm, which belongs to the standard configuration . The drilling position is rotated at high speed in reverse direction. The drilling row can freely adjust the working position and drilling depth, and can simultaneously process the hole position on one end face and front face. Commonly used are single-row, double-row, three-row, four-row and six-row drills. Generally, six-row drills can process two ends and one front simultaneously.
Fig. 14 Tracking the end face of trimming and edge sealing machine
For thicker material or workpiece edge sealing (thicker than 30mm), generally choose the upper rubber box. The reason why the upper rubber box is chosen is that when the lower rubber box is supplied to the upper rubber, it is easy to cause insufficient rubber supply to the super-thick material, which affects the sealing quality.
- Curve Edge Sealing
Curve edge sealing can be processed by several methods. At present, most manufacturers use manual edge sealing machine (as shown in Fig. 15) to process curved edge parts, especially plate parts with internal arc. The diameter of the wheel of edge sealing machine will determine the maximum curve depth that can be processed. The use of manual edge sealing machine has the characteristics of simple operation and low investment. However, due to the use of manual edge sealing, the quality is relatively low, mainly manifested in the lower bonding strength, poor repetition accuracy and high rework rate. At the same time, manual edge-sealing machine is relatively difficult to seal thick edges (2.0-3.0 mm), while thin edge-sealing strips (0.4-1.0 mm) used in some invisible parts can be processed straight and curved.
Fig. 16 Multi-row drilling machine a
Figure 17 Multi-row drilling machine B
Fig. 15 Curve Linear Edge Sealer (Manual Edge Sealer)
Fig. 16 Multi-row drilling machine a
Figure 17 Multi-row drilling machine B
Fig. 15 Curve Linear Edge Sealer (Manual Edge Sealer)
- CNC Machining Center or CNC Edge Sealer
In order to achieve a stable high quality level, curve edge-sealing machine needs to use CNC machining center or CNC edge-sealing machine. These two machines can show special advantages for some special curved surface edge-sealing. For example, the use of edge-sealing band length counter can make the circumferential edge docking clearance minimum, more suitable for manufacturing high-end furniture goods. The difference between the two is that the machining center can realize all the processes from plain plate sawing to final parts forming, while the special NC edge-sealing machine can only complete the edge-sealing and leveling processes. The disadvantage of using the machining center edge-sealing is that the total processing time of edge-sealing is large and the whole production efficiency is reduced.
- Multi-row and multi-axis drilling machine
Multi-row multi-spindle drilling machine (shown in Fig. 16 and Fig. 17) is a kind of equipment for processing holes such as joints of sheet metal workpieces. The equipment uses 32 mm drill seats adjacent to each drill bit, and each drill bit is arranged in 8 to 10 drill positions adjacent to each other.
Important parameters of multi-row drilling selection: maximum processing length, maximum processing width, maximum drilling depth, drill group positioning mode, drill bit form, etc. Here we need to elaborate on the positioning method of drill row and the form of quick bit joint.
One is the positioning method of drill row. The adjustment of drill group is generally through three ways: screw rod, linear gear rack guide rail and precise positioning guide rail. Screw rods are cheap and are generally used in low-end products. By adjusting the rotating screw rod (the adjusting speed is slower), no other positioning device is needed after the adjustment is in place, positioning accuracy is slightly worse by the blocking effect of the screw rod; the price of the linear gear rack guide rail is moderate, and it moves by the meshing between the rack and the gear after the rotation, the speed is relatively fast, and the pneumatic locking device is generally needed after the adjustment is in place; the precision positioning guide rail is generally locked by the pneumatic locking device. Connected with industrial computer (PLC), the data of locating points are input into the computer, which directly drives the drilling group to slide along the guide rail. Through the detection device on the drilling group, the magnetic points evenly distributed on the guide rail (the distance between magnetic points is 0.01-0.1 mm, the smaller the distance, the higher the positioning accuracy) are detected, and the detection results are converted into telecommunication signals and the industrial computer (PLC) for closed-circuit calculation. After reaching the locating point, the drilling group can automatically carry out pneumatic locking. The locating speed is fast, and the automatic locating can be realized. The cost is relatively high. It is generally used in advanced drilling row products.
The second is the form of quick joint of drill bit. The quick joint of drill bit is the main device connecting different specifications of drill bit and drill bit, mainly by the internal, external and screw type (as shown in Figure 18). The commonly used type is the inline type, and the screw type is gradually not used by drilling because of the slowest bonding speed (as shown in Figure 19).
To a certain extent, the positioning mode of drill row and the form of quick bit joints have an impact on the efficiency of drill row, especially on the processing efficiency of customized parts. Therefore, attention should be paid to the selection of row drilling.
Fig. 18 Common Quick Joints for Drill Bits
Fig. 19 Installation method of quick joint of drill bit
The third is the drill shaft. As a standard component, the drill shaft itself can not change the parameters. However, the overall angle adjustment of the drill shaft (as shown in Figure 20) has a great impact on drilling efficiency. For example, the side panels of cabinets usually have laminate holes, which are perpendicular to the direction of the main connecting holes at 90 degrees. If the drill shaft can not be adjusted, fractional processing is required. If the angle of the drill shaft is adjustable, the number of processing can be reduced and the production efficiency can be improved.
Fig. 20 Adjustment of Drilling Shaft of Row Drilling Machine
In a word, the selection of common equipment for panel furniture should be based on the data of product characteristics, process flow and output to obtain parameters. On this basis, the performance and parameters requirements of equipment are summarized. Only by selecting equipment according to requirements, can the specific needs of furniture production be more suitable, and better economic and social benefits be obtained.