Problems of Dimensional Precision
For the custom-made hinged doors in the factory, the dimensions of the door frames and window openings should meet the requirements. If the dimensions of the door frames and door panels do not conform to the design requirements, it will lead to difficulties in installation or poor sealing. For example, if the width or height dimension deviation of the door frame is too large, the door panel cannot be properly inserted; or if the thickness of the door panel is not uniform, it will affect the fitting with the door frame. For the produced doors and windows, they should be calibrated by equipment. The processing equipment such as sawing machines, milling machines, and planing machines should be calibrated for precision regularly. Professional measuring tools such as calipers and micrometers should be used to check the wear of the equipment cutters and replace the severely worn cutters in a timely manner. For example, after the saw blade has been used for a long time, the wear of the cutting edge will lead to dimensional deviation in cutting, and generally, the saw blade needs to be replaced after cutting a certain amount of materials. The calibration of equipment is very important. Process optimization should be carried out by formulating detailed processing operation procedures and clarifying the dimensional tolerance range of each process. For example, after the door panel is cut, an additional fine grinding process can be added to control the dimensional precision within a smaller range. For wooden materials, a sanding machine can be used for surface fine grinding to control the thickness tolerance within ±0.3mm. Strengthen quality inspection by setting multiple quality inspection points on the production line and conducting random dimensional inspections on semi-finished and finished products. Automated dimensional detection equipment such as laser rangefinders can be used to quickly and accurately measure the dimensions of the door frames and door panels. Once products with dimensional deviations are found, they should be reworked or scrapped in a timely manner.
Problems of Material Deformation
Another technical problem faced by the factory is that wooden materials may show bending and warping phenomena during processing or use. This may be caused by changes in the moisture content of the wood and uneven drying. For metal materials, for example, local deformation may occur in the aluminum alloy door frame after processing, which may be caused by uneven stress during the processing process or the release of internal stress of the material itself. Then, the following measures can be taken to solve the problems related to wood materials. Wood treatment: Pretreat the wood to control its moisture content. During the wood drying process, adopt scientific drying methods such as kiln drying. When kiln drying, appropriate drying temperatures, humidities, and times should be set according to the type and thickness of the wood. For example, for oak with a thickness of 40mm, the drying temperature can be set between 40 – 60°C, the relative humidity can be controlled between 30% – 50%, and the drying time is about 1 – 2 weeks, so that the moisture content of the wood reaches the appropriate range of 12% – 18%. At the same time, during the processing and storage processes, the relative humidity of the environment should be kept stable to avoid the deformation of the wood due to moisture absorption or loss. Then, in terms of the processing of materials by personnel, more personnel can be arranged for production and inspection to break down the problems. For example, strict screening should be carried out when collecting wood materials, and strict control should be exercised from the very beginning to avoid more problems when processing the wood later. And when processing the wood, a corresponding inspection mechanism should be set up to reduce the problems encountered in making doors and windows and make the production process more perfect and improve the production efficiency.
Stress Relief of Metal Materials
For metal materials, they should be processed according to relevant processing standards. After processing, stress relief annealing treatment should be carried . For aluminum alloy materials, the annealing temperature is generally around 300 – 400°C, and the time is 1 – 3 hours. Through this way, the internal stress generated during the processing process can be eliminated, and the possibility of deformation can be reduced. During the processing process, appropriate clamping methods should be adopted to ensure that the material is stressed evenly. For example, multi-point positioning fixtures can be used to prevent the material from deforming due to excessive local stress during processing.
Problems of Connection Firmness
Regarding the firm connection of doors and windows, the door frame and door panel should be processed to fit tightly to prevent loosening during future use. The connection parts between the door frame and door panel (such as the hinge area) may become loose, or the mortise and tenon jointed wooden structure may have the phenomenon of tenon opening. This will affect the normal use of the hinged door and reduce its structural strength. If it is about the door frame and door panel, the following measures can be taken to solve the problem of connection firmness. Selection and installation of connectors: For connectors such as hinges, quality-qualified and appropriately-sized products should be selected. The size and material of the hinges should be selected according to the weight and size of the door. For example, for heavier solid wood hinged doors, stainless steel hinges with a thickness of 3 – 5mm should be selected as they have stronger bearing capacity. When installing the hinges, ensure that the tightening torque of the screws is appropriate. Generally, a torque wrench is used for operation to control the tightening torque within the specified range. At the same time, holes can be pre-drilled at the screw holes and filled with materials such as bakelite to increase the gripping force of the screws.
Problems of Surface Treatment Quality
Regarding the surface treatment quality problems of hinged doors, phenomena such as peeling, blistering, or uneven color of the paint and coating on the surface of the hinged door may occur. This not only affects the appearance of the door but also may reduce the durability of the door. The following measures can be taken to solve the problems related to surface treatment. Surface pretreatment: Before carrying out surface treatment, ensure that the surface of the door is flat and clean. For wooden surfaces, sanding should be carried out to remove burrs and dust. The grit of the sandpaper can start from 80 grit and gradually increase to around 240 grit to make the surface smooth. For metal surfaces, rust removal and degreasing treatments should be carried out, which can be done by chemical pickling or mechanical grinding. Selection and application of coatings: Select coatings of good quality and suitable for the door materials. For example, for outdoor hinged doors, acrylic coatings or fluorocarbon coatings with good weather resistance should be selected.
