What to do if the shelves and door panels of customized furniture deform! Quality control and inspection
As is well known, the main components that make up panel furniture include side panels, shelves, door panels, top or panel panels, and back panels. The main deformations of panel components include elastic bending, warping, creep, and so on.
Among them, warping and creep largely depend on the inherent quality of the substrate itself, while the elastic bending of components mainly depends on the management of the production process and the treatment of the process, in addition to the quality of the plate itself.
The elastic deformation under external forces is a relatively complex problem, taking the long doors of shelves and high cabinets as examples.
What to do if the shelves and door panels of customized furniture deform, and how to prevent doorways!
Bending deformation of shelf
- The force form of the shelf
① Compressive stress: refers to the stress formed by the pressure of the load-bearing object and the self weight of the shelf (the main cause of shelf deformation);
② Bending pressure: refers to the stress formed by the load-bearing bending distance, which can cause the shelf to bend and creep;
③ Shear stress: formed by the shear force generated by the pressure and support force at the interface of the load-bearing shelf support or connector;
④ Coating curing stress: The internal stress generated by the inconsistent shrinkage of the inner surface of the coating curing on the shelf surface, causing the shelf to bend and deform;
What to do if the shelves and door panels of customized furniture deform, and how to prevent doorways!
- Methods to reduce shelf bending
① Using substrates with higher elastic modulus:
Such as blockboard, veneered fiberboard, veneered particle board, etc;
② Increase the cross-sectional width and thickness of the shelf:
That is to say, wider and thicker materials are used. However, for fiberboard and particle board, being too thick not only increases the cost but also affects the appearance. Therefore, it is generally appropriate to use a thickness of 19mm in actual production. Thin metal strips or hardwood strips with reinforcing ribs can also be used to reinforce the edges of the shelf.
③ Reduce the span of the shelf:
One is to reduce the length of the shelf itself, and the other is to add a middle partition for support. Therefore, 1000mm shelves are rarely used in actual production. Except for special circumstances, 800-900mm shelves are generally used.
What to do if the shelves and door panels of customized furniture deform, and how to prevent doorways!
④ Connect the shelf to the backplane:
If conditions permit, the shelf can be fixed on the back panel or placed on the back panel. Nowadays, most furniture backboards are made of 3mm plywood and 3mm medium density fiberboard, which have low strength and are not suitable for drilling holes on them. However, long strip shelves can be fixed with glue or special shelf pins can be added, which can greatly reduce the bending degree of the shelves.
What to do if the shelves and door panels of customized furniture deform, and how to prevent doorways!
⑤ Using movable shelves:
For many panel furniture, shelves have a certain degree of bending deformation. For those with larger spans, even if there is no load, they will sag due to their own weight. If movable shelves are used, when bending deformation occurs, the shelves can be turned over and used. After a period of time, they will be restored to their original state due to external force and action from the phase board, But this is easy to accelerate creep.
⑥ Strengthen process management:
Many bending deformations are caused by human factors during the processing, such as improper placement, moisture absorption, and improper coating techniques. Therefore, strengthening production process management is also an important means to reduce bending deformation of plates.
What to do if the shelves and door panels of customized furniture deform, and how to prevent doorways!
Deformation of door panel components
The quality of cabinets directly affects the sales of the entire cabinet and wardrobe. According to incomplete statistics, the most unsatisfactory aspect for consumers regarding cabinets is the warping and deformation of cabinet doors. In fact, in addition to material and design reasons, the influence of unfavorable factors during the processing is the main reason for the bending and deformation of high cabinet long doors.
What to do if the shelves and door panels of customized furniture deform, and how to prevent doorways!
- Deformation caused by component stacking
In production, some operators stack the plates randomly for the sake of convenience, or the pads for stacking the plates are uneven. Some even lean the plates against the wall, causing the plates to deform due to their own weight before entering the next process.
What to do if the shelves and door panels of customized furniture deform, and how to prevent doorways!
- Deformation caused by coating process
① The effect of applying putty:
When painting cabinet door parts, many manufacturers use pig blood putty or glue putty to reduce costs. Because these two kinds of putty contain a lot of water, and the commonly used base materials of panel furniture – medium density fiberboard and particle board are particularly hygroscopic, when one side of the door panel parts is not coated with putty, and the other side is coated with such moisture rich putty, This will cause deformation of the door panel components due to moisture absorption on one side.
② The impact of the drying process:
Many manufacturers in production, when the panels are coated with putty or paint, they must be placed on a drying rack for natural drying. If the support rods of the drying rack are too sparse or uneven, it can also cause bending and deformation of cabinet door components during the coating drying process.
What to do if the shelves and door panels of customized furniture deform, and how to prevent doorways!
③ The influence of internal stress in coatings
After the coating solidifies, it will form a certain coating, and even without external forces, it will generate an internal stress. If this internal stress is not handled properly, it will become one of the main reasons for the bending and deformation of cabinet door components.
- Several methods to avoid deformation of cabinet door components
① Reasonable stacking:
From the moment the raw materials enter the workshop, they should be kept flat, dry, and avoid leaning against other objects as much as possible.
② Proper use of drying racks:
Reasonably arrange the density of the drying and drying support frame for the board, generally requiring its width to be only slightly shorter than the length of the board. It is best to use angle iron welding to form multi-layer iron frames with a spacing of about 300mm.
③ Reduce the impact of putty moisture:
Multi use resin based putty (also known as atomic gray) that is compatible with the coating. It contains almost no moisture, but active groups that are compatible with the coating, which can form a solid paint film together with the coating, thereby reducing the wetting effect of moisture on the substrate.
What to do if the shelves and door panels of customized furniture deform, and how to prevent doorways!
④ Reasonable selection of coatings:
Using coatings with low shrinkage stress is a good choice, such as unsaturated polyester, polyurethane, and UV cured coatings, which have relatively low shrinkage stress, which helps to reduce the impact of internal stress on the bending of board components.
⑤ Using different film materials:
Nowadays, many panel furniture decorations use thin wood or decorative paper. During processing, materials with lower shrinkage stress can be applied to the front and materials with higher shrinkage stress can be applied to the back. This way, even when the coating on the front is thicker and the coating on the back is thinner, a portion of the shrinkage stress can be offset.
What to do if the shelves and door panels of customized furniture deform, and how to prevent doorways!
⑥ Using rigid door dumplings:
Usually, after using one or more of the above methods, a certain effect can be achieved, and the remaining slight warping and deformation can be corrected through strong door dumpling, which basically does not affect the appearance of the product.
⑦ Hard material edging:
Using hard, dry and shaped miscellaneous wood or metal strips for edge sealing and edging can not only serve as decoration and embellishment, but also effectively correct the deformation of cabinet door components.
