CN102189572B - Manufacturing method for mould forming of environment-friendly middle-density board - Google Patents

Abstract

The invention relates to a manufacturing method for the mould forming of a middle-density board. The manufacturing method is characterized by comprising the following processing steps of: selecting a middle-density board which takes softwood as a raw material; preparing a softener; softening a mould pressing board; forming the mould pressing board; and putting the pressure-released and formed mould pressing board in a postprocessing chamber for constant temperature and humidity processing. The manufacturing method has the advantages that: the utilization rate of the material can be increased; and the effect identical to that of the three-dimensional contouring of solid woods can be realized just by covering a layer of veneer on the mould pressing board without the need of cutting wood. According to the manufacturing method disclosed by the invention, waste water and exhaust gas are not produced and the large-scale and sustainable-development mould forming requirements are realized. The mechanical strength of a wooden door made of the mould pressing board is far stronger than that of a wooden mould pressing board processed by ammonia water and is not lower than that of the wooden door in unit weight, but the weight of the wooden door is far lighter than that of a solid wood door. The manufacturing method has identical advantages when used for producing fruit trays. The manufacturing method has the advantages of simpleness, remarkably effect, easiness in operation, environment-friendliness and convenience for popularization and application.

Description

Manufacturing method of MDF compression molding

technical field

The invention relates to a medium density board (MDF) molding manufacturing method, which belongs to the technical field of wood product manufacturing. the

Background technique

With the increasing awareness of environmental protection, the supply of wood is far from meeting the needs of people's lives. Therefore, the use of MDF molded wooden doors to replace solid wood wooden doors and other products has become more and more popular and welcomed by more and more consumers. At present, the manufacturing process of MDF compression molding is to soak in ammonia water and then use metal molds to heat it to form it. The ammonia water softening process and hot pressing process produce a large amount of waste water and waste gas, which pollutes the surrounding environment. The ammonia water softening process and its molding manufacturing technology are really restricted. the

Contents of the invention

The present invention proposes a manufacturing method of MDF compression molding, which aims to fully replace ammonia water softening and its molding process through a new softening method and a new molding process, overcome defects such as cracking in the molding process, and realize the production of MDF molded products in large quantities. The purpose of not polluting the environment during the production process. the

The technical solution of the present invention: it is characterized in that the method includes the following process steps: 1) select medium density board, select the medium density board of coniferous material as raw material, the thickness is 3mm, its specification is cut according to needs, and the width of a door 900mm×2100mm;

2) Prepare softener, prepare 20%-30% alcohol solution, use 30 liters of industrial grade alcohol, add 70 liters of water, mix for later use;

3) Use a roller or a brush dipped in softener and then evenly roll it once on the part of the molded plate that needs to be molded. When there is no clear water on the surface, apply it again on the opposite symmetrical part. Repeat the above actions to roll the front and back sides, and after finishing the second coat, set aside;

4) It is divided into one-time molding or one-time veneer molding. One-time molding is to heat the hot press that fixes the metal mold to 230°C, put the spare molded slab into the metal mold, and the closing speed is 2cm/min. The pressure is 2-3Kg/cm ² , and the holding time is 2-3 minutes. After the pressure is released, the molded molded plate is demoulded; the one-time veneer molding is to cut the veneer in advance according to the shape and size of the molded position. And use hot-melt glue to sew it into a whole. At this time, the veneer mosaic pattern must meet the design requirements of the wooden door. After the spare molded slab is coated with white latex on one side, it is combined with the sewn veneer, and the metal mold is fixed. Heat the hot press to 230°C, then put the spare molded slab into the metal mold, the closing speed is 2cm/min, the pressure is 2-3Kg/cm ² , and the holding time is 2-3 minutes , after the pressure is released, the molded molded plate is demoulded.

5) Put the molded plate that has been depressurized and formed into the post-processing room, and undergo constant temperature and humidity treatment. The specific parameters are temperature 30-40 ℃, humidity 70-80%, and treatment for 5-6 hours. (This step is optional and is intended to further improve product quality). the

The invention has the advantages of realizing the protection of the environment during the production process, improving the mechanical strength of the medium-density board molding, and improving the utilization rate of materials. Adding the synchronous veneer sticking action can reduce the consumption of logs, because the original three-dimensional wooden door needs to be planed or milled a certain amount of wood to realize the shape, but the present invention does not need to cut wood, only needs to be molded on the formed board Then a layer of veneer can be applied to achieve the same effect as the solid wood three-dimensional door. Environmentally friendly softening method, that is, no waste water and waste gas are produced, thereby realizing the sustainable development of compression molding, especially suitable for large-scale production. The mechanical strength of the wooden door made of environmentally friendly MDF molded is much higher than that of the ammonia softened MDF molded wooden door, not lower than the strength of the solid wood wooden door of the same unit weight, but its weight is far lighter than the weight of the solid wood wooden door. If it is used in the production of fruit tray, it also has the same advantages. The method is simple, has obvious effect, is easy to operate, protects the environment, and is convenient for popularization and application and large-scale production. the

Detailed ways

Embodiment 1, one-time compression molding:

Process flow: (1) Choose MDF, choose MDF made of coniferous wood, the thickness is 3mm, and its specifications are cut according to needs, such as a door width, 900mm×2100mm. (2) Prepare a softener, that is, use 30 liters of industrial grade alcohol, add 70 liters of water, mix and set aside. (3) Use a roller (the model is medium hair length) to dip in softener and then apply it evenly on the part of the molded plate that needs to be molded. After clearing the water, repeat the above action to roll the front and back sides. After completing the second coat of brushing, set aside. (4) Heat the hot press that fixes the metal mold (the mold is a male and female mold) to 230°C, put the spare molded slab into the metal mold, the closing speed is 2cm/min, and the pressure is 2-3Kg/ ^cm2 , The pressure holding time is 2-3 minutes, after the pressure is released, the molded molded plate is demoulded. (5) Put the molded plate that has been depressurized and formed into the post-processing room, and undergo constant temperature and humidity treatment (the specific treatment process varies according to the equilibrium moisture content of the wood in the place where this product is used, and this step is an option. used when further improving product quality).

Embodiment 2, one-time veneer compression molding:

Process flow: (1) Choose MDF, choose coniferous MDF boards as raw materials, the thickness is 3mm, and its specifications are cut according to needs, such as a door width, 900mm×2100mm; (2) Prepare softener, that is, use industrial grade 30 liters of alcohol, mixed with 70 liters of water, mixed for later use; (3) Use a roller (model of medium hair length) dipped in softener and then roll it evenly on the part of the molded plate that needs to be molded, and the surface will be obscured after coating When the water is wet, apply it again on the symmetrical part of the reverse side. After there is no clear water, repeat the above action to roll the front and back sides. The glue line is sewn into a whole. At this time, the veneer mosaic pattern is designed according to the shape of the wooden door. After the spare molded slab is coated with white latex on one side, it is assembled with the sewn veneer, and the fixed metal mold (the mold is (yin and yang mould) heat the hot press to 230°C, put the spare molded slab into the metal mold, the closing speed is 2cm/min, the pressure is 2-3Kg/cm ² , and the holding time is 2 -3 minutes, after the pressure is released, the molded plate is demoulded; (5) Put the molded plate that has been pressure-released into the post-processing room, and undergo constant temperature and humidity treatment (the specific treatment process depends on the location where the product is used) Equilibrium moisture content of wood varies and this step is an optional step to further improve product quality).

The method produces no waste water and waste gas, and is suitable for large-scale production;

Ammonia water softening will produce waste water and waste gas, and the amount of waste water is relatively large. If the waste water is treated, the initial investment is high and the maintenance cost is relatively high.

Cycle: This method adopts the brushing method, and the time is about 10 minutes. the

Softening with ammonia water is generally a method of soaking, and the time is about 4 hours or longer. the

Strength: This method does not destroy the original structure of MDF, so the strength of MDF is maintained. the

Ammonia treatment will destroy the MDF structure, and then heat glued together again, so its strength is much less than this method. After the MDF is soaked for a long time, its structure will become soft and the board will lose its strength. the

Mechanism: This method utilizes the characteristics of strong polarity and permeability of alcohol. The polarity of ammonia water is not as good as that of alcohol, and ammonia water is very volatile at room temperature, thus losing the softening effect, so it needs to be soaked for a long time, so that the water and the ammonia water remaining in the board can jointly play a softening role. MDF is a board made of wood fibers glued together by a small amount of adhesive. At the same time, lignin is also glued. The amount is too small (the normal board sizing amount does not exceed 6%), so the strength of the board drops sharply. the

Claims (1)

1. the manufacture method of medium-density plate die forming is characterized in that this method comprises following processing step: 1) select medium-density plate, choose the medium-density plate that softwood is raw material, thickness is 3mm, cuts out according to Yishanmen breadth 900mm * 2100mm and cuts medium-density plate;

2) the preparation softening agent with 30 liters of technical grade alcohol, is mixed 70 literss of water, mixing for standby use again;

3) adopt cylinder or select for use hairbrush to dip in softening agent needs die forming then at moulded board position, evenly roller coating is one time, when waiting to be coated with the no open fire in surface, be coated with again one time at the reverse side antimere again, wait not have open fire after, repeat the roller coating of above-mentioned action positive and negative, after finishing two times brushings, standby;

4) divide once die stamping forming or a veneer die forming, once die stamping forming is that the hot press with the fixing metal mould is heated to 230 ℃, and standby mold pressing slab is put among the metal die, and closing speed is 2cm/min, and pressure is 2-3Kg/cm ², the dwell time is 2-3 minute, after the release with the moulded board demoulding of die forming; A veneer die forming is to need shape and size to cut in advance according to the mold pressing position wooden dermatome, and becomes whole with the PUR linear slit, and this moment, wooden skin parquets pattern need meet timber shape-designing needs; With standby mold pressing slab, after single face is coated with white glue with vinyl, again with make wooden skin assembly, hot press with the fixing metal mould is heated to 230 ℃ simultaneously, the mold pressing slab behind the standby assembly is put among the metal die, closing speed is 2cm/min again, and pressure is 2-3Kg/cm ², the dwell time is 2-3 minute, after the release with the moulded board demoulding of die forming;

5) moulded board that release is shaped is put in the post-processed chamber, handles through constant temperature and humidity, and concrete parameter is that temperature is 30-40 ℃, and humidity is 70-80%, handles 5-6 hour.