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Process Flow Of Making Density Fiber Sheet In Environmental Protection
- Dec 26, 2017 -

       Medium Density Fiberboard is a very environmentally friendly material, our factory now produces MDF in line with the international environmental requirements. The Toroyal group will introduce the platemaking process flow sheet for you.

1. The first is to prepare the basic material

The production process of environmental MDF board preparation is the first step, we use the equipment mainly chipper, screening machine, belt conveyor, bucket elevator, storage silo etc.. MDF production of raw materials are mainly wood fiber raw material, which comprises a small wood, wood, fuelwood, processing residues, the ideal raw material for the preparation of softwood 60% ~ 70%, 30% ~ 40% hardwood bark content of not more than 5%.

2. second step is the preparation of fiber

The preparation of fiber is mainly fiber separation, which is the core of the production process of environmental MDF board. The equipment for separation and use of fiber includes a wooden silo (or a preheating material silo), a small hopper, a hot mill, a melting and application device for paraffin wax, and a sizing device. Then let's follow the steps of the fiber separation:

A: hot grinding. The qualified wood chips are transported into the wooden silo, and the wood chips are softened by steaming and then transported to the grinding chamber. The wood slices with high moisture content are squeezed out by the heat mill.

B: wax. Paraffin wax is heated and melted through steam coils, and the paraffin wax melts into the wood chips before entering the grinding chamber body through the pump pipeline. After paraffin separation, the paraffin wax distributes evenly on the fiber surface.

C: glue. The urea formaldehyde resin is injected into the double metering tank through the sensor and the glue delivery pump, then enters the pump to enter the discharge pipe, and the fiber is applied. The fiber in the discharge pipe is in a high-speed flow state, and the glue liquid is atomized and uniformly sprayed on the fiber surface. The glue can be mixed with curing agent, formaldehyde catcher and so on.


3.The third step is to dry the plate

The main equipment in the drying process of environmental MDF board production process consists of drying host, dry pipe and cyclone separator, fiber conveying device and dry fiber silo.  The wet pipe of the hot mill discharge pipe sucks into the drying pipeline, which is fully contacted with the hot air, and the fiber is suspended. It is transported by air in the air pipe. The fiber runs in the wind pipe for 4~5 seconds, and the moisture of the fiber is evaporated quickly, reaching the required moisture content (8% to 12%).

4, fourth step forming

Forming is a very important working procedure in the production of MDF, this process includes slab paving, preloading, trimming, cross section and other main part, the paving process requirements are: mat density is uniform and stable, the same thickness, weight per unit area of the slab continuous control is stable and consistent. Compactness.


5. Finally, the hot press for the plate

At present, the hot pressing process of high density fiberboard in China is a batch multi-layer hot pressing process, and various technological factors have an important influence on the performance of MDF.

A: hot pressing temperature. The selection of the hot pressing temperature is mainly based on the type and performance of the plate, the type of the adhesive and the production efficiency of the press. The selection of temperature depends mainly on the comprehensive factors such as raw material, tree species, moisture content of fiber, adhesive properties, slab thickness, heating time, pressure and equipment condition.

B: hot press pressure. The pressure change during hot pressing, pressing pressure gradually increased, reached the slab thickness, which should reduce the pressure, and the adhesive curing fibers formed between various binding force, water evaporation mainly at low pressure, the low pressure of the pressure is 0.6 ~ 1.3Mpa.

C: hot pressing time. The determination of hot pressing time is mainly related to the properties and curing time of the adhesive, the quality of fiber, the water content of the slab, the thickness, the temperature of hot press, and pressure. The hot pressing time is usually expressed in the time required by the thickness of the 1mm plate.

The water content of D: slab. In the hot pressing process, slab water effect is to increase the plasticity and thermal conductivity of the fiber, the suitable moisture content on the quality of plate is guaranteed, the general control in about 10%, if too high will increase the surface layer and core density gradient to core layer fiber bonding force, pressure steam, water it is difficult to get rid of steam, resulting in bubbling, stratification, if too low will make the surface soft, pre curing thick plate strength.

    If you are interested in our environmental protection medium density fiber sheet, please send inquiry to us.We are waiting for hearing from you , always~