Wood-plastic profiles are mainly processed from wood as the base material, thermoplastic polymer materials (plastics) and additives. After the thermoplastic polymer material is mixed evenly, it can be extruded on the surface of the profile by the mold equipment to make a high-tech wood-plastic profile. It has both the properties and characteristics of wood and plastic, and is a new type of composite material that can replace wood and plastic. During the use of the current mold, the thermoplastic polymer material will have uneven shunting after entering the mold cavity, resulting in a rough surface formed by the thermoplastic polymer material on the wood, and the poor water cooling effect will cause the formed surface to deform. . An enterprise proposes a wpc profile extrusion line for wood-plastic co-extrusion profiles and a production process thereof, which solves the problem that the surface of the plastic layer of the wood-plastic profiles is rough during production in the prior art.
Its principle and effect are as follows:
1. When the co-extrusion die in the present invention is used to produce wood-plastic co-extrusion profiles, the core body is firstly transferred to the feed port, feed cavity and extruder connected to the feed cavity through the core conveying device. out of the cavity. At the same time, the plastic supply device sequentially feeds the thermoplastic polymer material into the extrusion cavity through the channel and the gap communicating with the extrusion cavity, and the thermoplastic polymer material will cover the surface of the core body to form a plastic layer. When the thermoplastic polymer material enters the extrusion cavity through the channel and the gap, the gap can make the thermoplastic polymer material more uniform when entering the extrusion cavity in the plastic profile extruder, ensuring that the thermoplastic polymer material flows into the extrusion cavity uniformly and synchronously. The thermoplastic polymer material forms a fine and smooth plastic layer on the surface of the core, which solves the problem of the rough surface of the plastic layer of the wood-plastic co-extrusion profile.
2. The co-extrusion die is divided into three parts. The upper die, the lower die and the end die are connected together by bolts to form a co-extrusion die. The end die is provided with a feed cavity and a plastic flow channel, an extrusion cavity is formed between the upper die and the lower die, and the core body enters the extrusion cavity through the feed cavity. The thermoplastic polymer material enters the extrusion cavity through the plastic flow channel, and the thermoplastic polymer material is wrapped on the surface layer of the core body in the extrusion cavity to form a plastic layer.
3. The feeding cavity is surrounded by an annular edge, the outer wall of the annular edge is inclined, and the end away from the feeding port is inclined inward, so that the thermoplastic polymer material can flow into the extrusion cavity through the annular gap in all directions and evenly. , and cover the surface of the core to form a plastic layer.
4. The channel includes a plastic inlet channel arranged on the end mold for conveying plastic, and the plastic inlet channel is connected with the plastic supply device. The plastic inlet channel is connected with the extrusion cavity through the split channel and the gap in turn. The shunt flow channel will distribute the thermoplastic polymer material into the plastic flow channel evenly, so that the thermoplastic polymer material can flow into the extrusion cavity evenly through the surrounding gap, and the surface of the core in the extrusion cavity The formation of a uniform and smooth plastic layer can make the air tightness and waterproofness of the wood-plastic co-extruded profile better. The shunt runner is arranged on the side of the cavity mold in contact with the end die and surrounds the periphery of the extrusion cavity. The plastic inlet runner passes through the shunt main channel, several shunt branches, overflow channels, gaps and extrusion molds in turn. The cavity is connected, so the material can be supplied to the extrusion cavity from all directions, avoiding the situation that the plastic layer is not smooth or cannot completely cover the core body due to uneven feeding, so that a uniform surface can be formed on the surface of the core body. plastic layer.
5. The plastic layer is a thermoplastic polymer material, which is formed on the surface of the core at high temperature, so it needs to be cooled after the plastic layer is formed. In the prior art, most of the profiles are air-cooled or water-cooled after the profiles are transported out of the mold, and water-cooled after the profiles are transported out of the molds. At this time, the temperature of the plastic layer is still high, it is easy to deform, and the cooling effect is poor. Therefore, deformation or pitting may be formed on the surface during the conveying process, which affects the quality of the profile. In the present invention, a water-cooling channel is arranged on the co-extrusion die, and the water-cooling channel includes a plurality of upper channels and lower channels that are connected with each other, so the cooling area is larger, and the upper channel and the lower channel are respectively arranged on the upper and lower sides of the extrusion cavity, Therefore, it can have a good cooling effect on the profiles in the extrusion cavity, and the plastic layer will not be deformed or pitted, so that the plastic layer can form a smooth surface layer on the surface of the core body.
One end of the lower channel closest to the contact surface is connected with the water inlet pipe, the upper channel away from the contact surface is connected with the water outlet pipe, and the two ends of the remaining upper channels and lower channels are respectively connected through the first connecting pipe, so that several upper channels and several lower channels are connected. The channels can be connected, and the water inlet pipe and the water outlet pipe are connected to the water storage tank, so the water can circulate between the water storage tank and the water cooling channel, which has a good cooling effect on the wood-plastic co-extrusion profile. The plastic inlet flow channel is connected with a plastic supply device, and the plastic supply device can provide thermoplastic polymer material for the production process of the wood-plastic co-extrusion profile, so as to form a plastic layer on the surface of the core body.
6. The core body is transported into the jwell machinery extrusion cavity connected with the feed port through the core body conveying device. After starting the driving motor, the two roller conveyor belts will start to drive at the same time, thereby driving the core body in the core body conveying channel to the Feed port movement.
7. After the surface of the core body is coated with plastic layer to form a wood-plastic co-extrusion profile, after preliminary cooling through the water cooling channel, the co-extrusion extrusion cavity will be further cooled and shaped through the water cooling tank. The spraying device on one side of the water-cooling tank will spray the wood-plastic co-extrusion profiles in the water-cooling tank to realize the cooling and shaping of the wood-plastic co-extrusion profiles, and ensure that the plastic layer covered on the core body is smooth and uniform, without deformation or deformation. Pockmarks appear.
8. After the core body is transported into the extrusion cavity, the plastic is simultaneously transported into the extrusion cavity to cover the surface of the core body, and a plastic layer is formed on the surface of the core body. After the plastic layer, first pass cooling water into the water cooling channel to preliminarily cool the wood-plastic co-extrusion profile. The spray pipe is sprayed for further cooling and shaping to ensure that the plastic layer is uniform and the surface is smooth.