PVC advertisement board machine PVC advertisement board can be on the surface printing, membrane tentoria, printing, spraying, still can like wood saw, drill, hammer, plane, welding, viscosity and heat molding good processing properties, are widely used in advertising sculpture, advertising...Send InquiryChat Now
PVC advertisement board can be on the surface printing, membrane tentoria, printing, spraying, still can like wood saw, drill, hammer, plane, welding, viscosity and heat molding good processing properties, are widely used in advertising sculpture, advertising photo, light box advertising, guidepost exhibition board, building decoration, outer wall flip chart, the room partition, hutch ark bath ark, plane, car decoration, chemical corrosion resistance, cold storage heat preservation and so on.
SJSZ80/156 Conical Twin-screw extruder-- Mould-- Calibrating Platform--Cooling Bracket--Haul Off unit--Cutting Unit--Automatic Stacker PVC advertisement board machine include the special Twin-screw extruder, mould and other auxiliary machines. We supply you the best material formulation and all of technology. It is with big output, stable extrusion, high foaming, good and wear-resisting surface and so on.
According to the production process, PVC foam board can be divided into PVC co-extruded foam board, PVC crust foam board and PVC free foam board.
PVC co-extruded foam board has a very high surface hardness, is difficult to produce scratches, has a smooth surface, and has a certain mirror effect. It is widely used in decoration, construction, etc.
PVC crust foam board has medium hardness and is difficult to produce scratches. It is widely used in cabinets, decoration, etc.
PVC free foaming board has a general surface hardness and is widely used in advertising panels, enamel boards, silk screens, sculptures, etc.
First, the foaming mechanism:
In the PVC foamed product, the purpose of adding ultra-high molecular weight polymer is as follows: one is to promote the plasticization of PVC; the other is to improve the melt strength of the PVC foaming material and prevent the combination of bubbles to obtain a uniformly foamed product. The third is to ensure that the melt has good fluidity to obtain a product with good appearance. Due to the different products of different foamed product manufacturers, the equipment, process, raw materials and lubrication system used are different. Therefore, we have developed foaming regulators with different properties to meet the different needs of users.
1. Definition of foaming material
Foamed plastic is also called foam plastic. It is based on plastic and contains a lot of bubbles. It can be said that it is a gas-filled composite.
2. Classification of foamed sheets
According to the different expansion ratio, it can be divided into high foaming and low foaming. According to the softness and hardness of the foam texture, it can be divided into hard, semi-rigid and flexible foam. According to the cell structure, it can be divided into closed cell foam and open cell foam. The commonly used PVC foam sheet is a hard closed-cell low foam sheet.
3.Application of PVC foam sheet
PVC foam sheets have the advantages of chemical resistance, weather resistance, flame retardancy, etc., and are widely used in many aspects, including display panels, markings, billboards, partitions, building boards, and furniture sheets.
4. Key factors in evaluating the quality of foamed sheets
For foamed materials, the size and uniformity of the cells is a key factor affecting the quality of the sheet. For the low-expansion foam sheet, the cells are small and uniform, and the foamed sheet has good toughness, high strength and good surface quality. From the viewpoint of reducing the density of the foamed sheet, only the cell is small and uniform, and there is a possibility that the density is further lowered. It is difficult to further reduce the density when the bubble is large and scattered.
5. Key points of PVC foaming process control
Plastic foam molding is divided into three processes: the formation of a bubble core, the expansion of a bubble core, and the solidification of a bubble. For a PVC foamed sheet to which a chemical foaming agent is added, the expansion of the bubble core plays a decisive influence on the quality of the foamed sheet. PVC is a linear molecule with a short molecular chain and low melt strength. In the process of bubble nuclei expanding into bubbles, the melt is not enough to cover the bubbles, and the gas easily overflows into large bubbles, reducing the product quality of the foamed sheet. .
A key factor in improving the quality of PVC foamed sheets is to increase the melt strength of PVC. There are many ways to improve the melt strength of PVC from the analysis of processing characteristics of polymer materials, but the most effective way is to add additives to improve the melt strength and reduce the processing temperature. PVC is an amorphous material, and the melt strength decreases as the melt temperature increases. Conversely, the melt strength decreases as the melt temperature decreases, but the effect of cooling is limited to only play a supporting role. ACR-type processing agents all have the effect of increasing the melt strength, and the foaming regulator is most effective. The melt strength increases as the foaming regulator content increases. In general, as long as the screw has sufficient dispersing ability, the addition of a high viscosity foaming regulator is more effective in increasing the melt strength.
6. The role of processing aids in PVC foam sheets
ACR processing aids promote the melting of PVC, improve the surface finish, improve the elasticity of the melt, and enhance the elongation and strength of the melt. It is good for covering air bubbles and preventing the cells from collapsing. The molecular weight and amount of the foaming regulator have a great influence on the density of the foamed sheet: as the molecular weight increases, the PVC melt strength increases, the density of the foamed sheet can be made lower, and the amount of the adjusting agent is increased. Have the same effect. However, this effect does not have a linear relationship. Continue to increase the molecular weight or increase the amount, the effect on reducing the density is not very obvious, and the density will tend to be constant.
There is an important relationship between the foaming regulator and the foaming agent. The density of the foamed sheet and the foaming regulator have a balance point. Outside this equilibrium point, the density of the foamed sheet is not affected by the foaming agent content. Maintaining a constant, that is, increasing the amount of blowing agent does not reduce the density. This is caused by the fact that the melt strength of PVC is limited with a certain amount of foaming regulator, and excess gas causes the cell to collapse or merge.
1.It is very simple and convenient to operate;
2.The production machine has high production efficiency;
3.Good operating system;
4.Work does not produce a lot of noise;
Advertising materials can be divided into advertising plates, advertising light boxes, advertising stickers, advertising accessories, inkjet consumables, photo consumables, reflective consumables, display equipment. Photoelectric products. machine accessories. Advertising hardware. Advertising tools. Advertising paint. Advertising adhesives and other types.