Foam Plate Making Machine For Thermocol Paper Plate Making Machine PVC Free Foam Sheet Production

In PVC foamed products, the purpose of adding ultra-high molecular weight polymer: one is to promote the plasticization of PVC;Second, in order to improve the melt strength of PVC foaming materials, prevent the combination of bubbles, to obtain uniform foaming products;The third is to ensure that the melt has a good liquidity, in order to get a good appearance of the products.Due to different foaming products manufacturers of different products, the use of equipment, process, raw materials and lubrication system are different, so we developed a foaming regulator with different performance, to meet the different needs of users.

1. Definition of foaming materials

Foamed plastic is also called foam plastic, plastic as the basic component, contains a lot of bubbles, can be said to be filled with gas composite materials.

2. Classification of foamed sheets

According to different foaming rate, it can be divided into high foaming and low foaming, according to the soft and hard degree of foam body, it can be divided into hard, semi-hard, soft foam plastics.According to the structure of foam, it can be divided into closed-cell foam and open-cell foam.Generally common PVC foamed sheet belongs to the rigid closed-cell low foaming sheet.

3. Application of PVC foamed sheet

PVC foamed sheet has the advantages of chemical corrosion resistance, weather resistance, flame retardant and so on. It is widely used in many aspects, including display panel, mark, billboard, clapboard, building board, furniture board and so on.

4. Key factors to evaluate the quality of foamed sheet

The size and uniformity of foams are the key factors affecting the quality of foams.For low-power foamed sheet, the foam hole is small and uniform, the foamed sheet has good toughness, high strength and good surface quality.In terms of reducing the density of foamed sheet, only small and uniform foam holes have the possibility of further reducing the density, while large foam is difficult to further reduce the density.

5. Key points of PVC foaming process control

Plastic foam molding is divided into three processes: formation of bubble core, expansion of bubble core and solidification of bubble body.For PVC foamed sheet with chemical foaming agent, the expansion of bubble core has a decisive effect on the quality of foamed sheet.PVC belongs to the straight chain molecule, the molecular chain is short, the melt strength is low, in the bubble core expansion into the bubble process, the melt is not enough to cover the bubble, the gas is easy to overflow into the bubble, reduce the quality of foamed sheet products.

The key factor to improve the quality of PVC foamed sheet is to improve the melt strength of PVC.From the analysis of the processing characteristics of polymer materials, there are many ways to improve the melt strength of PVC, 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 with the increase of melt temperature. On the contrary, the melt strength increases with the decrease of melt temperature, but the cooling effect is limited and only plays an auxiliary role.ACR processing agents have the effect of improving melt strength, among which foaming regulators have the most effect.The melt strength increases with the increase of foaming regulator content.Generally speaking, as long as the screw has enough dispersing and mixing ability, adding high viscosity foaming regulator has more obvious effect on improving melt strength.

Machine list & Quotation (USD)