Yes. Roofing sheets can be made without a ASA layer. There are lots of PVC roofing products, made without a ASA layer and made of second grade raw materials, are now available in the market. The appearance of these products is similar to ASA/PVC sheets. But due to the usage of inferior quality raw materials and the non-availability of ASA layer, these products do not last long.

Variety colors can be available. The color of the ASA material is customized.

First, using ASA particle and PVC material, through co-extrusion method, we can get what we want.

Second, there is a new method that is ASA film covered in the PVC sheets directly. In this way, the finished products will be more advantages such as uniform surface thickness and cost saving. Here is the method.

(1) Obtaining an ASA film;

(2) Fixing the ASA film on a coating rack device. Hot-pressing and adhering the ASA film to the surface of a PVC sheet extruded from an extrusion die by a double roll pressing technique to obtain a preform of the PVC sheet coated with the ASA film, wherein the temperature of the PVC sheet is 100-250 ℃;

(3) Pulling the preform of the PVC sheets coated with the ASA film to a setting machine and performing compression moulding.

With the fierce competition of the market, many factories consider the cost of the material, then using a lot of reclaimed materials in PVC. Due to their poor quality and unstable cleanliness, in the process of production, there are much material cannot plastify, hence the co-extrusion surface will be some scratches.

Synthetic resin tile peeling phenomenon, that is, the surface of a layer of different sizes of the "bubble", sometimes no, not on a point, this is mainly the main vacuum system out of the problem. The water in the substrate material, volatile matter has not been removed, in the co-extrusion layer composite, a large number of volatile matters evaporate upward, forming bubbles, resulting in the separation of the substrate and the co-extrusion layer, the product peeling. The solution is to check the vacuum system of the pump, valve, pipeline, etc.

Irregular stripes appeared in the production, it should be noticed as follow:

First, the melt rate flow of ASA is not good;

Second, the host motor current is too high. The electrical flow of the host machine is an important indicator of the host speed and the production speed, and its size is related to the plasticizing time and plasticizing effect of the substrate and the matching of the co-extrusion machine. When too big, it can also cause "decorative pattern tile" appear, technical personnel should rely on experience to undertake adjustment.

When ASA co-extrusion materials are used, the uniformity of the co-extrusion surface is a very important quality indicator. Generally, the thickness of the co-extrusion layer is about 0.1-0.15mm. The homogeneity of the co-extruded layer must not be uneven. The unevenness of the thickness can be observed by visual inspection. The overall color of the co-extrusion surface is different, and there is a "flower" feeling. At this time, it is necessary to check whether the heating part of the equipment, such as the heating part of the distributor and the heating part of the mold, is overheated or too low. Of course, don’t forget to buy products with reliable quality and high coverage when buying ASA co-extrusion.

There are two main reasons for the rough surface of co-extrusion resin tile:

First, drying time and temperature setting do not meet the process requirements;

The drying time and temperature should be set in accordance with the properties of the co-extrusion materials, especially the water absorption and volatility. ASA co-extrusion manufacturers will generally provide drying technical parameters, such as the ASA requirements of Chuangmei drying conditions is 95-98 ℃, 1.5-2 hours (hot air drying). If not, the co-extrusion surface will occur "bubble" and rough appearance.

Second, the vacuum system of the main engine of the bottom tile fails.

The water and volatile matter contained in the bottom tile ingredients will also "bubble" when forming when the vacuum failure of the main engine occurs, and the co-extrusion layer will become like the rain hitting the beach, which looks ugly.

(1)The distribution block is worn

The distribution block is used for a long time, resulting in wear and tear, which breaks the curve of the co-extrusion design runner, changes in pressure, and prevents the fluid from reaching the boundary.

(2)Hot wire of upper mold is broken

Die heating system aging, hot wire fracture, resulting in no heating, low temperature, slow heating.ASA co-extrusion cannot reach the ideal flow state and coverage is incomplete.

When producing ASA synthetic resin tile, sometimes white spots will appear on the surface irregularly and a long tail will be held up to form white scratches, which will affect the quality and reduce the yield of finished products.

(1)ASA resin should be good quality

(2)Drying temperature and time

Here is the Advice:

Temperature: 95-98℃

Time: 1.5-2 hours (hot wind)

When it is rainy season, or the material is stocked for a long time, the time should be 0.5 hour longer. If matte surface of ASA, 0.5hour more will be better.

For the baking drying equipment, according to the characteristics of the equipment, reduce the drying temperature, extend the baking time, otherwise it will cause local overheating and melting caking, it is best to have 1 or 2 times in the middle to avoid uneven heating.

(3)Unscientific temperature settingof extruder

Generally, there are six zones in the heating section of the co-extruder. Starting from the raw material entering the side, the temperature is set from low to high to ensure the heat required for ASA melting. Due to the various manufacturers of equipment, temperature measurement points, screw assembly and screw barrel wear are different, individual guidance to meet the production needs.
If any help, pls contact us.

(1) To choose good quality ASA resin

The melt flow performance of ASA is an important part.

(2) Temperature of each mold

Whether distributor temperature is normal, host current is stable; raw material is drying, etc. Ensure that the equipment is in good working condition, technical parameters in the normal range of ASA co-extrusion is used to produce uniform coated synthetic resin tile essential conditions.