When we need to buy a new screw, how to choose a good quality and suitable screw is the first consideration for everyone. There are a lot of screw suppliers on the market. If you want to choose a good quality and suitable screw, we have to work hard to find a few screw suppliers or screw manufacturers to compare.
Now the network is very good, you can use the power of the network to find the manufacturer of the screw, and the convenience of using the network is extremely easy when we are looking for, so we can pass the network beforehand to buy. To understand the relevant situation of the screw, it will play a more important role in the purchase, can not be ignored.
We know that the specifications of the screw are different. Different plastic processing requirements have different requirements for the type of the screw. Generally, there are several types: mutant type, equal-depth unequal-distance gradient type, and equidistant unequal gradient type. Torpedo head type and so on. So when you make a purchase, you can first understand what kind of screw you need. So many models should be noted when choosing. Don't ignore this problem, so that the products you buy are not suitable. Whether it is exchange and return, it is extremely inconvenient, it is best to understand before buying.
So what kind of screw should I choose? Mainly from two major points: First, the production specifications of injection molding machines; Second, the physical properties of plastics.
1. The temperature range of softening the amorphous polymer is relatively wide, so the equidistant gradient screw is generally used in the production; on the contrary, the temperature range of the molten crystalline polymer is relatively loaded, so an equidistant abrupt screw is used;
2. The extrusion speed of small injection molding machine is relatively fast. It is generally used to extrude small-section sheath layer and insulation layer. The length of the selected screw is relatively short. In actual production, the full-thread type φ45 extrusion with equal distance is not equal. Plastic machine screw;
3. The ideal screw for the production of jacket and insulation for small and medium-sized injection molding machines is a full-thread type with equidistant and thread-depth gradient. The length of the screw is larger than that of the small screw, and the thread is shallow to deep from the root. And the pitch is equal. The advantage of using such a screw is that because of the thread characteristics, the plastic extrusion amount is large without affecting the screw strength, the extrusion speed is fast, and the plastic plasticization is good;
For large injection molding machines such as φ150, φ200, and φ250, large screws with a diameter of 150 mm or more are generally selected. The large screw is divided into two types, one is like φ150, φ200 extruder, which is equally unequal; the other is like φ250 extruder, which is divided into three sections (equal isometric, equidistant unequal , such that the screw compression ratio is between 2 and 3, which is mainly used to produce large-section wire and cable insulation layer and sheath layer, and the aspect ratio is about 15.
Determine the screw specifications you want, and the rest is to find the right screw manufacturer or supplier. The quality of the screw products produced by each manufacturer is different, so we need to consider in many aspects, such as: how the market reputation of this manufacturer, the size of the manufacturer and the attitude of after-sales service. The quality of the screw is relatively more expensive.