PVC can be divided into soft PVC and rigid PVC. Hard PVC market which accounts for about two-thirds of soft PVC 1/3. Soft PVC are generally used for surface floors, ceilings and leather, but because of soft PVC containing plasticizer (which is soft PVC and rigid PVC difference), physical performance is poor (as water pipes need to withstand a certain pressure, soft PVC not suitable for use), so its use has been limited. Hard PVC plasticizer-free, so easy to shape, good physical properties of pvc pipe processing, and therefore has great development and application value. PVC material in the production process, it is bound to add some additives, such as stabilizers, plasticizers, and so, if all the use of environmentally friendly additives Tech pvc pipe, PVC pipe that is also non-toxic and tasteless green products. There are also more than the number of production companies (nearly 400), yields a miscarriage can be large (2.8 million tons), a small demand (2003 sales of 1.2 million tons country profiles), production can not take full advantage of the current situation in the industry, this industry PVC profiles contradictions, more than 20,000 tons of annual production capacity of less than 10 enterprises, product quality is uneven, inferior products still have a market, quality and technology industry standard is too low, is not conducive to technological progress, leading to substitute aluminum comeback. The high-end market (30%) were occupied by foreign brands, middle and low market unprofitable, intense competition, the final pattern has not yet formed. From the factory distribution, at 392 profiles manufacturers in the southeast region of 37%, 12%, Shandong, the central region of 17%, 19% in the Northeast, 15 percent in the western region. From the point of view of production capacity Division 2003 National capacity 2.8 million tons, 9% in Shandong Province in the central region 1% pvc pipe manufacturers, 32% of the Northeast region, the western region of 7%, 39% in the Southeast region. Shaped windows and doors have a hard material assembled. Have jointly occupy the windows and doors and wooden doors and windows aluminum windows and other markets in some countries; wood materials, building materials and steel (north beach); hollow container. A virtual circuit is one of the services provided by the network packet switching (the other is a datagram service), simply put, is through the network of internal control mechanisms pvc pipe, establish a logical connection between virtual hosts, and to ensure that its Upload messenger bag correctness and sequential, before the communication to be set up and dismantle virtual circuit. PVC is a virtual circuit established during network initialization, and the virtual circuit remains. B-ISDN X.25 network and provides PVC services. PVC plastic bags are generally disabled. pvc pipe wall thickness, pvc pipe, sea Widex Widex provided by Qingdao Rubber Material Co., Ltd. Widex Qingdao Rubber Material Co., Ltd. (www.haihuidaxiangsu.com) strong, credible, in Qingdao, Shandong industrial products industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead the sea Widex and you work into the brilliant, for a better future!