PVC grating production line belongs to profile production line

Production lines for the plastic extrusion industry can generally be classified as pipe lines, board lines, sheet lines and profile lines. PVC grating-which is often applied as floor mats, footbridges, non-slipping surface, industrial flooring-hence definitely falls in the profile line category. At Jiangsu Xinhe Intelligent Equipment Co., Ltd., we regard our PVC grating production line as a specific kind of profile extrusion system. Such a classification is significant for customer to invest, choose dies, and organize subsequent process. The subsequent part is discussing why PVC grating belongs to profile line and how to manufacture with it.

Defining Characteristics of Profile Extrusion Lines

Profile extrusion lines are used to manufacture products with a continuous but non-uniform cross-section that cannot be described as either pipes (fully enclosed tubes), or sheets/boards (flat sheets). A PVC grating is characterized by its grid of overlapping and interlocking hollow sections, ribs and channels, which require a controlled and accurate distribution of melt through the tooling. A pipe die produces one single, fully enclosed channel or the profile tooling is responsible for distributing the material evenly between the numerous cavities. A pipe die only contains one manifold as opposed to the multiple manifolds within a grating die. In comparison, sheet dies simply produce a flat, even sheet. This capability to control melt flow and even wall thickness within a complex non-uniform profile is what defines profile tooling. It is this expertise in profile extrusion at Jiangsu Xinhe Intelligent Equipment Co., Ltd., that allows us to produce PVC grating.

Die Design Differences from Board or Pipe Lines

The die is the single most distinct component of a profile line and the die used for a PVC grating is characterized by its multiple channels. These channels must be precisely designed and balanced so that each section within the grid receives the correct amount of material at the correct speed. If flow distribution and balancing are incorrect, some parts of the grating cell might underfill while others are overpacked. In the case of an uneven filling, some sections could warp and be unstable. Pipe dies use a specific type of internal mandrel combined with multiple spider legs to generate a circular tube. A flat board die uses a large coat hanger manifold to form an even curtain shape. A grating die must have a multi-orifice design with precise adjustment and careful control of each land length to distribute the material. At Jiangsu Xinhe Intelligent Equipment Co., Ltd. we use advanced computer modeling to optimize flow dynamics and ensure even filling from one end of the die to the other.

Calibration and Sizing Methods for Grating Profiles

Similar to the die design, a PVC grating line has a different calibration and sizing method than boards or pipes. Boards are sized on a three-roller calender or a flat calibration table, and pipes rely on vacuum calibration tanks with internal mandrels. The grid of the PVC grating makes neither of these methods entirely suitable because of the lack of a solid surface to roll on or a completely enclosed area. Instead, profile lines utilize a vacuum sizing calibration table with both a vacuum on the exterior of the profile, pulling it against the calibrating tool, and an internal flow of compressed air to prevent the hollow sections from collapsing. This system is used across various other profile types such as window frames, cable trunking and decorative trimmings. While longer than pipe lines, grating calibration tables are considerably shorter than those used in a foamed board line.

Downstream Equipment Configuration for Grating

Pullers, cutters and stacking tables are all adjusted to suit the needs of grating production. For a grating, the best type of puller is a wide belt puller. A roller puller would press unevenly across the grid pattern, marking and possibly deforming the open grid structure of the profile, and could crush the ribs at each cell. The cutter should ideally have two parallel blades able to shear through a whole cell, as in other profile applications, and would typically be a reciprocating saw or a chipless cutter. Flying saws, normally found on board lines, and planetary cutters or swing saws, which tend to be used on pipes, are generally unsuitable for grating cutting. Stacking for grating products also requires careful interlocking, as the fragile grid profile is prone to deformation.

Material and Formulation Considerations

PVC grating formulation is different from standard pipes and boards in that it needs to maintain higher melt strength during cooling so that the open sections don’t collapse in on themselves. This requires a higher molecular weight PVC, the use of acrylic processing aids, carefully balanced lubrication and additive packages. Pipe and board formulations focus on high pressure ratings or cellular structure respectively. PVC grating formulation often combines features of both, with high melt strength and rigidity required, in particular where the load is applied in the vertical direction. We supply various PVC formulations to our customers to help ensure high quality production of PVC grating in the Vietnamese, Indonesian, Saudi Arabian and other markets, as well as offering advice to our customers on equipment choices.

Advantages of Recognizing the Correct Classification

Knowing that the grating line is part of the profile classification will help a manufacturer get the right spare parts when something breaks, assist operator training and also in troubleshooting potential problems. It also helps the manufacturer ordering equipment to clearly understand what they need. Jiangsu Xinhe Intelligent Equipment Co., Ltd. requires profile dies, not pipe or board tooling and this classification helps us to engineer a specific line that produces high-quality PVC grating to the desired specification, utilizing many years of experience in profile extrusions, and supported by branch offices in Indonesia and Vietnam, we have established ourselves as leaders in producing reliable PVC grating production equipment for global customers.