Normally, the surface of the IXPE master sheets obtained from the IXPE extruder should be smooth. However, in over water-cooled IXPE master sheets, sometimes longitudinal lines resembling ripples (usually parallel to the traction direction) appear on the surface or inside the IXPE master sheets. This phenomenon is called "water ripples" in the industry. Water ripples visually affect the appearance and lower the grade of IXPE foam products; performance-wise, they indicate uneven thickness of the IXPE foam sheet and localized degradation of physical properties (such as tensile strength and barrier properties). In short, water ripples have a significant impact on the quality of IXPE foam products. This article, drawing on over ten years of experience from several senior process engineers at Qin Ding Company, will provide a brief analysis of the causes of water ripples on IXPE master sheets and how to handle them, hoping to help our customers.

From December 13th to 14th, 2025, Qin Ding Company organized a two-day team-building trip to Xiandu, Jinyun County for all employees of the Shanggao Business Unit of Qinding. The main participants in this activity were all employees of the Shanggao Business Unit (Main produts: XPE and IXPE Finished Foaming products) and some of their family members. The main purpose was as an annual employee benefit; to increase cooperation among team members; and to enhance the relationship between employees and management.

The structural design of the special extruder screw for IXPE foaming machine production is crucial to the plasticization uniformity of IXPE mixture materials. For example, the configuration of the threaded elements of the screw, the number and arrangement of mixing zones, etc. Multiple kneading sections and mixing elements are installed on the extruder screw dedicated for the production of IXPE foaming machines, which can realize multiple dispersion and mixing of IXPE mixture materials. But at the same time, if the IXPE mixture material is overmixed in the screw, it will easily decompose, causing the IXPE foam mother sheet to foam when it exits the extruder die (pre-foaming phenomenon). Therefore, the design of the mixing unit needs to be optimized. Our company has added innovative functions such as barrier threads, reverse elements and distributed mixing elements to the design of the extruder screw dedicated to the production of IXPE foaming machines, which can further optimize the design of the mixing unit and achieve the purpose of fully plasticizing the very good IXPE mixture without decomposition.

This XPE foaming machine is the QDL-1500LG model. It can produce XPE foam products with a maximum width of 1500mm. Its thickness ranges from 3 to 20mm, and its density ranges from 200 to 20kg/cbm. The XPE foaming machine is 22 meters long, features two heating sections, and is equipped with two VP300 Mikaelson gas burners. Its foaming speed can reach up to 25m/min, and its maximum XPE foam output is 250kg/h. This is our company's most mature and common XPE foaming machine.

The IXPE foam coil unwinding and take-up auxiliary equipment under-beam system (arranged in order) consists of the first IXPE foam coil unwinder, the second IXPE foam coil unwinder, the IXPE foam coil storage rack (unwinding side), the EB electron beam under-beam system, the IXPE foam coil traction system, the IXPE foam coil guide system, the IXPE foam coil storage rack (rewinding side), the first IXPE foam coil unwinder, the second IXPE foam coil unwinder, and the electronic control system. The IXPE foam coil unwinding and take-up auxiliary equipment under-beam system is a key component of the IXPE irradiation process and, together with the accelerator mainframe, completes the physical cross-linking process of the IXPE foam mother sheet.

Qinding Company provided 4 sets of SPC-specific IXPE foaming machine lines at one time to the overseas production base of a domestic large multinational SPC production enterprise. According to customer requirements, the most advanced technology and production process were introduced in the design of the IXPE foaming machine production line; at the same time, many automation systems were added to the entire IXPE foaming machine production line. This set of IXPE foaming machine production line greatly saves labor costs, reduces waste and possible human errors; and introduces advanced catalytic combustion heat exchange system, which is very energy-saving.