ASO Co., Ltd.

 Our company specialises in manufacturing inner liners for the transport of heavy goods and liquids, such as drum cans, containers, and flexible containers.

 Furthermore, we handle various types, including those with differing viscosities and filling temperatures, as well as those containing acids, alkalis, oils, and aromatic organic solvents.

 Polyethylene is a material with outstanding resistance to acids and alkalis. However, this refers solely to the material itself.

 For transporting liquids, stainless steel containers, resin drums, or iron drums are predominantly used. Particularly with open iron drums, inner liners are frequently employed.

 However, it is an absolute prerequisite that no pinholes occur in this inner liner during filling. While this may seem obvious, it is also a highly troublesome issue.

 Should any external damage or pinholes occur when installing the inner liner into the drum, the inside of the drum can deteriorate to a disastrous state over time. Furthermore, “wrinkles” or “scratches” on the film that are not yet penetrated at the time of installation can gradually develop into pinholes during filling or transport. Pinhole defects or scratches can occur at various stages of the process.

 For example, they can occur on the production line. Pinhole defects can arise for various reasons during the film manufacturing process. Causes include issues with the raw material itself, production or machine conditions, impacts or falling objects within the line, external damage from workers' watches or rings, and abrasions to the selvedge edges (the cut edges on either side of the raw material) during transfer to the bag forming process.

 Furthermore, in the subsequent bag-making process, pinholes can occur through contact with production machinery, falling objects, or impact injuries caused by workers' watches or rings. Essentially, these are injuries resulting from carelessness.

 These include external damage occurring during installation onto drums, or impact marks caused by workers' watches or rings. As above, it is also common for impact marks on the flange to develop into pinholes.

 When it comes to polyethylene bags for drum cans, the larger bag size and the resulting difficulty in handling are contributing factors to damage. Furthermore, burrs or similar imperfections on the inner surface of the drum can catch during installation, causing external damage.

 Surprisingly common is damage neither from impact marks nor external sources: when installing the bag onto a drum can, if overlapping film is forcibly stretched apart, the overlapping area can stiffen and develop cracks.

 Finally, when inserting hoses into drums after fitting the inner bag for filling, the metal tip of the hose may contact and damage the film surface. Similarly, when mixing contents with rods after filling, the rod tip may contact the film and cause damage. The potential causes are as numerous as the stars in the sky.

 Therefore, when such damage occurs, our company examines enlarged photographs of the damaged area. First, we determine whether the damage runs from the inside outwards or from the outside inwards. We check if the damage penetrates both layers of film at the same location, the direction of the scratch, its length, and the number of affected sheets. We proceed with our investigation based on this diverse information.

 However, relying solely on the information that leakage has occurred makes it difficult to pinpoint the cause definitively, given the myriad possible reasons outlined above.