ISRI’s PSI to add release liner grade

The Paper Stock Industries (PSI) chapter of the Washington-based Institute of Scrap Recycling Industries (ISRI) has proposed the addition of a recovered fiber grade to ISRI’s Scrap Specifications Circular.

According to a notice published by ISRI, its board of directors will consider the addition of a specialty grade known as 37-S Silicon[e] Release Liner. The grade, if adopted, will be added to the guidelines for paper stock contained in the ISRI "Scrap Specifications Circular."

According to Norway-based Elkem, a maker of silicone release liner products, such liners “are used to protect sticky surfaces and to ease their handling.” The company adds, “Release liners are used in a wide array of markets and applications where it is critical to achieve a perfect coating to protect and deliver materials such as pressure-sensitive adhesives (PSA) used in tapes and labels to their end destination.”

On the recycling front, United Kingdom-based UPM says it has “created a solution to recycle used release base paper back to release liner production.” In 2018, the firm says its UPM Specialty Papers introduced UPM LinerLoop. The firm says in that process, used release liners are collected and the silicone is removed. The “desiliconized” release liners are then turned into pulp and used to produce new release base papers, according to UPM.

The new grade is being added as a PSI “Specialty Grade.” The group defines those as recyclable paper grades that “are produced and traded in carload and truckload quantities throughout the United States, and because of certain characteristics (i.e., the presence of wet strength, polycoatings, plastic, foil, carbon paper, hot melt glue), are not included in the regular grades of paper stock.”

Adds PSI, in its Specifications Circular (available here), “It is recognized that many mills have special equipment and are able to utilize large quantities of these grades.” PSI adds for such grades, however, that it does not establish “specific specifications, which would refer to such factors as the type of wet strength agent used, the percentage of wax, the amount of polycoating, whether it is on top of or under the printing, etc. The specification for each grade should be determined between buyer and seller, and it is recommended that purchase be made based on sample.”

The final vote on adding the grade will take place at ISRI’s Spring Board Meeting, held March 21 in conjunction with the ISRI2022 convention in Las Vegas.

The proposed change was approved by ISRI’s Paper Division last month. “The full board may choose to adopt, amend or reject the recommendations of the [Paper] Division or table them pending further review,” ISRI says.

Those with comments, recommendations or questions on the proposed grade are urged to contact ISRI Chief Economist Joe Pickard.