48-400 White Heat Seal Liner, Commonly used for food items, lotion, soaps, creams, and personal care items. Continuous thread caps are popular in a wide range of wholesale industries from food, personal care, pet care, household products, industrial products, health and beauty, arts, crafts, hobbies and just about any other market segment. This polypropylene (PP) cap has a high tolerance for heat and is very durable. Heat seal Liners provide tamper evident protection,and help prevent leakage. They are an important aspetc. of every continuous thread cap and products should best tested with the cap to determine which liner will be the best fit.