The liquid filling machine seal of Forever Seals use modified PTFE material. The spring can provide elastic force inside. And silicone fill the jacket. It is convenience for washing and avoid variouys kinds of liquid attach to the spring. It is widely applicable to juice, sodas, hard drink, mineral water, purified water, oils, aerosol, hair care articles, skin care products, toilet articles, cleaning products, yogurt, milk, wine etc.