When making filter bags, two different processes are often used: sewing and hot melting.
Sewing filter bagis a kind of filter bag that uses machine thread of sewing machine to connect the bag body with the ring mouth. It is sewn with five threads. The sewing needle shall not be less than 35 ± 5 stitches per 250px. The sewing thread is high-strength polyester/polypropylene white thread. The main materials of sewing filter bag used for liquid filtration are nylon (MO), polypropylene (PP), polyester (PE). The ring mouth mainly consists of stainless steel ring, plastic ring, and galvanized steel ring. For different materials, the sewing machine lines used are different. The sewing machine lines for sewing filter bags are divided into PP lines, PE lines, PTFE lines, etc. Different machine lines adapt to different filtering environments. Advantages of seam filter bag: good corrosion resistance, high toughness, good elasticity, high cost performance, good insulation and long service life. It is suitable for food and beverage, water treatment, pharmacy, electronic industry, textile industry, automobile, chemical industry, metal processing, paint and coating, ink and viscose industries.
The main material ofhot melt filter bagis special liquid filter material. The materials are MO nylon, polypropylene (PP) and polyester (PE). The filtering surface of the filtrate has been specially singed, which not only effectively prevents the fiber from separating from the contaminated filtrate, but also avoids the excessive blockage of the filter hole caused by the traditional rolling treatment and shortens the service life of the liquid filter bag. Different from the seam filter bag, the hot-melt filter bag is made by the hot-melt process. The bag mouth is designed with galvanized steel ring, stainless steel ring (SUS304) and plastic ring (PE/PP). The uniform thickness, stable opening rate and sufficient strength of the needle felt make the efficiency of the liquid filter bag stable and the use time longer.
The method of connecting the bottom, side and collar of the hot-melt filter bag is welded by the hot-melt method, which avoids the pinholes caused by the sewing of the line seam filter bag and is suitable for the field with higher precision requirements; The ultrasonic hot melt welding technology at the arc bottom of the filter bag has been designed and developed, which makes the filter bag more compact in structure, better in sealing and no side leakage, so as to prevent the occurrence of bag breakage. The filter bag can be processed and manufactured according to the customer’s needs.
In addition to the above, there are differences in the scope of use between the seam filter bag and the hot-melt filter bag. Scope of application of hot melt filter bag: electrophoretic paint coating line, pretreatment of wastewater discharge, circuit board production circulating water, automobile production coating line, metal casting, protective filtering and spraying water before ultrafiltration; Filtration, degreasing, filtration, etc.
SFFILTECH filter bag manufacturers can provide seam filter bags and hot-melt filter bags according to customer requirements.