Product Guide
There are essentially two processes: - Impulse Heat and Constant Heat.
Impulse Heat Sealers
Impulse heat is typically used to weld like-for-like thermo-plastic films (usually, but not always polythene.)
Standard impulse sealers weld up to 1000 Gauge (250 micron) polythene film without difficulty. Special purpose double- element machines are available for repetitive sealing of heavier gauge and gusseted polythene. Other thermo-plastic materials such as nylon laminates, polypropylene, polyurethane and some PVC's are sealable but should be tested first. We will willingly test samples for you prior to the purchase of any heat sealer.
Impulse heat sealers use low voltage element wires that heat up rapidly to a temperature that welds in seconds. The element then cools, allowing the seal to set under pressure.
All Hulme Martin impulse sealers are fitted with electronic timers to accurately control the welding period. Our Duo models are fitted with a higher specification timer that also indicates the cooling period, helping to control the quality and consistency of seals. The welding and cooling periods are independently adjusted to suit the type and thickness of material being used.
Cutters are available on many models to trim surplus material or to make bags from lay-flat polythene tubing. Modified wide seal elements and cut-and-seal elements can be specified on selected machines.
Constant Heat Sealers
This process is normally used to seal laminated materials made from layers of thermo-plastic film having different properties and melting points, such as foils, coated papers, cellophane and polypropylene laminates.
Constant heat sealers use temperature controllers to maintain the element bar at as stable and precise temperature. This seals the inner layer (or coating) without distortion of the backing material. To avoid de-lamination the seal is 14mm wide and crimped for added strength.