초록 ▼

Methods for forming a thermoplastic film with an attached closure strip are disclosed. The thermoplastic film can then be used to produce zippered reclosable plastic bags. The methods include providing a thermoplastic film web having a sealing surface and providing a closure strip having a binding s

Methods for forming a thermoplastic film with an attached closure strip are disclosed. The thermoplastic film can then be used to produce zippered reclosable plastic bags. The methods include providing a thermoplastic film web having a sealing surface and providing a closure strip having a binding surface, both being maintained in a non-melted condition at room temperature. A heated thermoplastic binder layer is then extruded and positioned between the sealing surface of the film web and the binding surface of the closure strip very quickly after extrusion. The hot freshly extruded binder layer transfers enough heat to the closure strip and to the film web to melt the binding surface of the closure strip and sealing surface of the film web. Pressure is then applied to the film web and the closure strip to seal the closure strip to the film web. An apparatus for practicing the method at high speed is also disclosed.

대표청구항 ▼

Methods for forming a thermoplastic film with an attached closure strip are disclosed. The thermoplastic film can then be used to produce zippered reclosable plastic bags. The methods include providing a thermoplastic film web having a sealing surface and providing a closure strip having a binding s

Methods for forming a thermoplastic film with an attached closure strip are disclosed. The thermoplastic film can then be used to produce zippered reclosable plastic bags. The methods include providing a thermoplastic film web having a sealing surface and providing a closure strip having a binding surface, both being maintained in a non-melted condition at room temperature. A heated thermoplastic binder layer is then extruded and positioned between the sealing surface of the film web and the binding surface of the closure strip very quickly after extrusion. The hot freshly extruded binder layer transfers enough heat to the closure strip and to the film web to melt the binding surface of the closure strip and sealing surface of the film web. Pressure is then applied to the film web and the closure strip to seal the closure strip to the film web. An apparatus for practicing the method at high speed is also disclosed. vided in said housing for generating combustion gas, wherein each pellet includes, a main body having at least one hole provided therein, an inside diameter d of said at least one hole being in a range of 0.2-1.5 mm, and a ratio L/d of a length L of said main body and the inner diameter d being 3 or larger to control an inner surface area of said hole that is initially ignited, relative to an entire inner surface area of said hole, and prevent the airbag from applying excessive impact to a passenger upon inflation of the air bag, wherein said combustion chamber contains only said gas generating pellets. 4. The gas generator for an air bag system according to claim 3, wherein the gas generator includes igniting means provided within said housing and igniting said gas generating means to generate combustion gas, and filter means for cooling said combustion gas and entrapping combustion residues, an outer periphery of said filter means being opposed to an inner surface of an outer circumferential wall of said housing with a space formed therebetween. 5. The gas generator according to claim 3, wherein said main body has an elongated shape. 6. The gas generator according to claim 3, wherein said at least one hole is provided in said main body in a longitudinal direction of said main body. 7. The gas generator according to claim 3, wherein said ratio L/d is set between 3 and 10. 8. A method of attaining a reduced initial inflation speed of an air bag that is inflated by combustion gas generated from a gas generator, comprising: providing a combustion chamber inside the gas generator; providing gas generating pellets, each pellet provided with a hole having an inner diameter d of 0.2-1.5 mm, and a ratio L/d of a length L of the main body and the inner diameter d being 3 or greater to control an inner surface area of said hole that is initially ignited, relative to an entire inner surface area of said hole, and prevent the air bag from applying excessive impact to a passenger upon inflation of the air bag; and providing the combustion chamber only with said gas generating pellets; and igniting and combusting said gas generating pellets, such that in a 60 liter sealed tank combustion test, in which the gas generator containing said pellets is placed in a 60 liter tank and the gas generator generates a maximum tank pressure of P (kPa) at T milliseconds after an initial rise in the tank pressure due to combustion of said pellets, a pressure at 0.25×T milliseconds after initial rise in the tank pressure is not higher than 0.25×P (kPa), and a pressure at 0.8×T milliseconds after the initial rise is not lower than 0.70×P (kPa). 9. The gas generator for an air bag system according to claim 8, wherein the maximum tank pressure P (kPa) is in the range of 110 to 220 (kPa), and the time T is in the range of 30 to 50 milliseconds. 10. The method according to claim 8, wherein said main body has an elongated shape. 11. The method according to claim 8, wherein said at least one hole is provided in said main body in a longitudinal direction of said main body. 12. The method, according to claim 8, wherein said step for providing gas generating pellets includes the step of setting said ratio L/d between 3 and 10. 13. Gas generating pellets for an air bag system, comprising: a main body; and at least one hole provided in said main body, wherein in a 60 liter sealed tank combustion test, where a gas generator containing said pellets is placed in a 60 liter tank, and the gas generator generates a maximum tank pressure of P (kPa) at T milliseconds after an initial rise in the tank pressure due to combustion of said pellets, a pressure at 0.2×T milliseconds after initial rise in the tank pressure is not higher than 0.2×P (kPa), and a pressure at 0.80×T milliseconds after the initial rise is not lower than 0.70×P (kPa), wherein the pellets include a non-azide gas generating composition, said non-azide gas generating composit