26 results about "Pre stretch" patented technology

The utility model relates to the technical field of heat shrink films, and discloses a heating device for heat shrink film production, which comprises a base, the top of the base is fixedly connected with a pre-stretching device and a heating box, the side surface of the heating box is fixedly connected with a thermal insulation plate, the side surface of the thermal insulation plate is provided with a feeding hole, and the feeding hole is communicated with the pre-stretching device and the heating box. A hot air circulating device is fixedly connected to the top of the heating box, a winding device is fixedly connected to the side face of the heat insulation plate and located in the heating box, a heating mechanism is fixedly connected to the bottom of the heating box, a winding device is fixedly connected to the top of the base, and a heat dissipation opening is formed in the bottom of the heating box. The interior of the heating box is fixedly connected with an adjustable heating plate; according to the utility model, the heating mechanism is arranged, and the film is uniformly heated through the adjustable heating plate and the heating coil, so that the film can reach an ideal shrinkage temperature in the heating process, and the product quality and the production efficiency are improved.

The invention relates to the technical field of composite membranes, and discloses a tensile multilayer composite membrane which comprises a composite membrane body and a plurality of first reinforcing ribs, the multiple first reinforcing ribs penetrate through the composite membrane body back and forth in the thickness direction of the composite membrane body; at least part of the first reinforcing ribs are in a pre-stretching state, and the other part of the first reinforcing ribs are in a loose state. According to the technical scheme, the technical problem of interlayer separation of the composite film caused by stress concentration of the anti-tensile multilayer composite film in the related technology can be solved.

This invention discloses an ultra-thin, tensile-reinforced packaging film, relating to the field of agricultural packaging film technology. The film has a seven-layer co-extruded structure with a total thickness of 15–22 micrometers. It comprises an outer surface unwinding weather-resistant layer, an inner surface adhesive layer, a core layer with pinhole self-sealing in the middle, and tensile-reinforced crack-blocking layers on both sides. The core layer contains a polyisobutylene sealing phase, a dynamic ionic framework composed of a blend of sodium and zinc ionomers and unneutralized ethylene-acid copolymer, and a compatibilizer containing epoxy-based ethylene copolymers. The molar ratio of epoxy to free acid groups is 0.05–0.25, resulting in polyisobutylene forming a sealing microdomain with a median particle size of 0.3–1.2 micrometers and 90% of the particles having a diameter no greater than 2.5 micrometers. The blocking layer contains a microfibrillated reinforcing phase. Under pre-tension, the film can quickly seal pinholes and reduce oxygen intrusion, while simultaneously inhibiting the migration of the sealing phase, reducing in-roll adhesion and downtime for repairs.

Various embodiments of the present disclosure provide a stretch-wrapping machine with at least three pre-stretch rollers sized, positioned, and otherwise configured to minimize necking and slippage as the film is drawn through and stretched by the pre-stretch rollers before the film is applied to the load.

A method of wrapping bundles is with stretch film from a reel. Bundles include products in transit through a wrapping machine including a wrapping unit having a ring winder which rotatably arranges stretch film around the bundles. During transit through the winding unit, the stretch film is unwound from the reel and passes through a pre-stretching group which generates axial deformation of the film predetermining an elastic return quantity. The axially deformed film interfaces with a vacuum having a vacuum box producing a constant auxiliary tensional stress on the pre-stretched film equal to the head inside the vacuum box. The film is then deposited on the bundles with a constant stress residue at each point of application of the pre-stretched film after adding the constant load generated by the vacuum box, producing bundles completely wrapped with a programmed stress residue.

A pre-stretching device (10) and a method for inserting a packaging film or other sheet material into the pre-stretching device, the pre-stretching device being suitable for being installed on a wrapping packaging machine that uses a packaging film (F) (specifically, a stretch film (F) or other sheet material) to wrap a load, the pre-stretching device comprising a support device (11) for a film roll (B) of the stretch film (F), a pair of pre-stretching rollers (13, 14) rotating around respective axes (X1, X2), and a quick insertion device (30) for inserting an edge of the packaging film (F) between the rollers of the pair of pre-stretching rollers (13, 14); the quick insertion device (30) comprising a flexible traction element (17) configured to advance along a path extending between the axes (X1, X2) and partially around them, thereby traction of the edge of the packaging film (F), the edge of the packaging film (F) being connected to the flexible traction element (17) by the rollers of the pair of pre-stretching rollers (13, 14) and a connecting element (20) arranged on the flexible traction element (17).

The invention discloses a method for improving the thickness consistency of an ETFE film, and relates to the technical field of polymer films, and the method specifically comprises the following steps: extruding and melting ETFE resin through a twin-screw extruder, and mixing through a static mixer to obtain a melt; carrying out gradient stretching on the melt, firstly carrying out pre-stretching at 70-80 DEG C, then carrying out primary stretching at 80 DEG C, then raising the temperature to 118-122 DEG C, carrying out secondary stretching, and finally raising the temperature to 148-152 DEG C, and carrying out tertiary stretching; and cooling and shaping the stretched film to obtain the ETFE film. Extrusion melting conditions are effectively optimized, gradient stretching is carried out during stretching, annealing treatment is carried out after gradient stretching and before cooling, and the prepared ETFE film is consistent in thickness and good in tensile property.

The invention discloses a thermal shrinkage film preparation device and a preparation process thereof, relates to the technical field of high polymer materials, and solves the problems that a thermal shrinkage film is uneven in thickness, unstable in shrinkage rate and not pre-stretched. The thermal shrinkage film preparation device and the preparation process comprise a fixed base and a thermal shrinkage film rolling film, and a melt co-extrusion structure is installed at one end of the fixed base; the melt co-extrusion structure is used for preparing a heat shrinkage film roll film, the transfer structure is mounted at one end of the melt co-extrusion structure, the template pre-pressing structure is mounted at one end, far away from the melt co-extrusion structure, of the transfer structure, the heat shrinkage film hot-pressing structure is mounted at one end, far away from the transfer structure, of the template pre-pressing structure, and the heat shrinkage film roll film is pre-stretched by the heat shrinkage film hot-pressing structure; according to the preparation method, pre-stretching is carried out in the preparation process of the thermal shrinkage film, the phenomenon that the thermal shrinkage film forms a high-orientation fibrous structure and net-shaped micropores due to the fact that the longitudinal stretching strength and the transverse stretching strength of the thermal shrinkage film are not uniform is avoided, and the mechanical property of the thermal shrinkage film is reduced through pre-stretching of the structure.

The agricultural bale wrapper comprises a bale support for supporting and rotating the bale 2 about a first axis, X, a film dispenser holding a roll 8 of stretch film 10, means configured to provide relative rotation between the bale support and the film dispenser about a second axis, Y, that extends substantially perpendicular to the first axis, so that the stretch film 10 forms a bale wrapping that substantially completely covers the bale, at least one film pre-stretcher unit 9a configured to pre-stretch the stretch film by an elongation amount before the stretch film is applied to the bale, the at least one film pre-stretcher unit comprises at least two pre- stretcher rollers 3, 7 configured to perform elongation of the stretch film, the at least two pre-stretcher rollers are configured to rotate relative to each other with a predetermined angular speed ratio 5 and the stretch film is drawn over the surfaces of the at least two pre-stretcher rollers, the ratio of the circumferential speeds of the at least two pre-stretcher rollers varies over the width, W, of the stretch film. At least one of the two pre-stretcher rollers may have a larger diameter in the middle of the roller than the diameter at the ends of the roller. The variation of ratio of the circumferential speed ratio may be adjusted based on the type of stretch film or the shape and / or size of the bale. Also disclosed is a method for wrapping an agricultural bale.

The invention belongs to the technical field of packaging tools, and particularly relates to a manual pre-stretching wrapping film and a production method thereof.The manual pre-stretching wrapping film comprises a film body and a winding drum, and the film body is driven by a plurality of stretching rollers to be pre-stretched. The film body is made of a mixture of metallocene polyethylene, linear polyethylene and tackifying master batch. The stretch rate of the film body which is subjected to plastic deformation caused by pre-stretching is 300%-450%, and the thickness of the film body is 10-15 microns. According to the manual pre-stretching wrapping film, pre-stretching is conducted through equipment before the wrapping film leaves a factory and is sold, the problems of poor consistency, insufficient stretching rate and material waste during manual stretching are solved, and therefore more cost is saved. And displacement and scattering of the cargoes caused by insufficient fastening performance of the cargoes due to continuous extension of the wrapping film which is not stretched in place in the transportation process during transportation of the cargoes can also be avoided.

The invention relates to a device (1, 21, 22) for laminating molded fiber parts (2) with a thermoplastic film (3), comprising a molding tool (4) having at least one mold cavity (5) for receiving a molded fiber part (2), and a forming tool (6) having at least one pre-stretching punch (8) and at least one heating device (15), wherein the molding tool (4) and the heating device (15) can be moved relative to one another from a spaced-apart position for receiving the plastic film (3) and / or delivering the laminated molded fiber part (7) into an approached position to form an at least substantially closed mold, wherein the pre-stretching punch (8) in the approached position can be moved from a retracted starting position into a pre-stretching position pre-stretching the plastic film (3) and back, wherein the heating device (15) is provided for heating at least two forming heating surfaces (13, 14) of the forming tool (6), wherein a forming heating surface (14) is provided on a free end of the pre-stretching punch (8) coming into contact with the plastic film (3) in the approached position at least during the pre-stretching of the plastic film (3), and wherein on the other side of the pre-stretching punch (8), preferably at least substantially circumferentially in relation to the pre-stretching punch (8), a forming heating surface (13) is provided for contact with the plastic film (3) in the approached position before the pre-stretching by the pre-stretching punch (8).

The present application relates to a kind of TEP / TEP-PEG bidirectional response shape memory composite film and its preparation method.The present application is with two-component TEP, PEG, accelerator as raw material, by the melting-dispersion technology of PEG, the polymerization-hardening forming technology of TEP and pre-stretching-laminating technology development TEP / TEP-PEG bidirectional response shape memory composite film.The composite film is with TEP as composite film passive layer, with high storage modulus and high T g , with TEP / PEG as composite film active layer, with low storage modulus and low T g . Through the coupling of double-layer structure, TEP / TEP-PEG composite film can produce shape change by responding temperature stimulus, realizes the bidirectional controllable intelligent response of temperature stimulus in single heating process.The composite film also has the function of repairable, recyclable-rework, and shows application potential in the field of flexible actuator and intelligent unit structure.

An edge banding machine and method for obliquely pressing and bonding the side of a disc-shaped sheet material, relating to the field of edge banding machine technology, includes a main frame; the main frame is equipped with a rotating support arm mechanism and an edge banding mechanism; it also includes an edge banding strip stretching mechanism and an oblique pressing mechanism, the edge banding mechanism further including a feeding pressure roller disposed above the disc-shaped sheet material. By pre-stretching the edge banding strip and setting the oblique pressing mechanism, precise pressing and bonding of the annular oblique side of the disc-shaped sheet material is achieved, thereby solving the problem of poor bonding. This effectively solves the problem of poor edge banding bonding of the annular oblique side of the disc-shaped sheet material, improving edge banding quality and product durability.

A wrapping machine for wrapping a load includes an unwinding unit, provided with a reel of film and rollers for unwinding and / or pre-stretching the film, a moving assembly for supporting and moving the unwinding unit along an operating direction and a transfer system fixed to and supported by the unwinding unit and configured to transfer an initial flap of film unwound by the rollers into a wrapping area of the wrapping machine where the load is wrapped with the film. The transfer system includes a blowing arrangement positioned downstream of the rollers and configured to blow air towards the wrapping area to push and guide the initial flap along an unwinding direction towards the wrapping area, and a gripping assembly adjacent to blowing arrangement and adapted to grasp and retain the initial flap during a pause step when the load is not wrapped with the film.

The application provides a preparation method of a composite dielectric elastomer film and a dielectric elastomer film actuator. The preparation method comprises the following steps: step 1: mixing BTRU@CDs giant electro-rheological particles with an electro-rheological liquid dispersion phase to obtain a suspension; step 2: uniformly mixing silicone rubber with the suspension to obtain a composite dielectric elastomer prepolymer, wherein the mass ratio of the silicone rubber to the suspension is 15:1 to 1:1, and the mass ratio of the BTRU@CDs giant electro-rheological particles in the composite dielectric elastomer prepolymer is 5-40%; and step 3: film forming is performed on the composite dielectric elastomer prepolymer to obtain a composite dielectric elastomer film. The composite dielectric elastomer film prepared by the preparation method of the composite dielectric elastomer film has better actuating performance, better mechanical performance and better cycle stability than traditional rubber elastomers. The problems of high driving voltage, large pre-stretching ratio, limited actuating strain, poor fatigue resistance and easy breakdown of existing dielectric elastomer materials are solved.

The invention relates to the technical field of film tension prefabrication, and discloses a film stretching tension prefabrication device which is characterized in that a film drawing module, a bearing module and a film pressing module are reasonably arranged through a rack, the film drawing module clamps and prestretches the edge of a film firstly, and a film foundation with certain tension is provided for subsequent shaping operation. A stable bearing plane is provided for further stretching and shaping of the film through the bearing face of the bearing module, when the film pressing die descends to press the film to the bonding face of the bonding structure, the film and the bonding structure are effectively bonded through the extrusion effect of the bearing module and the film pressing module on the film and the bonding structure, and therefore the film pressing efficiency is improved. According to the film stretching tension prefabrication device, prefabrication of film tension can be achieved, the tension can be adjusted and monitored, and the film stretching size can be adjusted and monitored.

The present disclosure provides a film carriage for a wrapping machine. The film carriage includes a film-carriage frame, a first prestretch roller rotatably mounted to the film-carriage frame, a third prestretch roller rotatably mounted to the film-carriage frame, and a roller support including a roller-support frame and a second prestretch roller rotatably mounted to the roller¬ support frame. A first space is defined between the first and third prestretch rollers. The roller support is movable relative to the film-carriage frame between a closed position in which the second prestretch roller at least partially occupies the first space and an open position in which the second prestretch roller is removed from the first space.

Described and illustrated is a device (1, 21, 22) for laminating fiber-molded parts (2) with a thermoplastic film (3), comprising a molding tool (4) having at least one mold cavity (5) for receiving a fiber-molded part (2) and a forming tool (6) having at least one pre-stretching die (8) and at least one heating device (15), wherein the molding tool (4) and the heating device (15) are adjustable relative to each other from a spaced-apart position for receiving the plastic film (3) and / or dispensing the laminated fiber-molded part (7) to an approximate position for forming an at least substantially closed shape, wherein the pre-stretching die (8) in the approximate position is adjustable from a retracted initial position to a pre-stretching position extending the plastic film (3) and back, wherein the heating device (15) is for heating at least two forming heating surfaces (13,14) of the forming tool (6) is provided, wherein a forming heating surface (14) is provided at a free end of the pre-stretching punch (8) that comes into contact with the plastic film (3) in the approximate position at least during the pre-stretching of the plastic film (3), and wherein, beyond the pre-stretching punch (8), preferably at least substantially circumferentially to the pre-stretching punch (8), a forming heating surface (13) is provided for contact with the plastic film (3) in the approximate position before pre-stretching by the pre-stretching punch (8).

The present application relates to apparatus for stretch wrapping goods with stretch wrap film including: a film roll carriage for dispensing at least one band of film from at least one stretch wrap film roll core, a roping mechanism for roping the at least one band of film by edging at least one lateral side edge of the film, a pre-stretcher for pre-stretching the film by passing the roped film through a pre-stretcher, a stretch wrap carousel for wrapping the roped and pre-stretched film around the goods, wherein the at least one band of film is passed through the roping mechanism prior to the pre-stretcher.

The invention discloses a two-step synchronous drawing process and equipment for producing BOPP (Biaxially-oriented Polypropylene). The two-step synchronous drawing process for producing the BOPP comprises the following steps: extruding a polypropylene raw material, and cooling and shaping the extruded polypropylene raw material into a basic sheet; the basic sheet is subjected to 1.1-3.0 times of one-way longitudinal stretching in a heating state, and a pre-stretching sheet is formed; the pre-stretched sheet is introduced into a synchronous two-way stretching system, and longitudinal stretching and transverse stretching are conducted at the same time; and cooling, shaping and winding the stretched film. According to the method, small-magnification longitudinal pre-stretching is firstly carried out to generate moderate pre-orientation and pre-leveling, and then synchronous two-way stretching is combined, so that the film forming stability is improved, the problems that the anisotropy of an existing step-by-step stretching method is serious and a process window of a full-synchronous stretching method is narrow are solved, and the high-performance BOPP film can be stably and efficiently produced.

The invention provides a flexible paper folding driving unit based on programmable stiffness folds, which comprises a curve paper folding structure, a film-shaped driver and a frame layer which are connected in sequence, the film-shaped driver comprises a pre-stretched dielectric elastomer, and electrode layers are arranged on the front face and the back face of the dielectric elastomer. The front end face of the dielectric elastomer coincides with the large end of the crease. The curve paper folding structure comprises a paper folding front section and a paper folding rear section which are formed by folding marks; the paper folding front section extends towards the back surface of the curve paper folding structure; the creases are arc-shaped; avoiding holes matched with the corresponding electrode layers are formed in the curve paper folding structures and the frame layers; a notch is formed in one side, facing the crease, of the avoiding hole in the frame layer, and the notch extends towards the electrode layer from the back surface; the curve paper folding structure and the frame layer are both made of flexible films, and the thickness of the frame layer is larger than that of the curve paper folding structure. And a voltage source. The driving control system of the flexible robot is simplified, and the structural complexity of the flexible robot is reduced.

A machine wrapping bundles with stretch film from a reel with continuous suction includes a ring wrapping machine arranging stretch film around the bundles. The film unwinds from a reel on a rotating ring of the wrapping machine to wrap around bundles, during the passing of the bundles. A pre-stretching group of the stretch film generates an axial deformation of the stretch film. A vacuum box downstream of the pre-stretching group continuously receives the deformed film. The pre-stretching group and vacuum box are arranged on the rotating ring around the bundles. A rotating magnetic track associated with the rotating ring causes a magnetic track wheel / disc to rotate, creating a magnetic transmission having a shaft supported in the pre-stretching group, which actuates a rubber roller on which the film passes. A dynamo connects directly to the magnetic transmission and batteries. A vacuum pump connects to the vacuum box and batteries.

Various embodiments of the present disclosure provide a stretch-wrapping machine with at least three pre-stretch rollers sized, positioned, and otherwise configured to minimize necking and slippage as the film is drawn through and stretched by the pre-stretch rollers before the film is applied to the load.

A machine wrapping bundles with stretch film from a reel with continuous suction includes a ring wrapping machine arranging stretch film around the bundles. The film unwinds from a reel on a rotating ring of the wrapping machine to wrap around bundles, during the passing of the bundles. A pre-stretching group of the stretch film generates an axial deformation of the stretch film. A vacuum box downstream of the pre-stretching group continuously receives the deformed film. The pre-stretching group and vacuum box are arranged on the rotating ring around the bundles. A rotating magnetic track associated with the rotating ring causes a magnetic track wheel / disc to rotate, creating a magnetic transmission having a shaft supported in the pre-stretching group, which actuates a rubber roller on which the film passes. A dynamo connects directly to the magnetic transmission and batteries. A vacuum pump connects to the vacuum box and batteries.

Various embodiments of the present disclosure provide a film carrier for a winding machine and a method of pre-stretching a film. The film carrier includes an upper holder and a lower holder, the upper holder and the lower holder being sized and shaped to hold portions of the film. In some embodiments, the pretensioner element is offset from the line between the upper holder and the lower holder and is positioned to pretension the film. In some embodiments, the upper holder and the lower holder diverge to pre-stretch the film.

Described is an apparatus (100) for wrapping with a pre-stretched film (200) a load (300) supported by a surface (310) comprising: a delivery head (1), provided with a delivery mechanism (2) for delivering the film (200); a drive unit, for generating a relative movement between the delivery head (1) and the load (300); a source of compressed air (3), for generating a flow of air in such a way that the flow of air blows the film (200) delivered; an electrostatic charger (4), for applying an electrostatic charge to the film (200); a deflector (5), movable between a first position, wherein the deflector orients the flow of air for blowing the film (200) delivered along a first vertical plane (P) which does not intersect the load (300), and a second position, wherein the deflector orients the flow of air for blowing the film (200) delivered along a second plane (Q), vertical and intersecting the load (300). A control unit controls the movement of the deflector (5) between the first position and the second position by means of an actuator (6).