An improved ventilation module is characterised by the following features, among others: a ventilation outlet channel (61) having a gas flow inlet side (61c) and an opposite gas flow outlet side (61d) is provided, the ventilation outlet channel (61) is separated in the longitudinal direction to form at least two ventilation channel portions (61a, 61b), such that the at least two ventilation channel portions (61a, 61b) are adjustable away from and towards one another transversely to the longitudinal extent of the ventilation outlet channel (61), whereby the width (B) of the ventilation outlet channel (61) and thus the flow cross section can be increased or decreased.

An improved ventilation module is characterised by the following features, among others: a ventilation outlet channel (61) having a gas flow inlet side (61c) and an opposite gas flow outlet side (61d) is provided, the ventilation outlet channel (61) is separated in the longitudinal direction to form at least two ventilation channel portions (61a, 61b), such that the at least two ventilation channel portions (61a, 61b) are adjustable away from and towards one another transversely to the longitudinal extent of the ventilation outlet channel (61), whereby the width (B) of the ventilation outlet channel (61) and thus the flow cross section can be increased or decreased.

A polymer layer includes a first in-plane refractive index extending along a first direction of the polymer layer, a second in-plane refractive index less than the first in-plane refractive index extending along a second direction of the polymer layer orthogonal to the first direction, a third refractive index along a direction orthogonal to both the first direction and the second direction, and a plurality of wrinkles extending along a surface of the polymer layer, where a difference between the first in-plane refractive index and the second in-plane refractive index is at least approximately 0.05, and the third refractive index is greater than the second in-plane refractive index.

A polymer layer includes a first in-plane refractive index extending along a first direction of the polymer layer, a second in-plane refractive index less than the first in-plane refractive index extending along a second direction of the polymer layer orthogonal to the first direction, a third refractive index along a direction orthogonal to both the first direction and the second direction, and a plurality of wrinkles extending along a surface of the polymer layer, where a difference between the first in-plane refractive index and the second in-plane refractive index is at least approximately 0.05, and the third refractive index is greater than the second in-plane refractive index.

A clip-type stretching apparatus includes a main link device, a sub-link device, a standard rail, a pitch setting rail, and drive sprockets, the main link device including a first clip support member having a clip, the sub-link device having the clip, the standard rail defining a circulation route of the clip, the pitch setting rail setting a pitch between the first clip support members by a distance from the standard rail, the drive sprockets engaged with a drive roller provided in a first shaft member of the first clip support member and causing the first clip support member to travel.

A clip-type stretching apparatus includes a main link device, a sub-link device, a standard rail, a pitch setting rail, and drive sprockets, the main link device including a first clip support member having a clip, the sub-link device having the clip, the standard rail defining a circulation route of the clip, the pitch setting rail setting a pitch between the first clip support members by a distance from the standard rail, the drive sprockets engaged with a drive roller provided in a first shaft member of the first clip support member and causing the first clip support member to travel.

A device for stretching a thermoplastic film simultaneously in the longitudinal direction and the transverse direction is provided. The device includes, on each side of the film (F) to be stretched, grasping members for grasping a lateral edge of the film (F), and guide members; first and second guide rails (R1, R2), on which the members and are respectively able to move; first connecting rods connecting the grasping members and the guide members. In an embodiment, each guide member is connected to a single grasping member by one or several of said first connecting rods, and is connected to a first longitudinal adjusting member by one or several second connecting rods connected to the first longitudinal adjusting member; and the device includes adjusting means for adjusting the position and orientation of said first longitudinal adjusting member relative to said first and second guide rail (R1, R2).

A device for stretching a thermoplastic film simultaneously in the longitudinal direction and the transverse direction is provided. The device includes, on each side of the film (F) to be stretched, grasping members for grasping a lateral edge of the film (F), and guide members; first and second guide rails (R1, R2), on which the members and are respectively able to move; first connecting rods connecting the grasping members and the guide members. In an embodiment, each guide member is connected to a single grasping member by one or several of said first connecting rods, and is connected to a first longitudinal adjusting member by one or several second connecting rods connected to the first longitudinal adjusting member; and the device includes adjusting means for adjusting the position and orientation of said first longitudinal adjusting member relative to said first and second guide rail (R1, R2).

The machine (1) includes at least one assistance subassembly (10) having: an endless chain or belt (16); a plurality of thrust members (20) connected to the chain or belt (16) in succession and projecting from the chain or belt (16), and a drive device (21) of this chain or belt (16), several thrust members (20) are brought into the path (3) of the sliders (8) connected to the grippers (4) for gripping the film (F), so that at least one of the thrust members (20) comes to bear against at least one of these sliders (8) and exerts a thrust on this slider to assist the displacement of this slider along the rail (5e) on which this slider moves.

The machine (1) includes at least one assistance subassembly (10) having: an endless chain or belt (16); a plurality of thrust members (20) connected to the chain or belt (16) in succession and projecting from the chain or belt (16), and a drive device (21) of this chain or belt (16), several thrust members (20) are brought into the path (3) of the sliders (8) connected to the grippers (4) for gripping the film (F), so that at least one of the thrust members (20) comes to bear against at least one of these sliders (8) and exerts a thrust on this slider to assist the displacement of this slider along the rail (5e) on which this slider moves.