[0001] The present invention relates to a method for changing the width and/or length of
a sandwich construction unit, said construction unit comprising a core element of
some thermally insulating material, having surface sheets attached to its two opposite
major surfaces.
[0002] Sandwich construction units are typically manufactured on a production line in certain
modular sizes, e.g. in a width of 1200 mm. Occasionally, however, it is necessary
to use a unit narrower than the standard width, for example for the highest row of
units in a system of tongued-and-grooved units to be mounted on top of each other,
or along a row of windows, which causes problems, especially in cases that such a
narrower unit must also have both of its opposite edges profiled.
[0003] Accordingly, it is an aim of the present invention to provide a method, which can
be used for reducing the width and/or length of a sandwich construction unit in such
a way that the downsized unit also has profiled edges. In order to accomplish this
aim, a method of the invention is characterized in that the method comprises splitting
and/or breaking the unit by cutting it longitudinally and/or laterally along a desired
line, followed by removing a piece of core element material from alongside the cut
edge to enable edge-profiling devices to fit in a space between the surface sheets,
followed by reprofiling the cut edge of the surface sheets and by replacing the removed
piece of core element material with a fresh piece of core element material.
[0004] According to one aspect of the invention, the method is applied to a construction
unit, which construction unit comprises a core element of some thermally insulating
material, having edge-profiled surface sheets attached to its two opposite major surfaces
with a bonding agent, whereby, in the process of manufacturing the unit, the method
comprises coating the inner surface of the unit's surface sheets along a desired cutting
line of the unit with a relatively narrow protective layer extending longitudinally
and/or laterally of the unit for preventing the adherence of a bonding agent to the
inner surface of a surface sheet, followed by attaching the surface sheets to the
core element by means of the bonding agent, whereafter the unit is cut along said
protective layer and the necessary removal of core element material is performed prior
to reprofiling the edge.
[0005] According to a second aspect of the invention, the method is applied to a construction
unit, in which construction unit a core element is formed by foaming a thermally insulating
material into a space between two surface sheets, whereby the foamed core element
material adheres to the surface sheets, whereby, in the process of manufacturing the
unit, the method comprises coating the inner surface of the unit's surface sheets
along a desired cutting line of the unit with a relatively narrow protective layer
extending longitudinally and/or laterally of the unit for preventing the adherence
of a foamed core element material to the inner surface of a surface sheet, followed
by foaming the core element material into a space between the surface sheets, whereafter
the unit is cut along said protective layer and the necessary removal of core element
material is performed prior to profiling the edge.
[0006] The invention will now be described in more detail with reference to the accompanying
drawings, in which:
- Fig. 1
- shows schematically a surface sheet used in a sandwich construction unit, and
- Figs. 2 -5
- show various phases in changing the width of a unit in schematic views.
[0007] The unit shown by way of example in the figures comprises a core element 2 of a thermally
insulating material, such as, for example, mineral wool, having surface sheets 3 and
4 attached to its opposite surfaces by means of a bonding agent, the opposite lengthwise
edges of said sheets being formed with edge profiles 5 and 6 for fastening adjacent
units to each other with a tongue-and-groove joint. The tongue is represented by reference
numeral 5 and the groove by reference numeral 6.
[0008] In a method of the invention, the unit 1 is first split along a desired line to a
certain width, e.g. by means of a saw represented in fig. 2 by reference numeral 9.
This is followed by removing from the unit a piece of core element material from alongside
a split edge 5a, for example to the depth of about 50 mm, and possible traces or residues
of the bonding agent and/or thermally insulating material are finally scraped off
the sheet's inner surface. The removal of the thermally insulating material can be
performed for example by means of a plane device 7 shown in fig. 3. Fig. 4 illustrates
the positioning of profiling rollers in a gap between the surface sheets 3 and 4 in
a space vacated by a planed-off piece of thermally insulating material 2a, and fig.
5 illustrates a split unit 1 formed with a new profile 5, the formation of said edge
profile being followed by replacing a fresh piece of thermally insulating material
2b in the vacated space between the surface sheets 3 and 4. After this, the narrowed
unit is ready for service. The added piece of thermally insulating material 2b may
consist of previously removed thermally insulating material or it may consist of a
fresh thermally insulating material, possibly even a material other than the previous
one.
[0009] Fig. 1 depicts one preferred implementation of the method, in which the unit's surface
sheets 3 and 4 are first coated with a protective layer 9 along a desired cutting
line, prior to attaching the surface sheets to the core element 2. The protective
layer can be applied prior to profiling the surface sheets 3, 4 on a production line,
or during or after the profiling process. The protective layer may comprise, for example,
a tape or an adhesive film, or a liquid material which sets on the inner surface of
a surface sheet to form a desired protective layer, or a greasy type of material,
and said protective layer being relatively easily removable from the sheet's inner
surface. By virtue of this protective layer 9, the removal of a bonding agent, intended
for the attachment of a core element and particularly a core element and a surface
sheet, to be performed after splitting the unit, will be considerably easier from
alongside a cut edge than the removal of a bonding agent from the surface sheets'
inner surface by scraping or in a similar fashion. The inventive method can be carried
out either on an installation site or completed in a factory, as the case may be.
[0010] Besides or in addition to the narrowing of a unit, the inventive method can be used
for the shortening of a unit and it is also applicable to reducing the width and/or
length of units with all edges tongued and grooved. The core element material may
comprise e.g. mineral wool or a corresponding heat insulating material, which is attached
by means of a bonding agent to surface sheets, or the thermally insulating material
may comprise a foamed material, which adheres directly to surface sheets when applied
in a space between the surface sheets.
1. A method for changing the width and/or length of a sandwich construction unit, said
construction unit (1) comprising a core element (2) of a thermally insulating material,
having surface sheets (3, 4) attached to its two opposite major surfaces, characterized in that the method comprises splitting and/or breaking the unit (1) by cutting it longitudinally
and/or laterally along a desired line, followed by removing a piece of core element
material (2a) from alongside the cut edge to enable edge-profiling devices (8) to
fit in a space between the surface sheets (3, 4), followed by profiling a cut edge
(5a) of the surface sheets and by replacing the removed piece of core element material
(2a) with a fresh piece of core element material (2b).
2. A method as set forth in claim 1, wherein the construction unit (1) comprises a core
element (2) of some thermally insulating material, having surface sheets (3, 4) attached
to its two opposite major surfaces, characterized in that in the process of manufacturing the unit (1), the method comprises coating the inner
surface of the unit's surface sheets (3, 4) along a desired cutting line of the unit
with a relatively narrow protective layer 9 extending longitudinally and/or laterally
of the unit for preventing the adherence of a bonding agent to the inner surface of
a surface sheet, followed by attaching the surface sheets (3, 4) to the core element
(2) by means of the bonding agent, whereafter the unit is cut along said protective
layer and the necessary removal of core element material is performed prior to profiling
the edge.
3. A method as set forth in claim 1, wherein a core element in said construction unit
is formed by foaming a thermally insulating material into a space between two surface
sheets, whereby the foamed core element material adheres to the surface sheets, characterized in that in the process of manufacturing the unit, the method comprises coating the inner
surface of the unit's surface sheets along a desired cutting line of the unit with
a relatively narrow protective layer extending longitudinally and/or laterally of
the unit for preventing the adherence of a foamed core element material to the inner
surface of a surface sheet, followed by foaming the core element material into a space
between the surface sheets, whereafter the unit is cut along said protective layer
and the necessary removal of core element material is performed prior to profiling
the edge.
