Thermic-welded cover with fixed laminations




Thermic-welded cover with fixed laminations
Bellows with fixed laminations are used on every type of machine tool: often used in machining centres and metal-cutting machines.
Metal elements, called “laminations”, protect the bellows from shavings and prevent damages.
PEI thermo-welded flat bellows are composed of:
- Bellows (3): fabrics resistant to water, oil, coolants, dust and shavings.
- PVC supports (4): give rigidity to the entire bellows and are cut to size according to the profile of the customer’s guides.
- Connection flanges (1 and 2): for simple attachment to the machine.
Working positions:
– Horizontal
– Vertical
– Frontal
Data
Data

Definition of data for the calculation of the closed length of PEI thermic-welded flat bellows
P.A. = Open length
P.C. = Closed length
LC (Stroke) = Open length – Closed length
AP = Open fold
B = Bellows size
a = Bellows height
x = Fold height

Overall dimensions of the fixed laminations as a function of the width of the bellow fold
| Bellows fold width = | x (mm) | 15 | 20 | 25 | 30 | 35 | 40 | 45 |
| Lamination stack thickness = | L (mm) | 16 | 21 | 26 | 33 | 43 | 48 | 56 |
| Size of the laminations above the rails = | Z (mm) | 45 | 55 | 65 | 75 | 85 | 95 | 105 |
Formulae

Indicative formula for the calculation of the closed length of thermo-welded flat bellows with fixed laminations
Contact our technical office

Example of calculation
* We hypothesize that the material of the bellows is the code “TEMAT151”
** We hypothesize that the thickness of the support is 1 mm
*** We hypothesize that the thickness of the flange is 3 mm
Standard Materials
Standard Materials
The fabrics selected by PEI have excellent mechanical resistance and resist bending and bending that occur during operation in the machine. They have excellent resistance to petroleum products, oils and strong abrasion, small welding splashes or incandescent material.
The fabric material list is currently being updated for the 2027 edition.
Contact info@pei.it to request the updated version.
Flanges
Fixing

- = Flange
Attachment flange fixing system
– Type A and Type I
- Solution with connection flange Type A: Flange covered by the fabric of the bellows (without last support)
- Solution with connection flange Type I: Painted flange fixed to the last support of the bellows
- Solution with sheet steel, aluminium or PVC flange
- Shape and drilling according to the customer’s drawing

Attachment flange fixing system
– Type B1 and Type B2
- Solution with connection flange Type B1: Flange that protrudes entirely from the shape of the bellows
- Solution with connection flange Type B2: Flange that protrudes externally with respect to the shape of the bellows
- Solution with sheet steel, aluminium or PVC flange
- Shape and drilling according to the customer’s drawing

Attachment flange fixing system
– Type C
- Solution with Type C attachment flange: Painted flange fixed to the last support of the bellows with threaded holes
- Solution with sheet steel flange
- Shape and drilling according to the customer’s design
- Threaded flange holes

- = PVC cover stiffener
- = Strip of Velcro applied to the machine
- = PVC stiffener
- = Flange
- = Strip of Velcro applied to the machine
Attachment flange fixing system
– Type E and H
Solution using VELCRO type quick fixing.
The task of the attachment flange is carried out by a PVC support to which VELCRO is applied. A Velcro strip is applied directly to the machine.
This solution offers the following advantages:
- Quick application and removal of the bellows
- Reduced cost
Recommended in dry work environments

- = PVC stiffener
- = Flange
- = PVC stiffener
- = Flange
- = Counterflange
Attachment flange fixing system
– Type F and G (Entire fold in PVC)
Solution through HIGH TENACITY quick fixing.
The attachment flange is made of sheet steel, aluminium or PVC, with shape and drilling according to the customer’s design.
This solution offers the following advantages:
- Quick application and removal of the bellows
- Perfect perimeter sealing by applying mousse.
Recommended in a humid working environment
Structures
Structures

Standard structures for flat thermic-welded bellows
UL-OS = Folding fabric only
UL-2ST = Thermic-welded bellows with two weld seams and pull-out stop inside the bellows
UL-1S = One-sided bellow with PVC supports
UL-3S = One-sided thermic-welded bellows with three welded edges
DL-DXC = Thermic-welded bellows with two welded edges
TL-SIM = Thermic-welded bellows with three welded edges, symmetrical shape
TL-DXC = Thermic-welded bellows with three welded edges, asymmetrical shape
TL-DXI = Thermic-welded bellows with three welded edges, slanted shape
CL-SIM = Thermic-welded bellows with five welded edges, symmetrical shape
QL-QUAD = Thermic-welded bellow, square shape
QL-CAP = Thermic-welded bellow, roof shape
QL-RETT = Thermic-welded bellow, rectangular shape
QL-ASI = Thermic-welded bellows with four welded edge, asymmetrical shape
CL-ASI = Thermic-welded bellows with five welded edge, asymmetrical shape
