Flat protective bellows with mobile blades
Flat heat-sealed bellows with mobile blades
Flat heat-welded protective bellows with movable blades are widely used on all types of machine tools: their use is very frequent on machining centres. To protect the flat bellows when they are hit by hot chips, it is necessary to shield metal elements, called “lamellae”. The fixing system of the mobile blades on the flat bellows uses springs housed in special clips. These keep the blades adherent and loaded on top of each other to prevent the entry of contaminants and shavings. At the same time, they allow rotation of up to 90 °, to facilitate the fixing of the flat bellows flanges with mobile blades to the machine tool.
PEI thermo-welded flat bellows are made up of:
- Blades in steel Inox: they form the shield from hot and incandescent chips.
- Bellows: (3) made with fabrics resistant to water, oil, coolants, dust and shavings.
- Supports in PVC: (4) they give rigidity to the entire bellows and are cut to size according to the profile of the customer’s rails.
- Connection flanges (1 and 2) for simple attachment to the machine.
The working position of this application with movable blades are:
-Vertical
Data
Data
Definition of data for the calculation of the closed pack of PEI heat-sealed flat bellows
P.A. = Open parcel
P.C. = Closed parcel
Corsa = Open parcel – closed parcel
B = Bellows size
a = Bellows height
x = Fold height
Overall dimensions of the fixed blades as a function of the width of the bellow fold
| Bellows crease width = | x (mm) | 15 | 20 | 25 | 30 | 35 | 40 | 45 |
| Overall dimensions of the blade above the rail = | Z (mm) | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
Formulae
Indicative formula for the calculation of the closed pack of thermo-welded flat bellows with mobile blades
Contact our technical office
Example of calculation
* Let us hypothesise the material of the bellows with the code
“TEMAT151”
** Let us assume that the thickness of the support is 1 mm
*** Let us assume that the thickness of the flange is 2 mm
Standard materials
Standard materials
The fabrics selected by PEI have excellent mechanical resistance and resist bending and folding that occur during operation in the machine. They have excellent resistance to petroleum products, oils and strong abrasion, small welding splashes or incandescent material.
Main strength characteristics of the bellows materials:
| Fabric material code | Description | Thickness (mm) | Heat resistance | Primary resistance characteristics | ||||
| Visible side | Fabric insert | Internal side | Momentary contact °C | Continuous | ||||
| min. °C | max. °C | |||||||
| TEMAT 106 | Ptfe | Polyester | 0,30 | +200 | -30 | +120 | Excellent resistance to oils and chemical products. No adhesive surface. Low friction coefficient. Excellent chemical inertia. Excellent resistance to abrasion and bending strength. Mainly used in grinding machines. | |
| TEMAT 015 | Polyurethane | Polyester | Polyurethane | 0,25 | +200 | -30 | + 90 | Excellent resistance to petroleum products, oils and heavy abrasion. Excellent bending strength. |
| TEMAT 151 | Polyurethane | Polyester | Polyurethane | 0,35 | +200 | -30 | + 90 | |
| TEMAT 164 | Polyurethane | Kevlar* | Polyurethane | 0,35 | +350 | -30 | +180 | Excellent resistance to petroleum products, oils and heavy abrasion. Excellent bending strength. Excellent mechanical strength. Kevlar also has excellent shear strength. Normally used when there is heavy mechanical stress, a large amount of sharp shavings, and at high temperatures. |
| TEMAT 165 | Polyurethane | Nomex* | Polyurethane | 0,36 | +300 | -30 | +130 | Excellent resistance to petroleum products, oils and heavy abrasion. Excellent bending strength. Excellent mechanical strength. Good resistance to minor welding splatter or hot material. Widely used in laser cutting machines. Self-extinguishing. |
| TEMAT 169 | Polyurethane | Panox*/Kevlar | Polyurethane | 0,33 | +300 | -30 | +130 | Excellent resistance to petroleum products, oils and heavy abrasion . Excellent bending strength. Excellent mechanical strength. Good resistance to minor welding splatter or hot material. It may be considered as the best fabric on the market for use in laser cutting machines. Self-extinguishing. |
| TEMAT 017 | PVC | Polyester | PVC | 0,36 | +100 | -30 | + 70 | Mainly used around heavy ambient dust, minor splatters of coolant and oil. Also suitable for use around acids. |
| TEMAT 020 | PVC | Polyester | PVC | 0,25 | +100 | -30 | + 70 | |
Other SPECIAL materials are available for specific sectors of use. Ask our technical department
| Materials for the attachment flanges | |||
| Material supports | Description | Thickness (mm) | Notes |
| PVC 05 | PVC | 0,50 | Bellows length (B) up to 300 mm |
| PVC 10 | PVC | 1,00 | Bellows length (B) from 301 to 700 mm |
| PVC 15 | PVC | 1,50 | Bellows length (B) from 701 to 1500 mm |
The PVC support, shaped to measure with the structure of the customer’s rails and welded to each fold of the bellows, gives the heat-sealed bellows excellent stability.
| Flange material | Description | Thickness (mm) |
| AL | Aluminium | 2-3-4-5 |
| INOX | AISI304 | 1-1,5-2-2,5-3 |
| AC | Carbon steel | 1-1,5-2-2,5-3-4-5 |
| PVC | PVC | 1-1,5-2-3 |
The anchoring of the bellows to the machines takes place through the end part of the bellows equipped with rigid flanges in aluminium, stainless steel, carbon steel and PVC.
Flanges
Fixing
- = Flange
Attachment flange fixing systems
-Type A et Type I
- Solution with connection flange Type A: Flange covered by the fabric of the bellows (without last support)
- Solution with Type I attachment flange: Painted flange fixed to the last support of the bellows
- Solution with attachment flange in steel, aluminium or PVC sheet
- Shape and drilling according to the customer’s design
Attachment flange fixing systems
–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 attachment flange in steel, aluminium or PVC sheet
- Shape and drilling according to the customer’s design
Attachment flange fixing systems
–Type C
- Solution with Type C attachment flange: Painted flange fixed to the last support of the bellows with threaded holes
- Solution with steel sheet attachment flange
- Shape and drilling according to the customer’s design
- The flange holes are threaded
- = PVC cover stiffener
- = Strip of Velcro applied to the machine
- = PVC stiffener
- = Flange
- = Strip of Velcro applied to the machine
Attachment flange fixing systems
–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 systems
–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 heat-sealed bellows
UL-2ST = Thermo-welded bellows with two welds and internal traction strap
Documentation
Questionnaire
