Advice

Polypropylene (PP) bonding: how it’s done

Polypropylene (PP) is a lightweight material and highly suitable for commercial vehicle construction. But how do you bond polypropylene (PP)? Our experts give tips for a rock-solid bond.

What is polypropylene (PP)?

Polypropylene (PP) is a lightweight plastic. It is used in sandwich panels such as MonoPan®, Twintex® and Holypan®. The core of the sandwich panel consists of PP honeycomb. This honeycomb is strengthened with a glass fiber-reinforced PP top layer.

If you would like additional information on bonding PP, please download our free flyer ‘PP bonding: how it’s done'. This explains the exact steps needed for a strong bond.

Download flyer >
 
SABA
PP sandwich panel
Lightweight transporter - Rapid Leichtbau GmbH
Advantages of polypropylene (PP)

Polypropylene (PP) is a lightweight but also very strong plastic. An ideal combination for commercial vehicle construction.

The use of PP enables you to produce lighter and, therefore, more environmentally friendly vehicles. It means less fuel consumption and lower emissions.

Lighter vehicles are also more flexible, faster and more aerodynamic, can carry heavier loads and are less of a burden on the infrastructure.
 

Can you bond PP, and if so, how?

PP naturally has fairly low surface tension and is therefore difficult to bond. At SABA, we therefore increasingly receive queries from the market on this theme. Our Research & Development team has conducted in-depth research and developed its own primers for bonding PP sandwich panels such as Monopan®, Twintex® and Holypan®.

Use primers

SABA Primer 4518 is suitable for pre-treatment of bare PP substrates. SABA Primer 9002 was developed for pre-treatment of the coated side of PP materials.

Please note!
A very large number of PP materials are available in the market. SABA has tested the most common materials, but cannot guarantee that the correct pre-treatment is recommended in this blog for all variants available in the market. We therefore recommend that you always contact SABA for a bonding test with the materials you use.
 

An excellent bond in just 3 steps!

Step 1: Clean the substrate
Are you unsure about whether the substrate is properly clean? By using a good cleaner such as Sabaclean 48, you will always be safe.

Apply the cleaner with a clean, lint-free (paper) cloth which you rub in one direction several times. Do not rub back and forth; you will only spread the dirt back over the substrate again. Let the substrate dry before you continue with the next step (the minimum drying time depends on the cleaner).
 
Also watch our instruction video for the right way to apply Sabaclean 48. Start video >

Step 2: Apply the primer
A primer fills small holes or irregularities so that an even, larger contact surface is created for a better bond. A primer undergoes a chemical reaction with the adhesive or sealant, for a better bond. A primer can also be applied with a clean, lint-free (paper) cloth, rubbing the product in one direction. 

Step 3: Bond the PP
After the pre-treatment has been completed, the PP can be bonded. PP bonding is possible with the Sabatack® product line.
 

Ask for our free flyer: ‘PP bonding: how is that done?’

If you would like additional information on bonding PP, please download our free flyer ‘PP bonding: how it’s done'. This explains the exact steps needed for a strong bond.

Download flyer

Did you know that if an adhesive bond fails, in about 90% of cases this is due partly to incorrect application?

This could be because of incorrect pre-treatment, for instance (or even no pre-treatment at all). For this reason, the DIN 2304 standard was developed. This standard is analogous to the ISO 9001 quality system and helps with process-secure bonding. Do you want to improve your bonding process? Then it is a good idea to keep to this standard. We do this at SABA too. 

Prof Andreas Groβ is head of the Personnel Training and Technology Transfer Department of Fraunhofer IFAM, a German research institute for production technologies and applied material research. As part of his work in the field of quality assurance for adhesive bonds, he has chaired the DIN/FSF working group on 'DIN 6701' and the ‘Adhesion and DIN 6701’ working group since 2001. 

Prof Andreas Groβ is also a member of the ‘DIN 2304’ working group. We spoke to him in detail about the DIN 2304 standard, which has been in force since March 2016.
 

Interview Andreas Groß
Customer experiences

KVB Chemnitz
On commission from KVB Chemnitz, SABA conducted a test of the bond (with Sabatack® 780) of profiles to WIHAG MonoPan® material. The result of this test showed that the bonding of Monopan® and the aluminum profile was excellent.

The video shows that the aluminum fixing rail is pulled apart, while the bond between the sandwich panel and the rail remains intact.

Twiga Travel Cars
Before Twiga Travel Cars switched to SABA, they used a polyurethane adhesive. However, the adhesion to MonoPan® was not entirely satisfactory. The switch to Sabatack® 750 optimized their bonding process.

Willem Thijssen, owner of Twiga Travel Cars, is happy to talk about his experience with SABA.
 

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