Q-Cel® Ultra-Light Hollow Microspheres
Automotive Putty: Small Particle Technology
In the past, many auto repair shops had to choose between two types of body repair putties: lightweight
putty that was easy to work or conventional heavyweight putty that produced a smoother surface but was
difficult to sand.
In addition to our standard putty grade Hollow Microspheres, Potters Hollow Spheres has introduced a
small particle-sized Hollow Microsphere, Q-Cel® 5020FPS, specifically for the auto-body repair market.
Putties made with these small particle-sized Hollow Microspheres maintain the smooth surface
characteristics of conventional resin-talc formulations. At the same time putties formulated with Q-Cel®
Hollow Microspheres also offer the advantages of lower overall cost and enhanced ease of handling that
characterise lightweight putties. A lightweight putty made with Q-Cel® Hollow Microspheres consumes
less resin during manufacturing and thus can be less expensive to produce than putty made with
conventional fillers.
Economic Benefits
Polyester resin accounts for 60 to 70% of the volume in heavyweight putties. When Q-CEL® Hollow
Microspheres are added to the formulation, resin content may be reduced to 50 to 60% by volume. The
spherical shape of Q-Cel® Hollow Microspheres presents a non-absorptive, low surface area and thus
permits a higher filler content.
Talc and other irregularly shaped platelets have a larger surface area, which in turn requires more resin to
wet-out. Lower resin consumption in a Hollow Sphere/polyester resin mixture can reduce total raw material
costs.
For purposes of illustration, we have compared simplified formulations of standard lightweight and small
particle sized putties in the table. The putties were made without colouring additives. Two batches of putty
were formulated to a viscosity of 150,000 cps. The Q-Cel® 5020FPS mix results in a smoother, finer
finish, when cured.
In actual manufacturing or laboratory conditions, the amount of resin in both the heavyweight and the
lightweight putties will vary as a function of the type of resin and heavy filler. Potters Hollow Spheres
technical representatives are available to work with you in formulating a putty suitable to the standards and
conditions of your business.
TYPICAL PUTTY FORMULATIONS
Component
Polyester Resin
Thixotrope
Talc
Q-CEL 5020FPS
Titania (TiO2)
TOTAL
Component
Polyester Resin
Thixotrope
Talc
Q-CEL 5020FPS
TOTAL
Formulation without Q-Cel® – Heavy weight Density of 1.79 g per ml
Weight kg
Weight %
Volume %
Volume litres
400
40
62
348
8
1
1
4
580
58
37
204
12
1
1
3
1000
100
100
558
Formulation with Q-CEL® – Intermediate weight Density of 1.26 g per ml
Weight kg
Weight %
Volume %
Volume litres
400
50
54
348
6
1
0
2
369
45
21
130
32
4
25
162
808
100
100
641
Information contained in this publication (and otherwise supplied to users) is based on our general experience and is given in good faith, but we are unable to accept the responsibility in respect of
factors which are outside our knowledge or control.
Potters Europe (EGM Division, Pottters Hollow Spheres & Potters Europe are trading names of Potters Ballotini Limited
Q-Cel®, Sphericel®, Spheriglass®, Spheriwhite® and Luxsil® are registered trademarks of Potters Industries LLC.
Ref:3-02-004-1-02
Component
Polyester Resin
Thixotrope
Talc
Q-CEL 5020FPS
TOTAL
Formulation with Q-CEL® – Light weight Density of 1.0 g per ml
Weight kg
Weight %
Volume %
Volume litres
400
58
50
348
6
1
0
2
232
34
13
82
52
7
37
259
808
100
100
690
Ease of Handling
A typical auto-body repair shop may spend twice as much on sandpaper as it does on putty. A lightweight
putty made with Q-Cel® Hollow Microspheres sands faster than a conventional heavyweight putty and will
not clog sandpaper as quickly. With a lightweight putty, consumption of sandpaper may be reduced.
Lightweight putties may be sanded soon after curing but will remain workable longer than conventional
putties. A longer total working time allows considerable latitude in scheduling shop labour and can result in
further economies.
Conventional sanding, primer coating and painting techniques are recommended for use with lightweight
putties formulated with Q-Cel®. Shop owners will appreciate the rapid sanding of the repaired area and
fine feather-edges.
Your sales representatives will be happy to calculate raw material costs for adding Q-Cel® Hollow
Microspheres to your system. They can also assist you in developing promotional materials and training
sessions for your sales force or distributors.
Automotive Putty Products and Formulating Procedures
Conventional heavyweight putty formulations typically contain about 40% by weight resin and 60% by
weight talc. Minor quantities of colouring pigment and fumed silica or another thixotropic agent may also
be present.
Lightweight autobody putties typically contain 4 to 6% by weight Q-Cel® Hollow Spheres. Proportions of
other materials in the formulation must be adjusted to produce a putty with a proper viscosity. Adjustments
in the formulation are dependent on the specific properties of the raw materials. Suggesting a general
starting formulation is difficult. Adjust the formulation to a suitable viscosity by fine tuning with the addition
of resin or hollow spheres.
Mixing Equipment and Methods
High-speed, high-shear mixing efficiently disperses the resin with the thixotrope and blends in the talc.
Hollow Microspheres, while strong enough for conventional mixing, cannot withstand mixers such as
Cowles dissolvers, dispersators, or roll mills that commonly are used in paint production. Horizontal mixers,
such as ribbon blenders or sigma blade mixers, are more suitable for use with Hollow Microspheres. A
planetary mixer or other vertical mixers at low shear and speed may also be used.
Variable speed mixers with two blades that operate independently also work well to blend in Hollow
Microspheres. Operate the mixer at high speed to incorporate talc, thixotrope and pigments into the resin.
Use the lower speed to disperse the Hollow Microspheres. Keep blending time for the Hollow
Microspheres to a minimum.
The best way to determine an acceptable formulation is to prepare a small batch in the laboratory. We
suggest a general procedure, expressed in grams (g), as a starting point.
Information contained in this publication (and otherwise supplied to users) is based on our general experience and is given in good faith, but we are unable to accept the responsibility in respect of
factors which are outside our knowledge or control.
Potters Europe (EGM Division, Pottters Hollow Spheres & Potters Europe are trading names of Potters Ballotini Limited
Q-Cel®, Sphericel®, Spheriglass®, Spheriwhite® and Luxsil® are registered trademarks of Potters Industries LLC.
Ref:3-02-004-1-02
Step 1 650g resin (or resin plus styrene), 15g of thixotrope
Mix for 10 minutes with a high-shear mixer. If you do not add a thixotrope, skip this step and add all the resin with the
talc.
Step 2 1000g resin (remainder), 1200g talc
Add these materials to the mix and continue high-shear mixing for another 10 minutes. At this point a colouring
pigment may also be added.
Step 3 150g Q-Cel® Hollow Microspheres
Add about half of the Hollow Spheres and mix on the lowest speed of a planetary type mixer for one to three minutes.
Step 4 Add the balance of the Q-Cel® Hollow Microspheres.
Continue low speed mixing for an additional one to three minutes.
Step 5 Observe viscosity and trowelability of the putty.
Use a viscometer if one is available.
Putty should not slide off a spatula but should remain mixable at proper viscosity. If the viscosity is too
high, add more resin. If the viscosity is too low, add more Q-Cel® Hollow Spheres in one part by weight
increments.
Adjustments to Formulations
Products made for local markets may not require a thixotrope to maintain a homogeneous mixture if the
product is not scheduled to be stored for long periods. In moderate climates, where longer storage may be
anticipated, 0.5 to 1.0% thixotrope may be required to keep the mixture homogeneous. In hot climates, we
suggest adding 1.0 to 1.50% fumed silica or another thixotrope.
Use great caution in adjusting amounts of resin, talc, thixotrope and Q-Cel® Hollow Microspheres. For
example, changing the weight loading of Q-Cel® from 5.0 to 5.5% will increase viscosity and may make the
putty too stiff to mix. Test changes in formulation in the laboratory before making the change in production.
A PQ Hollow Spheres technical service representative can assist in customising your formulation or with
any Q-Cel® product handling difficulties.
Safety Information
Q-Cel® Hollow Spheres are moderately alkaline, and prolonged exposure may irritate the respiratory tract.
In dusty environments, the use of a NIOSH-approved mask or respirator is recommended. Material Safety
Data Sheets (MSDS) can be supplied on request.
Other Product Range:
Sphericel® Ultra-Fine Weight Reducing Hollow Glass Microspheres
Spheriglass® Performance-Enhancing Solid Glass Microspheres
Spheriwhite® Colour-Enhancing Solid Glass Microspheres
Luxsil® Cosmetic Microspheres
For further information about our range of Hollow Glass Microspheres, please do not hesitate to contact us:
Potters Hollow Spheres
Pontefract Road
Tel. +44 (0) 1226 704 516
Barnsley S71 1HJ
Fax. +44 (0) 1226 207 615
South Yorkshire
E-mail: [email protected]
United Kingdom
Website:www.potterseurope.com
Information contained in this publication (and otherwise supplied to users) is based on our general experience and is given in good faith, but we are unable to accept the responsibility in respect of
factors which are outside our knowledge or control.
Potters Europe (EGM Division, Pottters Hollow Spheres & Potters Europe are trading names of Potters Ballotini Limited
Q-Cel®, Sphericel®, Spheriglass®, Spheriwhite® and Luxsil® are registered trademarks of Potters Industries LLC.
Ref:3-02-004-1-02