Stains; Marking The Masking; Storing The Material; Machining Methods - Vetus Poly-wood Instrucciones De Instalación

1.9.2 Stains

Poly-wood is resistant to most stains. However, Poly-wood can be
stained by some materials.
The most common problem is with teak oil. Teak oil can cause per-
manent stains when it comes in contact with Poly-wood.
When marking the Poly-wood, use China markers or wax pensils that
wipe off easily. Do not use pencils, pens or magic markers which can
leave a permanent discoloration.

1.9.3 Marking the masking

If you should find it necessary to write on the masking, for identifi-
cation purposes, you may use a grease pencil or certain felt tip mark-
ers.

1.9.4 Storing the material

The product should be stored flat or if necessary inclined (fully
supported) at no more than a 10° angle.
2

Machining methods

2.1

General instructions

Thermoplastics can be given a machine finish with all known tools
used in wood and metal processing.
The normal machining operation becomes one of friction and defor-
mation, with most of the energy finally converted into heat.
Metals are generally good thermoconductors. Thermoplastics are
approx. 100 to 1000 times less thermoconductive than steel.
Where there is a large amount of machining to be done, it is advisa-
ble to work at high cutting speeds and law depth. Parameters such as
tool size, feed, cut and input speed shall be selected to remove heat
produced with the chip.
Deeper cuts should be tooled so that the materiaI does not smear or
melt. Cooling can be provided by means of compressed air or emul-
sions. Exceptionally smooth surfaces and finished parts with high
tolerance specifications must be cooled during machining.
2.2

Stresses in semi-finished products

Semi-finished plastic products produced by extrusion or pressing
have varying levels of internaI stress. Such stresses are usually caused
by the process, not external forces. Semi-finished products which are
straight, flat and within tolerance will balance stress. Mechanical pro-
cessing disturbs this equilibrium and can distort the part concerned.
2.3

Machining technology

Nearly all high speed tools used in the timber and metal industries
are able to machine our materials. Efficient removel of swarf is essen-
tial to prevent build up of heat in the machining zone. Any heat pro-
duced should be removed together with the swarf. Swarf removaI is
possible by rinsing with coolant, vacuuming or both. Using a coolant
has a positive effectt on the surface quality achieved. Coolants can
be used freely with Poly-wood, as there is no moisture absorption.
2.4

Choice of tool

High-speed steel is adequate for cutting Poly-wood. Carbide tipped
tools are long-lasting and achieve high productivity. 'K' type hard
10
110705.01
metals (K 10) are best due to their low thermal expansion coefficients
and high thermoconductivity.
Minimum cutting force is required for machining plastic. Blunt
blades require greater force for cutting and produce a poorer surface
finish. Working life is particularly affected by cutting speed, feed and
width and depth of cut.
The greater the clearance and rake angle, the less cutting force is
involved. To avoid excessive weakening of the cut wedge, there are
limits to the clearance and rake angle that may be used. The cut-
ting force should run in the direction of cut. Selecting the rake an-
gle allows the direction of working to affect the processed material.
Spiral-toothed end mills have proved suitable in practice. Take care
during machining to avoid deep scoring or sharp crossover marks
which, given the known notch effect, can cause early breakage of the
material under load. Final polishing with a polishing wheel can im-
prove surface finish. Edges left after sawing, drilling or milling can be
reworked with blunt scrapers or special deburring equipment and
chamfered. The following tables give guidelines for the machining
process. Data for machi ning plastics is given in VDI Guideline 2003.
2.5

Methods of processing

2.5.1 Sawing

Fast-running band and circular saws are suitable for cutting thermo-
plastic materials. The cut surfaces can be smooth when the teeth are
lightly set. Saw blades with teeth more than 15 mm apart have been
shown to produce a better quality cut. Hard metal saw blades im-
prove performance and have a longer working life.
a Clearance [degrees]:
10-15 HM / 30-40 SS
g
Rake angle [degrees]:
0-5 HM / 3-8 SS
t Gullet [mm]: 5-10
Set [mm]: 0.8-1.0
Cutting speed [m/min]: 3000
Feed [mm/tooth]: 0.1-0.3

2.5.2 Planing

Surface and panel planers used in woodwork are also suitable for
Poly-wood. Surface quality largely depends on feed, cutting speed,
clearance and rake angle as well as ths state of the cutters. The ma-
chines should have extra strong bearings.
Clearance [degrees]: 15-30
Rake angle [degrees]: 15-20
Cutting speed[m/min]: 3000
Feed [mm/tooth]: 0.1-0.3

2.5.3 Milling

In milling, particular care should be taken to keep the machining
cross-section as large as possible, to reduce heat generation. Cutting
depth and feed also need to be Iarge, and cutting speeds low. Fast
woodworking machines with fairly high feed rates and rpm have
been used as well as universal milling machines from mechanical
engineering.
polywm002
Poly-wood