Screw Design MultiTM-Purpose Posi-Melt XLTM

Features of the PM Posi-Melt XL

Meter depths designed for maximum

throughput.

Average of 45% more exposure to the

barrel wall for more efficient melting.

Stepped design adds a high degree of

mixing to the melt stream.

Extended melting lengths compared to a

standard GP design.

More thorough melting while using a low

compression design.

Large leading and trailing flight radii for

pressurized flight channels and no mate-

rial contamination.

Positive feeding pressure, designed to

feed even the hard to feed materials.

Low RMS value for better solids convey-

ing.

Consistent recovery times on all screw

sizes.

Feed lengths based on resin type and

application.

POSI-MELTTM METERING SECTION

TRANSITION SECTION

FEEDING SECTION

R e s u l t s : W e i g h t d i s p e r s i o n o f t h e m o ld e d p a r t s c a n b e r e d u c e d d u e t o a m o r e u n i f o r m m e l t

p o o l .

. 4 0. 7 1C O E F F I C I E N T O F V A R I A T I O N

3 . 97 . 0V A R I A T I O N o f R A N G E ( M m a x M m i n )

. 8 11 . 3 8S T D . D E V I A T I O N

9 8 2 . 79 8 8 . 9A V E R A G E W T . ( G R A M )

A d v a n c e dD e s i g n

G P D e s i g nI T E M \ S C R E W

. 4 0. 7 1C O E F F I C I E N T O F V A R I A T I O N

3 . 97 . 0V A R I A T I O N o f R A N G E ( M m a x M m i n )

. 8 11 . 3 8S T D . D E V I A T I O N

9 8 2 . 79 8 8 . 9A V E R A G E W T . ( G R A M )

A d v a n c e dD e s i g n

G P D e s i g nI T E M \ S C R E W

Md Plastics Incorporated 1361 Wardingley Ave., Columbiana, OH., 44408 USA

(330) 482-5100 fax (330) 482-5211 www.mdplastics.com

Channel volume controlled by previous

channel meter depths for low pressure

loss.

Disruption of melt stream with exten-

sional strain, relaxation and cross flow

for distributive mixing.

SMQI of at least 6.0 times better than

a GP design.

XL MIXING SECTION

The revolutionary MultiTM-Purpose Posi-MeltTM

screw is the Ultimate Multi-Purpose screw for tough

injection molding applications. The XLTM design adds

a high degree of additional melting and mixing to the

polymer making this design one of the most advanced

designs in the world. Repeatability and melt homoge-

neity are the basis for high productivity from an

injection unit. From a process engineering perspective,

the control variables that help us determine the

correct injection screw design are: Resin type,

Residence time, Swept volume, Plasticating rate,

Screw torque, Cycle time, Melt temperature and Melt

homogeneity. When the application demands precise

color match with residence times lower than 90 se-

conds only an advanced design such as the XL will be

able to deliver a quality molded part (see fig. 2).

Patent Applied For

Better melting and mixing at a cooler processing tem-

perature means higher quality molded parts, (see

results graph) greater yields and increased profits!

fig. 2