Green Packaging Material--- the Application Study and Market Prospect of Molded
Pulp Technology
Ting Li 1, Chang Xiao2
1
2
Institute of Art & Fashion, Tianjin Polytechnic University, Tianjin, China
Institute of Art & Fashion, Tianjin Polytechnic University, Tianjin, China
(251985214@qq.com, 79874397@qq.com)
Abstract - At present, the new green packaging material
is exactly a hotspot of current packaging material
researching. At the same time, the exploration of green
packaging material has been the most active field of
packaging science. The application of packaging material
will definitely influence function of the wrap page and
impression of the packaging design. The pulp molding
material, as the typical green packaging material, will draw
much attention of researchers, due to its recyclability and
remarkable market prospect.
At present, the pulp molding material has been mainly
used into two fields: food packaging and industrial
packaging [3].
TABLE I
FOOD PACKAGING AND INDUSTRIAL PACKAGING
Application Areas
Medical appliance
Solider article packaging
Keywords - Green packaging material, molded pulp,
recyclability, market prospect
Glass and ceramic fragile
Planting seeding
I. INTRODUCTION
The pulp molding industry has a history for several
decades in some developing countries. Now, it has been
developed on a large scale in some countries, such as
U.S.A, Japan, and Canada and so on. The raw materials of
pulp molding products are almost waste paper. The
number of its products has grown by 40% or so per year
since 1994. In China, the pulp molding industry also has
more than 20 years history, and it had been invested into
amount of money and manpower[1].According to
incompletely statistics, there are about four to five
hundred manufacturers who are engaging in producing
and equipment manufacturing of pulp molding, so it has a
remarkable market prospect.
II. METHODOLOGY
A. Definition of Molded Pulp
Pulp molding material is made of certain
concentration of dehydrated paper pulp by vacuum or
pressing method with defined amount of chemical
accessories in molding machine with a filter. This
material could be recycled [2].Because of its special
geometry, it has some prime functions, for example,
earthquake prevention, impact resistance, antistatic and its
protection function to the inner contents due to its
elasticity and the similar or better containing quality than
foamed plastics in force testing.
B. Application areas of pulp molding material
Table ware
Auto industry
Material Advange
Exempt disinfect, no poisonous effect,
affordability
Good buffering, plasticity, moisture-proof,
antistatic, anti shallow radiation
Sanitation, cushioning, low crafting
requirement, controllable cost
It is not necessary for second transplant,
time and labor saving
Low cost and high safety
Component protection packaging, it has
been applied for more than 40 years in
some overseas enterprise
C. Age demand of pulp molding material application
1) Selecting principle of sustainable development:
The recyclable, degradable raw material that has no
pollution to human and environment throughout its usage
cycle should be selected.
2) Selecting packaging design and material
appropriately: In China, there are a lot of over-packaging
phenomena now. These packaging pursue modeling and
high grade packaging blindly, so the packaging cost is
skyrocketed even more expensive than contents wrapped
in. It increases the burden on consumers and waste
packaging material. According to the statistic of
Sanitation Sector, among about 3 million tons rubbish,
varied merchandise packages are about 830 thousand tons.
Among that packaging rubbish, excessive packages
occupy 600 thousand tons, which could have been
reduced [4].
3) Showing specific aesthetic and design style
through pulp molding material selecting: [5]Getting rid of
similarity and exploring creativity are pursued by
domestic and foreign enterprises. It is necessary for us to
concern with the product design from form and color
perspectives, together with pursuing functionality of the
packaging [5].
D. The problems about packaging material’s application
and exploration
1) The functional quality and protection requirements of
the packed commodities for selling.
2) The manufactural technique and usability of the
material.
3) The manufactural technique and usability of the
material.
4) The consistency of sanitary quality, material and
commodities.
5) The requirements of external packing design and
printing.
6) The environmental and economic nature of the
packaging material [6].
E. The problems about packaging material’s application
and exploration
Characteristics of molded pulp, The mechanics and
physical characteristics of molded pulp are presented as
following:
TABLE II
MECHANICS CHARACTERISTICS
Mechanical property
Tensile strength
Overview
The maximum pressure beared by
per sectional unit area
The maximum pressure endured
by per unit area
The bursting capability of surface
and coating film
The power needed for tearing
certain length at a specific cut on
pulp molding product
Bursting strength
Surface strength
Tear resistance
Loading capability
Folding capability
Tension resistance
Hot and humid weight-bearing
Transmitted intensity
The changes of form under certain
pressure
The number of folding times
between two 180 degree flat
surfaces
The tension needed for tearing
pulp molding flat surface
The bursting characteristic under
certain temperature
The power needed for an article to
pierce through a pulp molding flat
surface
Raw material selection. Waste paper, the raw material
of pulp molding production, has extensive sources,
abundant supplies and is low costing[8].
1) Recycling of waste paper.
2) Selection of wastepaper: It is necessary to classify,
store and dispose separately the wastepaper depending on
its types, properties and purposes. When the wastepaper is
selected, it also need to be filtered some impurities, such
as metal, sawdust and gravel and so on, in order to get
certain purity grade.
3) Classifying of wastepaper: The sources, collecting
funnel, quality and wastepaper fiber types are the
conditions to classify the recycling wastepaper.
The manufactural process of raw is wastepaper
material. Due to the different wastepaper types and
different kinds of final products that it makes, the
processing procedure and equipments needed are also
different. Generally speaking, the processing procedure
has the following steps: wastepaper classifying,
wastepaper pulp separation, optimization and purification,
deinking, concentration, bleaching and pulping. [9]
The general procedure of pulping includes four phases:
pulping separation, optimization, purification and
concentration [9].
1)
Pulping separation: separating the wastepaper
into fiber and fiber suspension, and parted the solid
pollutant and some kind of bulky impurities from the
wastepaper effectively under the condition of protecting
the fiber original tension to the furthest.
2)
Defibering: the process of pulping the
disintegrated wastepaper into a single fiber.
3) Optimization: removing the impurities and solid
pollutants from the recycled pulping as much as possible,
and reducing the loss of fiber to the furthest during the
pulping process [10]. The following picture shows the
Isolation of the curve. (Figure .1)
TABLE III
PHYSICAL CHARACTERISTICS
Physical characteristics
Whiteness
Precision
Moisture
Breathability
Water resistance
Thermal insulation
Overview
The clean situation of pulp
molding product
Per cubic centimeter quality
Moisture of per unit area
Air passing quantity of per minute
under vacuum condition on certain
unit area
The capability of resisting water
during a certain period of time
The capability of insulating heat
source during a certain period of
time
F. The manufactureral techniques of pulp molding plastic
product[7].
Fig. 1. Optimization
4)
Purification: centrifugal purification means to
remove, to the furthest, the impurities that degrade the
quality of the pulping and abrade the equipment, such as
the gravel, metal piece, glass, plastic and other light
plastic material impurities.
5)
Concentration: after the optimization, it is
necessary to dehydrate the pulping and concentrate to
certain required density, in order to fulfill the following
manufactural procedure requirements--- removing pitch,
deinking and bleaching.
The molding process of pulp molding production [11].
1) Vacuum fine pulp molding process: The vacuum
fine pulp molding process means to put a mould with wire
net into the attenuate pulp. It formed the vacuum
environment in the mould cavity. Under the vacuum
environment, a layer of pulp fiber will be sucked onto the
surface of the mould wire net, and then we could get the
pulp molding product.
2)
Casting method: The pulp will flow from the
pulp box onto the mould with wire net, and water will
flow away through the mesh, however, the fiber will be
left on the surface of the mould. When the water runs off,
the wet molded pulp could be removed, and it will be
extruded and made drying.
3)
The method of hydroform: The pulp should be
sent into the batcher with stuff pump from pulp vat, after
that, pouring drainage molding device. Then, the
extrusion head, under the hydraulic pressure action, will
stretch into the former to extrude the pulp. [Water will be
eliminated from the mesh of the reticular membrane, and
the fiber will be molded between the reticular membrane
and extrusion head. After the molding, the extrusion head
will connect to vacuum to suck out the molding from the
mould, then, connect to compressed air to seperate the wet
molding and the extrusion head.
4)
Compressing air method: The fiber pulp will be
input to the pulp vat by the stuff pump, and get to the
batcher with wire net mould through valve. Then, the vat
should be given some hot compressed air and it will press
the liquid pulp surface.]Water will be eliminated from the
mesh of the mould, and the fiber pulp will be sedimented
evenly on the surface of the mould.
5)
Compact setting wringing: In order to improve
strength of the product to realize the setting and wringing
purpose by compacting, one of the effective methods is to
use the compact setting equipment to compact the wet
pulp between the two membranes [12].
6)
Dryin: The drying of the wet pulp needs to be
operated periodically or continuously in chamber dryer
channel. When the weather is good, the wet pulp could be
dried by using the solar or wind energy. If we put the pulp
molding product casually on the drying rack, it will
deform easily. So the pulp product could be nested in the
dry collating mould and control the drying time and
temperature, and the linear dimension changes could be
limited.
7) Integer: Hot integer is the most common way for
integrating. Hot compressing integer should be operated
on hot pressing shaped-machine. Under the same pressure
condition, the pressure per unit bearing is smaller, if the
size of the work piece is bigger, so the integer effect will
be poorer than the others. The water content should be
kept between 12%-15%, when the hot compressing
integer is operated.
IV. DISCUSSION
The properties comparison between pulp molding
products and EPS foaming plastic products has been listed
below [13] .
TABLE I
THE PROPERTIES COMPARISON BETWEEN PULP MOLDING
PRODUCTS AND EPS FOAMING PLASTIC PRODUCTS HAS BEEN
LISTED BELOW.
Item
Pulp molding product
Environment
protection
Recyclable
Buffering capacity
ratio
price
Output
Storage
danger
Item
Certain buffering
bigger
Expensive
product Continuously
Small piling
No pyrophorisity
Pulp molding product
Earthquake prevention
good
No poisonousness
Could absorb some
moisture
poisonousness
Moisture proof
recycling
Resources
regeneration
Market prospect
Raw material origin
EPS foaming plastic
product
Big volume, no
decomposing, white
pollutant
Good buffering
smaller
Cheap
Mass production
Big piling
flammable
EPS foaming plastic
product
better
poisonous
No moisture proof
100% Recyclable
Yes
Not recycling
No
Price restriction
Regenerated pulp or
waste pulp
Face elimination
No fixed source
V. CONCLUSION
Through what have been listed, the characteristics,
properties and manufacture process of the pulp molding
products, we can see that, the molded pulp dose have a
remarkable market prospect. It is also in accordance with
the green economy, low carbon economy and recycling
economy development pattern proposed by the
international community.
The pulp molding material, as a kind of packaging
material, should adapt to the aesthetic concept on
transmitting visual design, and link up the dealers the
consumers. The modern packaging should capture the link
point of science and art, and the final selection of
packaging
material
should
reflect
consumers’
psychological and visual needs. This could be the
developing trend of molded pulp application field.
ACKNOWLEDGMENT
I would like to express my gratitude to the teachers
Xiao Chang, Zhang Li and Ma Yu who have given me a
lot of generous support and help. Their suggestions are so
instructive that prepare me for my present thesis.
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