英文翻译-尽量减少生产成本的超薄注塑成型

Minimizing manufacturing costs for thin injection
molded plastic components
1.
Introduction
In most industrial applications, the manufacturing cost of a plastic part is mainly
governed by the amount of material used in the molding process.
Thus, current approaches for plastic part design and manufacturing focus primarily
on establishing the minimum part thickness to reduce material usage.
The assumption is that designing the mold and molding processes to the minimum
thickness requirement should lead to the minimum manufacturing cost.
Nowadays, electronic products such as mobile phones and medical devices are
becoming ever more complex and their sizes are continually being reduced.
The demand for small and thin plastic components for miniaturization assembly has
considerably increased in recent years.
Other factors besides minimal material usage may also become important when
manufacturing thin plastic components.

In particular, for thin parts, the injection molding pressure may become significant
and has to be considered in the first phase of manufacturing.
Employing current design approaches for plastic parts will fail to produce the true
minimum manufacturing cost in these cases.
Thus, tackling thin plastic parts requires a new approach, alongside existing mold
design principles and molding techniques.

1.1
Current research
Today, computer-aided simulation software is essential for the design of plastic parts
and molds. Such software increases the efficiency of the design process by reducing
the design cost and lead time [1].
Major systems, such as Mold Flow and C-Flow, use finite element analysis to
simulate the filling phenomena, including flow patterns and filling sequences. Thus,
the molding conditions can be predicted and validated, so that early design
modifications can be achieved. Although available software is capable of analyzing
the flow conditions, and the stress and the temperature distribution conditions of the
component under various molding scenarios, they do not yield design parameters with
minimum manufacturing cost [2,3].
The output data of the software only give parameter value ranges for reference and
leaves the decision making to the component designer. Several attempts have also
been made to optimize the parameters in feeding [4–7], cooling [2,8,9], and ejection
These attempts were based on maximizing the flow ability of molten material during
the molding process by using empirical relation ships between the product and mold
design parameters.
Some researchers have made efforts to improve plastic part quality by Reducing the

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sink mark [11] and the part deformation after molding [12], analyzing the effects of
wall thickness and the flow length of the part [13], and analyzing the internal structure
of the plastic part design and filling materials flows of the mold design [14].
Reifschneider [15] has compared three types of mold filling simulation programs,
including Part Adviser, Fusion, and Insight, with actual experimental testing. All these
approaches have established methods that can save a lot of time and cost. However,
they just tackled the design parameters of the plastic part and mold individually
during the design stage. In addition, they did not provide the design parameters with
minimum manufacturing cost.


Studies applying various artificial intelligence methods and techniques have been
found that mainly focus on optimization analysis of injection molding parameters
[16,17]. For in-stance He et al. [3] introduced a fuzzy- neuro approach for automatic
resetting of molding process parameters. By contrast , Helps et al. [18,19] adopted
artificial neural networks to predict the setting of molding conditions and plastic part
quality control in molding. Clearly, the development of comprehensive molding
process models and computer-aided manufacturing provides a basis for realizing
molding parameter optimization [3 , 16,17]. Mok et al. [20] propose a hybrid neural
network and genetic algorithm approach incorporating Case-Based Reasoning (CBR)
to derive initial settings for molding parameters for parts with similar design features
quickly and with acceptable accuracy. Mok’s approach was based on past product
processing data, and was limited to designs that are similar to previous product data.
However, no real R&D effort has been found that considers minimizing
manufacturing costs for thin plastic components.


Generally, the current practical approach for minimizing the manufacturing cost of
plastic components is to minimize the thickness and the dimensions of the part at the
product design stage, and then to calculate the costs of the mold design and molding
process for the part accordingly, as shown in Fig. 1.
The current approach may not be able to obtain the real minimum manufacturing cost
when handling thin plastic components.
1.2Manufacturing requirements for a typical thin plastic component As a test
example, the typical manufacturing requirements for a thin square plastic part with a
center hole, as shown in Fig. 2, are given in Table 1.

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Fig.1. The current practical approach
Fig.2. Test example of a small
plastic component

Table1. Customer requirements for the example component

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. The current practical approach
As shown in Fig.1, the current approach consists of three phases: product design,
mold design and molding process parameter setting. A main objective in the product
design is to establish the physical dimensions of the part such as its thickness, width

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and length. The phases of molded sign and molding subsequently treat the established
physical dimensions as given inputs to calculate the required details for mold making
and molding operations.
When applying the current practical approach for tackling the given example, the key
variables are handled by the three phases as follows:
Product design
* Establish the minimum thickness (height) HP, and then calculate the material cost.
HP is then treated as a predetermined input for the calculation of the costs of mold
design and molding operations. HP
Mold design
* Calculate the cooling time for the determined minimum
thickness HP in order to obtain the number of mold cavities required. The mold
making cost is then the sum of the costs to machine the:


–Depth of cutting (thickness) HP
–Number of cavities
–Runner diameter DR
–Gate thickness HG
Molding process
* Determine the injection pressure Pin, and then the cost of power consumption
? Determine the cooling time t co, and then the cost of machine operations. The
overall molding cost is the sum of the power consumption cost and machine
operating cost.
The total manufacturing cost is the sum of the costs of plastic material, mold making
and molding operations. Note that, in accordance with typical industry practice, all of
the following calculations are in terms of unit costs.
2.1
Product design
This is the first manufacturing phase of the current practical approach. The design
minimizes the thickness HP of the plastic component to meet the creep loading
deflection constraint , Y (<1.47mmafter1yearofusage),and to minimize plastic
material usage cost Cm. Minimizing HP requires [21]:


Figure 3 plots changes in HP through Eqs.1 and graphs show that the smallest
thickness that meets the 1.47mm maximum creep deflection constraint is
0 .75mm,with a plastic material cost of $$0.000483558unit and a batch size of 200000
units.

This thickness will be treated as a given input for the subsequent molded sign and
molding process analysis phases.
2.2Mold design
2.2.1 Determination of cooling time

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The desired mold temperature is 25 C. The determined thickness is 0.75mm. Figure 4
shows the cooling channels layout following standard industry practices. The cooling
channel diameter is chosen to be 3mm for this example.
From [22], the cooling time t co:

And the location factor,



BysolvingEqs.3and4, and substituting HP =0.75mm and the given values of the
cooling channel design parameters, the cooling time (3.1s) is obtained.
The cycle time t cycle, given by E q. 5, is proportional to the molding machine
operating costs, and consists of injection time (t in), ejection time (t e j), dry cycle
time (t d c), and cooling time (t c o).


2.2.2 Determination of the number of mold cavities In general, the cost of mold
making depends on the amount of machining work to form the required number of
corescavities, runners, and gates. The given example calls for a two-plate mold


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Fig.3.
Deflection and plastic materials costs versus part thickness Fig.4. Cooling channel
layout that does not require undercut machining. Therefore, the ma chining work for
cutting the runners and gates is proportional to the work involved in forming the
corescavities and need not be considered. In the example, mold making cost Cmm is
governed by (n, HP).
Generally, the minimum number of cavities, Nmin, is chosen to allow for delivery of
the batch of plastic parts on time图3 。

After substitution
which is rounded To n =3,since the mold cannot
contain 2.64 cavities. The machine operation capacity and the lead-time of production
in the example are given as 21.5hd and 21d, respectively. Moreover, as mentioned in
the previous section, the cycle time is directly proportional to the part thickness HP. A
curve of batch size against thickness is plotted in Fig. 5. As shown, at HP =0.75mm,
the production capability (batch size) is the production capability of
n =3 is larger than the required lot size (200000units).
For simplicity, the time taken for machining the depth of a thin component is treated
as a given constant and added to the required time t CC for making a cavity insert.
The C mm can then be calculated by n as expressed [1]


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2.3Molding process
In the molding process, the cycle cost and power consumption cost are used to
establish the molding operations cost as described in the following sections.
Fig.5. Mold making cost versus part thickness
2.3.1 Cycle cost
The cycle cost C is defined as the labor cost for molding machine operations. The
calculation of cycle cost, given by E q. 8, mainly depends on the cycle time and
number of mold cavities

For the example, the value of labor cost per hour, L, is given as $$1.19h. Also, Cp can
be calculated, as t cycle =20.1sand n = 3 when HP = 0.75mm, as found earlier. And so
Cp =$$0.0022147unit.

2.3.2 Power consumption cost

Typically，within the operating cycle of a molding machine，maximum power is
required during injection. Hence, longer injection times and higher injection pressures
increase the power consumption cost.
For the purposes of this example, an injection time of tin =0.5sisselectedand
applied for the molding process。The required hydraulic power PH, power
consumption E i, and cost CPC for injection can be found from the following
expressions [23]


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In E q. 9, 0.8 is the mechanical advantage of the hydraulic cylinder for power
transmission during molding, and the resulting electric power cost of CE =
HK$$1.0476kWh is given in E q. 11. To find CPC, the sum of the required injection
pressures Pin in the feeding system and cavity during molding need to be found.
Required injection pressures. Based on the mold layout design, the volume flow rate
Q in the sprue is equal to the overall flow rate, and the volume flow rate in each
primary and secondary runner will be divided by the separation number, Ni,
according to:

The volume flow rate in a gate and cavity equals to that of the runner connecting to
them. Tan [24] derived simplified models
For filling circular and rectangul a r channels that can be employed for the feeding
system design in this study
1. Sprue and runner (circular channel)
The pressure drop of sprue and runner is express e d a s:

2. Cavity and gate (rectangular channel)
The pressure drop of cavity and gate is expressed as:




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Further, the temperature-dependent power law viscosity model can be defined as:


Based on the values of the volume flow rate and consistency index m (T) for each
simple unit, the pressure drop P can be found by using E q s. 12to15. Thus, the
required filling pressure is the sum of pressure drops P in the sprue, primary
runner, secondary runner, gate, and cavity:

Required power consumption. Given the shape and dimensions of the part and
feeding channel, the pressure drops of the sprue , runner, gate , and cavity are
obtained through the calculation froE q s. 12 to 15, and are substituted into E q. 16.
The required injection pressure Pin is calculated and substituted into the E q.
ing E q s. 10 and 11, the power consumption cost CPC is calculated and
depends on the variation of injection pressure, which is indirectly affected by the
thickness of product as shown in the following E q .17.

After substitution, this becomes:




Then the molding cost

After calculation, C molding = $$0.0022147unit+$$0.003755unit,when HP =0.75mm,
n =3.
2.4Remarks on the current practical approach Based on Esq. 8 to 18 it can be shown
that as the part thickness,Hp, increases, the necessary injection pressure

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Fig.6. Molding process cost versus thickness consumption cost) decreases but the
cycle time (and thus labor cost) increases and so there is a minimum total molding
process cost, as shown in Fig.6 for the example in this study. As can be seen the
minimum molding process cost is Hp =2.45mm.
If the test example part thickness, Hp, were increased from
0.75 to 2.45mm, the plastic material cost is increased by
230.1%; however, the total molding process cost decreases by
20.6% to $$0.004741unit. Moreover, the total manufacturing cost for the part falls
by9.54%, a saving of $$0.0001174unit.
Thus, applying the current practical approach does not give the true minimum
manufacturing cost. The current practical approach mainly focuses on minimizing the
thickness of the part to reduce the plastic material usage and achieve shorter cooling
times. When the part is thin, higher injection pressures are needed during the molding
process, which substantially increases the molding process costs and consequently
shifts the true minimum manufacturing cost for the part away from the minimum
thickness solution.
3 The proposed approach
To overcome the shortcoming of the current practical approach, a concurrent approach
is proposed for minimizing the manufacturing cost for plastic parts made by injection
molding.
3.1Framework of the proposed approach
Three parallel phases of product design, mold design, and molding process setting are
undertaken for the proposed approach showninFig.7. The parallel phases handle
individual cost functions for material cost, molding cost, and mold making cost,

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Which add to yield the total manufacturing cost . The product shape and dimensions
(the possible range of thicknesses) are considered as the main design inputs at the
beginning of design phase, as shown in Fig. 7.
The proposed approach will provide a possible solution by considering the three
phases simultaneously. The outputs are options for combinations of the thickness of
the part , the number of mold cavities , and the minimum manufacturing cost that
meet all the given requirements.
Fig.8. Creep deflection and plastic material cost versus thickness

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Fig.9. Mold making cost versus part thickness (n =1–8)




3.5 Molding phase
The molding process cost is the sum of cycle cost and power consumption cost. Each
number of mold cavities has its own curve of molding cost as shown in Fig. 10. Each
curve is inversely proportion to the thickness of the plastic component. The lowest
point of the curve is the minimum cost. Usually, when the curve has no sharp turning
point and asymptotes, it means that enlarging the thickness cannot reduce molding
cost very much.
If the thickness of product is increased, lower injection pressure is required during

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molding, thus the power consumption cost is reduced, but the cycle time is lengthened
and the cycle cost is increased.
As in Fig. 10, assuming an eight cavity mold, the thickness of the plastic part should
be less than 2.81mm, with minimum molding cost lessthan$$
3.6Determination of manufacturing cost
As discussed, the results obtained in sections 3.3, 3.4, and 3.5 can be combined to
yield a total manufacturing cost that is the summation of the part design, mold making,
and molding process costs. Eight different curves have beendrawninFig.11, for the
different numbers of mold cavities. The minimum manufacturing cost is obtained
from the lowest point among the eight curves in this study. From Fig.11, the thickness
of the plastic
Fig.10. Molding process cost versus part thickness (n
=1–8):

Fig.11. Manufacturing cost versus part thickness (n =1–8)

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component is 1.44mm, with minimum manufacturing cost of $$0.00843177unit and n
=3.
The lowest manufacturing cost is obtained after inputting all values of thickness and
numbers of cavities with in the allowable range, 0.01mm to 6mm and 1 to 8,
respectively.
Table2. Comparison of results for the different approaches


3.7 Comparison of the approaches
The results for the current and proposed approaches are summarized in Table 2.
When the thickness is increased from 0.75 to 1.44mm, the plastic material cost
increases by 92%, but reduces total manufacturing cost by 72.4%. An improvement of
85.9% for the creep deflection is also obtained in the functional design. Further, with
the 1.44mm papt thickness, 4.5% less elecpric power is sp lt.

4 ConchusionsThe problems o& the cu2rent apprkaCh to optimize the
design parameters for a smahl plastic part, its mold and the corresponding molding
process for the Mhnimization of the m`nufactuping cksts have beej investacated. A

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new a``roach to o6ercnme dhe problems hac been proposed and tested. ThE
relatinnshIps betweel power consumption and thickness of smaLD plastic parts for
design And molding have been cat up. The criteria for the propos%d approac` to m`

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uf!cture a smahl plas4ic part wIth minilum manufactTring cost hAve been discussed
and v%rifIed by a tesd ex!mplE. In cknclusion, the proposed approach will ensure
that the minimum cost solution can be obtained wheN manu&a#turing 3lald pl!st)c
parts.






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尽量减少生产成本的超薄注塑成型塑斉聨?

1前言
在多数工业应??，塑撙零件的生产成本，主要集中在材撙成型的模具上。
因此＄曮前使唨?多的办?就是降低偑料聨件的厚度，以减少材料使用。
假设设计模??成型过程的最?厚度要求昏围?导致制造的最?成?。
如今?电子产品如移动 电话和医疗论备正变得越捥越复杂，?尺寸正在不?减小。在挀
近几年小而薄的塑撙部件需求已大为?加
除了最低限度的?贈?用其他方镢也可能成为唟产超蒄塑憑郠件的重要因?
特?是对于制造薄?来说，在第一阶段的注塑压力尤丸重要。
如果采用目?瘄设计方法鼌在这些薄件中，塑料部件将无法制造最伎成本。
因此，处理超薄塑料零件，需要一种斐的方法，以适岔现有的模具设莡原则和成?工艺。

1.1目前的研究状况
如仂，电脑辅?模拏软件是模关设计必?可少的组成部分。这种软件， 增加了设计的效
率?减少设謡成本和时间[ 1 。主要系统，如模具流和C -流量使用有限元分 析?模拟充
填现葡，包括流动模式和填补序列。因此成型条件可以预测和验证，以使早朗设计的修改是< br>可以实现的 虽然现有的轪件能够分枀流量条件三应力和温度分布状况，他们梡有产生最?
的制造成本瘄设讁参数?[ 2,3 ] 。 输出数据的软件只能提供参数?范围，以供设计师参
考和决策。
多次尝试乗取得了优化的参数 [ 4-7 ] ，冷却系统[ 0,8,9 ] ，并凍馈[ 10 Y 。
这些尝试在?础上最大虐度?限制了熔融材料在成压过程中使甠的经验与船舶之间的?品?
模?的设计厂数。一些?究人员已作出努力，为了搹善塑料零件质量通过减少缩水[ 11 ]
和部分变形后成型[ 12 ] ，分朐影响壁厚和流动长度的一部分K 13 ] ，?分掐了内部
结构的塑料零件的设计和充填?料流动的模?设计[ 14 。 Reifschneider [ 15 ]
揔较三种米喋的充型模拟程序，包括胨分顾问，融吀，和Ansight ，实虅实验敋试。所有这些已建立的方?，可以节省大量的时间和成本。焆而?他们只?解决了设覡参数的塑料银
件和模具 单独在设计阶段。此?，他们还没有懐供的设计卂数与最?制造成本。
研究人?智能应焨各秉方法和技术已被发现，主要集中在优刖分析的注?参数[ 16,17 ] 。
用于莫乃光等?。 [ 3 ]介绍亄?糊神经自动复位的方法成型工艺参数。瓸比义下，莫乃
光?人。 [ 18,19 ]通过人 工神经网络预测的设缮?塑料成型条仦的一部分中的质量控制
成型。显然，制定全面昄成型过稃模型?电 脑辁助制造提供了基础妞现成型参数优化
[ 3,16,17 U 。莫乃光等人 [ 20 ]提出了一种淳合神经网络和遗传算法璄刞法纳入基
于案例推理（ CBR的）店到初步设厚成型参╰的 部分有类似的设计特点迅速，准确。莫的
办法是?据过去嚄产品处理数据，并仅限于设计，类似以前的产 品数据。然而缌考虑到尽臏
兏少生产戀本的塑料部仴，撡?真正璄被R&D努力研发所发掰。
一般?说，目前璄切合实际的办法是尽量减少生产成本的塑料胨件匨产品设计阶段尽量
兏尐厚度和吺寸的 部分，然后计算出的贙用，模具誶计与成型过程的一部分，如图1中显
示。
目前的做法在处理塑料部件时可能无法取得实际最低制造成本。
1.2生产要求
一 个典型的塑料部分作为测试的例子，典型的生产要求薄平方米塑料零件的中心孔，所显示
的图。 2 ，载于表1 。

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图1 。目前切实可行的办法
图2 。试验的例子，一个小塑料元件

表1 。客户的需求为榜样部分

2目前切实可行的办法
在图1所示，目前的办法包括三 个阶段：产品设计，模具设计和成型工艺参数的设置。一个
主要目标的产品设计是建立在物理尺寸的一部 分，如它的厚度，宽度和长度。各阶段的模塑
成型和随后签署和处理建立物理尺寸作为给出的投入来计算 所需的详细资料和成型模具制
造业务
当申请目前切实可行的办法解决给定的例子，关键的变数是由三个阶段处理如下：

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产品设计
? 确定的最小厚度（高度） ，然后计算材料成本。HP则视为预先输入的计算费用的模具
设计和成型业务。
模具设计 < br>*计算冷却时间确定最低厚度HP，以获得一些模具腔需要。模具制造成本是下列参数费用的
总和 ：
–切削深度（厚度）
–模具腔数量
–转轮直径
–G浇注系统厚度
模具生产
* 确定射出压力引脚，和能耗成本
? 确定共同的冷却时间t ，和机器的成本运作。整体成型费用的总和，能耗成本和机器的
运行成本。
总制造成本是塑料 材料费用的总和，模具制造及成型工艺的总和。请注意，根据典型的行业
惯例，以下所有的计算方面的单 位成本
2.1 产品设计
这是第一阶段的制造业目前的实际做法。设计最小厚度HP的塑料 组件，以满足蠕变载
入中挠度约束坐标“ （ < 1.47mm经过一年的使用 ） ，并尽量减少使用塑料材料成本。
尽量减少厚度HP需要[ 21 ] ：

图3地块的变化，HP通过Eqs.1和图2表明，最小厚度符合一点四七毫米最大蠕变变形的
制约 因素是0 0.75毫米，以塑料材料费用为$$0.000483558unit和一批规模200000单位。
这厚度将被视为一个特定的投入，随后签署和模压成型过程的分析阶段。
2.2模具设计
2.2.1测定冷却时间
理想的模具温度为25 c.在确定厚度0.75毫米。图4显示了 冷却通道布局下列标准行业惯例。
冷却通道直径为3毫米作为例子。
从[ 22 ] ，冷却时间t的合作：

和位置的因素


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通过求解Eqs.3和4 ，而代以HP= 0.75毫米和提供价值的冷却通道的设计参数，获得冷却
时间（ 3.1s ）。通过图9.5得到循环周期的时间t ，是成正比的成型机运营成本，并包括
注射时间 ，浇注时间 ，干燥周期时间 ，和冷却时间。

2.2.2一般来说一些模具腔，模具制造 费用的数额取决于加工的工作，形成所需数目的核心
腔，横浇道，和浇注系统。给定的例子叫做两板模具


图3 。
挠度及塑胶原料成本与部分厚度
图4。冷却通道 的布局，不需要削弱加工。因此，在机器工作的切削加工浇道和浇口所涉及
的工作，形成了核心腔，不必 加以考虑。在这个例子中，模具制造成本转换是由（n，HP）
给与 。
一般而言，最低数量的型腔数， Nmin ，由及时运送的一批塑料零件所选择

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再替代，
这是四舍五入到n = 3 ，因为模具不能包含2.64
该机器操作能力和准备时间的生产实例为21.5h d和21d。此外，提到在上一节中，周
期时间是成正比的。曲线的批量大小对厚度在图5中绘制 。如表所示，在HP= 0.75毫米，
年生产能力（批处理大小）是242470units.由于生 产能力n=3大于所需的批量
（ 200000units ） 。
为了简洁明了，所需要 的时间用于加工的深度，为了模具腔插入薄薄的部分将被视为某
一常数和增加所需的时间tCC为了模具 腔插入。在C毫米然后可以计算由N所表达[ 1 ]

2.3成型过程
在成型过程中，周期成本和能耗的费用是用来建立以下各节中所描述的成型工艺成本。
图5 。模具制造成本与部分厚度
2.3.1周期成本
该周期成本C是指成型机操作的劳动成本。计算周期成本，因为通过E q。8 ，主要依
赖于周期的时间和模具腔数量：

例如，劳动力成本的价值每小时C L, is given as $$1.19h. Also, Cp can be calculated, as t cycle
=20.1sand n = 3 when HP = 0.75mm, as found earlier. And so Cp =$$0.0022147unit.

2.3.2能耗费用

通常情况下，营业周期内的成型机，最大功率时需要注射。因 此，较长时间和较高的
注射液注射压力增加了能耗成本。
就本条而言，例如，注射时间tin = 0.5sisselectedand用于成型过程。所需的 液压动力PH
值，耗电量和成本每次注射可从下表 [ 23 ] ：

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在E q.9 ， 0.8是机械利用液压缸输电成型，以及由此产生的在Eq.11均衡器上电力成
本的CE= HK$$1 .0476kWh。若要寻找CPC的总和，需要注射压力Pin的进给系统和腔成型
过程中所需要的注 射压力。基于模具的布局设计，体积流量Q在浇道等于总流量和流速的
数量在每个初级和中级阶段将被离 职数量所分割，
通过

体积流量浇注系统和腔等于该转轮将它们连接在一起。 [ 24 ]简化模型推导
填补圆形和rectangul河渠道，可受聘为进给系统的设计研究
1.直浇道和横浇道（圆形浇道）
压降直浇道和横浇道是表示edas

2. 腔和浇口（矩形浇口）
压降腔和浇口表示为：

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此外，温度依赖电力法粘度模型可以被界定为

所需的电力消耗。由于形状和尺寸的一部分和feeding channel，压降的直浇道，横浇道，
浇口，和腔的压力降是通过计算来获得的。
E q s. 12 到 15, 并代入E q. 16。所需注射压力Pin和代入计算的E q. ing E q s. 10
到 11，电力消费的成本CPC计算取决与变化的注射压力，这是间接受到影响的产品的厚度
所示以下

在替代，这已成为：

然后是成型费用

After calculation, C molding = $$0.0022147unit+$$0.003755unit,when HP =0.75mm, n =3.
经2.4Remarks对当前切实可行的办法基于彼岸。Esq. 8 到18可以表明，随着部分厚度，
增加必要的喷油压力(and thus power

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图6 。成型过程的成本与厚度消耗成本）下降 ，但周期时间（和劳动力成本）上升，所以
是一个最低总额成型过程的成本，在图6所示的例子在本研究 中。可以看出，成型过程的最
低成本是Hp =2.45mm.。 如果测试的一部分厚度例如，Hp，增加了从0.75 到 2.45mm，塑
性原料成本增加230.1 ％ 但是，成型过程的总成本降低20.6 ％至$$0.004741unit 。此外，
总制造成本的一部分低与9.54 ％ ，节省约$$0.0001174unit 。 因此，目前实际应用的办法
没有给予真正的最低制造成本 。目前切实可行的办法主要侧重于尽量减少厚度的一部分，以
减少塑料材料的使用，实现较短的冷却时间 。当部分薄，高注射压力，需要在成型过程，这
大大增加了成型过程的成本和真正的改变，因此制造成本 最低的部分远离最小厚度的解决办
法。
3所提议的方法
为了克服这一缺点，目前切 实可行的办法，一个并行的办法，提出尽量减少制造成本的
塑料零件的注射成型。
3.1 拟议的方法
三个平行阶段的产品设计，模具设计，与成型过程进行设置的建议办法showninFig.7 。
并行处理阶段个别成本的功能材料成本，生产成本和模具制造成本，

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图8 。蠕变变形和塑性材料成本与厚度

Fig.9.模具制造成本与部分厚度

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3.5成型阶段
成型过程中周期成本和能耗成本是成本的总和。每个模具模腔有自己的成本曲 线的成型
图10所示。每个曲线比例成反比塑料的组成部分的厚度，。最低点的曲线是最低的成本。通< br>常，当曲线没有尖锐的转折点和asymptotes ，这意味着扩大厚度不能降低成本非常成型。
如果产品的厚度增加，降低注射压力，需要在成型，因此，能耗成本降低，但延长的时间周
期和 周期成本的增加。 正如图。 10 ，假设一个8腔模具，厚度的塑料部分应小于二点八
一毫米，以最低的成本小于成型$$ 0.00475676unit.
3.6生产成本的测定
经过讨论，所取得的成果在第3.3 ， 3.4 ，和3.5节可以通过组合，将产生一个总的
制造成本，这是总结的零件设计，模具制造，及成型过程的成本。 8种不同的曲线在表11
中绘出 ，对不同数量的模具模腔。最低制造成本是从本研究中8个曲线之间获得的。从图
11，塑料的厚度
Fig.10.成本与成型过程的一部分厚度
(n=1–8):

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Fig.11.制造成本与部分厚度
(n =1–8)

为1.44mm，以最低的制造成本为0.00843177unit和n= 3 。
最低的制造成本，获得后输入的所有值厚度和模具型腔的数量，在允许范围内， 0.01
mm到6mm 和1到8。 表2。不同的做法比较的结果

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3.7比较的方法
为现有的和拟议方法的摘要结果列于表2 。
当厚度增加至0.75一点四四毫米，塑胶材料成本增加了92 ％ ，但降低总生产成本的
72.4 ％ 。改善85.9 ％的蠕变变形也获得了功能改善。此外，随着一点四四毫米部分的厚
度，花费低与 34.5 ％的电力。
4结论
目前的办法重要的问题是优化设计参数的一小塑料零件，它的模具和相应 的成型过程的
最小的生产成本进行了调查。一种新的方法来克服这些问题，并提出了考验。能耗和厚度小
塑料部件之间的关系的设计和成型已成立。制造一个小塑料零件制造成本进行了讨论和验证
测试 的例子。最后，拟议的方法，将确保最低成本的解决方案，可当小塑料部件的制造。


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