当Colorin颜色喂食器如何提高质量g at the Machine

Along with correct dimensional and mechanical properties, processors know thatgood color properties在客户接受塑料产品方面的主要因素之一。颜色通常是产品标识和品牌方案的组成部分，在某些情况下可能是用户选择产品选择因素。

With so much value riding on color consistency and quality, it’s important to understand the process of coloring at the machine, typical coloring problems and their solutions, and the impact of coloring on the bottom line.

The Benefits of Coloring at the Machine

Compared with the cost of buying pre-colored resin or installing a large-capacity central2019新万博appmanbetⅩ，在机器上的颜色可以提供显着的成本收益, including lower material inventory costs and improved process flexibility.

机器上的着色如何工作

At-the-machine color addition usually involves acolor feederinstalled at the base of the material hopper on a processing machine.

Following installation and calibration, feeders meter colorant through a throat adapter, where it mixes with the mainstream of natural resin before plastication in the barrel of the machine.

机器着色时的3个问题

There arethree basic problem areasthat occur with coloring at the machine:

1. Delivering the right ratio of colorant tovirgin material.
2. Cleaning up and changing overfrom one color to another.
3. Calculating and delivering the right ratio of colorant to a维珍/磨碎的混合物.

Let’s take a look at each of these problem areas.

Deliver the Right Ratio to Color Virgin Material

从理论上讲，着色是一个简单的过程。着色剂（或主批量）制造商为其产品提供推荐的着色与黄质混合率。例如，可以以25：1的比率添加特定颜色，该比率等于总材料混合物的4％。

正确获得这个比率需要三件事：

1. Calibrating to ensure that your feeder can and does deliver the right amount of color
2. 确保您的处理设备运行顺利
3. Maintaining the correct ratios throughout the course of the job

The amount of colorant metered out can be controlled in two ways – by volume or by weight.

Until relatively recently,大多数彩色馈线都是体积的. Colorant is usually fed by an auger screw, with the feed rate calculated based on the volume of colorant delivered with each turn of the screw. Calibration is accomplished by cycling the feeder at a particular speed, catching and weighing a series of feed samples, then comparing the sample weights to ensure that the auger is dispensing consistently.

Weight-basedgravimetric feeding是一种较新的方法，是20多年来一直是聚合物搅拌机的首选喂养方法。但是，直到几年前，它在通常用于单个塑料处理机上的简单馈线中却非常昂贵。

重量法馈线没有依靠固定体积螺旋钻来提供一致的重量，而是利用负载电池。该单元不断地记录着着色剂料斗的重量损失，并相应地调整了进料速率。

By comparing the delivery setting (i.e., grams/sec) in the control with the actual changes in hopper weight during the same period, gravimetric feeders can be essentiallyself-calibrating和self-regulating.

表I显示了自动校准如何节省时间和金钱。

Table 1. Automatic Calibration Saves Time and Money
校准时间/一天 (20 minutes/change x 3 changes)	60 minutes
生产天/年 (5 days/week x 50 weeks/year)	250 days
校准时间/年 （60分钟x 250天）	250小时
Billable Machine Time	$ 45/小时
Potential Savings with Automatic Calibration (250 hours x $45/hr)	$11,250/year

Signs of On-The-Machine Color Feeder Problems

So, what might indicate you have a problem with an on-the-machine feeder?

• Product is incorrectly or insufficiently colored.
• Costs for labor are higher than planned, usually due to feeder calibration, or maintenance/job changeover problems.
• Costs for colorant are higher than calculated.

解决问题的第一步是检查和验证着色剂饲料率。Is the rate setting correct?

如果是的话，但是产品颜色不足，诱人的“快速修复”将涉及将着色量的添加速率向上调整，例如，从4％到5％。虽然这可能“解决”直接问题，但it could mask other problems, since coloring consistency is also affected by:

• Material factors:
  • Type
  • Bulk density
  • Pellet geometry and flow
• Feeder behavior（螺丝，电动机，控制）
• Small errors in measurement or calibration

其中，测量和校准是问题的最常见原因。校准可能需要时间 - 体积馈线可能需要收集和个人称重多达12个样品，以预测适当的准确性水平。

Even then, small variations in any of several factors — collection method, number of samples, rounding errors, bulk density of the colorant or masterbatch — can introduce additional errors into the volume-to-weight calculations that predict accurate colorant delivery in a volumetric feeder.

Figure 2 illustrates the inherent variability of the typical volumetric feeder.With such wide swings in output, processors often raise the setpoint to make sure that enough colorant is always delivered.

However, this can be costly, as shown in Table 2:

Table 2. Over-Coloring is Costly
机器吞吐量(Assumed)	150 lb/hr
Additive Target Percent(Assumed)	4%
Additive Used/Hour(4% x 150 lb/hr)	6 lb/hr
添加成本(Assumed)	$3
添加成本/小时($3 x 6 lb/hr)	$18
生产时间/年(3 shifts x 5 days x 50 weeks)	6,000
添加成本/年(6,000 hrs x $18/hr)	$ 108,000

Cost of Over-Coloring	Actual % Dispensed	实际成本/年
10% Over Target	4.4%	$10,800
超过目标20％	4.8%	$21,600
30% Over Target	5.2%	$ 32,400
40% Over Target	5.6%	$ 43,200
50% Over Target	6.0%	$54,000

极高或低着色量的递送率may also complicate the coloring process. Even when augers are properly calibrated, the volume they deliver typically varies from dispense to dispense based on turn speed, material size and geometry, and vibration.

尽管这些差异通常平均且不会影响常规工作的质量，但如果没有重力技术的连续自我监控和自我校准功能，它们可能很难管理。毫不奇怪的是，测试表现出对体积馈线的分配一致性和人均材料消耗的较高可变性。

彩色馈线的行为也受到其影响metering technology. A simple auger keeps colorant flowing, yet may dispense more in the first half of a rotation than the last. This behavior is known as pulsing or surging. While this behavior would not affect the total amount of material dispensed over long periods of time, it could complicate the process of sample collection and make accurate calibration more difficult.

Conair offers an alternative metering technology, therotating dispensing cylinder, which evens out the flow of color particles as they flow out of the device. As a result, the dispense is delivered in an even stream−without surges.

图3比较了从螺旋钻和必要的分配缸的流量，以确保至少0.40 gm/hot的分配率。螺旋钻为其一部分旋转的着色剂涌动，其余的几乎没有或一无所有。

The dispensing cylinder feeds colorant very consistently, making everything from feeder calibration to downstream mixing and melting more predictable and easier to manage. The setpoint (gm/shot) can be set lower without worrying unnecessarily about consistent coloration. A lower setpoint reduces coloring costs and increases profitability.

Considerations for Colorant Cleanup and Changeover from One Color to Another

In addition to the costs of colorant, feeder equipment, and quality, there are labor and material costs associated with changing from one color to another on a machine. Of course, the注射成型机or extruder will need to be purged, but this activity is the same regardless of feeder type.

但加工机械停机时间和劳动力成本sociated with feeder cleaning and changeover can vary significantly by feeder type and can be considerable.

显然，您的颜色喂食器应设计用于易于清洁和颜色转换。

要简化清洁并降低人工和停机费用，请寻找：

• 易于拆卸和重新组装
• Easy access to key feeder components, with minimum disassembly
• 轻松删除剩余的着色剂或着色料斗的转换

Cleaning, Setting Up, and Calibrating Feeders

How often are colorants or other additives changed to meet job requirements in your plant? How long does each clean-out take? If the changes are required frequently, the minutes can add up quickly.

But savings can add up too. Thanks to continued advances in design, the latest ConairTrueFeed gravimetric feeders可以拆卸并清洁as little as one minute.

Once a color feeder is cleaned, how long does it take to set up and calibrate? How many adjustments are needed before color dispenses are consistent? How often is recalibration needed?

Amicroprocessor-controlled feeder允许使用存储的颜色或作业记录更快的设置，并提供连续的过程更新。

How fast can this be done? This depends on the type of feeder. Assuming that inputs of process, rate and material information require equal time, how much time is needed for feeder calibration before or during the job?

While the answer varies for volumetric feeders, the answer forTrueFeed gravimetric feedersis easy: calibration time is essentially eliminated.

如何计算和交付着色剂与处女/饮食混合物的正确比率

It can be a challenge to maintain consistent color when the ratio of regrind to virgin material changes.

通常可以假定饮食与成品的颜色百分比相同，因此与预着材料相似，因为它不需要额外的着色剂。

该图（图4）可用于确定需要多少着色剂才能将其混合在其混合的纯净（自然）材料上。

If you are running 10% regrind, for example, you only need 90% of the color you would have needed if you were running 100% natural resin. And, as shown in the graph, if you would normally add 3% colorant to 100% natural resin, you only need 2.7% colorant when running a 10%-regrind/90%-natural material mix.

可以提供重新磨碎和颜色的双重重量馈线，并带有奴隶共同完成该目标的控制。

喂养设备准确性的重要性

尽管机器上的着色应该是一个相对简单有效的过程，但有很多事情可能会出错。假设使用优质的材料并且着色剂与树脂的比率正确，那么大多数着色问题与喂养设备的固有质量和准确性有关。

Volumetric feederscontinue to offer lower acquisition costs and perform well in many coloring and additive feeding applications. Yet they can require a significant amount of labor time for setup, calibration, and recalibration. They also tend to cost more to operate in terms of coloring and additive materials because their dispense rates are not as accurate and processors tend to compensate by overfeeding.

Gravimetric feedersare becoming more competitive in price. Their self-calibration and self-regulation capabilities save setup time and virtually eliminate calibration and calibration-related errors and quality problems. Typically, they provide a higher level of predictability and operate with consistently lower colorant and additive costs due to their dispensing accuracy.